Grinding and dressing method, equipment and device applied to the machining process of cycloid gears

Abstract

This application relates to the technical field of cycloid gear dressing, and specifically relates to a grinding dressing method, equipment and device applied to the processing of cycloid gears. The method includes: by analyzing the difference between the energy of all cutting force data in the neighborhood of the main frequency in the frequency domain and the total energy within a preset time period before each moment, as well as the change trend of all temperature data, the high-frequency vibration heat risk degree; based on all the high-frequency vibration heat risk degrees and all vibration data within a preset time period before the current moment, using a modal decomposition algorithm to construct a first eigenvalue; based on all state data of all types and all high-frequency vibration heat risk degrees within a preset time period before the current moment, using a principal component analysis algorithm to construct a second eigenvalue, and combining the first eigenvalue to determine a comprehensive eigenvalue, and adjusting the dressing speed and feed rate. This application solves the problem of adaptive lag of dressing parameters and eliminates the distortion of the edge profile during the processing of cycloid gears under the interference of multiple physical fields.

Description

Technical Field

[0001] This application relates to the technical field of cycloid gear dressing, and specifically relates to a grinding dressing method, equipment and device applied to the processing of cycloid gears. Background Art

[0002] As the core component for the RV reducer to achieve high-precision power transmission, the tooth profile machining quality of the cycloid gear directly determines the transmission backlash, load-bearing stiffness and dynamic response characteristics of the reducer. The grinding dressing technology stabilizes the tooth profile error of the cycloid gear within the micron range by precisely controlling the grinding wheel topography and grinding trajectory. Compared with the tool wear cumulative error and cutting force deformation problems existing in the traditional milling process, grinding processing relies on the nano-level material removal amount, the high wear resistance of the super-hard CBN grinding wheel, and the real-time compensation ability of the on-line detection feedback system, which not only significantly improves the tooth surface profile accuracy, but also can obtain a mirror-level surface roughness, thereby reducing the frictional loss and vibration noise during the meshing process of the RV reducer.

[0003] Due to the multi-dimensional collaborative imbalance of dressing parameters with the theoretical tooth profile, dynamic wear and process system stiffness, problems occur in the matching of grinding wheel dressing parameters. Specifically, the matching of the grinding wheel dressing speed and feed rate needs to strictly follow the curvature change characteristics of the cycloid equation: when the dressing speed is too high and the feed rate is too small, the contact stress between the diamond roller and the grinding wheel is insufficient, resulting in uneven distribution of the microscopic cutting edges of the dressed grinding wheel and forming periodic ripples; conversely, if the feed rate is too large, the material removal rate exceeds the bearing capacity of the grinding wheel bond, causing profile collapse or passivation. More complicatedly, the dynamic coupling effect of the thermal deformation of the grinding wheel spindle and the reverse clearance of the dresser servo axis will further distort the spatial geometric accuracy of the dressing trajectory. Existing technologies mostly rely on off-line detection and static compensation models, and it is difficult to track the grinding wheel wear and thermo-mechanical coupling effect in real time, resulting in parameter self-adaptation lag and being unable to completely eliminate the distortion of the cutting edge profile during the processing of cycloid gears under the interference of multiple physical fields. Summary of the Invention

[0004] In a first aspect, an embodiment of this application provides a grinding dressing method applied to the processing of cycloid gears, and the method includes the following steps:

[0005] Obtain various state data during the processing of the cycloid gear in real time, where all the state data includes: cutting force data, vibration data and temperature data;

[0006] By analyzing the difference between the energy in the neighborhood of the main frequency in the frequency domain and the total energy of all cutting force data within a preset time period before each moment, determine the energy proportion during the processing of the cycloid gear at each moment; by analyzing the change trend of all temperature data within a preset time period before each moment, determine the thermal deformation intensity during the processing of the cycloid gear at each moment, and combine the energy proportion to determine the high-frequency vibration and heat risk degree during the processing of the cycloid gear at each moment;

[0007] Based on all high-frequency vibration and heat risks and all vibration data within a preset period before the current moment, the modal decomposition algorithm is used to construct the first eigenvalue of the processing process of the lower thread wheel at the current moment; based on all state data and all high-frequency vibration and heat risks within a preset period before the current moment, the principal component analysis algorithm is used to construct the second eigenvalue of the processing process of the lower thread wheel at the current moment, and in combination with the first eigenvalue, the comprehensive eigenvalue of the processing process of the lower thread wheel at the current moment is determined;

[0008] Obtain the dressing speed and feed rate during the processing of the lower swing wheel at the current moment, and in combination with the comprehensive eigenvalue, adjust the dressing speed and feed rate.

[0009] Preferably, the energy proportion in the processing process of the lower thread wheel at each moment is: the result of the sum of the energies of all cutting force data within the 3 dB bandwidth at the main frequency in the frequency domain divided by the total energy of all cutting force data in the frequency domain before each moment.

[0010] Preferably, the construction process of the thermal deformation strength of the processing process of the lower thread wheel at each moment is:

[0011] Take all temperature data within a preset period before each moment as the input of the finite element thermal-stress coupling simulation model, output the thermal deformation nephogram, calculate the extreme value of the thermal stress of all nodes in each grid unit in the thermal deformation nephogram, and take the maximum extreme value of the thermal stress in all grid units as the thermal deformation strength of the processing process of the lower thread wheel at each moment.

[0012] Preferably, the expression of the high-frequency vibration and heat risk degree of the processing process of the lower thread wheel at each moment is: ; where represents the high-frequency vibration and heat risk degree of the processing process of the lower thread wheel at moment i; represents the energy proportion in the processing process of the lower thread wheel at moment i; represents the thermal deformation strength of the processing process of the lower thread wheel at moment i; norm( ) represents the normalization function.

[0013] Preferably, the construction method of the first eigenvalue of the processing process of the lower thread wheel at the current moment is:

[0014] Take all high-frequency vibration and heat risks and all vibration data within a preset period before the current moment as the input of the modal decomposition algorithm, output the energy proportion, modal frequency, and modal damping ratio of each modal component respectively, record the modal component with the highest energy proportion as the dominant modal component, and take the result of the product of the energy proportion of the dominant modal component and the dominant modal frequency divided by the modal damping ratio as the first eigenvalue of the processing process of the lower thread wheel at the current moment.

[0015] Preferably, the construction process of the second eigenvalue of the lower cycloid wheel machining process at the current moment is as follows:

[0016] Take all cutting force data, all vibration data, all temperature data, and all high-frequency vibration heat risk degrees within a preset time period before the current moment as the input of the principal component analysis algorithm, and take the output first principal component score as the second eigenvalue of the lower cycloid machining process at the current moment.

[0017] Preferably, the comprehensive eigenvalue of the lower cycloid wheel machining process at the current moment is the result of the positive fusion of the first eigenvalue and the second eigenvalue of the lower cycloid wheel machining process at the current moment.

[0018] Preferably, the adjustment of the dressing speed and the feed rate includes:

[0019] If the comprehensive eigenvalue of the lower cycloid wheel machining process at the current moment is less than or equal to the preset threshold, then maintain the dressing speed and the feed rate in the lower cycloid wheel machining process at the current moment;

[0020] Otherwise, adjust the dressing speed and the feed rate in the lower cycloid wheel machining process at the current moment. The specific process is as follows:

[0021] The adjustment relational expression of the dressing speed is: ; where represents the adjusted dressing speed at the current moment; represents the dressing speed before adjustment at the current moment; represents the comprehensive eigenvalue of the lower cycloid wheel machining process at the current moment; represents the preset threshold; norm( ) represents the normalization function;

[0022] For the feed rate, construct the adjustment relational expression of the feed rate according to the construction method of the adjustment relational expression of the dressing speed, and adjust the feed rate in the lower cycloid wheel machining process at the current moment.

[0023] In a second aspect, an embodiment of the present application provides a grinding dressing device applied to the cycloid wheel machining process. A computer program is stored in the device, and when the computer program is executed by a processor, the grinding dressing method applied to the cycloid wheel machining process described in any one of the above is implemented.

[0024] In a third aspect, an embodiment of the present application further provides a grinding dressing apparatus applied to the cycloid wheel machining process, 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, the steps of the grinding dressing method applied to the cycloid wheel machining process described in any one of the above are implemented.

[0025] As can be seen from the above embodiments, the grinding and dressing method provided by the embodiments of the present application for the cycloid gear machining process has at least the following beneficial effects:

[0026] In response to the problems of unmatched grinding wheel dressing parameter and thermo-mechanical coupling effect, the present application uses frequency-domain energy analysis and finite element thermal-stress coupling simulation to quantify the high-frequency vibration and heat risk degree in the cycloid gear machining process, and reflects in real time the characteristics of grinding wheel edge wear and passivation and local thermal stress concentration, solves the lag problem that traditional off-line detection cannot dynamically track multi-physical field interference, and significantly reduces the risk of profile distortion; further, in response to the problems of grinding wheel vibration instability and contour accuracy decline caused by multi-physical field coupling, the present application uses modal decomposition and principal component analysis to construct comprehensive eigenvalues, dynamically reflects the system stability characteristics in the grinding wheel dressing process, effectively eliminates the coupling interference of high-frequency vibration, uneven thermal expansion and servo axis backlash, and improves the controllability of the machining process; further, the present application uses a hierarchical closed-loop control strategy and a parameter adaptive adjustment mechanism, based on the normalized deviation between the calculated real-time grinding wheel distortion coefficient and the preset threshold, dynamically adjusts the dressing speed and feed rate proportionally, solves the problem of adaptive lag of dressing parameters, suppresses problems such as edge passivation and collapse caused by excessive material removal and heat accumulation, and eliminates the distortion of the edge profile in the cycloid gear machining process under multi-physical field interference. Description of the Drawings

[0027] In order to more clearly illustrate the technical solutions and advantages in the embodiments of the present application or the prior art, the following will briefly introduce the drawings required for the description of the embodiments or the prior art. Obviously, the drawings in the following description are only some embodiments of the present application. For those of ordinary skill in the art, without creative efforts, other drawings can also be obtained based on these drawings.

[0028] Figure 1 It is a flowchart of the steps of the grinding and dressing method applied to the cycloid gear machining process provided by an embodiment of the present application;

[0029] Figure 2 It is a schematic diagram of the comprehensive eigenvalue extraction process provided by an embodiment of the present application. Detailed Embodiments

[0030] In order to further elaborate on the technical means and effects adopted by the present application to achieve the predetermined invention purpose, the following, in combination with the drawings and preferred embodiments, details the specific embodiments, structures, features and effects of the grinding and dressing method, equipment and device applied to the cycloid gear machining process proposed by the present application. In the following description, different "one embodiment" or "another embodiment" do not necessarily refer to the same embodiment. In addition, the specific features, structures or characteristics in one or more embodiments can be combined in any suitable form.

[0031] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the technical field to which this application belongs.

[0032] The following specifically describes the specific solutions of the grinding and dressing method, equipment, and device applied to the cycloid gear processing process provided by this application in conjunction with the accompanying drawings.

[0033] Please refer to Figure 1 , which shows a flowchart of the steps of a grinding and dressing method applied to the cycloid gear processing process provided by an embodiment of this application. The method includes the following steps:

[0034] S1: Real-time obtain various state data during the cycloid gear processing process. Among them, all kinds of state data include: cutting force data, vibration data, and temperature data.

[0035] In order to realize real-time monitoring of the grinding wheel wear and thermal-mechanical coupling risk, various state data during the cycloid gear processing process are obtained in real time. Among them, various state data include: cutting force data, vibration data, and temperature data. The specific acquisition process of various state data is as follows. Specifically: Install an embedded force sensor at the end of the grinding wheel spindle to collect the cutting force time-domain data; install an infrared temperature sensor near the surface of the grinding wheel to collect the spatial temperature data; install vibration accelerometers on the machine tool spindle box and the workbench to collect vibration data. Set the acquisition frequency of the above sensors to be f, perform normalization processing on all the collected data, and synchronize and align the multi-source data through timestamps to eliminate the sampling delay, so as to analyze the processing state of the cycloid gear in real time.

[0036] It should be noted that the value of the acquisition frequency f is set manually. In this embodiment, the value of the data acquisition frequency f is 100Hz. In the actual application process, as other implementation manners, the implementer can also set it by himself in combination with the specific situation. This embodiment does not make special restrictions.

[0037] In addition, it should be understood that there are many common normalization processing methods. In this embodiment, the z-score normalization method is used to perform normalization processing on the data. In the actual application process, as other implementation manners, the implementer can also use other normalization methods such as the maximum-minimum normalization method in combination with the specific situation. Regarding the selection of the normalization method, this embodiment does not make special restrictions.

[0038] Among them, the z-score normalization method is a well-known technology, and its specific principle will not be elaborated here.

[0039] S2: By analyzing the difference between the energy within the neighborhood of the main frequency in the frequency domain and the total energy of all cutting force data within a preset time duration before each moment, determine the energy proportion during the machining process of the lower pendulum wheel at each moment; by analyzing the variation trend of all temperature data within a preset time duration before each moment, determine the thermal deformation intensity during the machining process of the lower pendulum wheel at each moment, and combine the said energy proportion to determine the high-frequency vibration and heat risk degree during the machining process of the lower pendulum wheel at each moment.

[0040] Due to the dynamic matching imbalance between the dressing speed and the feed rate during the grinding wheel dressing process, and the coupling effect of the thermal deformation of the grinding wheel spindle and the backlash of the dresser servo axis, the uneven distribution of the micro-edge of the grinding wheel and the contour distortion are caused, specifically manifested as periodic ripples or edge collapse, seriously reducing the tooth profile accuracy.

[0041] Therefore, in this embodiment, by analyzing the difference between the energy within the neighborhood of the main frequency in the frequency domain and the total energy of all cutting force data within a preset time duration before each moment, determine the energy proportion during the machining process of the lower pendulum wheel at each moment; by analyzing the variation trend of all temperature data within a preset time duration before each moment, determine the thermal deformation intensity during the machining process of the lower pendulum wheel at each moment, and combine the said energy proportion to determine the high-frequency vibration and heat risk degree during the machining process of the lower pendulum wheel at each moment, so as to judge whether it is necessary to adjust the dressing speed and the feed rate during the grinding wheel dressing process. The specific process is as follows:

[0042] (1) In this embodiment, by analyzing the difference between the energy within the neighborhood of the main frequency in the frequency domain and the total energy of all cutting force data within a preset time duration before each moment, determine the energy proportion during the machining process of the lower pendulum wheel at each moment, specifically:

[0043] In this embodiment, the result of dividing the total energy within the 3dB bandwidth at the main frequency in the frequency domain of all cutting force data within a preset time duration before each moment by the total energy of all cutting force data in the frequency domain is used as the energy proportion during the machining process of the lower pendulum wheel at each moment, quantifying the wear degree of the grinding wheel edge. The larger the energy proportion, the more severe the risk of grinding wheel edge passivation or cracking.

[0044] It should be noted that in this embodiment, the fast Fourier transform algorithm is used to convert all cutting force data within the preset time duration to the frequency domain. In the actual application process, as other implementation manners, the implementer can also use other methods such as wavelet transform according to the specific situation. This embodiment does not make special restrictions.

[0045] It is further explained that the value of the preset time duration is set artificially. In this embodiment, the value of the preset time duration is 1 min. In the actual application process, as other implementation manners, the implementer can also set it by himself according to the specific situation. This embodiment does not make special restrictions.

[0046] Among them, the fast Fourier transform, the main frequency, and the 3 dB bandwidth are all well-known technologies, and their specific principles and concepts will not be elaborated further.

[0047] (2) Further, in this embodiment, by analyzing the change trends of all temperature data within a preset duration before each moment, the thermal deformation intensity of the lower swing line wheel during the machining process at each moment is determined, specifically as follows:

[0048] All temperature data within the preset duration before each moment are used as the input of the finite element thermal-stress coupling simulation model, and a thermal deformation nephogram is output. The range of thermal stress of all nodes within each grid unit in the thermal deformation nephogram is calculated, and the maximum range of thermal stress among all grid units is taken as the thermal deformation intensity of the lower swing line wheel during the machining process at each moment. The greater the thermal deformation intensity, the more significant the thermal stress concentration, and the higher the risk of distortion of the grinding wheel edge profile.

[0049] Among them, the finite element thermal-stress coupling simulation model, the thermal deformation nephogram, and the thermal stress are all well-known technologies, and their specific principles, concepts, and acquisition processes will not be elaborated further.

[0050] (3) Further, in this embodiment, by comprehensively considering the thermal deformation intensity and the energy proportion during the machining process of the lower swing line wheel at each moment, the high-frequency vibration and heat risk degree during the machining process of the lower swing line wheel at each moment is determined, specifically as follows:

[0051] As an implementation method, in this embodiment, the high-frequency vibration and heat risk degree of the lower swing line wheel during the machining process at moment i is expressed as: ; in the formula, represents the energy proportion during the machining process of the lower swing line wheel at moment i; represents the thermal deformation intensity during the machining process of the lower swing line wheel at moment i; norm( ) represents the normalization function.

[0052] It can be understood from the high-frequency vibration and heat risk degree during the machining process of the lower swing line wheel at each moment that if the energy proportion is larger, the high-frequency vibration and heat risk degree is higher, which means that the larger the energy proportion of vibration and thermal effects, the higher the risk of problems during the machining process. And if the thermal deformation intensity is larger, the high-frequency vibration and heat risk degree is higher, which indicates that during the machining process, the local thermal deformation caused by high-frequency vibration and thermal effects is more serious, and the machining risk is higher;

[0053] On the contrary, if the energy proportion is smaller, the high-frequency vibration and heat risk degree is lower, which indicates that the energy proportion in the high-frequency band is small, and the influence of vibration and thermal effects is small, and the machining process is relatively stable with low risk. And if the thermal deformation intensity is smaller, the high-frequency vibration and heat risk degree is lower, which means that the local thermal deformation is lighter, and the influence of high-frequency vibration and thermal effects on the machining process is small, and the risk is low.

[0054] So far, by converting the cutting force data into the frequency domain and calculating the energy proportion within the neighborhood of the main frequency to quantify the wear degree of the grinding wheel edge, further, by analyzing the temperature data through a finite element thermal-stress coupling simulation model to determine the thermal deformation intensity, so as to evaluate the degree of thermal stress concentration and the risk of grinding wheel edge profile distortion; finally, by combining the energy proportion and the thermal deformation intensity, the high-frequency vibration and heat risk degree of the cycloid gear machining process at each moment is obtained, which is used to judge whether it is necessary to adjust the dressing speed and feed rate during the grinding wheel dressing process, and can more accurately reflect the potential risks caused by high-frequency vibration and thermal effects during the cycloid gear machining process, contribute to timely adjusting the machining parameters, optimizing the machining quality and efficiency, reducing the machining risk, and improving the machining accuracy and stability.

[0055] S3: Based on all the high-frequency vibration and heat risk degrees and all the vibration data within a preset time period before the current moment, adopt the modal decomposition algorithm to construct the first eigenvalue of the cycloid gear machining process at the current moment; based on all the state data and all the high-frequency vibration and heat risk degrees within a preset time period before the current moment, adopt the principal component analysis algorithm to construct the second eigenvalue of the cycloid gear machining process at the current moment, and combine the first eigenvalue to determine the comprehensive eigenvalue of the cycloid gear machining process at the current moment.

[0056] Due to the dynamic matching imbalance of the dressing speed and feed rate during the grinding wheel dressing process, and the coupling effect of the thermal deformation of the grinding wheel spindle and the backlash of the dresser servo axis, it leads to uneven distribution of the microscopic edges of the grinding wheel and profile distortion, seriously reducing the stability of machining quality.

[0057] Therefore, in this embodiment, based on all the high-frequency vibration and heat risk degrees and all the vibration data within a preset time period before the current moment, adopt the modal decomposition algorithm to construct the first eigenvalue of the cycloid gear machining process at the current moment; based on all the state data and all the high-frequency vibration and heat risk degrees within a preset time period before the current moment, adopt the principal component analysis algorithm to construct the second eigenvalue of the cycloid gear machining process at the current moment, and combine the first eigenvalue to determine the comprehensive eigenvalue of the cycloid gear machining process at the current moment. The specific process is as follows:

[0058] (1) In this embodiment, based on all the high-frequency vibration and heat risk degrees and all the vibration data within a preset time period before the current moment, adopt the modal decomposition algorithm to construct the first eigenvalue of the cycloid gear machining process at the current moment, specifically:

[0059] In this embodiment, all the high-frequency vibration and heat risk degrees and all the vibration data within a preset time period before the current moment are used as the input of the modal decomposition algorithm, and the energy proportion, modal frequency, and modal damping ratio of each modal component are output. The modal component with the highest energy proportion is denoted as the dominant modal component, and the result of multiplying the energy proportion of the dominant modal component by the dominant modal frequency and dividing it by the modal damping ratio is used as the first eigenvalue of the cycloid gear machining process at the current moment.

[0060] It can be understood from the first eigenvalue of the cycloid wheel machining process at the current moment that the modal frequency of the dominant modal component reflects the vibration characteristic frequency of the grinding wheel. The larger the modal frequency, the more obvious the vibration, and the risk of grinding wheel edge passivation or cracking increases. The dressing speed and feed rate should be adjusted in a timely manner. The modal damping ratio characterizes the vibration attenuation ability. The smaller the modal damping ratio, the more intense the vibration. The energy proportion represents the contribution degree of the corresponding mode to the vibration data. The larger the energy proportion, the more intense the vibration, that is, the risk of grinding wheel edge passivation or cracking increases. Therefore, if the modal frequency of the dominant modal component is larger, the energy proportion is larger, and the modal damping ratio is smaller, the corresponding first eigenvalue is larger, indicating a greater risk of grinding wheel edge passivation or cracking. On the contrary, if the modal frequency of the dominant modal component is smaller, the energy proportion is smaller, and the modal damping ratio is larger, the corresponding first eigenvalue is smaller, indicating a smaller risk of grinding wheel edge passivation or cracking, and the stability of the cycloid wheel machining process is relatively high.

[0061] It should be noted that there are many commonly used modal decomposition algorithms. In this embodiment, the dynamic modal decomposition algorithm is used to perform two-dimensional decomposition on the high-frequency vibration and heat risk degree and vibration data. In the actual application process, as other implementation manners, implementers can also use other decomposition methods such as the empirical modal decomposition algorithm according to specific situations. Regarding the selection of the modal decomposition algorithm, this embodiment does not make special restrictions.

[0062] It is further explained that the value of the length of the preset time period is set artificially. In this embodiment, the length of the preset time period is 1 min. In the actual application process, as other implementation manners, implementers can also set it by themselves according to specific situations. This embodiment does not make special restrictions.

[0063] Among them, the dynamic modal decomposition algorithm, the calculation process of the energy proportion, and the acquisition processes of the modal frequency and modal damping ratio are all well-known technologies, and their specific principles will not be elaborated here.

[0064] (2) Further, based on all state data and all high-frequency vibration and heat risk degrees within the preset time period before the current moment, this embodiment uses the principal component analysis algorithm to construct the second eigenvalue of the cycloid wheel machining process at the current moment, specifically:

[0065] In this embodiment, all cutting force data, all vibration data, all temperature data, and all high-frequency vibration and heat risk degrees within the preset time period before the current moment are used as the input of the principal component analysis algorithm, and the output first principal component score is used as the second eigenvalue of the cycloid wheel machining process at the current moment. The second eigenvalue comprehensively reflects the thermal-mechanical coupling and wear risks. The higher the first principal component score, the worse the stability of the cycloid wheel machining process.

[0066] Among them, the principal component analysis algorithm is a well-known technology, and the specific process of obtaining the first principal component score using the principal component analysis algorithm will not be elaborated here.

[0067] (3) Further, based on the first eigenvalue of the lower pendulum wheel machining process at the current moment and in combination with the second eigenvalue, this embodiment determines the comprehensive eigenvalue of the lower pendulum wheel machining process at the current moment, specifically:

[0068] The result of positively fusing the first eigenvalue and the second eigenvalue of the lower pendulum wheel machining process at the current moment is used as the comprehensive eigenvalue of the lower pendulum wheel machining process at the current moment.

[0069] It should be understood that positive fusion means combining two or more indicators through addition, multiplication, etc., in order to obtain a comprehensive indicator, so as to more comprehensively and accurately evaluate a certain phenomenon or problem. This fusion method is not limited to simple arithmetic operations, but can also include more complex statistical models and analysis methods, and the implementer can choose according to specific circumstances, and this embodiment does not make special restrictions.

[0070] Preferably, as an implementation manner, in this embodiment, the product of the first eigenvalue and the second eigenvalue of the lower pendulum wheel machining process at the current moment is used as the comprehensive eigenvalue of the lower pendulum wheel machining process at the current moment.

[0071] From the comprehensive eigenvalue of the lower pendulum wheel machining process at the current moment, it can be understood that the comprehensive eigenvalue is used to evaluate the overall stability of the grinding wheel dressing process. The larger the comprehensive eigenvalue, the more severe the high-frequency vibration energy, significant thermal deformation, insufficient damping capacity, and superposition of principal component risks in the grinding wheel dressing process, and the higher the risk of decreased machining accuracy, that is, the larger the first eigenvalue and the second eigenvalue; on the contrary, the smaller the comprehensive eigenvalue, the more effectively the high-frequency vibration is controlled during the grinding wheel dressing process, the better the state of the grinding wheel edge, and the higher the machining stability, that is, the smaller the first eigenvalue, and the thermal-mechanical coupling and wear problems during the grinding wheel dressing process are effectively controlled, the grinding wheel state is stable, and the machining stability is high, and the corresponding second eigenvalue is smaller.

[0072] Preferably, the schematic diagram of the comprehensive eigenvalue extraction process provided in this embodiment is as Figure 2 shown.

[0073] So far, by using the modal decomposition algorithm to analyze the high-frequency vibration heat risk degree and vibration data, the eigenvalue of the dominant modal component is extracted as the first eigenvalue. Further, by using the principal component analysis algorithm to synthesize data such as cutting force, vibration, temperature, and high-frequency vibration heat risk degree, the first principal component score is obtained as the second eigenvalue, and the comprehensive eigenvalue is obtained by combining the first eigenvalue, which is used to evaluate the overall stability of the grinding wheel dressing process. This method can more comprehensively reflect the instability state under the multi-physical field coupling effect in the grinding wheel dressing process, which helps to timely adjust the dressing parameters and processes, optimize the machining quality and efficiency, and reduce the machining risk.

[0074] S4: Obtain the dressing speed and feed rate during the lower swing wheel machining process at the current moment, and combine the comprehensive eigenvalue to adjust the dressing speed and feed rate.

[0075] Due to the dynamic matching imbalance between the dressing speed and feed rate during the grinding wheel dressing process, and the coupling effect of the thermal deformation of the grinding wheel spindle and the backlash of the dresser servo axis, the uneven distribution of the micro-edge of the grinding wheel and the contour distortion are caused. When the dressing speed is too high and the feed rate is too small, the contact stress between the diamond roller and the grinding wheel is insufficient, and the proportion of high-frequency vibration energy increases significantly, resulting in edge passivation or chipping; when the feed rate is too large, the material removal rate exceeds the bearing capacity of the grinding wheel bond, and the severe change of the local temperature gradient is superimposed, resulting in uneven thermal expansion and stress concentration, and aggravating the risk of contour distortion. In addition, the instability of the grinding wheel vibration mode further deteriorates the machining stability, making it difficult to meet the micron-level requirements for tooth profile accuracy.

[0076] Therefore, in this embodiment, by obtaining the dressing speed and feed rate during the lower swing wheel machining process at the current moment, and combining the comprehensive eigenvalue to adjust the dressing speed and feed rate, the specific process is as follows:

[0077] If the comprehensive eigenvalue of the lower swing wheel machining process at the current moment is less than or equal to the preset threshold, then maintain the dressing speed and feed rate during the lower swing wheel machining process at the current moment;

[0078] On the contrary, if the comprehensive eigenvalue of the lower swing wheel machining process at the current moment is greater than the preset threshold, then adjust the dressing speed and feed rate during the lower swing wheel machining process at the current moment. The specific process is as follows:

[0079] The adjustment relationship formula for the dressing speed is: ; In the formula, represents the adjusted dressing speed at the current moment; represents the dressing speed before adjustment at the current moment; represents the comprehensive eigenvalue of the lower swing wheel machining process at the current moment; represents the preset threshold; norm( ) represents the normalization function.

[0080] For the feed rate, according to the construction method of the adjustment relationship formula of the dressing speed, construct the adjustment relationship formula of the feed rate, and adjust the feed rate during the processing of the lower cycloid wheel at the current moment. Specifically:

[0081] The adjustment relationship formula of the feed rate is: ; In the formula, represents the adjusted dressing speed at the current moment; represents the dressing speed before adjustment at the current moment; represents the comprehensive characteristic value during the processing of the lower cycloid wheel at the current moment; represents the preset threshold; norm( ) represents the normalization function;

[0082] It should be noted that the value of the preset threshold is set manually. As an implementation manner, the value of the preset threshold in this embodiment is 1.2. In actual application, as other implementation manners, the implementer can also set it according to the specific situation by himself / herself, and this embodiment does not make special restrictions.

[0083] So far, in this embodiment, by calculating the normalized deviation between the comprehensive characteristic value and the preset threshold in real time, the dressing speed or the feed rate is dynamically reduced in proportion, so that the dressing parameters are adaptively adjusted according to the risk level, which not only inhibits the profile collapse and edge passivation caused by heat accumulation and excessive material removal, but also balances the vibration stability, thereby accurately suppressing the multi-physical field coupling interference.

[0084] Based on the same inventive concept as the above method, the embodiment of the present application also provides a grinding dressing device applied to the processing process of the cycloid wheel. A computer program is stored in the device, and when the computer program is executed by a processor, it implements the grinding dressing method applied to the processing process of the cycloid wheel described in any one of the above.

[0085] Based on the same inventive concept as the above method, the embodiment of the present application also provides a grinding dressing device applied to the processing process of the cycloid wheel, 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 grinding dressing methods applied to the processing process of the cycloid wheel.

[0086] It should be noted that: the above sequence of the embodiments of the present application is only for description and does not represent the superiority or inferiority of the embodiments. And the above describes specific embodiments of this specification. In addition, the processes depicted in the drawings do not necessarily require the specific order or continuous order shown to achieve the desired results. In some embodiments, multitasking and parallel processing are also possible or may be advantageous.

[0087] Each embodiment in this specification is described in a progressive manner. For the same or similar parts among the embodiments, reference can be made to each other, and the key point of each embodiment is to illustrate the differences from other embodiments.

[0088] The above are only the preferred embodiments of the present application and are not intended to limit the present application. Any modifications, equivalent replacements, improvements, etc. made within the principle of the present application shall be included within the protection scope of the present application.

Claims

1. A grinding and dressing method applied to the machining process of a cycloid gear, characterized in that, The method includes the following steps: Obtain various state data during the cycloid gear machining process in real time, where all the state data includes: cutting force data, vibration data, and temperature data; By analyzing the difference between the energy within the neighborhood of the main frequency in the frequency domain and the total energy of all cutting force data within a preset time period before each moment, determine the energy proportion during the cycloid gear machining process at each moment; by analyzing the change trend of all temperature data within a preset time period before each moment, determine the thermal deformation intensity during the cycloid gear machining process at each moment, and combine the energy proportion to determine the high-frequency vibration and heat risk degree during the cycloid gear machining process at each moment; Based on all the high-frequency vibration and heat risk degrees and all the vibration data within a preset time period before the current moment, adopt a modal decomposition algorithm to construct the first eigenvalue of the cycloid gear machining process at the current moment; based on all the state data and all the high-frequency vibration and heat risk degrees within a preset time period before the current moment, adopt a principal component analysis algorithm to construct the second eigenvalue of the cycloid gear machining process at the current moment, and combine the first eigenvalue to determine the comprehensive eigenvalue of the cycloid gear machining process at the current moment; Obtain the dressing speed and feed rate during the machining process of the lower cycloid gear at the current moment, and combine the comprehensive eigenvalue to adjust the dressing speed and feed rate.

2. The grinding and dressing method applied to the machining process of the cycloid gear as claimed in claim 1, wherein The energy proportion during the cycloid gear machining process at each moment is: the result of dividing the total energy within the 3dB bandwidth at the main frequency in the frequency domain of all cutting force data within a preset time period before each moment by the total energy of all cutting force data in the frequency domain.

3. The grinding and dressing method applied to the machining process of the cycloid gear according to claim 1, characterized in that, The construction process of the thermal deformation intensity during the cycloid gear machining process at each moment is as follows: Take all temperature data within a preset time period before each moment as the input of a finite element thermal-stress coupling simulation model, output a thermal deformation nephogram, calculate the extreme difference of thermal stress of all nodes within each grid cell in the thermal deformation nephogram, and take the maximum extreme difference of thermal stress among all grid cells as the thermal deformation intensity during the cycloid gear machining process at each moment.

4. The grinding and dressing method applied to the machining process of the cycloid gear as claimed in claim 1, characterized in that, The expression for the high-frequency vibration and heat risk degree in the processing of the lower pendulum line wheel at each moment is as follows: ; In the formula, represents the high-frequency vibration and heat risk degree in the processing of the lower pendulum line wheel at moment i; represents the energy proportion in the processing of the lower pendulum line wheel at moment i; represents the thermal deformation strength in the processing of the lower pendulum line wheel at moment i; norm( ) represents the normalization function.

5. The grinding and dressing method applied to the machining process of the cycloid gear as claimed in claim 1, characterized in that, The construction method of the first eigenvalue of the cycloid gear machining process at the current moment is as follows: Take all the high-frequency vibration and heat risk degrees and all the vibration data within a preset time period before the current moment as the input of a modal decomposition algorithm, output the energy proportion, modal frequency, and modal damping ratio of each modal component respectively, record the modal component with the highest energy proportion as the dominant modal component, and take the result of dividing the product of the energy proportion of the dominant modal component and the dominant modal frequency by the modal damping ratio as the first eigenvalue of the cycloid gear machining process at the current moment.

6. The grinding and dressing method applied to the processing of cycloid gears according to claim 1, characterized in that, The construction process of the second eigenvalue of the cycloid gear machining process at the current moment is as follows: Take all cutting force data, all vibration data, all temperature data, and all high-frequency vibration and heat risk degrees within a preset time period before the current moment as the input of a principal component analysis algorithm, and take the first principal component score output as the second eigenvalue of the cycloid gear machining process at the current moment.

7. The grinding and dressing method applied to the machining process of the cycloid gear as described in claim 1, wherein, The comprehensive eigenvalue of the cycloid gear machining process at the current moment is the result of the positive fusion of the first eigenvalue and the second eigenvalue of the cycloid gear machining process at the current moment.

8. The grinding and dressing method applied to the machining process of the cycloid gear as claimed in claim 1, wherein, The adjustment of the dressing speed and feed rate includes: If the comprehensive eigenvalue of the lower pendulum line wheel machining process at the current moment is less than or equal to the preset threshold value, then maintain the dressing speed and feed rate in the lower pendulum line wheel machining process at the current moment; Otherwise, adjust the dressing speed and feed rate in the lower pendulum line wheel machining process at the current moment. The specific process is as follows: The adjustment relationship formula for the dressing speed is as follows: ; In the formula, represents the adjusted dressing speed at the current moment; represents the dressing speed before adjustment at the current moment; represents the comprehensive characteristic value of the cycloid wheel machining process at the current moment; represents the preset threshold; norm( ) represents the normalization function; For the feed rate, construct an adjustment relationship formula for the feed rate according to the construction method of the adjustment relationship formula for the dressing speed, and adjust the feed rate in the lower pendulum line wheel machining process at the current moment.

9. A grinding and dressing device applied to the machining process of a cycloid gear, wherein a computer program is stored in the device, characterized in that When the computer program is executed by the processor, it implements the grinding dressing method applied to the cycloid gear machining process according to any one of claims 1-8.

10. A grinding and dressing device applied to the machining process of a cycloid gear, 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, it implements the steps of the grinding dressing method applied to the cycloid gear machining process according to any one of claims 1-8.

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