Planetary carrier drilling method and drilling device for rv reducer

Abstract

The application relates to the technical field of planet carrier drilling, in particular to a planet carrier drilling method and a drilling device for an RV reducer. The method comprises the following steps: obtaining planet carrier to-be-processed hole position coordinates, grouping the hole positions into inner layer holes and outer layer holes; preferentially processing the outer layer holes, generating an initial processing path based on a historical database and matching similar hole position layouts; performing first hole processing according to the initial processing path; after processing one hole, collecting temperature data of the processed hole position through an infrared thermal imager, and optimizing the processing path by using a simulated annealing algorithm; performing drilling processing according to the optimized processing path sequence, and recording the processing path and hole position layout features in the historical database after the current planet carrier is processed. The application aims to reduce the influence of heat accumulation on the planet carrier and improve the hole diameter precision and surface quality.

Description

Technical Field

[0001] The present application relates to the technical field of planetary carrier drilling, and in particular to a planetary carrier drilling method and a drilling device for an RV reducer. Background Art

[0002] RV reducers are high-precision gear transmissions commonly used in industrial robotics, automation equipment, and other fields. Their primary function is to achieve high torque output and precise motion control through multi-stage gear reduction. Their core advantages lie in high rigidity, low backlash error, and long life. As a key component of the RV reducer's planetary gear mechanism, the planet carrier supports the planetary gears and transmits power. Its structural precision directly determines the reducer's transmission stability and load-bearing capacity.

[0003] The purpose of drilling holes in the planetary carrier is to produce positioning holes or connecting holes for installing bearings, pins, gears and other parts. The accuracy of these holes directly affects the assembly accuracy and meshing performance of each transmission component, thereby ensuring that the RV reducer can maintain stable power transmission and motion accuracy under high-speed and heavy-load conditions.

[0004] Planetary carrier drilling typically involves machining multiple holes. Traditional drilling path planning fails to consider the impact of machining sequence on heat accumulation and focuses solely on minimizing the straight-line distance between holes. When machining adjacent holes consecutively, cutting heat accumulates in localized areas, leading to uneven temperature gradients in the spindle and tool. Localized overheating causes spindle runout, further amplifying thermal deformation errors and resulting in cumulative precision degradation. Summary of the Invention

[0005] In view of the above, it is necessary to provide a planetary carrier drilling method and a drilling device for an RV reducer to solve the above problems.

[0006] A first aspect of the present application provides a planet carrier drilling method for an RV reducer, the method comprising:

[0007] Extract the holes to be processed of the planetary carrier of the RV reducer and group them to obtain outer holes and inner holes;

[0008] Based on the similarity between the hole distribution characteristics of the planetary carrier and the workpiece in the historical database, the initial processing path of the planetary carrier's outer holes is determined; combined with the initial processing path of the planetary carrier's outer holes and the preset processing path of the inner holes, the initialization path of the simulated annealing algorithm is determined;

[0009] The planetary carrier is machined according to the initialization path. After each hole is machined, the temperature data of the machined hole is extracted through infrared thermal imaging.

[0010] Based on the required tool travel distance of the planetary carrier's current machining path and the depth of the machined hole, the proportion of idle tool travel distance is calculated. For each machined hole within the preset range of the unmachined hole, the heat accumulation factor of each unmachined hole is calculated based on the difference between its temperature data and the ambient temperature, combined with the distance characteristics between the machined and unmachined holes and the completion time of the machined hole. The cumulative sum of all heat accumulation factors is used as the heat accumulation penalty. The weighted sum of the idle tool travel distance proportion and the heat accumulation penalty is taken to obtain the objective function of the current machining path.

[0011] A new path is generated based on the heat accumulation factor of each unmachined hole and the distance distribution between the unmachined hole and the last machined hole. The optimal machining path is determined based on the objective function values ​​of the current machining path and the new path. The unmachined holes are drilled according to the optimal machining path.

[0012] The process of extracting the holes to be processed of the planetary carrier of the RV reducer and grouping them to obtain outer holes and inner holes is as follows:

[0013] For the planetary carrier, the distance between each hole to be processed and the center axis of the planetary carrier is obtained, and the hole to be processed with a distance less than the preset grouping threshold is regarded as an inner hole; otherwise, the hole to be processed is regarded as an outer hole.

[0014] The process of determining the initial machining path of the outer hole of the planet carrier is as follows:

[0015] Calculate the similarity measure between the hole feature vectors of the planetary carrier and each workpiece in the historical database, select the workpiece in the historical database with the largest similarity measure that is greater than a preset threshold, and use the corresponding optimal machining path as the initial machining path of the planetary carrier;

[0016] The hole position feature vector is determined by the number of inner layer holes, the number of outer layer holes, the average outer layer hole radius, and the average inner layer hole angle;

[0017] The historical database stores the optimal processing path and hole position feature vector after each planet carrier drilling process.

[0018] The specific parameters for processing the planetary carrier are: spindle speed 8000~12000rpm, feed speed 0.12~0.18mm / r, and cooling pressure 8~12MPa.

[0019] The step of obtaining the ratio of idle tool distance is as follows:

[0020] Calculate the sum of the distances between all adjacent unprocessed holes in the current machining path as the idle tool distance; and record the sum of the idle tool distance and the machining depths of all unprocessed holes in the current machining path as the total path length.

[0021] The ratio between the air walking distance and the total path length is taken as an air walking distance proportion.

[0022] The heat cumulative factor of each unprocessed hole is obtained, and the heat cumulative factor of each unprocessed hole is specifically obtained by:

[0023] For each processed hole within the preset range of each unprocessed hole in the current machining path, the temperature difference between the ambient temperature and the temperature data of each processed hole is calculated, and the negative correlation mapping result of the temperature difference is taken as the temperature weight of each processed hole.

[0024] The negative correlation mapping result of the distance between each unprocessed hole and each processed hole within the preset range is calculated as the distance weight of each processed hole.

[0025] The negative correlation mapping result of the completion time of each processed hole within the preset range of each unprocessed hole is calculated as the time weight of each processed hole.

[0026] The product of the temperature weight, the distance weight and the time weight of each processed hole within the preset range of each unprocessed hole is accumulated to obtain the heat cumulative factor of each unprocessed hole.

[0027] The heat cumulative factor of each unprocessed hole is combined with the distance distribution between the unprocessed hole and the last processed hole to generate a new path.

[0028] The heat cumulative factors of all unprocessed holes in the current machining path are taken as weights, and the unprocessed hole closest to the last processed hole is exchanged with the unprocessed hole with the smallest weight to generate a new path.

[0029] If the current machining path and the new path are the same, the machining order of two unprocessed holes is randomly exchanged.

[0030] The target function value of the current machining path and the new path is used to determine the optimal machining path, and the target function value of the current machining path and the new path is specifically determined by:

[0031] If the target function value of the new path is less than the target function value of the current machining path , and the distance between adjacent unprocessed holes in the new path is greater than or equal to the preset distance, the new path is taken as the current path; otherwise, the new path is accepted with a probability , wherein T is the current preset annealing parameter, and exp() represents the exponential function with natural constant as the base number.

[0032] When the termination condition of the simulated annealing algorithm is met, the current machining path is determined as the optimal machining path.

[0033] The termination condition of the simulated annealing algorithm is any one of the following: reaching the maximum number of iterations, the objective function value remains unchanged for multiple consecutive iterations, and the current annealing temperature is lower than the termination temperature.

[0034] In a second aspect, an embodiment of the present application also provides a planetary carrier drilling device for an RV reducer, 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.

[0035] This application has at least the following beneficial effects:

[0036] This application generates the initial processing path by grouping the planetary carrier hole positions and combining it with the historical database. Compared with the random generation of the traditional scheme, it can accelerate the convergence speed of the simulated annealing algorithm, further shorten the path optimization time, and make the processing process more efficient.

[0037] This application calculates the thermal accumulation penalty of unprocessed holes based on the temperature data of processed holes within a certain range of unprocessed holes, and then combines the proportion of idle tool time as the objective function. Compared with the traditional solution that only considers the shortest straight-line distance between holes, by optimizing the processing path, it can not only reduce the idle tool time, but also avoid continuous processing of high-temperature holes in close proximity, reduce the impact of heat accumulation on the planetary carrier, improve the aperture accuracy and surface quality, reduce the scrap rate, and thus reduce production costs.

[0038] Furthermore, the introduction of temperature constraints for neighborhood operations can adapt to dynamic temperature changes during the processing process compared to the traditional direct exchange scheme, thereby generating a more optimal processing path and reducing the iteration time of the simulated annealing algorithm. BRIEF DESCRIPTION OF THE DRAWINGS

[0039] Figure 1 A flowchart of a planetary carrier drilling method for an RV reducer according to one embodiment of the present application;

[0040] Figure 2 A flowchart of obtaining an optimal processing path using a simulated annealing algorithm provided in one embodiment of the present application. DETAILED DESCRIPTION

[0041] 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.

[0042] 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.

[0043] 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.

[0044] 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.

[0045] The following describes in detail the planetary carrier drilling method and drilling device for the RV reducer provided in this application with reference to the accompanying drawings.

[0046] See also Figure 1 , which shows a flowchart of a planetary carrier drilling method for an RV reducer provided by one embodiment of the present application, the method comprising the following steps:

[0047] Step 1: Extract the holes to be processed of the planetary carrier of the RV reducer and group them to obtain outer holes and inner holes.

[0048] The holes of the planetary carrier of the RV reducer are usually evenly distributed on the circumference of circles of different radii with the center axis as the center point. For the holes on the same planetary carrier, the heat dissipation capacity of holes with different radii varies significantly. The outer holes (large radius) are close to the edge of the workpiece, with a large heat dissipation area and easy diffusion of cutting heat. The inner holes (small radius) are located near the center of the workpiece, with dense surrounding materials, poor heat dissipation, and easy formation of heat accumulation.

[0049] First, extract the hole positions in the planetary carrier: Use 3D modeling software to extract the Cartesian coordinates of the center position of the planetary carrier hole to be processed from the 3D model of the planetary carrier. , and number the hole positions. In this embodiment, the numbering starts from 0 and increases by 1.

[0050] Obtain the hole position parameters of each hole from the planet carrier design drawing, including hole diameter, depth and verticality.

[0051] Furthermore, all holes in the planetary carrier are grouped according to their distance from the central axis. The grouping rule is as follows: when the distance from the central axis is greater than or equal to a preset grouping threshold, the corresponding hole is classified as an outer hole; otherwise, the corresponding hole is classified as an inner hole. Outer holes, which are farther from the central axis, have better heat dissipation and are processed first. Inner holes, which are closer to the central axis, have poorer heat dissipation and are prone to heat accumulation. In this embodiment, the grouping threshold range is 80-120 mm, with a value of 100 mm in this embodiment. In other embodiments, the average of the central axis positions of all holes can be used as the grouping threshold. Implementers can select an appropriate grouping threshold based on actual conditions, and this application does not impose any restrictions on this.

[0052] By grouping the holes, the geometric properties of the planetary carrier holes are converted into quantifiable processing strategies, which is the basis for initial path planning that prioritizes heat dissipation capacity. It also provides key feature input for subsequent simulated annealing optimization and dynamic temperature feedback.

[0053] Step 2: Based on the similarity between the hole distribution characteristics of the planetary carrier and the workpiece in the historical database, the initial processing path of the outer hole of the planetary carrier is determined.

[0054] During drilling, cutting heat is a key factor affecting machining quality. If inner holes are machined first, the temperature in these areas will continue to rise as machining progresses, leading to increasingly severe heat accumulation. Prioritizing outer holes can remove some of this heat, reducing the risk of heat accumulation in the inner areas and creating more favorable temperature conditions for subsequent machining of these inner holes.

[0055] During long-term production, a vast amount of historical data accumulates for planetary carrier machining with various hole layouts. This data contains the optimal machining sequence for each layout. While simulated annealing algorithms can find the global optimal solution to a certain extent, the search space is typically large and the search time is long. Leveraging a historical database to match similar layouts and generate an initial machining sequence significantly reduces the algorithm's search space and speeds up convergence, eliminating the need to start the search from a random initial state.

[0056] First, generate the initial processing path. The specific steps are:

[0057] (1) Cross-sort the outer holes of the planetary carrier to avoid continuous processing of holes with adjacent angles to reduce local heat accumulation. In one embodiment of the present application, the outer holes of the planetary carrier are 8 and are evenly distributed on the circumference, that is, the angular interval is , you can follow the interval Sort by cross selection. The angle to the right of the central axis is recorded as , then the order of the outer holes in the planet carrier is This ensures that there is enough distance between each two adjacent outer holes, which is conducive to heat dissipation.

[0058] (2) Extract key features from the hole layout of the current planetary carrier. In this application, the hole layout features of the planetary carrier include: the number of inner holes, the number of outer holes, the average outer hole radius, and the average inner hole angle; all features are combined to form a hole feature vector for each planetary carrier.

[0059] (3) Compare the hole feature vector of the current planetary carrier with the hole feature vector of each workpiece in the historical database, and calculate the similarity measure between the current workpiece and the historical workpiece. In the embodiment of the present application, the historical database stores the optimal path and hole layout characteristics of each planetary carrier after drilling; the similarity measure is calculated using cosine similarity. In other embodiments, the negative correlation mapping of the Euclidean distance can be used for calculation, and the specific formula is: ;in represents an exponential function with a natural constant as the base, and A represents the Euclidean distance between the hole feature vectors of the current workpiece and the historical workpiece.

[0060] (4) Select the historical workpiece with the largest similarity metric greater than a preset threshold, and use the corresponding optimal machining path as the initial machining path for the current planetary carrier. If no historical workpiece with a similarity greater than the preset threshold is found, the outer holes are machined in the cross-sequence order. In one embodiment of the present application, the preset threshold is 0.8.

[0061] It should be understood that prioritizing the machining of outer holes reduces heat accumulation, minimizes machining errors caused by thermal deformation, and reduces the number of reworks, thereby improving overall machining efficiency. Furthermore, generating an initial machining sequence based on a historical database accelerates the convergence of the simulated annealing algorithm, further shortening path optimization time and making the machining process more efficient. By rationally arranging the machining sequence, the effects of thermal deformation can be minimized, ensuring the machining accuracy of the planetary carrier and improving product quality.

[0062] Step 3: Process the first hole according to the initial processing path.

[0063] The specific steps for the first hole processing are as follows: install the tool and use the tool setting instrument to set the tool; place the planetary carrier on the three-point floating support fixture, fit the bottom surface to the positioning pin, and tighten the bolts; start the fixture with the built-in laser rangefinder to measure the deformation of the three support points on the top surface of the workpiece, requiring single-point deformation , overall flatness If the deformation of a certain support point exceeds the tolerance, the support block height is adjusted through the hydraulic fine-tuning mechanism until the requirement is met; the processing parameters are set, specifically the spindle speed is 8000~12000rpm, the feed rate is 0.12~0.18mm / r, and the cooling pressure is 8~12MPa.

[0064] In one embodiment of the present application, the processing parameters are set to a spindle speed of 10,000 rpm, a feed rate of 0.15 mm / r, and a cooling pressure of 10 MPa; in other embodiments, the processing parameters are set to a spindle speed of 8,000 rpm, a feed rate of 0.12 mm / r, and a cooling pressure of 8 MPa; in some other embodiments, the processing parameters are set to a spindle speed of 12,000 rpm, a feed rate of 0.18 mm / r, and a cooling pressure of 12 MPa.

[0065] After each hole on the planetary carrier is machined, an infrared thermal imager is used to collect temperature data; all collected infrared thermal images are processed, and the average temperature of all infrared thermal images is calculated as the temperature of the machined hole. In one embodiment of the present application, the infrared thermal imager is a focal plane array infrared thermal imager installed above the spindle of the machine tool. The field of view covers an area of ​​200mm×200mm on the workpiece surface, ensuring that the temperature within 50mm around a single hole is scanned without blind spots, and a temperature sensor is used to collect the ambient temperature.

[0066] After each hole is machined, immediately activate the infrared thermal imager to collect temperature data. The acquisition time should be controlled within 1-2 seconds after machining to ensure that the collected temperature data accurately reflects the thermal state at the end of machining. Each acquisition should capture at least 3-5 infrared thermal image frames. The acquisition frequency should be adjusted based on the machining speed and heat transfer rate, generally 1-5 frames per second. It should be noted that image processing of infrared thermal images is well known, and the specific steps will not be repeated here.

[0067] Step 4: After each hole is processed, the temperature around the processed hole is collected using an infrared thermal imager, and the simulated annealing algorithm is used to optimize the processing path.

[0068] During the drilling process for planetary carriers in RV reducers, traditional machining path planning often focuses solely on machining efficiency, ignoring the impact of heat accumulation on machining accuracy. Heat accumulation can cause workpiece deformation, which in turn affects aperture accuracy and surface quality, increasing scrap rates. Maximizing the effects of heat accumulation can lead to excessive idle tool time, which in turn reduces machining efficiency and increases production costs. Therefore, it is necessary to comprehensively consider both idle tool time and heat accumulation to achieve a balance between machining efficiency and accuracy.

[0069] The simulated annealing algorithm is a general probabilistic algorithm often used to find the optimal solution to a problem within a large search space. It simulates the solid annealing process, accepting less favorable solutions with a certain probability, thereby avoiding local optimal solutions and ultimately finding the global optimal solution.

[0070] In the present application, the air walking time ratio and the heat accumulation penalty are taken as the objective function, the path is changed by exchanging the machining sequence, the objective function value is minimized, and whether to accept the new path is determined according to the acceptance criterion of the simulated annealing algorithm, and the optimal path is searched iteratively. On the premise of ensuring machining accuracy, the machining efficiency is maximized. By optimizing the machining path, the air walking time is reduced, and the influence of heat accumulation on the workpiece is reduced, the hole diameter accuracy and surface quality are improved, and the waste rate is reduced, thereby reducing the production cost.

[0071] (1) Define the objective function of the algorithm The specific formula form is: Wherein represents the air walking time ratio, represents the heat accumulation penalty, represents the weight coefficient, the value range is 0~1, since the main purpose of the present application is to suppress the heat accumulation effect in the drilling process, the heat accumulation penalty weight is larger, The value is 0.4.

[0072] The air walking time refers to the time spent by the tool moving between different machining holes, and the air walking time ratio is an important indicator to measure the machining efficiency. In the drilling process, the path length of the tool moving from one hole to another directly affects the air walking time, the shorter the path, the shorter the air walking time, and the higher the machining efficiency. Therefore, by optimizing the machining path to minimize the air walking distance, and then reducing the air walking time ratio, it is the key to improve the machining efficiency.

[0073] The formula form of the air walking distance ratio defined in the present application is: Wherein n represents the total number of holes in the current planetary carrier, under the current machining path, represents the straight line distance between the i th hole and the i+1 th hole in the current machining path, represents the depth of the i th hole, the numerator represents the total distance of the tool moving between each hole in the current machining path, i.e. the air walking distance, and the denominator represents the total machining depth of all holes, so the denominator is the total path length of the tool moving under the current machining path.

[0074] In the objective function, reflects the efficiency of the machining path. By minimizing , the tool moving time between holes can be reduced, the overall machining efficiency can be improved, and the production cost can be reduced.

[0075] During the drilling process, friction between the tool and the workpiece generates heat. If closely spaced holes are drilled continuously, this heat can accumulate in a localized area, causing the workpiece temperature to rise. Excessive temperatures can cause thermal deformation in the workpiece, affecting hole diameter accuracy and surface quality, and increasing scrap rates. Therefore, heat accumulation must be controlled and mitigated to avoid high-temperature holes produced in close proximity.

[0076] The formula for defining the heat accumulation penalty in this application is: , where J represents the number of unprocessed holes, Indicates the number of processed holes within 50mm of the jth unprocessed hole. represents the temperature weight of the i-th processed hole position, represents the distance weight of the i-th processed hole position, represents the time weight of the i-th processed hole position, Represents the thermal accumulation factor of the jth unprocessed hole.

[0077] In this embodiment, , where represents the temperature of the i-th processed hole, Indicates the ambient temperature. When the ambient temperature is close to It is close to a constant. It should be understood that the temperature of the processed hole is greater than or equal to the ambient temperature. The greater the difference between the temperature of the processed hole and the ambient temperature, the greater the difference between the temperature of the processed hole and the ambient temperature. The higher the temperature, The larger the value of , the greater the influence of the temperature of the i-th processed hole position on the unprocessed hole position. .

[0078] In this embodiment, , where It represents the Euclidean distance between the jth unprocessed hole position and the ith processed hole position within 50 mm. As the distance between the processed hole and the unprocessed hole increases, it decreases, which is in line with the physical law that heat conduction decreases with increasing distance. Close to 1, it means that the heat effect of the processed holes at close distances on the unprocessed holes is greater; when the distance increases, In other embodiments, ,in, Represents an exponential function with a natural constant as its base.

[0079] In this embodiment, , where e represents a natural constant, It represents the time interval from the completion of machining of the i-th machined hole to the current moment. After machining is completed, the accumulated heat caused by cutting will dissipate over time. As time goes by, it decreases, which reflects that the thermal impact of the processed hole will gradually weaken over time. The thermal impact of the hole just processed is greater, and as time goes by, the thermal impact gradually decreases. In other embodiments, .

[0080] In the objective function, It reflects the relationship between the processing path and the heat accumulation effect. , which can reduce the heat accumulation effect during the processing process and avoid precision errors caused by intensive processing of high-temperature holes.

[0081] (2) Setting the initialization path of the algorithm, including the initialization path of the outer layer holes and the initialization path of the inner layer holes. In some embodiments of the present application, the initialization path of the outer layer holes is the initial processing path in step 2, and the initialization path of the inner layer holes is processed in a clockwise order. The final initialization path is processed in the order of first processing the outer layer holes and then processing the inner layer holes.

[0082] Set the algorithm's annealing parameters: initial annealing temperature of 100-1000, cooling rate of 0.9-0.999, final annealing temperature of 0.01-10, and number of iterations at each annealing temperature of 50-500. In this example, the values ​​are: initial annealing temperature of 500, cooling rate of 0.98, final annealing temperature of 10, and number of iterations at each annealing temperature of 50.

[0083] (3) Perform neighborhood operations to obtain a new path; in traditional schemes, neighborhood operations mainly generate new paths by directly exchanging the processing order of adjacent holes. However, the temperature distribution during the processing is dynamically changing and is affected by various factors such as cutting parameters, workpiece materials, and tool wear. Traditional neighborhood operations cannot adapt to this dynamic change, so this application introduces temperature constraints for neighborhood operations. When generating a new path, the weight of the heat accumulation factor of all unprocessed holes in the original path is calculated, and then the unprocessed hole closest to the last processed hole is exchanged with the unprocessed hole with the smallest weight. If there are multiple unprocessed holes with the same minimum weight, the one with the closest distance is exchanged. If the generated new path is the same as the original path, the processing order of the two unprocessed holes is randomly exchanged.

[0084] It should be understood that the neighborhood operation method based on temperature constraints prioritizes separating the unprocessed holes most affected by the high-temperature holes, reducing the heat accumulation caused by continuous cutting, reserving longer natural cooling time for the high-temperature holes, and adjusting the processing sequence to make the subsequent processed holes farther apart and with longer time intervals. This generates a more optimized new path and reduces the algorithm's search time.

[0085] (4) Calculate the objective function values ​​of the current path and the new path respectively;

[0086] (5) Decide whether to accept the new path according to the acceptance criteria of the simulated annealing algorithm; the specific content of the acceptance criteria in some embodiments of the present application is: calculate the objective function value of the current path respectively and the objective function value of the new path ,if , then accept the new path and make it the current path; if , then with probability The new path is accepted, where T is the current annealing temperature (annealing parameter); if the distance between two consecutively processed holes in the new path is less than a preset distance, the new path is rejected. In this embodiment, the preset distance is 50 mm.

[0087] (6) Update the annealing temperature and reduce the current annealing temperature according to the cooling rate. That is, the new annealing temperature is the product of the old annealing temperature and the cooling rate.

[0088] (7) Determine whether the termination condition is met. In this embodiment, the termination condition is that the maximum number of iterations is reached; in other embodiments, the termination condition is that the objective function value remains unchanged after multiple consecutive iterations; in still other embodiments, the termination condition is that the current annealing temperature is lower than the termination temperature.

[0089] If the termination condition is met, the iteration stops and the current optimal path is output; otherwise, the neighborhood operation is performed to continue the iteration.

[0090] Among them, the flowchart of the simulated annealing algorithm to obtain the optimal processing path is as follows: Figure 2 shown.

[0091] The unprocessed holes are drilled according to the optimized processing path sequence, and the processing parameters and hole position parameters are processed according to step three.

[0092] After the current planetary carrier is processed, its processing path and hole layout features are recorded in the historical database to generate the initial processing path for subsequent planetary carrier processing.

[0093] In order to verify the validity of this application, several comparative examples are set, specifically:

[0094] Comparative Example 1: Processing is performed according to the hole numbering without performing processing path optimization.

[0095] Comparative Example 2: Processing is performed according to the hole number, and the thermal deformation compensation value (such as radial , axial ), the compensation value does not change with the machining process.

[0096] Comparative Example 3: During the machining process, the simulated annealing algorithm with minimizing the idle tool distance as the objective function is used to optimize the machining path without considering the heat accumulation effect.

[0097] Except for the explanation, the process flow and parameters of Comparative Examples 1, 2 and 3 are consistent with those of this embodiment.

[0098] The comparison between the traditional solution and this application is shown in the following table:

[0099] Table 1: Processing comparison table

[0100]

[0101] Among them, the position accuracy represents the deviation between the actual position of the hole (center coordinates) and the theoretical position (ideal coordinates) in the design drawing. The thermal deformation error represents the deviation between the position of the hole just after machining and the position of the hole after cooling. The hole spacing error represents the deviation between the actual center distance of the two holes and the designed center distance. The abnormal porosity represents the proportion of holes that do not meet the tolerance requirements of the drawing after machining. The above data are taken as the average of all holes in a planetary carrier.

[0102] From the comparison in the table, it can be seen that in comparative example 1, there is no path optimization, and continuous processing of close-range holes leads to serious heat accumulation. Comparative example 2 relies on the preset model and cannot adapt to processing changes in real time. Comparative example 3 ignores thermal factors. This application avoids heat-sensitive areas through real-time temperature acquisition and dynamic path adjustment to effectively suppress the heat accumulation effect, thereby reducing thermal deformation errors.

[0103] Comparative Example 1 has invalid movement and repeated positioning, Comparative Example 2 static compensation is difficult to accurately match the actual deformation, and Comparative Example 3 only optimizes the straight-line distance without considering the interference of thermal deformation on positioning. This application uses a simulated annealing algorithm to fuse real-time temperature and hole position coordinates, optimize the tool movement path, reduce the impact of empty tool passes and thermal deformation on positioning, and achieve more accurate processing positioning, thereby improving positioning accuracy and reducing hole spacing errors.

[0104] In comparison example 1, abnormal holes are caused by heat accumulation and positioning deviation. In comparison example 2, static compensation may cause over-compensation and other problems, and the abnormal hole rate is higher. In comparison example 3, thermal factors are ignored, resulting in unstable hole quality. This application stabilizes the processing process through real-time data-driven path optimization, which can effectively reduce the abnormal hole rate.

[0105] Based on the same inventive concept as the above method, an embodiment of the present application also provides a planetary carrier drilling device for an RV reducer, comprising 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 any one of the above-mentioned planetary carrier drilling methods for the RV reducer are implemented.

[0106] 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.

[0107] 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 carrier drilling method for an RV reducer, characterized in that: The method comprises the following steps: Extract the to-be-machined holes of the planetary carrier of the RV reducer and group them to obtain outer and inner holes. Specifically, for the planetary carrier, obtain the distance between each to-be-machined hole and the center axis of the planetary carrier. The to-be-machined holes with a distance less than the preset grouping threshold are classified as inner holes; otherwise, the to-be-machined holes are classified as outer holes. Based on the similarity between the hole distribution characteristics of the planetary carrier and the workpieces in the historical database, the process of determining the initial machining path of the planetary carrier's outer holes is as follows: calculating the similarity measure between the hole feature vectors of the planetary carrier and each workpiece in the historical database, selecting the workpiece in the historical database with the maximum similarity measure and greater than a preset threshold, and using the corresponding optimal machining path as the initial machining path of the planetary carrier; the hole feature vector is determined by the number of inner holes, the number of outer holes, the average outer hole radius, and the average inner hole angle; the historical database stores the optimal machining path and hole feature vector of each planetary carrier after drilling; Determine the initialization path of the simulated annealing algorithm by combining the initial machining path of the planet carrier outer hole and the preset inner hole machining path; The planetary carrier is machined according to the initialization path. After each hole is machined, the temperature data of the machined hole is extracted through infrared thermal imaging. According to the distance of the planetary carrier's current machining path and the depth of the machined hole, the steps for obtaining the idle tool distance ratio are as follows: calculating the sum of the distances between all adjacent unmachined holes in the current machining path as the idle tool distance; recording the sum of the idle tool distance and the machining depth of all unmachined holes in the current machining path as the total path length; and taking the ratio of the idle tool distance to the total path length as the idle tool distance ratio; For each processed hole position within the preset range of the unprocessed hole position, based on the difference characteristics between its temperature data and the ambient temperature, combined with the distance characteristics between the processed hole position and the unprocessed hole position and the completion time of the processed hole position, the thermal accumulation factor of each unprocessed hole position is obtained, and the cumulative sum of all thermal accumulation factors is used as the thermal accumulation penalty; the weighted sum of the proportion of idle tool distance and the thermal accumulation penalty is taken to obtain the objective function of the current processing path; the thermal accumulation factor is obtained by accumulating the product of the temperature weight, distance weight and time weight of each processed hole position within the preset range of each unprocessed hole position, the temperature weight is the negative correlation mapping result of the temperature difference between the ambient temperature and the temperature data of each processed hole position, the distance weight is the negative correlation mapping result of the distance between each unprocessed hole position and each processed hole position, and the time weight is the negative correlation mapping result of the completion time of each processed hole position; Based on the heat accumulation factor of each unprocessed hole position and the distance distribution between the unprocessed hole position and the last processed hole position, the process of generating a new path is as follows: the heat accumulation factors of all unprocessed holes in the current processing path are used as weights, and the unprocessed hole position closest to the last processed hole position is exchanged with the unprocessed hole position with the smallest weight to generate a new path; if the current processing path and the new path are the same, the processing order of the two unprocessed holes is randomly exchanged; Based on the objective function values ​​of the current processing path and the new path, the optimal processing path is determined as follows: if the objective function value of the new path is Less than the objective function value of the current machining path , and the distances between adjacent unprocessed holes in the new path are greater than or equal to the preset distance, the new path is used as the current path; otherwise, the probability Accept the new path, where T is the current preset annealing parameter and exp() represents an exponential function with a natural constant as the base; when the termination condition of the simulated annealing algorithm is met, the current processing path is determined as the optimal processing path; Drill the unprocessed holes according to the optimal processing path; The ratio of idle tool distance satisfies the following formula: ； Where n represents the total number of holes in the current planet carrier, Indicates the straight-line distance between the i-th hole and the i+1-th hole in the current machining path. represents the depth of the i-th hole, Indicates the idle tool distance. It represents the sum of the machining depths of all holes, and the denominator is the total path length; The thermal cumulative penalty satisfies the following formula: ； Among them, J represents the number of unprocessed holes, Indicates the number of processed holes within 50mm of the jth unprocessed hole. represents the temperature weight of the qth processed hole position, represents the distance weight of the qth processed hole position, represents the time weight of the qth processed hole position, Represents the thermal accumulation factor of the jth unprocessed hole.

2. The planetary carrier drilling method of the RV reducer according to claim 1, characterized in that: The specific parameters for processing the planetary carrier are: spindle speed 8000~12000rpm, feed speed 0.12~0.18mm / r, and cooling pressure 8~12MPa.

3. The planetary carrier drilling method of the RV reducer according to claim 1, characterized in that: The termination condition of the simulated annealing algorithm is any one of the following: reaching the maximum number of iterations, the objective function value remains unchanged for multiple consecutive iterations, and the current annealing temperature is lower than the termination temperature.

4. A planetary carrier drilling device for an RV reducer, 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 3 are implemented.

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