A method for spiral dividing processing of bevel gear tooth addendum line milling

Abstract

The application provides a kind of for bevel gear tooth top line milling edge rotary division processing method, this method includes: S1, the space coordinate data of the tooth top edge of bevel gear is collected multiple teaching points, and teaching point at least includes big end point position, small end point position and intermediate point position;S2, multiple teaching points are fitted, and fitting track is obtained, and coordinate transformation is carried out to fitting track, and the machining track of tool box cutter is obtained;S3, according to the gear parameters of bevel gear and tool parameters, the rotational speed of bevel gear and the rotational speed of tool are calculated, and the rotational speed ratio of tool and bevel gear is equal to the gear ratio of bevel gear gear number ratio tool head number;S4, according to the rotational speed obtained in step S3 control spindle box and tool box, make bevel gear and tool rotate, and according to the tool machining track obtained by fitting in step S2 control cutter feed, process the tooth top edge of bevel gear. Through fitting and coordinate transformation to teaching point, the machining track is obtained, guarantees that tool track and bevel gear tooth top edge form surface height match, improves overall machining precision.

Description

Technical Field

[0001] This invention relates to the field of gear machining technology, specifically a rotary machining method for milling the tip line of bevel gears. Background Technology

[0002] Spiral bevel gears are core transmission components in high-end equipment such as automotive gearboxes and aircraft engines. Burrs and edge defects at the tooth tip line can cause stress concentration, increased noise, and early failure. Therefore, precision milling (also known as chamfering) is a key process to improve gear performance.

[0003] In terms of existing technology, some companies have launched CNC milling equipment. For example, Tianjin Daxin's YKJZ9350 uses bar milling cutters and parametric programming to achieve one-time machining of the tooth tip line, but its machining continuity still needs optimization. Shaanxi Baoji Guoxi's YMDV series uses full-tooth profile grinding technology, and the machining accuracy can reach ISO 6 level, but the surface roughness stability still lags behind the advanced level. Zhejiang Wenling Yuhong's YKF9332 equipment has a high cost performance, but it is mainly suitable for cylindrical gears, and the machining accuracy is limited. In addition, research institutions such as Nanjing University of Technology and Huazhong University of Science and Technology have carried out beneficial explorations in the optimization of conical tool paths, online measurement and error compensation, but there are still problems such as insufficient control accuracy and lack of engineering application in the field of spiral bevel gears. In other words, the existing spiral bevel gear milling technology has the following main defects: the equipment is still insufficient in terms of processing continuity, surface quality stability, and precision control; there is a lack of a complete, efficient, and high-precision rapid milling solution to address the complex and varied spatial curves of the spiral bevel gear tooth tip line; and traditional manual milling methods are inefficient, inconsistent, and pose occupational health and safety hazards such as dust and noise.

[0004] Therefore, there is an urgent need to develop a high-precision, high-efficiency, and automated milling technology suitable for the tooth tip line of spiral bevel gears to meet the pressing needs of high-end equipment manufacturing for gear transmission performance and reliability. Summary of the Invention

[0005] The purpose of this invention is to overcome the shortcomings of the prior art and provide a rotary machining method for milling the tip line of bevel gears.

[0006] This invention is achieved through the following technical solution: A rotary machining method for milling the tip line of bevel gears includes: S1. Collect spatial coordinate data of multiple teaching points on the tooth tip edge of the bevel gear. The teaching points include at least the large end point, the small end point, and the intermediate point located between the large end point and the small end point. S2. Fit multiple teaching points to obtain the fitted trajectory, perform coordinate transformation on the fitted trajectory to obtain the machining trajectory of the tool box tool; S3. Calculate the rotational speed of the bevel gear and the rotational speed of the tool based on the gear parameters and tool parameters. The ratio of the rotational speed of the tool to that of the bevel gear is equal to the ratio of the number of teeth of the bevel gear to the number of tool heads. S4. Control the spindle box and tool box according to the rotation speed obtained in step S3 to make the bevel gear and tool rotate, and control the tool feed according to the tool machining trajectory obtained in step S2 to machine the tooth tip edge of the bevel gear.

[0007] Furthermore, in step S1, the spatial coordinate data of multiple teaching points of the bevel gear's tooth tip edge are collected using the teaching method.

[0008] Furthermore, in step S2, based on the collected teaching point data, non-uniform spline curve fitting is used to obtain the tool machining trajectory.

[0009] Furthermore, in step S2, a weight adjustment mechanism is introduced to adjust the fitting of the non-uniform spline curve. The weight adjustment mechanism can adjust the weight value of each teaching point to fine-tune and optimize the processing trajectory.

[0010] Furthermore, the fitted trajectory is constructed using the NURBS curve fitting algorithm. The matrix expression of the NURBS curve fitting algorithm is as follows: ; In the formula, T is the basis function row vector; M is the transformation matrix; W is the fitting weight; P is a control point.

[0011] Furthermore, in step S4, the tool is configured as a single-head milling tool, and during machining, the single-head milling tool is used to mill the bevel gear edges according to the fitted tool machining trajectory.

[0012] Furthermore, in step S4, the tool is configured as a double-headed tool, and during machining, the double-headed tool is used to mill the bevel gear edges according to the fitted tool machining trajectory.

[0013] A CNC machine tool uses the above-mentioned rotary machining method for milling the tip line of bevel gears.

[0014] A computer software, applied to the aforementioned CNC machine tool, is used to generate a tool machining trajectory based on bevel gear parameters. The computer software includes a user interface, a data input interface, and a trajectory generation interface.

[0015] The advantages and beneficial effects of this invention are as follows: By fitting and transforming the teaching points to obtain the machining trajectory, the height of the tool trajectory and the bevel gear tooth tip prism surface are matched, achieving consistency between the machined surface and the designed surface, and improving the overall machining accuracy. Based on the gear and tool parameters, the dual rotation speed is accurately calculated, allowing the rotation speed of the spindle box and tool box to adapt to the bevel gear forming characteristics, resulting in more uniform cutting contact and avoiding local overcutting or undercutting. Attached Figure Description

[0016] To more clearly illustrate the technical solutions in this application or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0017] Figure 1 This is a flowchart of the rotary machining method for milling the tip line of bevel gears according to the present invention.

[0018] Figure 2 This is a schematic diagram of the tool path structure of the present invention.

[0019] Figure 3 This is the single-head milling trajectory of the present invention.

[0020] Figure 4 This is the double-head milling trajectory of the present invention.

[0021] Figure 5 This is a schematic diagram showing the user interface of the present invention.

[0022] Figure 6 This is a schematic diagram of the data input interface of the present invention.

[0023] Figure 7 This is a schematic diagram showing the trajectory generation interface of the present invention. Detailed Implementation

[0024] To enable those skilled in the art to better understand the present invention, the technical solution of the present invention will be further described below with reference to specific embodiments.

[0025] This embodiment provides a rotary machining method for milling the tip line of bevel gears, such as... Figures 1-2 As shown, the rotary machining method includes: S1. Collect spatial coordinate data of multiple teaching points on the tooth tip edge of the bevel gear. The teaching points include at least the large end point, the small end point, and the intermediate point located between the large end point and the small end point. S2. Fit multiple teaching points to obtain the fitted trajectory, perform coordinate transformation on the fitted trajectory to obtain the machining trajectory of the tool box tool; S3. Calculate the rotational speed of the bevel gear and the rotational speed of the tool based on the gear parameters and tool parameters. The ratio of the rotational speed of the tool to that of the bevel gear is equal to the ratio of the number of teeth of the bevel gear to the number of tool heads. S4. Control the spindle box and tool box according to the rotation speed obtained in step S3 to make the bevel gear and tool rotate, and control the tool feed according to the tool machining trajectory obtained in step S2 to machine the tooth tip edge of the bevel gear.

[0026] Understandably, by fitting the teaching points and transforming the coordinates to obtain the machining trajectory, the tool trajectory is ensured to be highly matched with the bevel gear tooth tip prism surface, achieving consistency between the machined surface and the designed surface, and improving overall machining accuracy. Based on the gear and tool parameters, the dual rotation speeds are precisely calculated, allowing the rotation speeds of the spindle box and tool box to adapt to the bevel gear forming characteristics, resulting in more uniform cutting and avoiding local overcutting or undercutting.

[0027] Furthermore, in step S1, as Figure 2 As shown, in step S2, based on the collected teaching point data, non-uniform spline curve fitting is used to obtain the tool machining trajectory.

[0028] Understandably, using the teaching method to collect spatial coordinate data of teaching points is intuitive and easy to implement. It does not require complex preliminary modeling and calculation, can quickly adapt to the collection needs of bevel gears of different specifications, and directly fits the actual shape of the workpiece, effectively reducing data collection errors and providing more realistic raw data for subsequent trajectory fitting, further ensuring the accuracy of the machining trajectory.

[0029] Furthermore, in step S2, based on the collected teaching point data, non-uniform spline curve fitting is used to obtain the tool machining trajectory.

[0030] Understandably, using non-uniform spline curves to fit teaching points can flexibly adapt to the complex spatial curve shape of bevel gear tooth tip edges. The fitted trajectory is smooth and continuous, avoiding the trajectory inflection points and discontinuities that occur in traditional fitting methods. This makes the cutting process of the tool more stable, reduces vibration and burrs during the machining process, and improves the surface machining quality and accuracy of the tooth tip edges.

[0031] Furthermore, in step S2, a weight adjustment mechanism is introduced to adjust the fitting of the non-uniform spline curve. The weight adjustment mechanism can adjust the weight value of each teaching point to fine-tune and optimize the processing trajectory.

[0032] Understandably, introducing a weight adjustment mechanism to regulate the fitting of non-uniform spline curves allows for targeted adjustment of the weight value of each teaching point, enabling fine-tuning and optimization of the machining trajectory. Based on the precision requirements of bevel gear machining, it can focus on enhancing the trajectory fitting accuracy at key positions while correcting local fitting deviations, making the machining trajectory more in line with design requirements, and further improving the machining accuracy and surface consistency of the bevel gear tooth tip edge.

[0033] In step S2, for the fitted trajectory obtained by the teaching method, a teaching coordinate system and a machine tool coordinate system are first established. Then, the transformation relationship between the teaching coordinate system and the machine tool coordinate system is determined. This transformation relationship includes translation and rotation. In this embodiment, by selecting three or more reference points in the teaching coordinate system and the machine tool coordinate system, the relationship between the two is solved by the least squares method to complete the confirmation. After that, the fitted trajectory is interpolated and optimized to convert the fitted trajectory into an interpolation format supported by the machine tool, while ensuring the smoothness of the trajectory.

[0034] Furthermore, the fitted trajectory is constructed using the NURBS curve fitting algorithm. The matrix expression of the NURBS curve fitting algorithm is as follows: ; In the formula, T is the basis function row vector (the basis function row vector is composed of the teaching point t and the B-spline basis function); M is the transformation matrix. Before fitting, a geometric transformation matrix is ​​preset based on the size of the teaching points. In this embodiment... ; W represents the fitting weight. In this embodiment... ; P is the control point (the control point is the unknown quantity that needs to be solved during the fitting process). In this embodiment, , ( x i , y i ( ) represents multiple control points that need to be solved.

[0035] Understandably, the NURBS curve fitting algorithm constructs a fitted trajectory, and uses explicit matrix expressions to achieve digital and precise calculations in the fitting process, replacing the traditional experience-based fitting method. This provides a quantitative basis for trajectory fitting and reduces errors from manual fitting. The synergistic effect of the feature matrix, weight matrix, and coordinate matrix in the algorithm can precisely control the shape of the fitted trajectory, adapting to the complex spatial curves of the bevel gear tooth tip, ensuring the smoothness and accuracy of the fitted trajectory, and providing a high-precision trajectory basis for subsequent processing.

[0036] Furthermore, in step S4, as Figure 3As shown, the tool can be configured as a single-head milling tool, and during machining, the single-head mills the bevel gear edges according to the fitted tool path; or, as... Figure 4 As shown, the tool can also be configured as a double-headed tool. During machining, the double-headed tool is used to mill the bevel gear edges according to the fitted tool machining trajectory.

[0037] Understandably, when configured with a single cutting head and using single-head turning machining, the tool structure is simple, equipment debugging and maintenance are more convenient, and the equipment and operating costs are reduced. When configured with a double cutting head and using double-head turning machining, the two cutting heads can cut simultaneously along the machining trajectory, significantly improving machining efficiency without reducing machining accuracy, making it suitable for mass production of bevel gears. The cutting method of double cutting heads can disperse cutting forces, reduce the wear of individual cutting heads, extend tool life, and reduce the risk of workpiece deformation during machining, ensuring the surface accuracy and dimensional stability of the bevel gear after machining. Therefore, in this embodiment, the double-cutting head method is selected for machining.

[0038] Furthermore, in step S4, the inclination angle of the tool shaft is adjusted according to the taper of the bevel gear to be processed, so that the inclination angle of the tool shaft is equal to the tooth tip taper of the bevel gear, thereby matching the two.

[0039] Example 2: This embodiment provides a CNC machine tool that uses the above-described rotary machining method for milling the tip of bevel gears.

[0040] It is understandable that applying the spin-machining method of this invention to CNC machine tools fully leverages the automation and digital control advantages of CNC machine tools, solving the problems of low trajectory fitting accuracy and mismatch between machining methods and bevel gears when machining bevel gears on traditional CNC machine tools. This significantly improves the bevel gear machining capabilities of CNC machine tools. Furthermore, it eliminates the need for large-scale machine tool modifications, enabling machining solely through program adaptation, thus reducing equipment modification costs and expanding the application scope of CNC machine tools in the gear machining field. It also achieves full-process digitalization of bevel gear machining, improves the consistency of batch processing, and adapts to the production needs of modern intelligent manufacturing.

[0041] Example 3: This embodiment provides computer software applied to the aforementioned CNC machine tool, used to generate tool machining paths based on bevel gear parameters, such as... Figures 5-7 As shown, the computer software includes a user interface, a data input interface, and a trajectory generation interface.

[0042] Understandably, this computer software is specifically designed for use with CNC machine tools. It can automatically generate machining trajectories based on bevel gear parameters, replacing the traditional method of manually drawing and calculating trajectories. This significantly shortens trajectory design time, improves design efficiency, and reduces manual design costs. The software features separate user interaction, data input, and trajectory generation interfaces, with clear functional divisions and simple operation, lowering the operating threshold for CNC machine tools. No professional CNC programmers or gear designers are required to operate it. The generated trajectory can be directly transmitted to the machine tool control system, achieving seamless integration between trajectory design and machine tool processing. This avoids errors caused by manual data conversion and further ensures machining accuracy. The parameterized input mode can quickly adapt to the trajectory generation needs of different specifications and models of bevel gears, possessing good versatility and flexibility to meet diverse bevel gear processing requirements.

[0043] For ease of explanation, spatial relative terms such as “up,” “down,” “left,” and “right” are used in the embodiments to describe the relationship of one element or feature shown in the figures relative to another element or feature. It should be understood that, in addition to the orientations shown in the figures, spatial terms are intended to include different orientations of the device in use or operation. For example, if the device in the figures is inverted, an element described as being “down” of other elements or features would be positioned “up” of those other elements or features. Therefore, the exemplary term “down” can encompass both up and down orientations. The device may be positioned in other ways (rotated 90 degrees or in other orientations), and the spatial relative descriptions used herein will be interpreted accordingly.

[0044] Moreover, relational terms such as “first” and “second” are used merely to distinguish one component from another that has the same name, without necessarily requiring or implying any such actual relationship or order between the components.

[0045] The above description is only a preferred embodiment of the present invention. It should be noted that, for those skilled in the art, several improvements and modifications can be made without departing from the principle of the present invention, and these improvements and modifications should also be considered within the scope of protection of the present invention.

Claims

1. A rotary machining method for milling the tip line of bevel gears, characterized in that, include: S1. Collect spatial coordinate data of multiple teaching points on the tooth tip edge of the bevel gear. The teaching points include at least the large end point, the small end point, and the intermediate point located between the large end point and the small end point. S2. Fit multiple teaching points to obtain the fitted trajectory, perform coordinate transformation on the fitted trajectory to obtain the machining trajectory of the tool box tool; S3. Calculate the rotational speed of the bevel gear and the rotational speed of the tool based on the gear parameters and tool parameters. The ratio of the rotational speed of the tool to that of the bevel gear is equal to the ratio of the number of teeth of the bevel gear to the number of tool heads. S4. Control the spindle box and tool box according to the rotation speed obtained in step S3 to make the bevel gear and tool rotate, and control the tool feed according to the tool machining trajectory obtained in step S2 to machine the tooth tip edge of the bevel gear.

2. The rotary machining method for milling the tip line of bevel gears according to claim 1, characterized in that, In step S1, the spatial coordinate data of multiple teaching points of the tooth tip edge of the bevel gear are collected using the teaching method.

3. The rotary machining method for milling the tip line of bevel gears according to claim 2, characterized in that, In step S2, based on the collected teaching point data, non-uniform spline curve fitting is used to obtain the tool machining trajectory.

4. The rotary machining method for milling the tip line of bevel gears according to claim 3, characterized in that, In step S2, a weight adjustment mechanism is introduced to adjust the fitting of the non-uniform spline curve. The weight adjustment mechanism can adjust the weight value of each teaching point to fine-tune and optimize the processing trajectory.

5. The rotary machining method for milling the tip line of bevel gears according to claim 3, characterized in that, The fitted trajectory is constructed using the NURBS curve fitting algorithm. The matrix expression of the NURBS curve fitting algorithm is as follows: ； In the formula, T is the basis function row vector; M is the transformation matrix; W is the fitting weight; P is a control point.

6. The rotary machining method for milling the tip line of bevel gears according to claim 1, characterized in that, In step S4, the tool is configured as a single-head milling tool. During machining, the single-head milling tool is used to mill the bevel gear edges according to the fitted tool machining trajectory.

7. The rotary machining method for milling the tip line of bevel gears according to claim 1, characterized in that, In step S4, the tool is configured as a double-head milling tool. During machining, the double-head milling tool is used to mill the bevel gear edges according to the fitted tool machining trajectory.

8. A CNC machine tool, characterized in that, The rotary machining method for milling the tip line of bevel gears as described in any one of claims 1-8 was used.

9. A computer software, characterized in that, Applied to the CNC machine tool as described in claim 9, the computer software is used to generate a tool machining trajectory based on bevel gear parameters, and includes a user interface, a data input interface, and a trajectory generation interface.

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