Wide-line machining path planning method for bull-nose-shaped milling cutter

Abstract

The invention relates to the technical field of blade machining, and discloses a bull-nose milling cutter wide-line machining path planning method which comprises the following steps: taking two isoparametric lines on a curved surface of a blade to be machined as a machining boundary, and uniformly dividing a plurality of isoparametric lines in the machining boundary based on a preset tool path number; a plurality of sampling points are uniformly arranged on each isoparametric line, sampling point interpolation is carried out on any two adjacent isoparametric lines, and spiral cutting contacts are obtained; generating a self-adaptive spiral cutter path based on all spiral contact points and the effective cutting radius and cutting width of the cutter of the bull-nose milling cutter; obtaining the effective cutting radius, the cutting width and the cutter center position of the cutter corresponding to each spiral cutting contact on the self-adaptive spiral cutter path; based on the self-adaptive spiral cutter path and the effective cutting radius, cutting width, optimal cutter shaft and cutter center positions of the cutter at all spiral cutting contacts on the self-adaptive spiral cutter path, a wide-line machining path of the bull-nose-shaped milling cutter is formed.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of blade machining, in particular to a kind of wide path planning method of bull-nose cutter. BACKGROUND

[0002] In five-axis numerical control machining, bull-nose cutter has the double advantages of ball-end mill and flat-bottomed mill, its cutting edge is a small radius fillet, when tool axis inclination changes, tool effective cutting radius also changes, in the process of machining free surface, it can significantly increase cutting speed and effectively improve cutting efficiency, while ensuring the quality of machining surface, so compared with ball-end mill, bull-nose cutter can realize wide path machining effect by fewer tool path quantity.When using bull-nose cutter to machine blade, tool axis inclination at cutting point needs to be dynamically adjusted according to residual height and blade curvature change, to ensure that the overall residual height meets the requirements, while avoiding overcut caused by too large tool cutting radius, so the path planning of bull-nose cutter and tool axis inclination control are the key to improve blade machining efficiency and ensure machining quality.

[0003] But the existing blade wide path machining technology, when planning the tool path, adopts equal residual height method, equal section method and equal parameter method to directly plan tool cutting point and tool axis vector;Among them, the optimal tool axis inclination of each cutting point needs to be calculated independently, which depends on multiple iterations and optimization, and the calculation amount is large and the calculation efficiency is low;Local optimization of each cutting point leads to discontinuous change of tool axis vector, which further leads to non-smooth tool axis and affects the quality of machining surface;At the same time, there may be tool axis mutation, which increases the burden of machine tool dynamic adjustment and requires high machine tool motion performance.

[0004] In summary, the existing blade wide path machining lacks global optimization strategy, which is difficult to improve machining efficiency while ensuring surface quality, and restricts the efficient and precise machining of blade. SUMMARY

[0005] Therefore, the technical problem to be solved by the present application is to overcome the problem that the prior art lacks global optimization strategy, which is difficult to improve machining efficiency while ensuring surface quality, and restricts the efficient and precise machining of blade.

[0006] To solve the above technical problems, the present application provides a kind of wide path planning method of bull-nose cutter, comprising: Two equal parameter lines on the blade surface to be machined are taken as machining boundary, and based on the preset tool path quantity, a plurality of equal parameter lines are evenly divided within the machining boundary; A plurality of sampling points are evenly arranged on each equal parameter line, and for any two adjacent equal parameter lines, sampling point interpolation is carried out to obtain spiral contact point; Based on all spiral contact points, tool effective cutting radius and cutting width of bull-nose cutter, adaptive spiral tool path is generated; Obtain the effective cutting radius, cutting width, and tool center position of the tool corresponding to each helical cutting contact point on the adaptive helical tool path. For each helical cutting contact point, the following are included: Based on the curvature at its location, as well as the maximum and minimum tilt angles, the feasible region of the cutter axis tilt angle at each helical cutting contact point is obtained, and the optimal tilt angle is selected from it as the optimal cutter axis; Based on the optimal tilt angle and the tool radius and fillet radius of the bullnose end mill, the effective cutting radius of the bullnose end mill at the helical contact point is obtained; Based on the effective cutting radius of the bullnose end mill at the helical cutting contact point and the preset toolpath residual height, the cutting width of the bullnose end mill at the helical cutting contact point is obtained. Based on the direction from the center of the rounded surface at the helical cutting contact point to the tool center position, the difference between the tool radius and the tool rounded corner radius, and the product of the difference and the center of the rounded surface, the tool center position corresponding to each helical cutting contact point is obtained. Based on the adaptive helical toolpath and the effective cutting radius, cutting width, and optimal tool axis and tool center positions at all helical cutting contact points, a wide-path machining method for the bullnose end mill is constructed.

[0007] Preferably, obtaining the helical contact point includes: Multiple isoparametric lines within the machining boundary are obtained, represented as follows: , , For the number of toolpaths, isoparameter lines and For processing boundaries; In each isoparametric line Multiple sampling points are evenly distributed on the top , This represents the total number of sampling points; For adjacent isoparametric lines and By performing sampling point interpolation, multiple helical contact points between adjacent isoparametric lines are obtained, represented as: .

[0008] Preferably, based on interference checking, the maximum and minimum tilt angles at each helical cutting contact point on the adaptive helical cutter path are obtained, including: The normal to the surface of the blade to be machined at the helical cutting contact point is taken as the initial cutter axis; Starting from the initial cutter axis position, rotate the bullnose end mill around the machining rotation axis to perform a geometric interference check: The minimum tilt angle is obtained when the bullnose end mill does not interfere with the blade being machined. The angle at which the bullnose end mill interferes with the blade to be machined is taken as the maximum angle.

[0009] Preferably, for each helical touch point on the adaptive spiral tool path, based on the curvature at the position where the helical touch point is located, and the maximum inclination angle and the minimum inclination angle, an available range of tool axis inclination angle at the helical touch point is obtained, and an optimal inclination angle is selected from the available range as an optimal tool axis, including: based on the curvature at the position where the helical touch point is located , and the maximum inclination angle , and the minimum inclination angle , an available range of tool axis inclination angle at the helical touch point is obtained, denoted as: ; An optimal tool axis is selected from the available range of tool axis inclination angle by using a genetic algorithm, with the optimization objectives of uniform change of adjacent tool axis vectors, minimization of tool axis inclination angle change rate, no collision, and no undercut.

[0010] Preferably, based on the optimal inclination angle and the tool radius of the bull-nose cutter and the tool corner radius, an effective tool cutting radius of the bull-nose cutter at the helical touch point is obtained, denoted as: ; wherein, represents the effective tool cutting radius of the bull-nose cutter, represents the tool corner radius of the bull-nose cutter, represents the tool radius of the bull-nose cutter, represents the tool axis inclination angle.

[0011] Preferably, based on the effective tool cutting radius of the bull-nose cutter at the helical touch point and a preset tool path residual height, a cutting width of the bull-nose cutter at the helical touch point is obtained, denoted as: ; wherein, represents the cutting width of the bull-nose cutter at each helical touch point, represents the preset tool path residual height.

[0012] Preferably, the corresponding tool center position at each helical touch point is obtained, including: Based on the normal of the blade surface to be machined at the helical touch point and the tool corner radius, a corner surface ball center position is calculated and obtained; Based on the normal of the blade surface to be machined at the helical touch point and the vector of the optimal tool axis, a direction of the corner surface ball center pointing to the tool center position is obtained; Based on the difference between the tool radius and the tool corner radius, the direction of the corner surface ball center pointing to the tool center position, and the corner surface ball center position, the tool center position corresponding to each helical touch point is obtained.

[0013] ​Preferably, the ball center position of the fillet surface is calculated based on the normal of the blade surface to be machined at the helical cutting contact point and the tool fillet radius, and is represented as: ; wherein, represents the ball center position of the fillet surface, represents the tool fillet radius, represents the normal of the blade surface to be machined at the helical cutting contact point, represents the position of the helical cutting contact point.

[0014] Preferably, the direction of the ball center of the fillet surface pointing to the tool center position is obtained based on the normal of the blade surface to be machined at the helical cutting contact point and the vector of the optimal tool axis, and is represented as: ; wherein, represents the direction vector of the ball center of the fillet surface pointing to the tool center position, represents the vector of the optimal tool axis.

[0015] Preferably, the tool center position corresponding to each helical cutting contact point is obtained based on the difference between the tool radius and the tool fillet radius, the direction of the ball center of the fillet surface pointing to the tool center position, and the ball center position of the fillet surface, and is represented as: ; wherein, represents the tool center position corresponding to the helical cutting contact point, represents the tool radius of the bull-nose cutter.

[0016] The above technical solutions of the present application have the following beneficial effects compared with the prior art:

[0017] The bull-nose cutter wide-row machining path planning method provided by the present application ensures smooth transition of the contact points between adjacent tool paths, avoids sudden changes in the tool axis vector, constructs helical cutting contact points, and generates smooth adaptive helical tool paths based on the interpolation of uniformly divided sampling points on the equal parameter lines; at the same time, based on the requirements of anti-overcutting and anti-collision, in combination with the curvature of the surface at the helical cutting contact point, the tool axis inclination angle feasible region of each cutting contact point is calculated in real time, the search space is compressed to a reasonable range to ensure machining accuracy; and the optimal tool axis is searched in the feasible region with smoothness, inclination stability and no interference as multiple targets, which avoids invalid calculation of the inclination angles that may cause overcutting or collision, and improves the search efficiency; at the same time, based on the inclination angle corresponding to the optimal tool axis, the effective cutting radius and cutting width of the bull-nose cutter at each helical cutting contact point are calculated to realize wide-row machining; based on the adaptive helical tool path and the optimal tool axis, the machining accuracy is ensured, and the machining efficiency is improved through the cooperation optimization of the tool axis inclination angle feasible region and multiple targets. BRIEF DESCRIPTION OF DRAWINGS

[0018] In order to make the content of the present application more easily understood, the present application will be further described in detail below according to specific embodiments of the present application and in conjunction with the accompanying drawings, in which: Figure 1 is a step flow chart of the wide-path machining path planning method of the bull-nose milling cutter of the present application; Figure 2 is a tool profile of the bull-nose milling cutter; Figure 3 is a schematic diagram of the principle of calculating the width of cut; Figure 4 is a schematic diagram of the helical cutting contact point; Figure 5 is a schematic diagram of the minimum inclination angle; Figure 6 is a schematic diagram of the maximum inclination angle; Figure 7 is a schematic diagram of the radius of curvature at the cutting contact point; Figure 8 is a schematic diagram of the calculation of the position of the tool center. DETAILED DESCRIPTION

[0019] The present application will be further described below in conjunction with the accompanying drawings and specific embodiments, so that those skilled in the art can better understand the present application and implement it, but the embodiments are not limiting to the present application.

[0020] Referring to Figure 1 , the step flow chart of the wide-path machining path planning method of the bull-nose milling cutter of the present application, the specific steps include: S101: taking two equal-parameter lines on the blade surface to be machined as the machining boundary, and based on a preset number of tool paths, evenly dividing a plurality of equal-parameter lines within the machining boundary, represented as: , , is the number of tool paths, and the equal-parameter lines and are the machining boundaries; S102: evenly setting a plurality of sampling points on each equal-parameter line, and for any two adjacent equal-parameter lines, performing sampling point interpolation to obtain helical cutting contact points; the plurality of sampling points are represented as , is the total number of sampling points; the plurality of helical cutting contact points are represented as: ; S103: based on all the helical contact points, and the effective cutting radius and the width of cut of the bull-nose milling cutter, generating an adaptive helical tool path; S104: Obtain the effective tool cutting radius, the cutting width and the tool center position corresponding to each helical touch point on the adaptive helical tool path, and for each helical touch point, it includes: S104-1: Based on the curvature at the position where it is located, and the maximum inclination angle and the minimum inclination angle, obtain the tool axis inclination angle feasible region at each helical touch point, and select the optimal inclination angle from it as the optimal tool axis; S104-2: Based on the optimal inclination angle and the tool radius and the tool corner radius of the bull-nose cutter, obtain the effective tool cutting radius of the bull-nose cutter at the helical touch point , which is expressed as: ; Wherein, represents the tool corner radius of the bull-nose cutter, represents the tool radius of the bull-nose cutter, represents the tool axis inclination angle; S104-3: Based on the effective tool cutting radius of the bull-nose cutter at the helical touch point and the preset tool path residual height, obtain the cutting width of the bull-nose cutter at the helical touch point , which is expressed as: ; Wherein, represents the preset tool path residual height; S104-4: Based on the direction of the spherical center of the corner surface at the helical touch point pointing to the tool center position, the difference between the tool radius and the tool corner radius, and the product of the spherical center position of the corner surface, obtain the corresponding tool center position at each helical touch point. S105: Based on the adaptive helical tool path and the effective tool cutting radius, the cutting width, the optimal tool axis and the tool center position at all helical touch points on the adaptive helical tool path, a bull-nose cutter wide row machining path is formed.

[0021] In the embodiment of the present application, based on the interference check, the maximum inclination angle and the minimum inclination angle at each helical touch point on the adaptive helical tool path are obtained, including: The normal of the blade surface to be machined at the helical touch point is taken as the initial tool axis; Let the bull-nose cutter start from the initial tool axis position and rotate around the machining rotation axis to perform geometric interference check: Obtain the inclination angle of the bull-nose cutter when it just does not interfere with the blade to be machined as the minimum inclination angle; Obtain the inclination angle of the bull-nose cutter when it just interferes with the blade to be machined as the maximum inclination angle.

[0022] After obtaining the corresponding maximum inclination angle and minimum inclination angle, obtain the tool axis inclination angle feasible region at each helical touch point, and select the optimal inclination angle from it as the optimal tool axis, including: Based on the curvature at the position of the helical cutting contact point , and the maximum inclination angle , and the minimum inclination angle , the inclination angle of the tool axis at each helical cutting contact point is obtained The feasible region of the tool axis is represented as ; A genetic algorithm is used to select the optimal tool axis from the feasible region of the tool axis inclination angle, with the optimization objectives of uniform changes in adjacent tool axis vectors, minimization of the tool axis inclination angle change rate, and no collision and undercutting.

[0023] Specifically, in step S104-4, the acquisition of the corresponding tool core position at each helical cutting contact point includes: Based on the normal of the blade surface to be machined at the helical cutting contact point and the tool corner radius, the tool corner position is calculated and obtained , represented as ; wherein represents the tool corner radius, represents the normal of the blade surface to be machined at the helical cutting contact point, represents the position of the helical cutting contact point; Based on the normal of the blade surface to be machined at the helical cutting contact point and the vector of the optimal tool axis, the direction of the tool corner position pointed to by the tool corner ball center is obtained , represented as ; wherein represents the vector of the optimal tool axis; Based on the difference between the tool radius and the tool corner radius, the direction of the tool corner position pointed to by the tool corner ball center, and the tool corner ball center position, the corresponding tool core position of each helical cutting contact point is obtained , represented as ; wherein represents the tool radius of the bullnose cutter.

[0024] The bullnose end mill wide-path planning method of this invention uses sampling points evenly distributed on uniformly divided isoparametric lines for interpolation to ensure smooth transitions between adjacent toolpaths and avoid abrupt changes in the tool axis vector, thereby constructing helical contact points and generating smooth adaptive helical toolpaths. Simultaneously, based on the requirements of preventing overcutting and collisions, and combined with the surface curvature at the helical contact points, the feasible region of the tool axis tilt angle at each contact point is calculated in real time, compressing the search space to a reasonable range to ensure machining accuracy. Furthermore, with smoothness, tilt angle stability, and no interference as multiple objectives, the optimal tool axis is searched within the feasible region, avoiding invalid calculations for tilt angles that may lead to overcutting or collisions, thus improving search efficiency. Simultaneously, based on the tilt angle corresponding to the optimal tool axis, the effective cutting radius and cutting width of the bullnose end mill at each helical contact point are calculated to achieve wide-path machining. While ensuring machining accuracy based on adaptive helical toolpaths and optimal tool axes, machining efficiency is improved through the feasible region of the tool axis tilt angle and multi-objective collaborative optimization.

[0025] Based on the above embodiments, the bullnose end mill wide-path planning method provided by this invention is used to perform helical milling on the blade body, and the specific steps are illustrated below: S201: Calculate the relationship between the tool axis tilt angle and the effective cutting radius; Reference Figure 2 The image shows a cross-section of a bullnose end mill. The effective cutting radius of the bullnose end mill at the contact point can be calculated based on the cutter axis inclination angle. The center of the circle containing the cutting radius is shown in the image. The distance to the blade is the effective cutting radius of the tool. , represented as: ; in, Indicates the fillet radius of the cutting tool. Indicates the tool radius. Indicates the cutter shaft tilt angle; Reference Figure 3 The diagram shown illustrates the principle of cutting width calculation; if the required toolpath residual height is... Then the calculated cut width can be approximated as: ; S202: Calculate the spiral contact trajectory: Reference Figure 4 The diagram shown is a schematic of a spiral cutting contact. Let the machining boundary be the blade surface, etc. Wire , Based on the number of toolpaths, several uniform samples can be taken within the machining boundary. Wire , , , Number of knife paths; In each of the following Several points can be sampled evenly online. , , This represents the number of sampling points; In adjacent two equal Wire , Interpolation can be used to obtain the position of the helical contact point. Thus, all helical cutting trajectories within the processing boundary can be obtained; S203: Determine the feasible region of the tool axis: Because the curvature of the blade varies at different locations, the inclination angle of the cutter at each contact point is... It should be smaller than the radius of curvature at that location. To avoid overcutting, if the tilt angle is too small, the tool's rear side is prone to collision with the concave side of the blade; if the tilt angle is too large, the tool holder will also collide with the blade body. Therefore, it is necessary to calculate the minimum tilt angle by combining interference checks. and maximum tilt angle From this, the range of the tool axis tilt angle can be obtained, and then the feasible region of the tool axis direction can be calculated.

[0026] Reference Figure 5 The diagram shown is a schematic of the minimum tilt angle; refer to... Figure 6 The diagram shown is a schematic of the maximum tilt angle; refer to... Figure 7 The diagram shows the radius of curvature at the contact point; the blade normal at the contact point is... As the initial tool axis, the tool rotates around the machining rotation axis to search for a range of non-interfering tilt angles, such as... Figure 5 As shown, the minimum tilt angle is reached when the back side of the tool just does not interfere with the blade. ;like Figure 6 As shown, the maximum tilt angle is reached when the tool holder just interferes with the blade. Therefore, the range of the tool axis tilt angle can be obtained as follows: Then, the feasible region in the tool axis direction can be calculated.

[0027] S204: Search for the optimal tool axis: Based on the feasible region of the tool axis direction at each tool point on the toolpath, the tool axis is made to meet the machining requirements; To ensure uniform changes in the tool axis vectors between adjacent tool positions, minimize changes in the tool axis tilt angle, and avoid tool axis oscillation, a genetic algorithm, combined with interference checks, is used to search for the optimal tool axis from the feasible region of the tool axis.

[0028] S205: Calculate the trajectory of the bullnose end mill: To determine the cutter axis direction at the contact point, based on the bullnose end mill's tool structure, when the tool is cutting the blade, it is necessary to ensure the contact point... Fall on the fillet surface, therefore, the fillet surface is in the spherical center to The distance is always ; refer to Figure 8 The schematic diagram for calculating the tool center position is shown; the blade normal at the tangent point is , then the spherical center position of the fillet surface is , The direction of the tool center position is , thus , and then the tool center position corresponding to all tangent points is obtained.

[0029] The blade wide row machining path planning method for the bull-nose cutter provided in the application can realize efficient planning of the wide row machining path by quickly planning the cutter tangent point, accurately calculating the bull-nose cutter tool shaft inclination angle feasible region, and then optimizing the tool shaft vector as a whole, and can improve the problems of low calculation efficiency and unsatisfactory machining quality of the existing method.

[0030] Based on the above embodiment, the bull-nose cutter wide row machining path planning method provided in the application is integrated in software, and the bull-nose cutter is used for spiral milling on the blade blade body, and when wide row machining is performed, the specific operation process includes: S301: selecting a blade machining strategy; For example, the blade machining strategy includes blade machining, rim surface machining, blade trimming, damping platform machining and blade roughing, etc.; the blade machining type is selected in this embodiment; S302: selecting a bull-nose cutter and setting tool parameters; The tool parameters include blade part parameters and non-blade part parameters; The blade part parameters include diameter, blade length, taper, fillet radius and blade number; The non-blade part parameters include tool total length and tool bar diameter.

[0031] S303: setting tool path cutting range and residual height parameters; For the setting of the tool path, the output point density, output point constraint and cutting width are included; For the setting of the cutting range, the cutting start type is set as the blade tip, and the cutting termination type is set as the blade root.

[0032] The blade wide row machining path planning method using the bull-nose cutter will be widely applied in single blade blade finishing machining strategy, and the machining efficiency is obviously improved. The method can prevent overcutting by constraining the optimal tool shaft search range based on the tool shaft feasible region, can improve the tool service life, and can ensure the workpiece material machining quality and precision, thereby producing huge economic benefits.

[0033] The wide-row machining path planning method of the bull-nose milling cutter disclosed in the application ensures smooth transition of the contact points between adjacent tool paths, avoids sudden changes of the tool shaft vector, constructs a spiral contact point, and generates a smooth adaptive spiral tool path; meanwhile, based on the requirements of over-cutting prevention and collision prevention, in combination with the curvature of the curved surface at the spiral contact point, the feasible domain of the tool shaft inclination angle of each contact point is calculated in real time, the search space is compressed to a reasonable range, and the machining accuracy is ensured; and the optimal tool shaft is searched in the feasible domain with smoothness, inclination stability, and no interference as multiple targets, which avoids invalid calculation of the inclination angles that may cause over-cutting or collision, and improves the search efficiency; meanwhile, based on the inclination angle corresponding to the optimal tool shaft, the effective cutting radius and cutting width of the bull-nose milling cutter at each spiral contact point are calculated, and wide-row machining is realized; based on the adaptive spiral tool path and the optimal tool shaft, the machining accuracy is ensured, and the machining efficiency is improved through the feasible domain of the tool shaft inclination angle and the multi-target collaborative optimization.

[0034] Those skilled in the art will understand that the embodiments of the present application can be provided as methods, systems, or computer program products. Therefore, the present application can take the form of an entirely hardware embodiment, an entirely software embodiment, or an embodiment combining software and hardware aspects. Moreover, the present application can take the form of a computer program product implemented on one or more computer-usable storage media (including, but not limited to, disk storage, CD-ROMs, optical storage, etc.) containing computer-usable program code.

[0035] The present application is described with reference to flowcharts and / or block diagrams of the methods, devices (systems), and computer program products according to the embodiments of the present application. It should be understood that each flow and / or block in the flowcharts and / or block diagrams, and the combination of the flows and / or blocks in the flowcharts and / or block diagrams can be implemented by computer program instructions. These computer program instructions can be provided to a general-purpose computer, a special-purpose computer, an embedded processor, or other programmable data processing devices to produce a machine, so that the instructions executed by the computer or other programmable data processing devices generate a device that implements the functions specified in the flowcharts and / or block diagrams. Figure 1 The functions specified in one or more flows and / or blocks. Figure 1 The devices that implement the functions specified in one or more flows and / or blocks.

[0036] These computer program instructions can also be stored in a computer-readable memory that can guide the computer or other programmable data processing devices to work in a specific manner, so that the instructions stored in the computer-readable memory produce a manufactured product including instruction devices that implement the functions specified in the flowcharts and / or block diagrams. Figure 1 The functions specified in one or more flows and / or blocks. Figure 1 The devices that implement the functions specified in one or more flows and / or blocks.

[0037] These computer program instructions can also be loaded into a computer or other programmable data processing devices, so that a series of operational steps are performed on the computer or other programmable data processing devices to generate a computer implemented process, so that the instructions executed on the computer or other programmable data processing devices provide steps for implementing the function specified in the flowchart Figure 1 one flow or multiple flows and / or blocks Figure 1 one block or multiple blocks.

[0038] Obviously, the above-mentioned embodiments are only examples for clearly illustrating the present application, and are not intended to limit the embodiments. Based on the above description, other different forms of changes or variations can be made by those skilled in the art. Here, all the embodiments are not required to be exhausted, and the obvious changes or variations derived therefrom are still within the protection scope of the present application.

Claims

1. A method for planning a wide-path machining operation of a bullnose end mill, characterized in that, The method comprises the following steps: Two equal parameter lines on the surface of the blade to be machined are taken as machining boundaries, and based on a preset tool path quantity, a plurality of equal parameter lines are evenly divided within the machining boundaries; A plurality of sampling points are evenly arranged on each equal parameter line, and for any two adjacent equal parameter lines, sampling point interpolation is performed to obtain spiral contact points; Based on all the spiral contact points and the effective cutting radius and cutting width of the bull-nose milling cutter, an adaptive spiral tool path is generated; For each spiral contact point on the adaptive spiral tool path, the effective cutting radius, the cutting width and the cutter center position corresponding to the spiral contact point are obtained, and each spiral contact point comprises the following steps: Based on the curvature at the position, the maximum inclination angle and the minimum inclination angle, the feasible region of the tool axis inclination angle at each spiral contact point is obtained, and the optimal inclination angle is selected as the optimal tool axis from the feasible region; Based on the optimal inclination angle, the tool radius and the tool corner radius of the bull-nose milling cutter, the effective cutting radius of the bull-nose milling cutter at the spiral contact point is obtained; Based on the effective cutting radius of the bull-nose milling cutter at the spiral contact point and the preset tool path residual height, the cutting width of the bull-nose milling cutter at the spiral contact point is obtained; Based on the direction of the spherical center of the corner surface at the spiral contact point pointing to the cutter center position, the difference between the tool radius and the tool corner radius, and the product of the spherical center position of the corner surface, the corresponding cutter center position at each spiral contact point is obtained; Based on the adaptive spiral tool path and the effective cutting radius, the cutting width, the optimal tool axis and the cutter center position at all the spiral contact points on the adaptive spiral tool path, a bull-nose milling cutter wide-row machining path is constructed.

2. The method of claim 1, wherein, The acquisition of the spiral contact point comprises the following steps: A plurality of equal parameter lines within the machining boundary are acquired and represented as: , , is the number of tool paths, and the equal parameter lines and are the machining boundary; A plurality of sampling points are uniformly arranged on each equi-parametric line A plurality of sampling points are uniformly arranged on each equi-parametric line , is the total number of sampling points. For adjacent iso-parameter lines With , the sampling point interpolation is performed to obtain a plurality of spiral contact points between the adjacent iso-parameter lines, denoted as: .

3. The method of claim 1, wherein, Based on interference checking, the maximum inclination angle and the minimum inclination angle at each spiral contact point on the adaptive spiral tool path are obtained, which comprises the following steps: The normal of the surface of the blade to be machined at the spiral contact point is taken as the initial tool axis; The bull-nose milling cutter is rotated around the machining rotation axis from the initial tool axis position to perform geometric interference checking: The inclination angle of the bull-nose milling cutter when it just does not interfere with the blade to be machined is obtained as the minimum inclination angle; The inclination angle of the bull-nose milling cutter when it just interferes with the blade to be machined is obtained as the maximum inclination angle.

4. The method of claim 3, wherein, For each spiral contact point on the adaptive spiral tool path, based on the curvature at the position, the maximum inclination angle and the minimum inclination angle, the feasible region of the tool axis inclination angle at each spiral contact point is obtained, and the optimal inclination angle is selected as the optimal tool axis from the feasible region, which comprises the following steps: Based on the curvature at the location of the helical cut contact point and the maximum tilt angle and the minimum tilt angle Obtaining the tool axis tilt angle at each helical cut contact point The feasible region is represented as: ; By using a genetic algorithm, the optimal tool axis is selected from the tool axis inclination angle feasible region by taking the uniform change of adjacent tool axis vectors, the minimization of the tool axis inclination angle change rate, the non-collision and the non-overcut as optimization objectives.

5. The method of claim 4, wherein, Based on the optimal inclination angle, the tool radius and the tool corner radius of the bull-nose milling cutter, the effective cutting radius of the bull-nose milling cutter at the spiral contact point is obtained, which is represented as: ； wherein, Rc denotes the effective cutting radius of the nose cutter, Rc denotes the effective cutting radius of the nose cutter, Rc denotes the effective cutting radius of the nose cutter, Rc denotes the effective cutting radius of the nose cutter, 6. The method of claim 5, wherein, Based on the effective cutting radius of the bull-nose milling cutter at the spiral contact point and the preset tool path residual height, the cutting width of the bull-nose milling cutter at the spiral contact point is obtained, which is represented as: ； wherein, represents the width of cut of the nose mill at each helical touch point, represents the preset tool path residual height.

7. The method of claim 1, wherein, The corresponding cutter center position at each spiral contact point is obtained, which comprises the following steps: Based on the normal of the surface of the blade to be machined at the spiral contact point and the tool corner radius, the spherical center position of the corner surface is calculated and obtained; Based on the normal of the surface of the blade to be machined at the spiral contact point and the vector of the optimal tool axis, the direction of the spherical center of the corner surface pointing to the cutter center position is obtained; Based on the difference between the tool radius and the tool corner radius, the direction of the corner surface ball center pointing to the tool center position, and the corner surface ball center position, the tool center position corresponding to each spiral cutting touch point is obtained.

8. The method of claim 7, wherein, Based on the normal of the blade surface to be machined at the spiral cutting touch point and the tool corner radius, the corner surface ball center position is calculated and obtained, which is expressed as: ； wherein, denotes the center position of the rounded surface, denotes the radius of the tool rounding, denotes the normal of the blade surface to be machined at the helical tool contact point, denotes the position of the helical tool contact point.

9. The method of claim 8, wherein, Based on the normal of the blade surface to be machined at the spiral cutting touch point and the vector of the optimal tool axis, the direction of the corner surface ball center pointing to the tool center position is obtained, which is expressed as: ； wherein denotes a direction vector of the rounded face ball center pointing to the position of the tool center, denotes a vector of the optimal tool axis.

10. The method of claim 9, wherein, Based on the difference between the tool radius and the tool corner radius, the direction of the corner surface ball center pointing to the tool center position, and the corner surface ball center position, the tool center position corresponding to each spiral cutting touch point is obtained, which is expressed as: Based on the difference between the tool radius and the tool corner radius, the direction of the corner surface ball center pointing to the tool center position, and the corner surface ball center position, the tool center position corresponding to each spiral cutting touch point is obtained, which is expressed as: ； wherein, represents the location of the tool core corresponding to the helical cut contact point, represents the tool radius of the bullnose mill.

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