Blade margin plate surface machining path planning method

Abstract

The invention relates to the technical field of machining path planning, and discloses a blade marginal plate surface machining path planning method, which comprises the following steps of: obtaining a marginal plate cutter path layering surface and a plurality of blade body extension cutter path layering surfaces by offsetting a marginal plate surface of a blade to be machined; the method comprises the following steps: acquiring an outer ring boundary and an inner ring boundary of a margin plate cutter center track, performing uniform sampling, calculating continuously distributed cutter location points by combining basic offset and spiral increment offset along a sampling point direction, and performing fitting to generate a plurality of smooth spiral cutter path curves to form a target margin plate cutter path. And for the blade body, intersection is carried out on each sub-layer and the blade curved surface to obtain a section line, discrete points are connected into a continuous spiral curve through tangential and height offset after sampling, then offset is carried out in the normal direction to obtain a cutter center track, and a target blade body extension cutter path is formed. The target margin plate tool path and the target blade body extending tool path are combined, efficient and high-quality integrated machining of the blade margin plate face is achieved, continuity and smoothness of the tool paths are guaranteed, and machining efficiency and surface quality are effectively improved.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of machining path planning, in particular to a kind of blade rim face machining path planning method. BACKGROUND

[0002] Rim face processing is an important part of single-blade part processing, generally using ball end mill helical milling, to reduce the air cutting tool path of the outer side of the rim, the rim processing tool path is divided into inside winding tool path and outside cutting tool path;The path planning of cutting tool path directly affects the overall machining efficiency, and at the same time, the rim surface is the connecting surface between the blade blade and the tenon, which is connected with the blade through the transition fillet, and the tool path needs to reasonably avoid the fillet during processing, and ensure the smooth connection with the blade, how to reasonably plan the rim processing path is the key to ensure the rim processing quality and improve the processing efficiency.

[0003] There are few existing rim face machining path planning methods, although the rim face can be machined by general milling strategy tool path or through blade root milling, but the path planning method lacks pertinence, needs to be completed for many times, the processing efficiency is low, and the tool path lacks reasonable avoidance of blade fillet parameters and has blade connection problem, resulting in low part processing quality. SUMMARY

[0004] Therefore, the technical problem to be solved by the present application is to overcome the lack of rim face machining path planning method in the prior art, resulting in low processing efficiency and poor quality.

[0005] To solve the above technical problems, the present application provides a kind of blade rim face machining path planning method, comprising: Offset the rim face of the blade to be processed, obtain a rim tool path layer surface and a plurality of blade extension tool path layer surfaces; Intersect the rim tool path layer surface with the rim face of the blade to be processed, obtain the rim intersection line, and based on the preset total cutting distance and the blade allowance of the blade to be processed, obtain the outer circle boundary of the rim tool path and the inner circle boundary of the rim tool path; Respectively, the outer circle boundary of the rim tool path and the inner circle boundary of the rim tool path are uniformly sampled to obtain the outer circle sampling point sequence and the inner circle sampling point sequence; With the first sampling point in the inner circle sampling point sequence as the starting point, and the last sampling point in the outer circle sampling point sequence as the ending point, based on the rim tool path cutting width and the preset tool path number, carry out basic offset, and carry out helical incremental offset along the direction of the corresponding outer circle sampling point of the inner circle sampling point, to obtain each tool position point in each tool path; Based on all tool position points in each tool path, a plurality of helical tool path curves are generated by fitting, to form the target rim tool path; The plurality of blade body extension tool paths are intersected with the blade rim surface to be processed respectively in different layer planes to obtain corresponding blade body intersection lines; each blade body intersection line is uniformly sampled respectively to obtain a plurality of blade body sampling points, and the spiral point positions are generated through tangential offset and height offset, and the blade body spiral curve is connected by connecting all the blade body sampling points; the blade body spiral curve is offset along the normal direction of the blade to be processed to obtain a target blade body extension tool path; Based on the target rim tool path and the target blade body extension tool path, the rim surface of the blade to be processed is machined.

[0006] Preferably, the rim surface of the blade to be processed is offset to obtain a rim tool path layer plane and a plurality of blade body extension tool path layer planes, including: Based on the sum of the tool radius and the rim allowance , the distance between the tool center point of the rim tool path and the rim surface is calculated as the offset distance . The rim surface of the blade to be processed is offset to obtain a rim tool path layer plane . Based on the sum of the tool radius and the rim allowance , and the number of extension layers and the tool cutting width , the offset distance of different layer planes is obtained . The rim surface of the blade to be processed is offset to obtain a plurality of blade body extension tool path layer planes . , .

[0007] Preferably, based on the preset total cutting distance and the blade allowance of the blade to be processed, the outer circle boundary of the rim tool center trajectory and the inner circle boundary of the rim tool center trajectory are obtained, including: If , the sum of the tool radius and the blade allowance is calculated as the offset distance of the inner circle boundary of the rim tool center trajectory, and the sum of the tool radius, the blade allowance and the preset total cutting distance is calculated as the offset distance of the outer circle boundary of the rim tool center trajectory; If , the sum of the thickness of the rim tool path layer plane at the fillet position, the tool radius and the blade allowance is calculated as the offset distance of the inner circle boundary of the rim tool center trajectory, and the sum of the thickness of the rim tool path layer plane at the fillet position, the tool radius, the blade allowance and the preset total cutting distance is calculated as the offset distance of the outer circle boundary of the rim tool center trajectory; Wherein, represents the fillet radius of the blade to be processed.

[0008] Preferably, the thickness of the rim tool path layer plane at the fillet position is obtained, including: Based on the geometric relationship between the fillet knife path layering surface and the round corner surface of the blade to be machined, the connecting line between the spherical center of the round corner surface and the spherical center of the cutter is obtained, and the cosine value of the included angle between the spherical center of the round corner surface and the vertical line of the fillet surface is obtained , which is expressed as: ; Based on the cosine value, the coordinates of the spherical center of the round corner surface, the coordinates of the intersection point of the round corner surface and the blade to be machined, and the coordinates of the spherical center of the cutter, the coordinates of the spherical center of the cutter are obtained; The difference between the horizontal coordinate of the spherical center of the cutter and the cutter radius is calculated as the thickness of the fillet knife path layering surface at the round corner position; wherein, represents the round corner radius of the blade to be machined, represents the cutter radius, represents the fillet allowance.

[0009] Preferably, each tool position point in each tool path is obtained based on the basic offset of the fillet knife path cutting width and the preset tool path number, and the spiral incremental offset in the direction from the inner circle sampling point to the corresponding outer circle sampling point, including: Based on the fillet knife path cutting width, the basic offset of the first tool path is obtained after times offset; ; Based on the fillet knife path cutting width and the total number of sampling points, the spiral incremental offset of the first tool position point is obtained after times offset; ; Based on the basic offset of the first tool path and the spiral incremental offset of the first tool position point, the offset is performed in the direction from the inner circle sampling point to the corresponding outer circle sampling point, and the first tool position point on the first tool path is obtained, which is expressed as: ; wherein, , , represents the preset tool path number, represents the insulating tool path cutting width, and the expression is ; , represents the total number of sampling points in the sampling point sequence; , represents the first inner circle sampling point in the inner circle sampling point sequence.

[0010] Preferably, after the target rim knife path is obtained, the method further comprises: based on the cutting distance of each spiral knife path curve and the preset winding distance, taking the spiral knife path curve exceeding the rim surface as an invalid knife path segment, obtaining the remaining knife path segment as an effective knife path segment; sorting all the effective knife path segments to obtain an updated target rim knife path, comprising: based on the preset number of knife paths and the preset total cutting distance , calculating the cutting distance of the first spiral knife path curve , which is expressed as: ; comparing the cutting distance of the first spiral knife path curve with the preset winding distance : if , there is no invalid road segment; if , projecting the boundary line of the rim surface to the rim knife path layer surface to obtain a rim boundary curve; intersecting the rim boundary curve with each spiral knife path curve respectively to obtain a plurality of clipping points, dividing the spiral knife path curve into a plurality of knife path segments, and obtaining the knife path segment located inside the rim boundary curve as an effective knife path segment.

[0011] Preferably, all the effective knife path segments are sorted to obtain the target rim knife path, comprising: based on the clipping points on each effective knife path segment, calculating the parameter position of each effective knife path segment on the rim boundary line; based on the parameter position, clustering the effective knife path segments to obtain a plurality of clustering areas, and processing them one by one; in each clustering area, processing according to the bidirectional sorting from outside to inside.

[0012] Preferably, the spiral point is generated by tangential offset and height offset, and is expressed as: ; wherein, , represents the total number of sampling points in the sampling point sequence; represents the distance between adjacent blade extension knife path layer surfaces, , represents the first blade extension knife path layer surface corresponding to the first sampling point in the blade intersection line.

[0013] Preferably, the blade radius and the blade allowance are offset as the offset distance, the blade normal vector to be machined is offset as the offset direction, and the blade body spiral curve is offset to obtain the target blade body extension tool path.

[0014] Preferably, after obtaining the target rim plate tool path and the target blade body extension tool path, the method further comprises calculating the tool axis direction feasible region of each tool position in the target rim plate tool path and the target blade body extension tool path, and obtaining the optimal tool axis, comprising: based on the curvature at the position where each tool position is located , the maximum inclination angle , and the minimum inclination angle , the tool axis direction feasible region at each tool position is obtained , and is expressed as: ; The genetic algorithm is used to select the optimal tool axis from the tool axis inclination angle feasible region, with the optimization objectives of uniform change of adjacent tool axis vectors, minimization of tool axis inclination angle change rate, no collision and no undercutting.

[0015] The above technical solutions of the present application have the following beneficial effects compared with the prior art:

[0016] The blade rim plate surface machining path planning method disclosed by the present application offsets the rim plate surface of the blade to be machined to obtain the rim plate tool path layer surface and the blade body extension tool path layer surface, ensures perfect butt joint of the two tool paths in height, and avoids the occurrence of tool joint marks or machining residues; then, through uniform sampling, vector calculation and spiral interpolation, a continuous spiral tool path completely conforming to the geometric shape of the rim plate surface is automatically generated to construct the target rim plate tool path and the target blade body extension tool path, and the correctness and integrity of the machining path in geometry are ensured; meanwhile, in the calculation of the spiral tool path, the basic offset and the spiral incremental offset are considered, the spiral thinking of winding around the edge while climbing is considered, the continuity of the trajectory is ensured, the continuous spiral tool path is generated, the frequent lifting and landing is avoided, the continuity and stability of the cutting process are ensured, and thus the machining efficiency and surface quality of the rim plate surface can be improved.

[0017] The present application defines the spiral tool path curve beyond the rim plate surface as an invalid tool path segment, obtains the remaining tool path segment as an effective tool path segment, and constructs the target rim plate tool path based on the effective tool path segment; by deleting the invalid tool path segment, the rapid empty running of the tool is avoided, unnecessary tool wear and stress are reduced, the machining time is saved, and the machining efficiency is improved.

[0018] The present application groups the effective tool path segments after cutting according to the position, and then processes them one by one according to the region, adopts bidirectional sorting from the outside to the inside within the group, maximally reduces the number of times of rapid movement of the tool between different regions, minimizes the idle travel, thereby shortens the total machining time and improves the machining efficiency.

[0019] The present application is the target edge plate knife path and the target blade extension knife path of each knife position, based on the feasible region of the tool axis direction, the optimal tool axis is set, so that the adjacent tool axis vector of each knife position changes uniformly, the tool axis inclination angle changes smaller, and then the tool axis oscillation is avoided, and the workpiece machining quality is improved. BRIEF DESCRIPTION OF DRAWINGS

[0020] 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 drawings, in which: Figure 1 is the step flow chart of the blade edge plate surface machining path planning method of the present application; Figure 2 is the layered surface schematic diagram of the edge plate surface; Figure 3 is the offset distance schematic diagram of the fillet position; Figure 4 is the edge plate surface spiral knife position schematic diagram; Figure 5 is the effective knife path segment schematic diagram; Figure 6 is the edge plate knife path sequencing schematic diagram. DETAILED DESCRIPTION

[0021] The present application will be further described below in conjunction with the 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 as a limitation on the present application.

[0022] Referring to Figure 1 , the step flow chart of the blade edge plate surface machining path planning method of the present application, the specific steps include: S101: offsetting the edge plate surface of the blade to be machined, obtaining an edge plate knife path layered surface and a plurality of blade extension knife path layered surfaces, including: S101-1: calculating the distance between the tool center point of the edge plate knife path and the edge plate surface based on the sum of the tool radius and the edge plate allowance , as the offset distance ; ; S101-2: based on the sum of the tool radius and the edge plate allowance , and the number of extension layers and the tool cutting width , obtaining the offset distance of different layered surfaces ; , obtaining , ; S102: intersect the edge plate tool path layer surface with the blade edge plate surface to be processed, obtain the edge plate intersection line, and obtain the outer circle boundary of the edge plate tool path and the inner circle boundary of the edge plate tool path based on the preset total cutting distance and the blade allowance of the blade to be processed; S103: uniformly sample the outer circle boundary of the edge plate tool path and the inner circle boundary of the edge plate tool path respectively to obtain an outer circle sampling point sequence and an inner circle sampling point sequence; take the first sampling point in the inner circle sampling point sequence as a starting point, take the last sampling point in the outer circle sampling point sequence as an ending point, perform basic offset based on the edge plate tool path cutting width and the preset tool path number, and perform spiral incremental offset in the direction of the inner circle sampling point pointing to the corresponding outer circle sampling point to obtain each tool position point in each tool path; based on all tool position points in each tool path, generate a plurality of spiral tool path curves to form the target edge plate tool path; S104: intersect the plurality of blade body extension tool paths layer surfaces with the blade edge plate surface to be processed respectively to obtain corresponding blade body intersection lines; uniformly sample each blade body intersection line respectively to obtain a plurality of blade body sampling points, and generate spiral points by tangential offset and height offset to connect all the blade body sampling points into a blade body spiral curve; offset the blade body spiral curve along the normal direction of the blade to be processed to obtain the target blade body extension tool path; S105: based on the target edge plate tool path and the target blade body extension tool path, process the edge plate surface of the blade to be processed.

[0023] The blade edge plate surface processing path planning method provided by the application offsets the edge plate surface of the blade to be processed to obtain the edge plate tool path layer surface and the blade body extension tool path layer surface, ensures perfect butt joint of the two tool paths in height, and avoids tool marks or processing residues; then, uniform sampling, vector calculation and spiral interpolation are used to automatically generate a smooth continuous spiral tool path completely fitted to the geometric shape of the edge plate surface to construct the target edge plate tool path and the target blade body extension tool path, and the correctness and integrity of the processing path in geometry are ensured; meanwhile, the basic offset and the spiral incremental offset are considered when the spiral tool path is calculated, the spiral thinking of winding around the edge while climbing is used to ensure the continuity of the trajectory, so that a continuous spiral tool path is generated, frequent lifting and landing are avoided, the continuity and stability of the cutting process are ensured, and thus the processing efficiency and surface quality of the edge plate surface can be improved.

[0024] Specifically, in step S102, based on the preset total cutting distance and the blade allowance of the blade to be processed, the outer circle boundary of the edge plate tool path and the inner circle boundary of the edge plate tool path are obtained, including: S102-1: if , the sum of the tool radius and the blade allowance is calculated as the offset distance of the inner circle boundary of the edge plate tool path, and the sum of the tool radius, the blade allowance and the preset total cutting distance is calculated as the offset distance of the outer circle boundary of the edge plate tool path. S102-2: If , calculate the sum of the thickness of the rim knife layer surface at the fillet position, the tool radius and the blade allowance as the offset distance of the inner circle boundary of the rim knife heart trajectory, and calculate the sum of the thickness of the rim knife layer surface at the fillet position, the tool radius, the blade allowance and the preset total cutting distance as the offset distance of the outer circle boundary of the rim knife heart trajectory;

[0025] wherein, the thickness of the rim knife layer surface at the fillet position is obtained, comprising: based on the geometric relationship between the rim knife layer surface and the fillet surface of the blade to be machined, obtaining the angle between the line connecting the fillet surface spherical center and the tool spherical center, and the cosine value of the angle between the fillet surface spherical center and the vertical line of the rim surface , expressed as: ; based on the cosine value, the coordinates of the fillet surface spherical center, the coordinates of the intersection of the fillet surface and the blade to be machined, and the coordinates of the intersection of the fillet surface and the blade to be machined, obtaining the coordinates of the tool spherical center; calculating the difference between the horizontal coordinate of the tool spherical center and the tool radius as the thickness of the rim knife layer surface at the fillet position; wherein, represents the fillet radius of the blade to be machined, represents the tool radius, represents the rim allowance.

[0026] Specifically, in step S103, the first th tool position on the first th tool path is obtained, comprising: after offsetting times based on the rim knife path cutting width, obtaining the basic offset of the first th tool path; after offsetting times based on the rim knife path cutting width and the total number of sampling points, obtaining the helical incremental offset of the first th tool position; based on the basic offset of the first th tool path and the helical incremental offset of the first th tool position, offsetting in the direction from the inner circle sampling point to the corresponding outer circle sampling point to obtain the first th tool position on the first th tool path, expressed as: ; wherein, , represents the preset number of tool paths, represents the insulation tool path cutting width, expressed as ; , This indicates the total number of sampling points in the sampling point sequence; , Represents the first sampling point in the inner circle sampling point sequence. One inner circle sampling point.

[0027] Specifically, in step S104, the spiral point is generated by tangential offset and height offset, as shown below: ;in, , This indicates the total number of sampling points in the sampling point sequence; This indicates the distance between the layers of the extended blade path of adjacent blades. , Indicates the first Each blade extends the cutting path in layers. The first in the corresponding blade intersection line One sampling point.

[0028] In this embodiment, the blade spiral curve is offset by the sum of the tool radius and the blade allowance, and the blade normal vector is used as the offset direction to obtain the target blade extension toolpath.

[0029] Based on the above embodiments, in this embodiment of the invention, after obtaining the target edge plate toolpath, the method further includes: based on the cutting distance of each helical toolpath curve and a preset turning distance, identifying helical toolpath curves extending beyond the edge plate surface as invalid toolpath segments, obtaining the remaining toolpath segments as valid toolpath segments; sorting all valid toolpath segments to obtain the updated target edge plate toolpath, including: Based on preset toolpath With the preset total cutting distance Calculate the first Cutting distance of a spiral toolpath curve , represented as: ; Compare the first Cutting distance of a spiral toolpath curve With preset circling distance : like Therefore, there are no invalid road segments; like Then, the boundary line of the edge plate surface is projected onto the edge plate toolpath layer to obtain the edge plate boundary curve; the edge plate boundary curve is intersected with each spiral toolpath curve to obtain multiple cutting points; the spiral toolpath curve is divided into multiple toolpath segments, and the toolpath segments located inside the edge plate boundary curve are obtained as effective toolpath segments.

[0030] Wherein, all the effective tool path segments are sorted to obtain the target edge plate tool path, including: based on the cutting points on each effective tool path segment, the parameter position of each effective tool path segment on the edge plate boundary line is calculated and obtained; based on the parameter position, the effective tool path segments are clustered to obtain a plurality of clustering areas, which are processed one by one; in each clustering area, processing is carried out according to the outer-to-inner bidirectional sorting.

[0031] The present application defines the spiral tool path curve beyond the edge plate surface as an invalid tool path segment, obtains the remaining tool path segment as an effective tool path segment, and constructs the target edge plate tool path based on the effective tool path segment; by deleting the invalid tool path segment, the rapid empty running of the tool is avoided, unnecessary tool wear and stress are reduced, the processing time is saved, and the processing efficiency is improved. At the same time, the present application groups the cut effective tool path segments according to the position, and then processes them one by one according to the area, and uses the outer-to-inner bidirectional sorting in the group to minimize the number of times the tool moves quickly between different areas and minimize the idle travel, thereby shortening the total processing time and improving the processing efficiency.

[0032] In the present embodiment, after obtaining the target edge plate tool path and the target blade body extension tool path, the tool axis direction feasible region of each tool position point in the target edge plate tool path and the target blade body extension tool path is calculated, and the optimal tool axis is obtained, including: based on the curvature at the position of each tool position point , the maximum inclination angle , and the minimum inclination angle , the tool axis direction feasible region at each tool position point is obtained , which is expressed as: Using a genetic algorithm, the optimal tool axis is selected from the tool axis inclination angle feasible region, with the optimization objectives of uniform change of adjacent tool axis vectors, minimization of tool axis inclination angle change rate, no collision and no undercutting.

[0033] The present application sets the optimal tool axis for each tool position point in the target edge plate tool path and the target blade body extension tool path based on its tool axis direction feasible region, so that the adjacent tool axis vectors of each tool position point change uniformly, the tool axis inclination angle changes less, and the tool axis oscillation is avoided, thereby improving the workpiece processing quality.

[0034] Based on the above embodiment, in the present embodiment, the blade edge plate surface processing path planning method provided by the present application is used for path planning, and the specific steps include:

[0035] S201: constructing a parallel tool path layer by surface offsetting; The tool path planned in the present embodiment is divided into an edge plate tool path and a blade body extension tool path, the edge plate tool path performs spiral milling on the edge plate surface, and the blade body extension tool path is a spiral tool path extending from the edge plate tool path to the blade body direction, which is used to ensure smooth tool connection; Referring to Figure 2As shown, it is a layered surface schematic diagram of the rim surface; first, offset the rim surface by curved surface offset to get the layered surface where the cutter center is located parallel to the tool path; For the rim cutter path, the distance between the cutter center point and the rim surface is always the cutter radius Additional rim allowance Therefore, the offset distance is The layered surface is denoted as ; For the blade extension cutter path, denote the extension layer number as , the cutting width as , and the layered surface The offset distance of the layered surface is , The obtained layered surface can be used to calculate all parallel cutter paths, and then calculate the spiral cutter path.

[0036] S202: Plan the rim cutter path trajectory: Based on the layered surface of the rim cutter path , first calculate the intersection line of the parameter domain and the blade surface by face-face intersection , and get the inner and outer boundary of the rim cutter center trajectory in the parameter domain by two-dimensional curve offset and ; If the layered surface offset distance is not less than the fillet radius, the boundary offset distance does not need to consider the fillet radius, the inner boundary offset distance is the cutter radius plus the additional blade allowance , and the outer boundary offset distance is , The total cutting distance; If the layered surface offset distance is less than the fillet radius, the offset distance also needs to add the thickness of the current layered surface at the fillet position ; as shown in Figure 3 , it is a schematic diagram of the offset distance at the fillet position; wherein and are the centers of the fillet surface and the cutter respectively, is the fillet radius, and are the intersection points of the blade and the rim surface at this position, and according to the set relationship, we can get: ; , and The coordinates of are known, and the coordinate position of can be calculated, and then the at this position is obtained; Figure 4 , it is a schematic diagram of the rim surface spiral tool position; based on the inner and outer boundary, all internal spiral trajectories can be calculated, first, the boundary is uniformly sampled, and the sampling point is denoted as , , Indicates the number of sampling points; The location of the spiral trajectory can be obtained by connecting the corresponding points. , , Indicates the number of toolpaths and the width of the rim toolpath. , .

[0037] S203: Edge cutting tool path trimming: Several edge plate toolpath positions were obtained, and several helical toolpath curves were fitted, denoted as... Therefore, the cutting distance parameter corresponding to each curve can be calculated. ; Users can set the circumference of the flange. ,like The portion of the cutting path that extends beyond the edge plate needs to be trimmed to reduce empty cutting and improve processing efficiency.

[0038] Reference Figure 5 The diagram shown is a schematic of the effective toolpath segment; based on the projection of the actual edge plate boundary points onto the sub-layers, the edge plate boundary curve can be obtained in the parameter domain. By intersecting the curve of the cutting toolpath with the curve to be cut, several cutting points can be obtained. , ,Will Divided into several segments, those located inside the edge plate boundary are the effective toolpath segments that need to be retained.

[0039] S204: Edge plate toolpath sequence: The acquired cut path segments are sorted to minimize transition toolpaths. (Refer to...) Figure 6 The diagram shown is a schematic of the cutting path arrangement for the edge plate; based on the cutting points of the cutting path, the cutting edge of each cutting section at the edge plate boundary line can be calculated. The parameter positions can be used to cluster all cutting paths by region; when processing is done region by region, and each region is sorted bidirectionally from the outside to the inside, the required transition path is the shortest. Therefore, the cutting paths can be sorted in this way.

[0040] S205: Planning the blade extension toolpath trajectory: Based on the blade extension knife path layering By intersecting the surfaces, the intersection line with the blade surface is calculated, and parallel points can be obtained by sampling. Based on the corresponding points in adjacent layers, the spiral points can be calculated. ,in By offsetting this point along the blade normal, the spiral blade center trajectory of the blade extension path can be obtained.

[0041] S206: Plan the tool axis vector: After all the tool position points are obtained, the tool axis direction feasible region at each tool position point needs to be calculated, and then the overall tool axis vector is planned.

[0042] The initial tool axis direction is the tangent direction of the tool position point projected on the rim plate surface, pointing to the outside of the blade, and based on the interference check, a tool axis direction feasible region can be searched near the initial tool axis. In order to make the adjacent tool axis vectors of each tool position point change uniformly, the tool axis inclination angle change is small, and the tool axis oscillation is avoided, the genetic algorithm is adopted in this embodiment to search the overall optimal tool axis vector from the tool axis feasible region.

[0043] The blade rim surface machining path planning method provided by the present application will be widely used in single blade rim surface finishing strategy; this method can quickly generate spiral machining tracks, and based on machining parameters, the tool path is cut and sorted, at the same time, the fillet surface is reasonably avoided and the blade body is smoothed and connected, which can effectively improve the machining efficiency, ensure the workpiece material machining quality and precision, and bring economic benefits.

[0044] Based on the above embodiment, the blade rim surface machining path planning method provided by the present application is integrated in software for blade rim surface machining, and the specific settings include: S301: creating a single blade rim surface machining strategy; selecting rim surface machining in the blade type machining, rim surface machining, blade trimming, damping platform machining and blade roughing machining and other machining types; S302: setting the rim cutting range; In this embodiment, the total cutting distance is set to 5mm, and the round cutting distance is set to 2mm; S303: setting the fillet compensation parameter to generate the blade body extension tool path; The compensation distance of the fillet compensation is set to 2mm, and the compensation step is set to 0.5mm.

[0045] The blade rim plate surface machining path planning method provided by the application ensures that the two tool paths are perfectly connected in height, avoids tool joint marks or machining residues, and then automatically generates a smooth continuous spiral tool path that completely matches the geometry of the rim plate surface through uniform sampling, vector calculation and spiral interpolation, to construct the target rim plate tool path and the target blade body extension tool path, ensuring the correctness and integrity of the machining path in geometry; meanwhile, the application considers the basic offset and spiral incremental offset when calculating the spiral tool path, based on the spiral thinking of winding around the edge while climbing, to ensure the continuity of the trajectory, so as to generate a continuous spiral tool path, avoid frequent lifting and lowering of the tool, ensure the continuity and stability of the cutting process, and thus improve the machining efficiency and surface quality of the rim plate; the spiral tool path curve beyond the rim plate is defined as an invalid tool path segment, the remaining tool path segment is obtained as an effective tool path segment, and the target rim plate tool path is constructed based on the effective tool path segment; by deleting the invalid tool path segment, the tool is prevented from running quickly and unnecessarily, tool wear and stress are reduced, machining time is saved, and machining efficiency is improved; the effective tool path segment after cutting is grouped according to position, and then processed region by region, bidirectional sorting is adopted from the outside to the inside in the group, the number of times of fast movement of the tool between different regions is minimized, and the idle stroke is minimized, so as to shorten the total machining time and improve the machining efficiency; for each tool position in the target rim plate tool path and the target blade body extension tool path, the optimal tool axis is set based on the feasible region of the tool axis direction, so that the adjacent tool axis vectors of each tool position change uniformly and the tool axis inclination angle changes less, and thus tool axis oscillation is avoided and workpiece machining quality is improved.

[0046] 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.

[0047] The present application is described with reference to flowcharts and / or block diagrams according to the methods, devices (systems), and computer program products of 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 produce a device that implements the flowcharts and / or block diagrams. Figure 1one or more processes and / or blocks Figure 1 an apparatus for performing the functions specified in the flowchart

[0048] These computer program instructions can also be stored in a computer readable memory that can direct a computer or other programmable data processing apparatus to function in a particular manner, such that the instructions stored in the computer readable memory produce an article of manufacture including instructions which implement the flowchart Figure 1 one or more processes and / or blocks Figure 1 an apparatus for performing the functions specified in the flowchart

[0049] These computer program instructions can also be loaded onto a computer or other programmable data processing apparatus to cause a series of operational steps to be performed on the computer or other programmable apparatus to produce a computer implemented process such that the instructions which execute on the computer or other programmable apparatus provide steps for implementing the flowchart Figure 1 one or more processes and / or blocks Figure 1 an apparatus for performing the functions specified in the flowchart

[0050] Obviously, the above-described embodiments are only examples and are not intended to limit the present application. Based on the above description, one of ordinary skill in the art can make other different forms of changes or modifications. Here, it is not necessary and impossible to enumerate all the embodiments. The obvious changes or modifications derived therefrom are still within the protection scope of the present application.

Claims

1. A method of blade shroud face machining path planning, characterized by, The method comprises the following steps: offsetting the rim surface of the blade to be machined to obtain a rim tool path layer surface and a plurality of blade body extension tool path layer surfaces; intersecting the rim tool path layer surface with the rim surface of the blade to be machined to obtain a rim intersection line, and obtaining an outer boundary of a rim tool path and an inner boundary of the rim tool path based on a preset total cutting distance and a blade allowance of the blade to be machined; uniformly sampling the outer boundary of the rim tool path and the inner boundary of the rim tool path to obtain an outer sampling point sequence and an inner sampling point sequence; taking the first sampling point in the inner sampling point sequence as a starting point, taking the last sampling point in the outer sampling point sequence as an ending point, performing basic offsetting based on a rim tool path cutting width and a preset tool path number, and performing spiral incremental offsetting in the direction of the inner sampling point pointing to the corresponding outer sampling point to obtain each tool position point in each tool path; fitting a plurality of spiral tool path curves based on all tool position points in each tool path to generate a target rim tool path; intersecting the plurality of blade body extension tool path layer surfaces with the rim surface of the blade to be machined respectively to obtain corresponding blade body intersection lines; uniformly sampling each blade body intersection line to obtain a plurality of blade body sampling points, and generating spiral points by tangential offsetting and height offsetting to connect all the blade body sampling points into a blade body spiral curve; offsetting the blade body spiral curve along the normal direction of the blade to be machined to obtain a target blade body extension tool path; machining the rim surface of the blade to be machined based on the target rim tool path and the target blade body extension tool path.

2. The blade shroud surfacing path planning method of claim 1, wherein, The method for offsetting the rim surface of the blade to be machined to obtain a rim tool path layer surface and a plurality of blade body extension tool path layer surfaces comprises the following steps: Based on tool radius The sum of the margin of the edge plate The distance between the tool center point of the edge plate tool path and the edge plate surface is calculated as the offset distance The edge plate surface to be machined is offset to obtain the edge plate tool path layer ; Based on tool radius Sum of margin of edge plate And the number of extension layers And tool cutting width Get different layer offset distance Offset the blade edge plate surface to be processed to get An extension tool path layer of the blade body , .

3. The blade shroud surfacing path planning method of claim 2, wherein, obtaining an outer boundary of a rim tool path and an inner boundary of the rim tool path based on a preset total cutting distance and a blade allowance of the blade to be machined, comprising: If , the sum of the tool radius and the blade allowance is calculated as the offset distance of the inner circle boundary of the shroud tool path, and the sum of the tool radius, the blade allowance and the preset total cutting distance is calculated as the offset distance of the outer circle boundary of the shroud tool path; If the sum of the thickness of the rim knife path layer surface at the fillet position, the tool radius and the blade allowance is calculated as the offset distance of the inner circle boundary of the rim knife heart trajectory, and the sum of the thickness of the rim knife path layer surface at the fillet position, the tool radius, the blade allowance and the preset total cutting distance is calculated as the offset distance of the outer circle boundary of the rim knife heart trajectory; wherein, denotes the fillet radius of the blade to be machined.

4. The blade shroud surfacing path planning method of claim 3, wherein, obtaining the thickness of the rim tool path layer surface at the fillet position, comprising: Based on the geometric relationship between the blade toolpath layer and the fillet surface of the blade to be machined, the angle between the line connecting the center of the fillet surface and the center of the tool sphere, and the angle between the center of the fillet surface and the perpendicular line from the blade surface are obtained. The cosine value of is expressed as: ； obtaining the coordinates of the tool ball center based on the cosine value, the coordinates of the ball center of the fillet surface, the intersection coordinates of the fillet surface and the blade to be machined, and the coordinates of the fillet surface and the blade to be machined; calculating the difference between the horizontal coordinate of the tool ball center and the tool radius as the thickness of the rim tool path layer surface at the fillet position; wherein represents the fillet radius of the blade to be machined, represents the tool radius, represents the shroud allowance.

5. The blade shroud surfacing path planning method of claim 1, wherein, performing basic offsetting based on a rim tool path cutting width and a preset tool path number, and performing spiral incremental offsetting in the direction of the inner sampling point pointing to the corresponding outer sampling point to obtain each tool position point in each tool path, comprising: Based on the width of the blade path of the edge plate After the secondary offset, the first The base offset of the strip blade path ; Based on the total number of sampling points and the width of the knife path cutting along the edge plate, the following is performed After the second offset, the helical increment offset of the first knife point is obtained ; Based on the first The basic offset of the first The helical increment offset of the first The first The first The first ; wherein, , represents preset number of tool paths, represents insulating tool path cutting width, and the expression is ; , represents total number of sampling points in the sampling point sequence; , represents the i-th inner circle sampling point in the inner circle sampling point sequence. ​ 6. The blade shroud surfacing path planning method of claim 1, wherein, After obtaining the target rim tool path, the method further comprises: based on the cutting distance of each spiral tool path curve and a preset wrapping distance, regarding the spiral tool path curve that exceeds the rim surface as an invalid tool path segment, obtaining a remaining tool path segment as an effective tool path segment; sorting all the effective tool path segments to obtain an updated target rim tool path, comprising: based on a preset number of passes and a preset total cutting distance , the cutting distance of the first helical pass curve is calculated , and is expressed as: ; Comparative Example 1 Cutting distance of a helical tool path curve From a preset winding distance : If then there is no invalid road segment; If the dividing line of the edge plate surface is projected to the edge plate tool path layer, and the edge plate boundary curve is obtained; the edge plate boundary curve is intersected with each spiral tool path curve respectively, a plurality of cutting points are obtained, the spiral tool path curve is divided into a plurality of tool path segments, and the tool path segment located inside the edge plate boundary curve is obtained as an effective tool path segment.

7. The blade shroud surfacing path planning method of claim 6, wherein, sorting all the effective tool path segments to obtain the target rim tool path, comprising: calculating the parameter position of each effective tool path segment on the rim boundary line based on the clipping point on each effective tool path segment; clustering the effective tool path segments based on the parameter positions to obtain a plurality of clustering regions, and processing them one by one; in each clustering region, processing them from the outside to the inside in a bidirectional manner.

8. The blade shroud surfacing path planning method of claim 1, wherein, generating spiral points by tangential offsetting and height offsetting, which are represented as: ； wherein, , denotes the total number of sampling points in the sequence of sampling points; denotes the distance between adjacent blade extension toolpath slice layers, , denotes the first blade extension toolpath slice layer corresponding to the first sampling point in the intersection line of the blades.

9. The blade shroud surfacing path planning method of claim 1, wherein, The target blade body extension tool path is obtained by offsetting the spiral curve of the blade body, taking the sum of the tool radius and the blade allowance as the offset distance, and taking the normal vector of the blade to be machined as the offset direction.

10. The blade shroud surfacing path planning method of claim 1, wherein, After the target shroud tool path and the target blade body extension tool path are obtained, the method further comprises calculating the feasible region of the tool axis direction of each tool position point in the target shroud tool path and the target blade body extension tool path, and obtaining an optimal tool axis, comprising: based on the curvature at the location where each tool position is located and the maximum inclination angle and the minimum inclination angle obtain the tool axis direction feasible region at each tool position is expressed as: ; The genetic algorithm is used to select the optimal tool axis from the tool axis inclination angle feasible region, taking the uniform change of adjacent tool axis vectors, the minimization of the tool axis inclination angle change rate, and the optimization objectives of no collision and no undercutting.

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