Triangularization tool path planning method, system and medium for impeller flow channel

Abstract

The application relates to a triangulation tool path planning method of an impeller flow channel, which comprises the following steps: S1, obtaining a plurality of layered surfaces between a hub surface and a shroud surface; S2, obtaining left and right boundary lines of a to-be-processed flow channel by intersecting one of the layered surfaces with a blade surface; S3, offsetting the left and right boundary lines to the middle at the same time, and stopping when the nth left boundary line is located on the right side of the nth right boundary line after the nth offset; S4, judging whether the mth left boundary line and the mth right boundary line intersect or not, if not, keeping the mth left boundary line and the right boundary line; if yes, only keeping the part of the mth left boundary line located on the left side of the intersection point and the part of the mth right boundary line located on the right side of the intersection point, and m is equal to [1, n]; S5, connecting all the intersection points to obtain a triangulation tool path of one layered surface; S6, repeating S2 to S5 to complete the triangulation tool paths of all the layered surfaces; and S7, performing transition and sorting on the triangulation tool paths of all the layered surfaces to obtain a complete tool path of the to-be-processed flow channel.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of impeller flow passage processing, in particular to a triangularization tool path planning method and system for impeller flow passage and a medium. BACKGROUND

[0002] Impellers are widely used in various fluid processing mechanical devices, such as aircraft engines, water pumps, compressors, etc.

[0003] For the whole impeller, five-axis milling is generally used. The front inlet of the impeller is narrow and the rear outlet is divergent, and the whole is radial, so the whole flow passage is narrow in front and wide at the rear. The traditional flow passage processing method is to use longitudinal tool paths in front and back directions to process the impeller flow passage.

[0004] However, when the traditional longitudinal tool path in front and back directions is used to process the impeller flow passage, the front tool path is prone to be too dense and the rear tool path is too sparse. On the one hand, the small front tool path spacing and the large rear tool path spacing cause quality differences between the front and rear parts of the processed part surface. On the other hand, too many tool paths are used to process the narrow front part of the impeller, which reduces the cutting efficiency and wastes manpower and resources.

[0005] To overcome the above-mentioned defects, Chinese patent CN103212760B discloses a machining method for the inter-blade flow passage of an equal-section blade profile with a shroud whole impeller, which uses numerical control electric spark technology to process the inter-blade flow passage of the impeller. However, a special electrode needs to be designed for each type of impeller, and the process is complex and the cost is high. SUMMARY

[0006] The technical problem to be solved by the present application is to provide a triangularization tool path planning method and system for impeller flow passage and a medium. By offsetting the left boundary line and the right boundary line of the flow passage to be processed, a triangular-shaped machining tool path can be generated, and the spacing of each tool path can be kept consistent, so that the machining effect is consistent in different regions, and the number of front tool paths is small, which can greatly improve the machining efficiency of the impeller flow passage.

[0007] To solve the above technical problems, the application provides a triangularization tool path planning method for a flow passage of an impeller, comprising the following steps: S1, obtaining a blade surface, a hub surface and a shroud surface of a preset impeller model; obtaining a plurality of layered surfaces between the hub surface and the shroud surface; S2, intersecting one of the layered surfaces with the blade surface to obtain a left boundary line and a right boundary line of a flow passage to be machined; S3, offsetting the left boundary line and the right boundary line to the middle at a preset step length for multiple times to generate a plurality of left boundary lines and a plurality of right boundary lines, and stopping offsetting when the nth left boundary line is completely located on the right side of the nth right boundary line after the nth offsetting; wherein n > 1; S4, judging whether the mth left boundary line and the mth right boundary line intersect with each other in sequence, if not, completely retaining the mth left boundary line and the mth right boundary line; if yes, retaining only the part of the mth left boundary line located on the left side of the intersection point and retaining only the part of the mth right boundary line located on the right side of the intersection point; wherein m ∈ [1, n]; S5, connecting the intersection points in S4 to obtain a triangularization tool path of one of the layered surfaces; S6, repeating steps S2 to S5 until the triangularization tool paths of all the layered surfaces are completed; and S7, performing transition processing on the triangularization tool paths of two adjacent layered surfaces and sorting the triangularization tool paths of the layered surfaces to obtain a complete tool path of the flow passage to be machined.

[0008] After obtaining the left boundary line and the right boundary line of the flow passage to be machined, the application offsets the flow passage boundary to generate triangular machining tool paths, the distance between each tool path is consistent, and the machining efficiency is improved.

[0009] Preferably, the determination method of the plurality of layered surfaces comprises: obtaining a plurality of revolution surfaces between the hub surface and the shroud surface based on a preset cutting depth or a preset number of tool paths by an equal parameter interpolation method.

[0010] Each revolution surface is used as a layered surface for determining a machining position in the depth direction.

[0011] Preferably, the left boundary line and the right boundary line cooperate to form the contour of the flow passage to be machined.

[0012] Preferably, the determination method of the preset step length comprises: specifying a cutting width by a user or calculating the cutting width by a preset residual height parameter; and taking the cutting width as the preset step length.

[0013] Preferably, in S7, the sorting method of the triangularization tool paths of the layered surfaces comprises: from top to bottom, from bottom to top, from left to right or from right to left.

[0014] Preferably, the impeller model is constructed based on a UG NX modeling module.

[0015] Preferably, the impeller model is in igs or step format.

[0016] The triangularization tool path planning system of the impeller flow channel is characterized in that it comprises: a layered surface acquisition module, which is used to form a plurality of layered surfaces between a hub surface and a shroud surface of a preset impeller model; a contour forming module, which is used to intersect one of the layered surfaces with a blade surface in the impeller model to obtain a left boundary line and a right boundary line of a flow channel to be machined, and the left boundary line and the right boundary line cooperate to form a contour of the flow channel to be machined; a biasing module, which is used to bias the left boundary line and the right boundary line to the middle multiple times to generate a plurality of left boundary lines and a plurality of right boundary lines, and stop biasing when the nth left boundary line is completely located on the right side of the nth right boundary line after the nth biasing; wherein n>1; a layered surface tool path acquisition module, which is used to judge whether the mth left boundary line and the mth right boundary line intersect in sequence, if not, completely retain the mth left boundary line and the mth right boundary line; if yes, only retain the part of the mth left boundary line located on the left side of the intersection point and the part of the mth right boundary line located on the right side of the intersection point; and connect each intersection point to obtain the triangularization tool path of one of the layered surfaces; wherein m∈[1, n]; and a flow channel to be machined tool path forming module, which is used to transition process the triangularization tool paths of adjacent two layered surfaces and sort the triangularization tool paths of each layered surface to obtain a complete tool path of the flow channel to be machined.

[0017] Preferably, the triangularization tool path planning system of the impeller flow channel, the impeller model comprises a blade surface, a hub surface and a shroud surface.

[0018] A computer readable storage medium, wherein instructions are stored, the instructions are executed by a processor to perform the triangularization tool path planning method of the impeller flow channel.

[0019] The above technical scheme of the present application has the following advantages compared with the prior art:

[0020] 1、The present application obtains the left boundary line and the right boundary line of the flow channel to be machined, and generates triangular machining tool paths by biasing the flow channel boundaries, so that the spacing of each tool path is consistent, and the machining effect is consistent without different tool path densities in different regions, and the number of front tool paths is small, thereby improving the machining efficiency.

[0021] 2、The present application sorts the triangularization tool paths of a plurality of layered surfaces, and adds transition tool paths between the layered surfaces, to finally form a complete tool path of the flow channel to be machined, which is ingenious in design and convenient to operate, and can realize impeller flow channel machining with fewer tool paths. BRIEF DESCRIPTION OF DRAWINGS

[0022] 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:

[0023] Figure 1 is a flowchart of the present application;

[0024] Figure 2 is a schematic diagram of the left and right boundary lines of the flow passage to be processed of the present application;

[0025] Figure 3 is a schematic diagram of the left and right boundary line offsets of the present application;

[0026] Figure 4 is a schematic diagram of the triangulation tool path of one of the layer planes of the present application;

[0027] Figure 5 is an effect diagram of the triangulation tool path of one of the layer planes of the present application. DETAILED DESCRIPTION

[0028] 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 of the present application.

[0029] The present application discloses a triangulation tool path planning method for a flow passage of an impeller, as shown in Figure 1 , comprising the following steps:

[0030] Step 1: Obtain the blade surface, hub surface and shroud surface of a preset impeller model.

[0031] Between the above-mentioned hub surface and shroud surface, a plurality of layer planes are obtained. Specifically, between the shroud surface and the hub surface, according to the user's preset cutting depth or tool path number, a rotary surface is determined in a manner of equal parameter interpolation, and each rotary surface is taken as a layer plane for determining the depth direction processing position.

[0032] Preferably, the impeller model can be constructed based on the UG NX modeling module.

[0033] Further preferably, the impeller model is in igs or step format.

[0034] Step 2: Intersect one of the layer planes with the blade surface to obtain the left boundary line and the right boundary line of the flow passage to be processed. As shown in Figure 2 , the above-mentioned left boundary line and right boundary line can cooperate to form the profile of the flow passage to be processed.

[0035] Step three, offset the left boundary line and the right boundary line to the middle at the same time for multiple times according to the preset step length, and stop until the nth left boundary line and the nth right boundary line completely exchange positions after the nth offset, that is, the nth left boundary line completely locates at the right side of the nth right boundary line.

[0036] Referring to Figure 3 In one of the preferred embodiments, n = 5.

[0037] Further, the determination method of the preset step length is that the cutting width is specified by a user or calculated by a preset residual height parameter, and the cutting width is taken as the preset step length.

[0038] Step four, cut the excess tool path, and the specific operation method is:

[0039] In turn, judge whether the mth left boundary line and the mth right boundary line intersect, if not, completely retain the mth left boundary line and the mth right boundary line; if yes, only retain the part of the mth left boundary line located on the left side of the intersection point, and the rest is cut off; retain the part of the mth right boundary line located on the right side of the intersection point, and the rest is cut off; wherein m ∈ [1, n];

[0040] In one of the preferred embodiments, when n = 5, the schematic diagram of the triangular tool path after cutting is shown in Figure 4 .

[0041] Step five, connect each intersection point in step four to obtain a triangular tool path of one of the layered surfaces. This method can generate a triangular machining tool path by offsetting the left boundary line and the right boundary line of the to-be-processed flow channel, and the distance between each tool path can be kept consistent, so that the machining effect is inconsistent in different regions.

[0042] Step six, repeat steps two to five until all triangular tool paths of the layered surfaces are completed;

[0043] Step seven, transition processing of adjacent triangular tool paths of the layered surfaces and sorting of the triangular tool paths of the layered surfaces are performed to obtain a complete tool path of the to-be-processed flow channel, and the number of front tool paths is small, which greatly improves the machining efficiency.

[0044] The triangular tool paths of multiple layered surfaces are sorted, and transition tool paths are added between the layered surfaces, and finally a complete tool path of the to-be-processed flow channel is formed, which is designed ingeniously and convenient to operate, can realize impeller flow channel machining with fewer tool paths, and ensures that the tool path distance is equal, greatly improving the impeller flow channel machining efficiency.

[0045] When sorting the triangular tool paths of the layered surfaces, the sorting method includes but is not limited to: from top to bottom, from bottom to top, from left to right or from right to left.

[0046] Referring to Figure 5 Figure 2 shows a triangularization tool path effect diagram of one of the layered faces when the residual height parameter of the present application is 0.1.

[0047] Based on the above-mentioned impeller passage triangularization tool path planning method. The present application also proposes an impeller passage triangularization tool path planning system.

[0048] The impeller passage triangularization tool path planning system is characterized in that it comprises:

[0049] The layered face acquisition module is configured to acquire the blade surface, the hub surface and the shroud surface of the preset impeller model, and acquire a plurality of layered faces between the hub surface and the shroud surface of the preset impeller model.

[0050] The contour forming module is configured to intersect one of the layered faces with the blade surface in the impeller model to obtain a left boundary line and a right boundary line of the passage to be machined, and the left boundary line and the right boundary line cooperate to form the contour of the passage to be machined.

[0051] The biasing module is configured to bias the left boundary line and the right boundary line towards the middle multiple times to generate a plurality of left boundary lines and a plurality of right boundary lines, and stop biasing when the nth left boundary line is completely located to the right of the nth right boundary line after the nth biasing. Wherein, n>1.

[0052] The layered face tool path acquisition module is configured to sequentially judge whether the mth left boundary line and the mth right boundary line intersect, if not, completely retain the mth left boundary line and the mth right boundary line; if yes, only retain the part of the mth left boundary line located to the left of the intersection point and retain the part of the mth right boundary line located to the right of the intersection point; connect each intersection point to obtain the triangularization tool path of one of the layered faces; wherein m∈[1,n].

[0053] The passage-to-be-machined tool path forming module is configured to transition process the triangularization tool paths of adjacent two layered faces and sort the triangularization tool paths of each layered face to obtain the complete tool path of the passage to be machined.

[0054] The present method can generate triangular-like machining tool paths by biasing the left boundary line and the right boundary line of the passage to be machined, the spacing of each tool path can be kept consistent, and the situation that different regions have different tool path densities and cause inconsistent machining effects will not occur, thereby effectively improving the machining efficiency of the impeller passage

[0055] The application further provides a computer readable storage medium, wherein instructions are stored, and the instructions are executed by a processor to perform the impeller flow channel triangulation tool path planning method.

[0056] 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.

[0057] The present application is described with reference to the 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 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 processor of a general-purpose computer, a special-purpose computer, an embedded processor, or other programmable data processing apparatus to produce a machine, so that the instructions executed by the processor of the computer or other programmable data processing apparatus generate a means for implementing the functions specified in the flowcharts and / or block diagrams. Figure 1 one or more flows and / or blocks Figure 1 an apparatus that carries out the functions specified in one or more flows and / or blocks.

[0058] These computer program instructions can also be stored in a computer-readable memory that can direct the computer or other programmable data processing apparatus to work in a specific manner, so that the instructions stored in the computer-readable memory produce a product including instruction apparatus, which implements the functions specified in the flowcharts and / or block diagrams. Figure 1 one or more flows and / or blocks Figure 1 an apparatus that carries out the functions specified in one or more flows and / or blocks.

[0059] These computer program instructions can also be loaded into a computer or other programmable data processing apparatus, so that a series of operation steps are performed on the computer or other programmable data processing apparatus to produce a computer-implemented process, so that the instructions executed on the computer or other programmable data processing apparatus provide a process for implementing the functions specified in the flowcharts and / or block diagrams. Figure 1 one or more flows and / or blocks Figure 1 an apparatus that carries out the functions specified in one or more flows and / or blocks.

[0060] Obviously, the above embodiments are merely example for clearly illustrating, and are not limitation to the embodiments. For ordinary skilled in the art, other different forms of changes or variations can be made on the basis of the above description. Here, all the embodiments need not and can not be exhausted. The obvious changes or variations derived therefrom are still within the scope of the present invention.

Claims

1. The triangulated tool path planning method for the impeller flow channel is characterized by: The following steps are involved: S1. Obtain blade curved surfaces, hub curved surfaces, and shroud curved surfaces of a preset impeller model; and obtain multiple layered surfaces between the hub curved surface and the shroud curved surface; S2, intersecting any one of the sub-surfaces with the blade curved surface to obtain a left boundary line and a right boundary line of the flow channel to be processed; S3, according to a preset step size, offsetting the left boundary line and the right boundary line toward the middle multiple times to generate multiple left boundary lines and multiple right boundary lines, until the nth left boundary line is completely to the right of the nth right boundary line after the nth offset, and then stopping the offset; wherein n>1; S4. Determine in sequence whether the mth left boundary line and the mth right boundary line intersect. If not, retain the mth left boundary line and the mth right boundary line completely. If so, retain only the portion of the mth left boundary line to the left of the intersection point and the portion of the mth right boundary line to the right of the intersection point; where m∈[1,n]. S5, connecting the intersection points in S4 to obtain the triangulated tool path of the layered surface; S6, repeating steps S2 to S5 until the triangulated tool paths of all the layers are completed; S7, performing transition processing on the triangulated tool paths of two adjacent sub-layers and sorting the triangulated tool paths of each sub-layer to obtain a complete tool path of the flow channel to be processed.

2. The triangulated tool path planning method for the impeller flow channel according to claim 1, characterized in that: The method for determining the multiple sub-levels is as follows: Between the hub surface and the shroud surface, a multi-layered surface of revolution is obtained by an isoparametric interpolation method based on a preset cutting depth or number of tool paths; Each rotation surface is used as a sub-surface to determine the machining position in the depth direction.

3. The method for triangulating the impeller flow channel according to claim 1, characterized in that: The left boundary line and the right boundary line cooperate to form the outline of the flow channel to be processed.

4. The method for triangulating the impeller flow channel according to claim 1, characterized in that: The method for determining the preset step length is: The cutting width is specified by the user or calculated by the preset residual height parameters; The cutting width is used as the preset step length.

5. The method for triangulating the impeller flow channel according to claim 1, characterized in that: In the above S7, when sorting the triangulated tool paths of each layer, the sorting methods include: from top to bottom and from bottom to top.

6. The method for triangulating the impeller flow channel according to claim 1, characterized in that: The impeller model is constructed based on the UG NX modeling module.

7. The method for triangulating the impeller flow channel according to claim 6, characterized in that: The impeller model is in igs or step format.

8. The triangulated tool path planning system for the impeller flow channel is characterized by: include A layered surface acquisition module is used to form multiple layered surfaces between the hub surface and the shroud surface of the preset impeller model; a contour forming module, configured to intersect one of the layered surfaces with a blade curved surface in the impeller model to obtain a left boundary line and a right boundary line of the flow channel to be processed, wherein the left boundary line and the right boundary line cooperate to form a contour of the flow channel to be processed; a biasing module configured to bias the left boundary line and the right boundary line toward the middle multiple times simultaneously to generate multiple left boundary lines and multiple right boundary lines, and to stop biasing when the nth left boundary line is completely to the right of the nth right boundary line after the nth biasing; wherein n>1; A layered tool path acquisition module is used to sequentially determine whether the mth left boundary line and the mth right boundary line intersect. If not, the mth left boundary line and the mth right boundary line are completely retained; if so, only the portion of the mth left boundary line located to the left of the intersection point is retained, and the portion of the mth right boundary line located to the right of the intersection point is retained; each intersection point is connected to obtain a triangulated tool path of one of the layered surfaces; wherein m∈[1,n]; The tool path forming module for the flow channel to be processed is used for performing transition processing on the triangulated tool paths of two adjacent sub-layers and sorting the triangulated tool paths of each sub-layer to obtain a complete tool path for the flow channel to be processed.

9. The impeller flow channel triangulation tool path planning system according to claim 8, characterized in that: The impeller model includes a blade surface, a hub surface and a shroud surface.

10. A computer-readable storage medium storing instructions, wherein when the instructions are executed by a processor, the method for triangulation tool path planning of an impeller flow channel according to claims 1-7 is executed.

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