Machining method for non-axisymmetric wheel disc face and circular bead and impeller

Abstract

The invention provides a non-axisymmetric wheel disc face and fillet machining method and an impeller, and the method comprises the steps that feeding machining is conducted from the air inlet edge to the air outlet edge of the impeller according to a streamline from L1 to L2, and a main blade pressure face long fillet is obtained; feeding machining is conducted from the air inlet side to the air outlet side of the impeller according to the streamline from L3 to L4, and a main blade suction surface long fillet is obtained; feeding machining is conducted from the air inlet side to the air outlet side of the impeller according to the streamline from L5 to L6, and the splitter blade pressure face short fillet is obtained; feeding machining is carried out from the air inlet side to the air outlet side of the impeller according to a streamline from L7 to L8, and a splitter blade suction surface short fillet is obtained; and obtaining a first reference wheel disc face tool nose processing track, and adding the non-axisymmetric wheel disc face as an additional curved surface to obtain the non-axisymmetric wheel disc face. Machining and manufacturing of the non-axisymmetric wheel disc face impeller are achieved, and a way is laid for application of the non-axisymmetric wheel disc face impeller.

Description

Technical Field

[0001] The present application belongs to the technical field of centrifugal pump impeller processing and manufacturing, and specifically relates to a processing method and an impeller for non-axisymmetric wheel disc surface and fillet. Background Art

[0002] Centrifugal compressors are a type of rotary machinery that uses fluid as a working medium to achieve functional conversion. They are widely used in petrochemical, metallurgical, civil air conditioning, aerospace and other fields. The improvement of their performance can often bring considerable economic benefits. As the core component of a centrifugal compressor, the spatial geometric shape of the centrifugal impeller will affect the flow conditions of the working medium inside it, which often determines the upper limit of the machine's performance. There is currently a semi-open centrifugal impeller with a freely concave and convex wheel surface and splitter blades, collectively referred to as a non-axisymmetric wheel surface impeller. This type of impeller is concave near the air inlet, which is beneficial to improving the maximum efficiency and increasing the blockage flow. The convexity near the splitter flow channel on the pressure side of the air outlet is beneficial to improving the maximum efficiency, but it will reduce the impeller's pressure ratio. This type of impeller has broad application prospects in improving the efficiency of turbine compressor units.

[0003] The structure of the non-axisymmetric disk impeller is different from the previous ones. The disk surface between the two main blades is composed of three free-form surfaces. The non-axisymmetric disk surface is obtained by evenly distributing the main blades around the circumference. The disk surface between the blades changes the gas flow direction and speed on the suction and pressure surfaces of the blades respectively, so the disk surface is required to be smoother. Since both the blades and the disk are free-form surfaces during the processing, the fillet processing at the intersection is difficult. Therefore, the existing three-dimensional impeller processing method can no longer meet the processing requirements of non-axisymmetric disk impellers. Summary of the invention

[0004] Therefore, the technical problem to be solved by the present application is to provide a method and impeller for processing non-axisymmetric disc surface and fillet, which can meet the processing requirements of disc surface and fillet in impellers with non-axisymmetric disc surface, and pave the way for the application of impellers with non-axisymmetric disc surface.

[0005] In order to solve the above problems, the first aspect of the present application provides a method for processing a non-axisymmetric wheel disc surface and a rounded corner, comprising:

[0006] Finishing of the main blade pressure surface long fillet, suction surface long fillet, splitter blade pressure surface short fillet, suction surface short fillet

[0007] The first offset surface of the non-axisymmetric disk surface intersects with the offset surface of the main blade pressure surface to obtain an intersection line L1; the second offset surface of the non-axisymmetric disk surface intersects with the offset surface of the main blade pressure surface to obtain an intersection line L2; the tool is moved from the air inlet side to the air outlet side of the impeller according to the streamline from L1 to L2 to obtain the tool center trajectory for machining the long fillet of the main blade pressure surface;

[0008] Among them, during the tool-feeding process, the pressure surface of the main blade is selected as the processing surface, and the non-axisymmetric wheel surface and the suction surface of the splitter blade are selected as the stop surface;

[0009] The first offset surface of the non-axisymmetric disk surface intersects with the offset surface of the main blade suction surface to obtain an intersection line L3; the second offset surface of the non-axisymmetric disk surface intersects with the offset surface of the main blade suction surface to obtain an intersection line L4; the tool is moved from the air inlet side to the air outlet side of the impeller according to the streamline from L3 to L4 to obtain the tool center trajectory for machining the long fillet of the main blade suction surface;

[0010] Among them, during the tool-feeding process, the suction surface of the main blade is selected as the processing surface, and the non-axisymmetric wheel surface and the pressure surface of the splitter blade are selected as the stop surface.

[0011] The first offset surface of the non-axisymmetric wheel surface intersects with the offset surface of the splitter blade pressure surface to obtain an intersection line L5; the second offset surface of the non-axisymmetric wheel surface intersects with the offset surface of the splitter blade pressure surface to obtain an intersection line L6; the tool is moved from the air inlet side to the air outlet side of the impeller according to the streamline from L5 to L6 to obtain the tool center trajectory for machining the short fillet of the splitter blade pressure surface;

[0012] Among them, during the cutting process, the pressure surface of the splitter blade is selected as the processing surface, and the non-axisymmetric wheel disk surface and the adjacent main blade suction surface are selected as the stop surface;

[0013] The first offset surface of the non-axisymmetric wheel surface intersects with the offset surface of the suction surface of the splitter blade to obtain an intersection line L7; the second offset surface of the non-axisymmetric wheel surface intersects with the offset surface of the suction surface of the splitter blade to obtain an intersection line L8; according to the streamline from L7 to L8, the tool is moved from the air inlet side to the air outlet side of the impeller to obtain the tool center trajectory for machining the short fillet of the suction surface of the splitter blade;

[0014] Among them, during the cutting process, the suction surface of the splitter blade is selected as the processing surface, and the non-axisymmetric wheel disc surface and the adjacent main blade pressure surface are selected as the stop surface;

[0015] Finishing of non-axisymmetric wheel surfaces

[0016] The tool tip machining trajectory of the first reference disc surface is obtained. Based on the tool tip machining trajectory of the first reference disc surface, the non-axisymmetric disc surface is added as an additional surface. The tool is moved from the air inlet side to the air outlet side of the impeller to obtain the tool tip machining trajectory of the non-axisymmetric disc surface.

[0017] Optionally, the first reference disc surface is selected by taking the extension line of the root line of the neutral plane of the main blade as the disc line, and rotating the disc line to generate an initial disc surface; the initial disc surface is offset along the normal phase toward the side of the impeller without blades, and the offset distance is the normal phase distance H from the concave part of the non-axisymmetric disc surface to the initial disc surface, to obtain the first reference disc surface.

[0018] Optionally, the first offset surface of the non-axisymmetric wheel disc surface is selected by offsetting the non-axisymmetric wheel disc surface along the normal phase toward the side of the impeller having blades, and the offset distance is M, so as to obtain the first offset surface of the non-axisymmetric wheel disc surface;

[0019] Among them, the offset distance M is the sum of the finishing tool radius R, the normal distance h from the convex part of the non-axisymmetric wheel surface to the initial wheel surface, and the normal distance H from the concave part of the non-axisymmetric wheel surface to the initial wheel surface;

[0020] The second offset surface of the non-axisymmetric disk surface is selected by shifting the non-axisymmetric disk surface along the normal phase toward the blade side of the impeller, and the offset distance is R1, so as to obtain the second offset surface of the non-axisymmetric disk surface;

[0021] Among them, the offset distance R1 is the finishing tool radius R.

[0022] Optionally, the main blade pressure surface offset surface is selected by offsetting the main blade pressure surface along the normal phase toward the splitter blade, with an offset distance of R2, to obtain the main blade pressure surface offset surface;

[0023] The main blade suction surface offset surface is selected by shifting the main blade suction surface along the normal phase toward the splitter blade, with the offset distance being R3, to obtain the main blade suction surface offset surface;

[0024] Among them, the offset distance R2 and the offset distance R3 are both the finishing tool radius R.

[0025] Optionally, the splitter blade pressure surface offset surface is selected by offsetting the splitter blade pressure surface along the normal phase toward the main blade direction, with an offset distance of R4, to obtain the splitter blade pressure surface offset surface;

[0026] The offset surface of the pressure surface of the splitter blade is selected, and the suction surface of the splitter blade is offset along the normal phase toward the main blade. The offset distance is R5, and the offset surface of the pressure and suction surface of the splitter blade is obtained;

[0027] Among them, the offset distance R4 and the offset distance R5 are both the finishing tool radius R.

[0028] Optionally, before finishing the long fillet of the pressure surface of the main blade, the long fillet of the suction surface, and the short fillet of the pressure surface of the splitter blade, the following steps may be further included:

[0029] Obtain a three-dimensional model of the impeller;

[0030] Select the non-axisymmetric disc surface finishing tool and the fillet finishing tool;

[0031] Constructing the machining model of the impeller

[0032] Select the main blades, splitter blades and the first reference wheel disc surface component impeller processing model in the impeller three-dimensional model;

[0033] Rough machining of main blades and splitter blades;

[0034] Finishing of main blades and splitter blades.

[0035] Optionally, the steps of selecting a non-axisymmetric disc surface finishing tool and a fillet finishing tool include:

[0036] The non-axisymmetric disk surface finishing tool and fillet finishing tool are selected according to the blade fillet marked in the impeller design drawing and should be consistent with the blade fillet size.

[0037] Optionally, the non-axisymmetric disk surface finishing tool and fillet finishing tool are selected according to the blade fillet marked in the impeller design drawing, and should be consistent with the blade fillet size. Steps include:

[0038] Perform curvature analysis on the non-axisymmetric disk surface in the impeller 3D model to obtain the minimum radius value of the concave area. When the minimum radius value of the concave area is smaller than the blade fillet marked in the impeller design drawing, select the finishing tool based on the minimum radius value of the concave area.

[0039] When the minimum radius value of the recessed area is greater than the blade fillet marked in the impeller design drawing, the finishing tool is selected based on the blade fillet marked in the impeller design drawing.

[0040] Optionally, the step of finishing the main blades and splitter blades includes:

[0041] The initial wheel disc surface is offset along the normal phase toward the side of the impeller with blades, and the offset distance is the normal phase distance h from the convex part of the non-axisymmetric wheel disc surface to the initial wheel disc surface, to obtain a second reference wheel disc surface;

[0042] The machining depth of the finishing main blades and splitter blades is from the wheel cover surface to the second reference wheel disc surface.

[0043] A second aspect of the present application provides an impeller, which is manufactured using any of the above-mentioned methods for processing a non-axisymmetric wheel disc surface and fillet.

[0044] Beneficial Effects

[0045] The embodiment of the present application provides a method for processing a non-axisymmetric wheel disc surface and a fillet, wherein the offset surface of the pressure surface of the main blade intersects with the first offset surface of the non-axisymmetric wheel disc surface and the second offset surface of the non-axisymmetric wheel disc surface, respectively, to obtain intersection lines L1 and L2; the offset surface of the suction surface of the main blade intersects with the first offset surface of the non-axisymmetric wheel disc surface and the second offset surface of the non-axisymmetric wheel disc surface, respectively, to obtain intersection lines L3 and L4; the offset surface of the pressure surface of the splitter blade intersects with the first offset surface of the non-axisymmetric wheel disc surface and the second offset surface of the non-axisymmetric wheel disc surface, respectively, to obtain intersection lines L5 and L6; The suction surface offset surface intersects with the first offset surface of the non-axisymmetric disc surface and the second offset surface of the non-axisymmetric disc surface, respectively, to obtain intersection lines L7 and L8; according to the streamlines L1 and L2, L3 and L4, L5 and L6, and L7 and L8, respectively, the tool is moved from the air inlet side to the air outlet side of the impeller to machine the long fillet of the pressure surface and suction surface of the main blade to divert the short fillet of the pressure surface and suction surface of the blade; on the basis of the tool tip machining trajectory of the first reference disc surface, the non-axisymmetric disc surface is added as an additional curved surface, and the tool is moved from the air inlet side to the air outlet side of the impeller to machine the non-axisymmetric disc surface. The present application solves the processing problems of the disc surface and fillet of the non-axisymmetric disc surface impeller, realizes the machining and manufacturing of the non-axisymmetric disc surface impeller, and paves the way for the application of the non-axisymmetric disc surface impeller. Compared with other impeller machining methods that cannot complete the machining and manufacturing of non-axisymmetric disc surface impellers, the present application has achieved it from scratch. BRIEF DESCRIPTION OF THE DRAWINGS

[0046] Figure 1 This is a flow chart of the wheel disc surface and fillet processing method of the embodiment of the present application;

[0047] Figure 2 A schematic diagram of a non-axisymmetric semi-open centrifugal impeller with splitter blades according to an embodiment of the present application;

[0048] Figure 3 This is an end view of a non-axisymmetric semi-open centrifugal impeller with splitter blades according to an embodiment of the present application;

[0049] Figure 4 A schematic diagram of a blade processing area according to an embodiment of the present application;

[0050] Figure 5 This is a schematic diagram of the long fillet processing area of ​​the main blade pressure surface in an embodiment of the present application;

[0051] Figure 6 This is a schematic diagram of the long fillet processing area of ​​the main blade suction surface in an embodiment of the present application;

[0052] Figure 7 A schematic diagram of a short fillet processing area on a pressure surface of a splitter blade according to an embodiment of the present application;

[0053] Figure 8A schematic diagram of a short fillet processing area on the suction surface of a splitter blade according to an embodiment of the present application;

[0054] Fig. 9 This is a schematic diagram of the tool tip machining trajectory of the first reference wheel disc surface in an embodiment of the present application;

[0055] Fig.10 Schematic diagram of tool tip machining trajectory for a non-axisymmetric wheel disc surface according to an embodiment of the present application.

[0056] The reference numerals are:

[0057] 1. Main blade, 2. Splitter blade, 3. First reference disc surface, 4. Main blade pressure surface, 5. Non-axisymmetric disc surface, 6. Splitter blade suction surface, 7. Splitter blade pressure surface, 8. Main blade suction surface, 9. Initial disc surface, 10. First offset surface of non-axisymmetric disc surface, 11. Second reference disc surface, 12. Blade machinable area, 13. Blade non-machinable area. DETAILED DESCRIPTION

[0058] In the description of the present application, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise" and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the referred device or element must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as a limitation on the present invention.

[0059] In addition, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" and "second" may explicitly or implicitly include one or more of the features. In the description of the present invention, the meaning of "plurality" is two or more, unless otherwise clearly and specifically defined.

[0060] In this application, unless otherwise clearly specified and limited, the terms "installed", "connected", "connected", "fixed" and the like should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be an indirect connection through an intermediate medium, or it can be the internal communication of two elements. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0061] The preferred embodiments of the present invention are described below in conjunction with the accompanying drawings. It should be understood that the preferred embodiments described herein are only used to illustrate and explain the present invention, and are not used to limit the present invention.

[0062] See also Figures 1 to 4 As shown, according to an embodiment of the present application, a method for processing a non-axisymmetric wheel disc surface and fillet is provided, which is used to process and manufacture an impeller with a non-axisymmetric wheel disc.

[0063] Among them, the impeller includes an impeller cover body, on which a plurality of main blades 1 and splitter blades 2 are arranged circumferentially, and the main blades 1 and the splitter blades 2 are arranged alternately; the main blades 1 and the splitter blades 2 are curved surface structures, the outer convex surface of the main blade 1 is the main blade pressure surface 4, and the inner concave surface is the main blade suction surface 8, the outer convex surface of the splitter blade 2 is the splitter blade pressure surface 7, and the inner concave surface is the splitter blade suction surface 8, and the surface of the impeller cover body on which the main blades 1 and the splitter blades 2 are arranged is a non-axisymmetric disc surface 5.

[0064] Processing methods, including:

[0065] Step S1: Fine-machining the fillet of the main blade pressure surface

[0066] like Figure 5 As shown, the intersection line L1 is obtained by the intersection of the first offset surface of the non-axisymmetric disk surface and the offset surface of the main blade pressure surface; the intersection line L2 is obtained by the intersection of the second offset surface of the non-axisymmetric disk surface and the offset surface of the main blade pressure surface; the tool is moved from the air inlet side to the air outlet side of the impeller according to the streamline from L1 to L2, and the tool center trajectory for machining the long fillet of the main blade pressure surface is obtained;

[0067] During the tool-feeding process, the main blade pressure surface 4 is selected as the processing surface, and the non-axisymmetric wheel disc surface 5 and the splitter blade suction surface 6 are selected as the stop surfaces;

[0068] Step S2: Fine-machining the long fillet of the suction surface of the main blade

[0069] like Figure 6 As shown, the intersection line L3 is obtained by the intersection of the first offset surface of the non-axisymmetric disk surface and the offset surface of the main blade suction surface; the intersection line L4 is obtained by the intersection of the second offset surface of the non-axisymmetric disk surface and the offset surface of the main blade suction surface; the tool is moved from the air inlet side to the air outlet side of the impeller according to the streamline from L3 to L4, and the tool center trajectory for machining the long fillet of the main blade suction surface is obtained;

[0070] During the tool-feeding process, the suction surface 8 of the main blade is selected as the processing surface, and the non-axisymmetric wheel surface 5 and the pressure surface 7 of the splitter blade are selected as the stop surface;

[0071] Step S3: Finishing the short fillet of the pressure surface of the splitter blade

[0072] like Figure 7As shown, the first offset surface of the non-axisymmetric wheel disc surface intersects with the offset surface of the splitter blade pressure surface to obtain an intersection line L5; the second offset surface of the non-axisymmetric wheel disc surface intersects with the offset surface of the splitter blade pressure surface to obtain an intersection line L6; the tool is moved from the air inlet side to the air outlet side of the impeller according to the streamline from L5 to L6 to obtain the tool center trajectory for machining the short fillet of the splitter blade pressure surface;

[0073] During the tool-feeding process, the splitter blade pressure surface 7 is selected as the processing curved surface, and the non-axisymmetric wheel disc surface 5 and the adjacent main blade suction surface 8 are selected as the stop curved surfaces;

[0074] Step S4: fine machining of the short fillet of the suction surface of the splitter blade

[0075] like Figure 8 As shown, the intersection line L7 is obtained by the intersection of the first offset surface of the non-axisymmetric disk surface and the offset surface of the suction surface of the splitter blade; the intersection line L8 is obtained by the intersection of the second offset surface of the non-axisymmetric disk surface and the offset surface of the suction surface of the splitter blade; the tool is moved from the air inlet side to the air outlet side of the impeller according to the streamline from L7 to L8, and the tool center trajectory for machining the short fillet of the suction surface of the splitter blade is obtained;

[0076] During the tool-feeding process, the suction surface 6 of the splitter blade is selected as the processing surface, and the non-axisymmetric wheel disc surface 5 and the adjacent main blade pressure surface 4 are selected as the stop surfaces;

[0077] Step S5, finishing the non-axisymmetric wheel surface 5

[0078] like Fig. 9 and Fig.10 As shown, the tool tip machining trajectory of the first reference disc surface 3 is obtained, and on the basis of the tool tip machining trajectory of the first reference disc surface 3, the non-axisymmetric disc surface 5 is added as an additional curved surface, and the tool movement is performed from the air inlet side to the air outlet side of the impeller to obtain the tool tip machining trajectory of the non-axisymmetric disc surface.

[0079] The offset surface of the pressure surface of the main blade intersects with the first offset surface of the non-axisymmetric disk surface and the second offset surface of the non-axisymmetric disk surface, respectively, to obtain intersection lines L1 and L2; the offset surface of the suction surface of the main blade intersects with the first offset surface of the non-axisymmetric disk surface and the second offset surface of the non-axisymmetric disk surface, respectively, to obtain intersection lines L3 and L4; the offset surface of the pressure surface of the splitter blade intersects with the first offset surface of the non-axisymmetric disk surface and the second offset surface of the non-axisymmetric disk surface, respectively, to obtain intersection lines L5 and L6; the offset surface of the suction surface of the splitter blade intersects with the first offset surface of the non-axisymmetric disk surface and the second offset surface of the non-axisymmetric disk surface, respectively, to obtain intersection lines ...7 and L8; the offset surface of the suction surface of the splitter blade intersects with the first offset surface of the non-axisymmetric disk surface and the second offset surface of the non-axisymmetric disk surface, respectively, to obtain intersection lines L8 and L9. The first offset surface of the disk surface and the second offset surface of the non-axisymmetric disk surface intersect to obtain intersection lines L7 and L8; according to the streamlines of L1 and L2, L3 and L4, L5 and L6, and L7 and L8, respectively, the tool is moved from the air inlet side to the air outlet side of the impeller to machine the long fillets of the pressure surface and suction surface of the main blade to divert the short fillets of the pressure surface and suction surface of the blade; on the basis of the tool tip machining trajectory of the first reference disk surface 3, the non-axisymmetric disk surface 5 is added as an additional curved surface, and the tool is moved from the air inlet side to the air outlet side of the impeller to machine the non-axisymmetric disk surface 5. The present application solves the processing difficulties of the disk surface and fillets of the non-axisymmetric disk surface impeller, realizes the machining and manufacturing of the non-axisymmetric disk surface impeller, and paves the way for the application of the non-axisymmetric disk surface impeller. Compared with other impeller machining methods that cannot complete the machining and manufacturing of non-axisymmetric disk surface impellers, the present application realizes it from scratch.

[0080] The method of the present application also has the advantages of reducing processing difficulty, improving processing accuracy and processing efficiency.

[0081] In an embodiment of the present application, the first offset surface of the non-axisymmetric disc surface intersects with the offset surface of the main blade pressure surface to obtain an intersection line L1; the second offset surface of the non-axisymmetric disc surface intersects with the offset surface of the main blade pressure surface to obtain an intersection line L2; according to the streamline from L1 to L2, the tool path is performed from the air inlet side to the air outlet side of the impeller to obtain the tool center trajectory of the long fillet of the main blade pressure surface; during the tool path processing, the main blade pressure surface 4 is selected as the processing surface, and the non-axisymmetric disc surface 5 and the splitter blade suction surface 6 are selected as the stop surface. The steps include:

[0082] Step S11, selecting the first offset surface of the non-axisymmetric disk surface, shifting the non-axisymmetric disk surface 5 along the normal phase toward the side where the impeller blades are, the offset distance is M, and obtaining the first offset surface 10 of the non-axisymmetric disk surface;

[0083] The offset distance M is the sum of the finishing tool radius R, the normal distance h from the convex part of the non-axisymmetric wheel surface 5 to the initial wheel surface 9, and the normal distance H from the concave part of the non-axisymmetric wheel surface 5 to the initial wheel surface 9;

[0084] Step S12, selecting the second offset surface of the non-axisymmetric disk surface, shifting the non-axisymmetric disk surface 5 along the normal phase toward the side where the impeller blades are, the offset distance is R1, and obtaining the second offset surface of the non-axisymmetric disk surface;

[0085] Among them, the offset distance R1 is the finishing tool radius R.

[0086] Step S13, selecting the offset surface of the main blade pressure surface, shifting the main blade pressure surface 4 along the normal phase toward the splitter blade 2, the offset distance is R2, and obtaining the offset surface of the main blade pressure surface;

[0087] Among them, the offset distance R2 is the finishing tool radius R.

[0088] The first offset surface of the non-axisymmetric disk surface intersects with the offset surface of the main blade suction surface to obtain an intersection line L3; the second offset surface of the non-axisymmetric disk surface intersects with the offset surface of the main blade suction surface to obtain an intersection line L4; according to the streamline from L3 to L4, a tool path is performed from the air inlet side of the impeller to the air outlet side to obtain a tool center trajectory for machining the long fillet of the main blade suction surface; during the tool path processing, the main blade suction surface 8 is selected as the processing surface, and the non-axisymmetric disk surface 5 and the splitter blade pressure surface 7 are selected as the stop surface, including:

[0089] Step S21, selecting the offset surface of the main blade suction surface, shifting the main blade suction surface 8 along the normal phase toward the splitter blade 2, the offset distance is R3, and obtaining the offset surface of the main blade suction surface;

[0090] Among them, the offset distance R3 is the finishing tool radius R.

[0091] The first offset surface of the non-axisymmetric wheel disc surface intersects with the offset surface of the splitter blade pressure surface to obtain an intersection line L5; the second offset surface of the non-axisymmetric wheel disc surface intersects with the offset surface of the splitter blade pressure surface to obtain an intersection line L6; according to the streamline from L5 to L6, a tool path is performed from the air inlet side to the air outlet side of the impeller to obtain a tool center trajectory for machining the short fillet of the splitter blade pressure surface; during the tool path processing, the splitter blade pressure surface 7 is selected as the processing surface, and the non-axisymmetric wheel disc surface 5 and the adjacent main blade suction surface 8 are selected as the stop surface, including:

[0092] Step S31, selecting the offset surface of the splitter blade pressure surface, offsetting the splitter blade pressure surface 7 along the normal phase toward the main blade 1, the offset distance is R4, and obtaining the splitter blade pressure surface offset surface; wherein the offset distance R4 is the finishing tool radius R.

[0093] The first offset surface of the non-axisymmetric disk surface intersects with the offset surface of the suction surface of the splitter blade to obtain an intersection line L7; the second offset surface of the non-axisymmetric disk surface intersects with the offset surface of the suction surface of the splitter blade to obtain an intersection line L8; according to the streamline from L7 to L8, the tool path is performed from the air inlet side to the air outlet side of the impeller to obtain a tool center trajectory for machining the short fillet of the suction surface of the splitter blade; wherein, during the tool path processing, the suction surface 6 of the splitter blade is selected as the processing surface, and the non-axisymmetric disk surface 5 and the adjacent main blade pressure surface 4 are selected as the stop surface, including:

[0094] Step S41, selecting the offset surface of the splitter blade pressure surface, offsetting the splitter blade suction surface 6 along the normal phase toward the main blade 1, the offset distance is R5, and obtaining the splitter blade pressure-suction surface offset surface; wherein the offset distance R5 is the finishing tool radius R.

[0095] The steps of obtaining a tool tip machining trajectory of the first reference disc surface 3, adding a non-axisymmetric disc surface 5 as an additional curved surface based on the tool tip machining trajectory of the first reference disc surface 3, and performing tool movement from the air inlet side to the air outlet side of the impeller to obtain the tool tip machining trajectory of the non-axisymmetric disc surface include:

[0096] Step S51, selecting the initial wheel disc surface, taking the extension line of the main blade neutral surface blade root line as the wheel disc line, rotating the wheel disc line to generate the initial wheel disc surface 9;

[0097] Step S52, selecting the first reference wheel disc surface 3, shifting the initial wheel disc surface 9 along the normal phase toward the side of the impeller without blades, the shifting distance being the normal phase distance H from the concave part of the non-axisymmetric wheel disc surface 5 to the initial wheel disc surface 9, and obtaining the first reference wheel disc surface 3.

[0098] A more specific processing method is provided in the embodiment of the present application, which includes, before the step of finely processing the long fillet of the main blade and the short fillet of the splitter blade:

[0099] Obtain a three-dimensional model of the impeller;

[0100] The pre-designed impeller 3D model is imported into the CAM-assisted processing software hyperCAD-S through the data interface.

[0101] Select the non-axisymmetric disc surface finishing tool and the fillet finishing tool;

[0102] The non-axisymmetric disk surface finishing tool and fillet finishing tool are selected according to the blade fillet marked in the impeller design drawing and should be consistent with the blade fillet size.

[0103] The curvature analysis of the non-axisymmetric disk surface in the impeller 3D model was performed to obtain the minimum radius value of the concave area.

[0104] When the minimum radius value of the concave area is smaller than the blade fillet marked in the impeller design drawing, the finishing tool is selected based on the minimum radius value of the concave area;

[0105] When the minimum radius value of the recessed area is greater than the blade fillet marked in the impeller design drawing, the finishing tool is selected based on the blade fillet marked in the impeller design drawing.

[0106] Among them, the wheel surface finishing tool and the fillet finishing tool are both ball-end cutters.

[0107] Among them, when finishing the long fillet of the pressure surface of the main blade, finishing the long fillet of the suction surface of the main blade, finishing the long fillet of the pressure surface of the splitter blade and finishing the long fillet of the suction surface of the splitter blade, the tool center spacing of each cut is one tenth of the radius R of the finishing tool.

[0108] Constructing the machining model of the impeller

[0109] Select the impeller processing model of the main blade 1, the splitter blade 2 and the first reference wheel disc surface 3 components in the impeller three-dimensional model;

[0110] The initial wheel disc surface 9 is offset along the normal phase to the side of the impeller without blades, and the offset distance is the normal phase distance H from the concave part of the non-axisymmetric wheel disc surface 5 to the initial wheel disc surface 9, so as to obtain the first reference wheel disc surface 3;

[0111] By using a processing model of the impeller and selecting a ball-end tool, the tool center processing trajectory of the main blade 1 and the splitter blade 2, as well as the tool tip processing trajectory of the first reference disc surface, can be generated through the CAM-assisted processing software hyperCAD-S.

[0112] Rough machining of main blade 1 and splitter blade 2;

[0113] The main blades 1 and the splitter blades 2 may be roughly machined by fixed-axis high-speed milling, or in other embodiments by cycloidal rough machining and strip milling.

[0114] Finishing the main blade 1 and the splitter blade 2;

[0115] The initial wheel disc surface 9 is offset along the normal phase toward the impeller blade side, and the offset distance is the normal phase distance h from the convex part of the non-axisymmetric wheel disc surface 5 to the initial wheel disc surface 9, to obtain a second reference wheel disc surface 11;

[0116] The CAM-assisted processing software hyperCAD-S can generate the tool center processing trajectory of the main blade 1 and the splitter blade 2; during processing, the tool is moved from the air inlet side to the air outlet side of the impeller, and the processing depth is from the wheel cover surface to the second reference wheel disc surface 11.

[0117] The second aspect of the present application provides an impeller, which is manufactured by using any of the above-mentioned methods for machining a non-axisymmetric wheel disc surface and fillet. The impeller manufactured by the method of the present application has the advantage of higher precision.

[0118] It is easy for those skilled in the art to understand that, under the premise of no conflict, the above-mentioned advantageous methods can be freely combined and superimposed.

[0119] The above are only preferred embodiments of the present application and are not intended to limit the present application. Any modifications, equivalent replacements and improvements made within the spirit and principles of the present application shall be included in the protection scope of the present application. The above are only preferred implementations of the present application. It should be pointed out that for ordinary technicians in this technical field, several improvements and variations can be made without departing from the technical principles of the present application, and these improvements and variations should also be regarded as the protection scope of the present application.

Claims

1. A method for processing a non-axisymmetric wheel disc surface and fillet, characterized in that: include: Finishing the main blade pressure surface fillet The first offset surface of the non-axisymmetric disk surface intersects with the offset surface of the main blade pressure surface to obtain an intersection line L1; the second offset surface of the non-axisymmetric disk surface intersects with the offset surface of the main blade pressure surface to obtain an intersection line L2; the tool is moved from the air inlet side to the air outlet side of the impeller according to the streamline from L1 to L2 to obtain the tool center trajectory for machining the long fillet of the main blade pressure surface; During the tool-feeding process, the main blade pressure surface (4) is selected as the processing surface, and the non-axisymmetric wheel disc surface (5) and the splitter blade suction surface (6) are selected as the stop surfaces; Fine machining of the main blade suction surface fillet The first offset surface of the non-axisymmetric disk surface intersects with the offset surface of the main blade suction surface to obtain an intersection line L3; the second offset surface of the non-axisymmetric disk surface intersects with the offset surface of the main blade suction surface to obtain an intersection line L4; the tool is moved from the air inlet side to the air outlet side of the impeller according to the streamline from L3 to L4 to obtain the tool center trajectory for machining the long fillet of the main blade suction surface; During the cutting process, the suction surface (8) of the main blade is selected as the processing surface, and the non-axisymmetric wheel disc surface (5) and the pressure surface (7) of the splitter blade are selected as the stop surface. Finishing the short fillet of the pressure surface of the splitter blade The first offset surface of the non-axisymmetric wheel surface intersects with the offset surface of the splitter blade pressure surface to obtain an intersection line L5; the second offset surface of the non-axisymmetric wheel surface intersects with the offset surface of the splitter blade pressure surface to obtain an intersection line L6; the tool is moved from the air inlet side to the air outlet side of the impeller according to the streamline from L5 to L6 to obtain the tool center trajectory for machining the short fillet of the splitter blade pressure surface; During the cutting process, the pressure surface (7) of the splitter blade is selected as the processing surface, and the non-axisymmetric wheel disc surface (5) and the adjacent main blade suction surface (8) are selected as the stop surface; Fine machining of short fillet on the suction surface of the splitter blade The first offset surface of the non-axisymmetric wheel surface intersects with the offset surface of the suction surface of the splitter blade to obtain an intersection line L7; the second offset surface of the non-axisymmetric wheel surface intersects with the offset surface of the suction surface of the splitter blade to obtain an intersection line L8; according to the streamline from L7 to L8, the tool is moved from the air inlet side to the air outlet side of the impeller to obtain the tool center trajectory for machining the short fillet of the suction surface of the splitter blade; During the cutting process, the suction surface (6) of the splitter blade is selected as the processing surface, and the non-axisymmetric wheel disc surface (5) and the adjacent main blade pressure surface (4) are selected as the stop surface; Finishing of non-axisymmetric wheel disc surfaces (5) A tool tip machining trajectory of a first reference wheel disc surface (3) is obtained, and based on the tool tip machining trajectory of the first reference wheel disc surface (3), a non-axisymmetric wheel disc surface (5) is added as an additional curved surface, and tool movement machining is performed from the air inlet side to the air outlet side of the impeller to obtain a tool tip machining trajectory of the non-axisymmetric wheel disc surface.

2. A method for processing a non-axisymmetric wheel disc surface and fillet according to claim 1, characterized in that: The first reference wheel disc surface is selected by taking the extension line of the blade root line of the neutral surface of the main blade as the wheel disc line, rotating the wheel disc line to generate an initial wheel disc surface (9); the initial wheel disc surface (9) is offset along the normal phase to the side of the impeller without blades, and the offset distance is the normal phase distance H from the concave part of the non-axisymmetric wheel disc surface (5) to the initial wheel disc surface (9), thereby obtaining the first reference wheel disc surface (3).

3. A method for processing a non-axisymmetric wheel disc surface and fillet according to claim 1, characterized in that: The first offset surface of the non-axisymmetric wheel disc surface is selected by shifting the non-axisymmetric wheel disc surface (5) along the normal phase toward the side of the impeller blades, and the offset distance is M, thereby obtaining the first offset surface (10) of the non-axisymmetric wheel disc surface; The offset distance M is the sum of the finishing tool radius R, the normal distance h from the convex part of the non-axisymmetric wheel surface (5) to the initial wheel surface (9), and the normal distance H from the concave part of the non-axisymmetric wheel surface (5) to the initial wheel surface (9); The second offset surface of the non-axisymmetric wheel disc surface is selected by shifting the non-axisymmetric wheel disc surface (5) along the normal phase toward the side where the impeller blades are located, and the offset distance is R1, thereby obtaining the second offset surface of the non-axisymmetric wheel disc surface; Among them, the offset distance R1 is the finishing tool radius R.

4. A method for processing a non-axisymmetric wheel disc surface and fillet according to claim 1, characterized in that: The main blade pressure surface offset surface is selected by offsetting the main blade pressure surface (4) along the normal phase toward the splitter blade (2) by a distance of R2, thereby obtaining the main blade pressure surface offset surface; The main blade suction surface offset surface is selected by offsetting the main blade suction surface (8) along the normal phase toward the splitter blade (2) by a distance of R3, thereby obtaining the main blade suction surface offset surface; Among them, the offset distance R2 and the offset distance R3 are both the finishing tool radius R.

5. The method for processing a non-axisymmetric wheel disc surface and fillet according to claim 1, characterized in that: The splitter blade pressure surface offset surface is selected by shifting the splitter blade pressure surface (7) along the normal phase toward the main blade (1) with a shift distance of R4 to obtain the splitter blade pressure surface offset surface; The splitter blade pressure surface offset surface is selected, and the splitter blade suction surface (6) is offset along the normal phase toward the main blade (1), and the offset distance is R5, so as to obtain the splitter blade pressure-suction surface offset surface; Among them, the offset distance R4 and the offset distance R5 are both the finishing tool radius R.

6. A method for processing a non-axisymmetric wheel disc surface and fillet according to claim 1, characterized in that: Before finishing the long fillet of the pressure surface of the main blade, the long fillet of the suction surface, and the short fillet of the pressure surface of the splitter blade and the short fillet of the suction surface, it also includes: Obtain a three-dimensional model of the impeller; Select the non-axisymmetric disc surface finishing tool and the fillet finishing tool; Constructing the machining model of the impeller Selecting the impeller processing model of the main blades (1), the splitter blades (2) and the first reference wheel disc surface (3) components in the impeller three-dimensional model; Rough machining of the main blade (1) and the splitter blade (2); The main blades (1) and the splitter blades (2) are finely machined.

7. A method for processing a non-axisymmetric wheel disc surface and fillet according to claim 6, characterized in that: The steps of selecting the non-axisymmetric disc surface finishing tool and the fillet finishing tool include: The non-axisymmetric disk surface finishing tool and fillet finishing tool are selected according to the blade fillet marked in the impeller design drawing and should be consistent with the blade fillet size.

8. A method for processing a non-axisymmetric wheel disc surface and fillet according to claim 7, characterized in that: The non-axisymmetric disk surface finishing tool and fillet finishing tool are selected according to the blade fillet marked in the impeller design drawing, and should be consistent with the blade fillet size. Steps include: Perform curvature analysis on the non-axisymmetric disk surface in the impeller 3D model to obtain the minimum radius value of the concave area. When the minimum radius value of the concave area is smaller than the blade fillet marked in the impeller design drawing, select the finishing tool based on the minimum radius value of the concave area. When the minimum radius value of the recessed area is greater than the blade fillet marked in the impeller design drawing, the finishing tool is selected based on the blade fillet marked in the impeller design drawing.

9. A method for processing a non-axisymmetric wheel disc surface and fillet according to claim 6, characterized in that: The step of fine-machining the main blade (1) and the splitter blade (2) comprises: The initial wheel disc surface (9) is offset along the normal phase toward the side of the impeller having blades, and the offset distance is the normal phase distance h from the convex part of the non-axisymmetric wheel disc surface (5) to the initial wheel disc surface (9), thereby obtaining a second reference wheel disc surface (11); The processing depth of the fine-machining main blade (1) and the splitter blade (2) is from the wheel cover surface to the second reference wheel disc surface (11).

10. An impeller, characterized in that: The impeller is manufactured by using the processing method of the non-axisymmetric wheel disc surface and fillet according to any one of claims 1 to 9.

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