Combined Milling Method for a Centrifugal Impeller with Split Blades

Abstract

The present invention discloses a combined milling method for a centrifugal impeller with split blades, comprising: S1. First, perform a rough machining on all the second grooves, and then perform a finishing machining on the rough machining areas on both sides of the second grooves; S2. Determine the number of layers for rough machining the first grooves, and successively machine each layer of blades; wherein, the steps for machining each layer of blades include: S21. First, perform a secondary rough machining on all the first grooves, and then perform a secondary finishing machining on the secondary rough machining areas on both sides of the first grooves; S22. First, perform a semi-finishing machining on the main blades and split blades adjacent to all the first grooves, and then perform a finishing machining on the main blades and split blades adjacent to the first grooves. The present invention machines the first grooves in multiple layers, and when machining each layer of blades, machines each layer of blades in the order of rough machining, semi-finishing machining, and finishing machining, which can effectively ensure the machining rigidity of each layer of blades, thereby effectively reducing the overall deformation amount of the blades and improving the machining quality of the blade surfaces.

Description

Technical Field

[0001] The present invention relates to the technical field of centrifugal impeller milling, and particularly relates to a combined milling method for a centrifugal impeller with splitter blades. Background Art

[0002] The blade structure design of medium and large centrifugal impellers has the characteristics of thin blades and long overhangs. Therefore, in the structural design, the machining rigidity of the blades is insufficient, and vibration is likely to occur during the machining process. In addition, due to the large machining area of the blades, the material removal rate during the finish milling of the blades increases, resulting in increased tool wear, and further causing an increase in cutting force. The insufficient machining rigidity and tool wear will cause the deformation of the blades during the machining process, and thus the technical indicators related to the blades cannot be guaranteed. How to solve the deformation problems caused by insufficient machining rigidity and tool wear has increased the work difficulty for machining process designers.

[0003] For the machining of existing centrifugal impellers, the technical route is roughly as follows: rough machine all slots - finish mill the blades (hybrid milling: one tool completes semi-finishing and finishing in one-time layering). This machining method requires the rough machining to leave enough allowance (not less than 1 mm) for the finish machining. During the finish machining, in order to ensure the machining rigidity, it is necessary to use hybrid milling to complete the semi-finishing and finishing of the blades. Machining with one tool will cause greater tool wear, and the allowance left by the rough machining for the finish machining is not enough to ensure the machining rigidity. Therefore, the existing machining method for centrifugal impellers is not sufficient to eliminate the blade deformation that occurs during the finish machining of the blades.

[0004] In summary, the existing milling methods for centrifugal impellers have the following defects:

[0005] 1. Increased tool cost: Machining in layers with one tool will cause an increase in the total cutting area. Therefore, higher wear resistance is required for the tool, increasing the tool cost;

[0006] 2. Increased machining time cost: In order to increase the rigidity of the finish machining of the blades, a lot of allowance is left by the rough machining for the finish machining. These allowances cannot be directly machined with only one layer of tool path (one layer of tool path in the cutting width direction), and it is necessary to use the hybrid milling method (that is, on the premise of using one tool, the semi-finish milling and finish milling tool paths are alternately carried out in the cutting depth direction), which involves a large number of semi-finishing and finish machining tool paths of the blades, resulting in an increase in time cost;

[0007] 3. Unable to effectively avoid deformation: Since the hybrid milling method cannot remove large allowances, it is impossible to leave enough allowance for the finish machining during the rough machining process. Therefore, the rigidity during the finish machining of the blades is insufficient, and deformation occurs during the machining process;

[0008] 4. Unstable surface quality: When using the hybrid milling method for machining, in order to ensure the tool life of the finishing tool, the rough machining cannot leave more allowance for the finishing, resulting in the overall thinness of the blade, insufficient rigidity, and the occurrence of chatter marks easily at the part of the blade surface near the tip. Moreover, the size of the chatter marks varies due to the difference in blade rigidity. Therefore, generally, the surface quality after finishing of the first few machined blades cannot be stably controlled. Summary of the Invention

[0009] The technical problem to be solved by the present invention is to provide a combined milling method for a centrifugal impeller with splitter blades, which has low cost and can ensure machining quality.

[0010] To solve the above problems, the present invention provides a combined milling method for a centrifugal impeller with splitter blades, which is used to machine a centrifugal impeller with splitter blades. The centrifugal impeller includes a plurality of main blades, and a splitter blade is arranged between two adjacent main blades. A first groove is formed between the splitter blade and one side of the main blade, and a second groove is formed with the main blade on the other side. The method includes the following steps:

[0011] S1. First, perform a first rough machining on all the second grooves, and then perform a first finishing machining on the first rough machining areas on both sides of the second grooves;

[0012] S2. Determine the number of layers for rough machining the first grooves according to the maximum blade height of the main blades, the maximum blade height of the splitter blades, and the tool edge length, and sequentially machine each layer of blades; wherein, the steps for machining each layer of blades include:

[0013] S21. First, perform a second rough machining on all the first grooves, and then perform a second finishing machining on the second rough machining areas on both sides of the first grooves;

[0014] S22. First, perform semi-finishing machining on the main blades and splitter blades adjacent to all the first grooves, and then perform finishing machining on the main blades and splitter blades adjacent to the first grooves;

[0015] S3. First, perform semi-finishing machining on the flow channels in all the first grooves and the second grooves, and then perform finishing machining on the flow channels in the first grooves and the second grooves;

[0016] S4. Perform finishing machining on the transition fillets at the roots of all the main blades and splitter blades.

[0017] As a further improvement of the present invention, step S1 includes:

[0018] S11. Determine the number of layers for performing the first rough machining on the second grooves according to the maximum blade height of the main blades and the tool edge length;

[0019] S12. Perform the first rough machining on each layer according to the determined number of layers, and perform the first finishing machining on the first rough machining areas on both sides of the second grooves.

[0020] As a further improvement of the present invention, in steps S1, S2 and S3, a ball-end milling cutter is selected to perform circular machining along the circumference of the centrifugal impeller in a cycloidal milling manner.

[0021] As a further improvement of the present invention, the number of layers divided in the secondary rough machining is greater than that in the primary rough machining.

[0022] As a further improvement of the present invention, after the primary rough machining, the allowance of the main blades and the splitter blades on both sides of the second groove is greater than 0.5 mm; after the rough machining of the secondary finishing treatment, the allowance of the main blades and the splitter blades on both sides of the first groove is greater than 0.5 mm.

[0023] As a further improvement of the present invention, after the primary finishing treatment, the allowance of the main blades and the splitter blades on both sides of the second groove is 0.5 mm; after the secondary finishing treatment, the allowance of the main blades and the splitter blades on both sides of the first groove is 0.5 mm.

[0024] As a further improvement of the present invention, after semi-finishing all the main blades and the splitter blades adjacent to the first groove, the allowance of the main blades and the splitter blades is 0.2 mm; after semi-finishing the flow channels in both the first groove and the second groove, the allowance of the flow channels in the first groove and the second groove is 0.2 mm.

[0025] The present invention also provides an electronic device, including a memory, a processor, and a computer program stored on the memory and executable on the processor. When the processor executes the program, the steps of the method described in any one of the above are implemented.

[0026] The present invention also provides a computer-readable storage medium, on which a computer program is stored. It is characterized in that when the program is executed by a processor, the steps of the method described in any one of the above are implemented.

[0027] The present invention also provides a centrifugal impeller with splitter blades for a silicon-based optical micro-ring filter, which is designed by using the combined milling method of the centrifugal impeller with splitter blades described in any one of the above.

[0028] Advantages of the present invention:

[0029] By first machining the second groove, then machining the first groove, and dividing the first groove into multiple layers for machining, and when machining each layer of blades, machining each layer of blades in the order of rough machining, semi-finishing and finishing, the machining rigidity of each layer of blades can be effectively guaranteed, thereby effectively reducing the overall deformation amount of the blades and improving the machining quality of the blade surface.

[0030] The above description is only an overview of the technical solution of the present invention. In order to better understand the technical means of the present invention, it can be implemented according to the content of the specification. In order to make the above and other objects, features, and advantages of the present invention more obvious and understandable, the following preferred embodiments are specifically given and described in detail in conjunction with the accompanying drawings as follows. Description of the Drawings

[0031] Figure 1 is the schematic diagram of layer-by-layer in the combined milling of the present invention;

[0032] Figure 2 is the model diagram of the centrifugal impeller with flow splitting vanes of the present invention;

[0033] Figure 3 is the schematic diagram of layer-by-layer in the rough machining and combined milling of the present invention;

[0034] Figure 4 is the first three-coordinate inspection report of the centrifugal impeller processed by the combined milling method of the centrifugal impeller with flow splitting vanes of the present invention;

[0035] Figure 5 is the second three-coordinate inspection report of the centrifugal impeller processed by the combined milling method of the centrifugal impeller with flow splitting vanes of the present invention. Detailed Embodiments

[0036] The present invention 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 invention and be able to implement it, but the specific embodiments given are not intended to limit the present invention.

[0037] Embodiment 1

[0038] The preferred embodiment of the present invention discloses a combined milling method for a centrifugal impeller with flow splitting vanes, which is used to machine a centrifugal impeller with flow splitting vanes. The centrifugal impeller includes a plurality of main vanes, and a flow splitting vane is arranged between two adjacent main vanes. A groove one is formed between the flow splitting vane and one side of the main vane, and a groove two is formed with the main vane on the other side. Refer to Figure 1 .

[0039] A combined milling method for a centrifugal impeller with flow splitting vanes in this embodiment includes the following steps:

[0040] S1. First, perform a rough machining on all the groove twos, and then perform a finishing machining on the rough machining areas on both sides of the groove twos;

[0041] S2. Determine the number of layers for rough machining the groove one according to the maximum blade height of the main vane, the maximum blade height of the flow splitting vane, and the tool edge length, and process each layer of blades in sequence; among them, the steps for processing each layer of blades include:

[0042] S21. First, perform secondary rough machining on all groove ones, and then perform secondary finish machining on the secondary rough machining areas on both sides of the groove one.

[0043] S22. First, perform semi-finish machining on the main blades and splitter blades adjacent to all groove ones, and then perform finish machining on the main blades and splitter blades adjacent to the groove one.

[0044] S3. First, perform semi-finish machining on the flow channels in all groove ones and groove twos, and then perform finish machining on the flow channels in the groove one and groove two.

[0045] S4. Perform finish machining on the transition fillets at the roots of all main blades and splitter blades.

[0046] The combined milling in the present invention is explained as follows: The blades are segmented for finish machining by combining three methods of rough machining + semi-finish machining + finish machining, that is, at a parameter depth, the blades are first rough machined, then semi-finish machined, and finally finish machined. After the machining in this depth direction is completed, the machining of the next depth is carried out in this cyclic manner. Through the combined milling method, the machining rigidity of each layer of blades can be effectively guaranteed, thereby effectively reducing the overall deformation amount of the blades and improving the machining quality of the blade surface.

[0047] Specifically, step S1 includes:

[0048] S11. Determine the number of layers for the first rough machining of the groove two according to the maximum blade height of the main blade and the tool edge length.

[0049] S12. Perform the first rough machining on each layer according to the determined number of layers, and perform the first finish machining on the first rough machining areas on both sides of the groove two.

[0050] Optionally, in steps S1, S2, and S3, a ball-end mill is selected to perform a full-circle cyclic machining along the circumferential direction of the centrifugal impeller in a trochoidal milling manner.

[0051] Optionally, the number of layers for the secondary rough machining is greater than the number of layers for the first rough machining. Because for some parts with relatively thin blades, the layering of groove one and groove two is different. It is due to the need to quickly rough machine the groove two to improve the machining efficiency, and the machining parameters can be set more aggressively. Parameters such as the trochoidal milling depth of cut can be set larger (that is, the number of trochoidal milling layers is set less), which can shorten the machining time. The rough machining of the groove one is because when performing combined milling, if the trochoidal milling depth of cut is too large (that is, the number of trochoidal milling layers is too small), it will cause insufficient rigidity of the blades in this layer during the finish machining of the blades, thus causing problems such as chatter, affecting the finish machining quality of the blades. Therefore, the number of trochoidal milling layers of the groove one will be set more. In the present invention, that is, the number of layers for the secondary rough machining is greater than the number of layers for the first rough machining.

[0052] Optionally, after the first rough machining, the allowance of the main blades and splitter blades on both sides of the second groove is greater than 0.5 mm; after the rough machining of the second finish machining, the allowance of the main blades and splitter blades on both sides of the first groove is greater than 0.5 mm. After the first finish machining, the allowance of the main blades and splitter blades on both sides of the second groove is 0.5 mm; after the second finish machining, the allowance of the main blades and splitter blades on both sides of the first groove is 0.5 mm. After semi-finishing all the main blades and splitter blades adjacent to the first groove, the allowance of the main blades and splitter blades is 0.2 mm; after semi-finishing the flow channels in both the first groove and the second groove, the allowance of the flow channels in the first groove and the second groove is 0.2 mm. Ensure that the allowances of the main blades, splitter blades, the first groove and the second groove reach the state before finish machining. Since side cutting edges are used, the tool life can be extended while removing materials quickly and effectively. Generally, the allowance left for the blades and flow channels in cycloidal milling can be set to 0.5 mm.

[0053] As Figure 2 shown, the combined milling method for the centrifugal impeller with splitter blades is used to machine this centrifugal impeller. The material of the centrifugal impeller is stainless steel. The maximum diameter of the flow channel part is 535 mm, the minimum diameter is 140 mm, the maximum diameter of the tip covering surface is 535 mm, and the minimum diameter is 328 mm. The maximum blade height of the main blade is 94 mm, and the thinnest thickness at the leading edge near the tip is 0.6 mm. The maximum blade height of the splitter blade is 82 mm, and the thinnest thickness at the leading edge near the tip is 0.6 mm. The minimum distance between the main blades is 26 mm, and the minimum distance between the main blade and the splitter blade is 14.6 mm. The transition fillet between the blade and the flow channel is 3 mm.

[0054] The processing method specifically includes the following steps:

[0055] (1) Plan the processing route

[0056] Since the centrifugal impeller has a relatively large blade height, about 95 mm at the maximum. According to the actual test machining results, after machining, the maximum downward deformation of the blade near the tip is about 0.5 mm, and the chatter marks on the surface of the blade after finish machining are serious and cannot be completely removed even by polishing, which does not meet the design requirements at all. Therefore, the traditional processing method of rough milling followed by finish milling is no longer applicable to the machining of this impeller.

[0057] After analysis, the deformation and unqualified surface roughness of the blade are caused by insufficient rigidity of the blade during the machining process. To increase the rigidity of the blade during the machining process, the combined milling method can effectively improve the rigidity of the blade during the machining process. Therefore, the milling processing route of this impeller is divided into two stages. The first stage is rough milling and grooving, and the second stage is combined milling of the blades, finish milling of the flow channels and transition fillets.

[0058] (2) Determine the allowance after each stage of machining of the centrifugal impeller

[0059] Rough milling and grooving: Since the combined milling method is adopted and the workpiece rigidity is consistent and stable during the finish machining process, there is no need to leave a large margin in the first step of rough milling and grooving. Therefore, the margin left by rough milling and grooving is set to 0.5 mm. After rough milling, the margin left by finish machining is 0.5 mm.

[0060] Combined milling of blades: The margin left by trochoidal milling for rough grooving is 0.5 mm, the margin left by finish machining of blades is 0.5 mm, the margin left by semi-finish milling is 0.2 mm, and finally the 0.2 mm margin is milled to the required precision.

[0061] (3) Selection of machining tools: Since the minimum distance between the main blade and the splitter blade is 14.6 mm, to ensure that the tool has enough swing space during machining, the tool specifications for rough and finish machining are set as the tapered ball nose mill D8*R4*3° *30*D12*100L*4F. Since the transition fillet is R3 mm, the tool for machining the transition fillet is set as D6*R3*4°*10*D10*90L*4F.

[0062] (4) Selection of cutting parameters:

[0063] Trochoidal milling: Vc = 55 - 60 m / min, fz = 0.18 - 0.2 mm, cutting width 0.15 - 0.25 mm, cutting depth 15 - 23 mm;

[0064] Finish machining of blades, semi-finish machining of blades: Vc = 65 - 75 m / min, fz = 0.12 mm;

[0065] Finish machining of blades: Vc = 80 - 100 m / min, fz = 0.05 - 0.08 mm.

[0066] (5) Machining settings for rough milling and grooving:

[0067] a. Rough grooving by trochoidal milling

[0068] There is a splitter blade between each group of main blades, dividing the flow channel into two parts, which we call groove 1 and groove 2. During rough milling and grooving, only the rough machining of groove 2 is carried out. The maximum blade height of the main blade is about 94 mm, and the maximum blade height of the splitter blade is about 82 mm. When using the tapered ball nose mill D8*R4*3°*30*D12*100L*4F for trochoidal milling, since the maximum cutting depth does not exceed the maximum edge length of the tool, which is 30 mm, groove 2 shown in the figure is divided into 4 layers in the depth direction for machining, and the maximum machining depth of each layer is about 23.5 mm. Other cutting parameters are Vc = 60 m / min, fz = 0.2 mm, cutting width 0.25 mm. For each layer, first perform trochoidal milling roughing, and complete the machining by circulating circumferentially for 11 times. After machining, the blade surface margin of the grooved part is not less than 0.5 mm.

[0069] b. Blade finishing

[0070] For the blade basins and backs of the slotted main blades and splitter blades, blade finishing is carried out. The single-side milling method in blade finish machining is adopted. By setting the machining area parameters, the surface allowance of the rough-machined parts of the main blades and splitter blades is evenly machined. The taper ball-end mill with the specification of D8*R4*3°*30*D12*100L*4F is also selected for the tool. The milling parameters are Vc = 75m / min, fz = 0.12mm, the residual height is set to 0.01mm, and a 0.5mm allowance is left on the blade surface. Continue to machine circularly along the circumferential direction for 11 times, and so on, until the end of the 4th layer at the bottom of groove 2. After machining, a total of 11 places are evenly machined along the circumferential direction at the position of groove 2 shown in the figure. At this time, the blade allowance at the slotted part is uniformly 0.5mm.

[0071] (6) Combined milling machining settings:

[0072] First, set the machining parameters for each sub-strategy under the combined milling strategy:

[0073] a. Cycloidal milling roughing

[0074] For the cycloidal milling roughing of groove 1, the taper ball-end mill with the specification of D8*R4*3°*30*D12*100L*4F is selected for the tool. It is machined in 6 layers from the blade tip to the flow channel, and the maximum cutting depth of each layer is 16mm. The settings of the remaining parameters are the same as those of the cycloidal milling slotting settings for groove 2. After roughing, the surface allowance is uneven, but not less than 0.5mm.

[0075] b. Blade finishing

[0076] The parameter settings for the finishing of groove 1 are the same as those of groove 2, except that the machining area needs to be set as the machined surfaces of the main blade and splitter blade corresponding to groove 1.

[0077] c. Blade semi-finishing

[0078] The parameter settings for the blade semi-finishing of groove 1 are the same as those for the blade finishing, except that the entire main blade and splitter blade need to be set as the machining area, and the machining method is double-sided. The surface residual height for blade semi-finishing is set to 0.02mm, and the machining allowance is set to 0.2mm.

[0079] d. Blade finishing

[0080] The machining method is the same as that for blade semi-finishing. The machining parameters are set as Vc = 100m / min, fz = 0.08mm, the surface residual height is set to 0.002mm, and the blade machining allowance is 0.

[0081] Combined step-by-step settings

[0082] Open the rough and finish combined milling settings dialog box, and set the step layers of trochoidal milling according to the number of layers when roughing the groove 1 in combined milling. Note that the number of divided layers is the same as the total number of layers when roughing the groove with trochoidal milling (the number of trochoidal milling layers for groove 1 is 6 layers, and the number of divided layers set here is 6 layers). Thus, the operation configuration of the combined milling of the centrifugal impeller is completed.

[0083] (7) First, semi-finish machine the flow channels in all groove 1 and groove 2, and then finish machine the flow channels in groove 1 and groove 2.

[0084] (8) Finish machine the transition fillets at the roots of all main blades and splitter blades.

[0085] Inspection Report

[0086] After being verified by machining test pieces, the coordinate measuring machine inspection reports are shown in the appendix Figure 4 and 5 , Figure 4 and Figure 5 are the coordinate measuring machine inspection reports of the blade profile contour degrees of different inspection sections of the centrifugal impeller respectively. From them, the deviation between the theoretical value and the actual value of the blade profile contour degree can be seen. It can be seen that the surface machining quality of the part has been significantly improved compared with the traditional machining method, the machining deformation has been effectively controlled, and the surface contour degree meets the design requirements.

[0087] Embodiment 2

[0088] This embodiment discloses an electronic device, including a memory, a processor, and a computer program stored on the memory and executable on the processor. When the processor executes the program, it implements the steps of the combined milling processing method of the centrifugal impeller with splitter blades described in Embodiment 1 above.

[0089] Embodiment 3

[0090] This embodiment discloses a computer-readable storage medium, on which a computer program is stored. When the program is executed by a processor, it implements the steps of the combined milling processing method of the centrifugal impeller with splitter blades described in Embodiment 1 above.

[0091] Embodiment 4

[0092] This embodiment discloses a combined milling of a centrifugal impeller with splitter blades, which is designed by using the combined milling processing method of the centrifugal impeller with splitter blades described in Embodiment 1 above.

[0093] The above embodiments are only preferred embodiments given to fully illustrate the present invention, and the protection scope of the present invention is not limited thereto. Equivalent substitutions or transformations made by those skilled in the art on the basis of the present invention are all within the protection scope of the present invention. The protection scope of the present invention is subject to the claims.

Claims

1. A combined milling method for a centrifugal impeller with splitter blades, which is used to machine a centrifugal impeller with splitter blades. The centrifugal impeller includes a plurality of main blades, and a splitter blade is arranged between two adjacent main blades. A first groove is formed between the splitter blade and one side of the main blade, and a second groove is formed between the splitter blade and the main blade on the other side. It is characterized in that, It includes the following steps: S1. First, perform a rough machining on all the second grooves, and then perform a finishing machining on the rough machining areas on both sides of the second grooves, including: S11. Determine the number of layers for the rough machining of the second grooves according to the maximum blade height of the main blade and the cutting edge length of the tool; S12. Perform a rough machining on each layer according to the determined number of layers, and perform a finishing machining on the rough machining areas on both sides of the second grooves; S2. Determine the number of layers for the rough machining of the first grooves according to the maximum blade height of the main blade, the maximum blade height of the splitter blade and the cutting edge length of the tool, and process each layer of blades in sequence; wherein, the steps for processing each layer of blades include: S21. First, perform a secondary rough machining on all the first grooves, and then perform a secondary finishing machining on the secondary rough machining areas on both sides of the first grooves; wherein, the number of layers for the secondary rough machining is greater than the number of layers for the primary rough machining; S22. First, perform a semi-finishing machining on the main blades and splitter blades adjacent to all the first grooves, and then perform a finishing machining on the main blades and splitter blades adjacent to the first grooves; S3. First, perform a semi-finishing machining on the flow channels in all the first grooves and the second grooves, and then perform a finishing machining on the flow channels in the first grooves and the second grooves; S4. Perform a finishing machining on the transition fillets at the roots of all the main blades and splitter blades.

2. The combined milling method for a centrifugal impeller with a flow splitting vane according to claim 1, characterized in that In steps S1, S2 and S3, a ball-end milling cutter is selected to perform a circular machining along the circumference of the centrifugal impeller in a cycloidal milling manner.

3. The combined milling method for a centrifugal impeller with flow splitting vanes as claimed in claim 1, characterized in that, After the primary rough machining, the remaining amount of the main blades and splitter blades on both sides of the second grooves is greater than 0.5 mm; after the secondary rough machining for the finishing treatment, the remaining amount of the main blades and splitter blades on both sides of the first grooves is greater than 0.5 mm.

4. The combined milling method for a centrifugal impeller with a splitter blade according to claim 3, characterized in that, After the primary finishing treatment, the remaining amount of the main blades and splitter blades on both sides of the second grooves is 0.5 mm; after the secondary finishing treatment, the remaining amount of the main blades and splitter blades on both sides of the first grooves is 0.5 mm.

5. The combined milling method for a centrifugal impeller with a diverter vane according to claim 4, characterized in that, After the semi-finishing machining of the main blades and splitter blades adjacent to all the first grooves, the remaining amount of the main blades and splitter blades is 0.2 mm; after the semi-finishing machining of the flow channels in all the first grooves and the second grooves, the remaining amount of the flow channels in the first grooves and the second grooves is 0.2 mm.

6. An electronic device, comprising a memory, a processor, and a computer program stored on the memory and executable on the processor, characterized in that, When the processor executes the program, it realizes the steps of the method described in any one of claims 1-5.

7. A computer-readable storage medium having a computer program stored thereon, characterized in that, When the program is executed by the processor, it realizes the steps of the method described in any one of claims 1-5.

8. A centrifugal impeller with a splitter vane, characterized in that, It is obtained by machining using the combined milling method of the centrifugal impeller with splitter blades as described in any one of claims 1-5.

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