Efficient alignment method for repeatedly clamping impeller blades

Abstract

The invention discloses an efficient alignment method for repeatedly clamping an impeller blade, which comprises the following five steps of: compiling and simulating a single-side back arc molded surface quantitative alignment program, rotating an initial angle error, resetting an initial angle, compiling and simulating a light-seeing trial cutting program, and finely adjusting the initial angle to realize the circumferential efficient alignment of the blade. And the repair efficiency and the repair quality are improved.

Description

Technical Field

[0001] The invention relates to the technical field of mechanical processing, and in particular to a high-efficiency alignment method for repeatedly clamping impeller blades. Background Art

[0002] With the rapid development of the impeller machinery industry in recent years, rotating impellers or blade disc parts often need to be repeatedly clamped, milled and repaired during the dynamic balancing process after milling or the maintenance process after the product is used. The impeller or blade disc parts after milling and disassembly are repeatedly clamped on the workbench of the five-axis machining center equipment to align the reference and circumference, and then the repeated milling of the micro-blank on the surface of the blade profile is completed. Repeated milling can solve problems such as dynamic balancing overweight or rough blade surface after use.

[0003] In order to ensure the performance and blade strength of the impeller profile after rework, the impeller blade profile after repeated milling is required to coincide with the original design, and the minimum blade thickness should not be less than the lower limit of the design tolerance. The thickness of the blank that can be cut on the surface of a conventional blade profile is usually small, and this value is basically controlled within 0-0.1mm, that is, the overall thickness of the impeller blade after rework is 0.2mm smaller than the original design at most. The specific value is determined by the initial milling thickness of the part blade and the design requirements.

[0004] In actual processing, the blade surface that needs to be repaired usually has slight stress deformation, surface roughness, local defects and other conditions. Combined with the fact that the surface layer of the blade surface can be used for milling repair with a smaller excess thickness, the difficulty of traditional impeller blade repair is mainly concentrated on the circumferential alignment of the blade surface. Different from the axial characteristic of easy alignment of the inherent end face, the only basis for circumferential alignment is the overlap between the virtual surface formed by the swing milling of the tool running the program on the equipment and the impeller blade surface with slight deformation after repeated clamping. The size of the overlap is mainly determined by the circumferential alignment accuracy of the impeller. The impeller structure, axial and circumferential specifics are as follows: Figure 1 shown.

[0005] The circumferential position of the traditional impeller is mainly aligned by the equipment operator running the blade surface fine milling program to repeatedly pass the tool, stop urgently, observe and measure. This method is not only inefficient, but the accuracy of the circumferential alignment is also closely related to the personal ability and processing experience of the equipment operator. Operators with different abilities and experiences repair the same impeller or the same operator repairs different impellers. This will cause a large difference in the final alignment accuracy of the impeller circumference. The most typical problem is the overcutting of the inner arc or back arc of the blade caused by the angle being biased to the left or right. The specific state is as follows Figure 2 As shown, the occurrence of this state greatly reduces the processing quality of blade surface repair, and in severe cases may even cause parts to be scrapped.

[0006] In view of the above situation, this invention provides a new and efficient alignment method for circumferential alignment of blades of such parts during repeated milling. This method is not limited by the operator's own experience, has high versatility, is easy to operate, has high alignment efficiency, and has small errors. It is suitable for high-precision circumferential alignment of all conventional rotating impeller or blade disc parts. Summary of the invention

[0007] The purpose of the present invention is to overcome the deficiencies of the prior art and provide an efficient alignment method for repeatedly clamping impeller blades, thereby improving the repair efficiency and repair quality.

[0008] The object of the present invention is achieved in that:

[0009] An efficient alignment method for repeatedly clamping impeller blades comprises the following steps:

[0010] Step 1: Compilation and simulation of quantitative alignment program for long blade back arc profile

[0011] According to the original model or data of the impeller, the tool is selected, and the back arc of any long blade of the impeller is taken as the processing object to complete the compilation of the initial angle circumferential alignment program. In the alignment program parameters, the side margin of the blade back arc profile W1=0mm, the tool tip clearance margin 2mm≤W2≤10mm, and the simulation software is selected to complete the simulation of the alignment program;

[0012] Step 2: Initial Angle Error Rotation

[0013] Run the alignment program on the processing equipment. At this time, the initial circumferential angle of the program is B = 0°. When the tool moves to the point adjacent to the large outer circle of the impeller, the processing equipment is paused and the tool position is observed. At this time, the tool position area is divided into two situations: A1 and A2:

[0014] In case A1, the tool as a whole should be aligned with the fan-shaped area between the back arc of the long blade and the inner arc of the adjacent splitter blade;

[0015] At this time, continue to execute the alignment program. When the tool as a whole moves completely to the inside of the large outer circle of the impeller, stop the processing equipment, and start the reset function of the processing equipment at the same time, and terminate the alignment program. At this time, there is no contact between the tool and the part. Read the current angle position parameter of the processing equipment workbench, record the parameter as α, enable the manual function of the processing equipment, rotate the workbench clockwise, and use a feeler gauge to detect the fit between the side edge of the tool and the back arc of the long blade. When the side edge of the tool fits the back arc of the long blade, stop the workbench from rotating, and record the current position angle parameter of the workbench as β. The tool rotates counterclockwise relative to the impeller part, and the angle rotation difference γ generated from the original α position to the current β position is γ=β-α;

[0016] In case A2, the tool as a whole does not correspond to the fan-shaped area between the back arc of the long blade and the inner arc of the adjacent splitter blade;

[0017] At this time, stop the processing equipment, and at the same time start the reset function of the processing equipment to terminate the operation of the alignment program. Record the current angular position parameter of the workbench of the processing equipment at this time as α1. Then rotate the workbench clockwise until the area where the tool is located reaches A1. At this time, the workbench stops rotating, and record the current angular position parameter of the workbench of the processing equipment as β1. At this time, the angular difference γ1 of the overall rotation of the workbench is γ1 = β1 - α1;

[0018] The initial angular difference for repeated clamping of this part is set as γ1. Reset the initial angle B of the program to γ1. According to situation A1, run the alignment program again, and finally obtain the final rotation angle difference of the tool in the case of A2 as γ + γ1, that is, β - α + β1 - α1;

[0019] The third step is to reset the initial angle

[0020] Reset the initial angle of the alignment program according to the rotation angle difference of the tool;

[0021] The fourth step is the compilation and simulation of the light-seeing trial cutting program

[0022] Compile the light-seeing trial cutting program, where W1 = 0mm and 0 < W2 < 0.2mm. After the compilation is completed, simulate the program to ensure the correctness of the program.

[0023] Preferably, in the first step, the tip clearance allowance W2 = 5mm.

[0024] Preferably, it further includes a fifth step, initial angle fine-tuning

[0025] Run the light-seeing trial cutting program to complete the trial cutting of the back arc surface of the long blade of the impeller to be repaired. When the back arc surface is not completely visible, continue to increase the initial angle B.

[0026] Preferably, the method for increasing the initial angle B is: assume that the maximum diameter of the part is D. For every 0.01mm of feed at the back arc surface at the maximum outer circle, the initial angle B increases by 360 / (πD * 100) degrees.

[0027] Due to the adoption of the above technical solution, the present invention proposes a new method for efficient alignment in the circumferential direction during the repair process of rotating impeller parts. The specific beneficial effects are mainly reflected in the following aspects:

[0028] 1. Improvement of repair efficiency

[0029] The new impeller circumferential alignment method involved in the present invention avoids the processes of repeated programming, trial cutting, debugging, etc. in the traditional alignment process, realizes the efficient alignment of any impeller circumferential direction through an efficient and regular fixed process, greatly reduces the circumferential alignment time of repeated clamping of parts, and effectively improves the overall repair efficiency of parts.

[0030] 2. Improved alignment accuracy

[0031] The present invention involves determining the initial angular difference of the impeller circumference through quantitative programming rotation, further improving the processing accuracy of the actual blade surface circumferential repeated alignment through micro-light trial cutting of the angle directional increment, and clarifying the final impeller circumferential deviation. At the same time, the method process of single-sided back arc surface alignment and trial cutting avoids the over-cutting of blades in the traditional impeller circumferential alignment process, and the alignment accuracy is significantly improved compared with the traditional method.

[0032] 3. Improved product repair quality stability

[0033] The circumferential alignment method proposed in the present invention can be applied and implemented in the repeated clamping circumferential alignment process of any rotating impeller or blade disk-type parts. The method is concise and clear, has high versatility, and has low requirements on the personal ability of the operators or technicians involved in the parts. According to the method flow, the parts can be quickly and accurately aligned in the circumference, avoiding the problem of parts rework and scrapping caused by traditional irregular circumferential alignment or the operator's lack of personal ability and experience, thereby ensuring the stability of the parts rework quality. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] Figure 1 It is a schematic diagram of the structure of the parts;

[0035] Figure 2 The figure is a schematic diagram of overcutting of the blade of the part;

[0036] Figure 3 This is a schematic diagram of the first step;

[0037] Figure 4-Figure 8 This is a schematic diagram of the second step. DETAILED DESCRIPTION

[0038] The present invention aims at the problems of low efficiency, poor versatility, low fault tolerance, high scrap rate, etc. in the alignment process of the circumference of the blades of rotating parts that are repaired by milling in the traditional irregular method. The present invention deeply analyzes the blade structure characteristics of the rotating impeller, and combines the two inherent position relationship characteristics of line contact or point contact between the tool and the blade in the conventional fine milling of the blade. The method flow of the five steps of preparing and simulating the quantitative alignment program of the single-sided back arc surface, rotating the starting angle error, resetting the initial angle, preparing and simulating the light trial cutting program, and fine-tuning the initial angle is successively carried out to achieve efficient alignment of the circumference of the blade, wherein the line contact is mainly for straight-grained blades, and the point contact is mainly for free-form surface blades. The circumferential alignment method involved in the present invention has the same application method in the alignment process of repeated milling of blade parts of the two structures. The specific circumferential alignment method process and principle involved in this invention are illustrated by taking the straight-grained blade impeller processed by line contact as an example, as follows:

[0039] Method flow:

[0040] The first step is to compile and simulate the quantitative alignment program of the single-sided back arc surface

[0041] The blade single-side back arc profile is selected as the object for the compilation of the alignment program, where the blade profile allowance W1 = 0, the tool tip clearance W2 = 5mm, and the specific allowance position relationship is as follows Figure 3 As shown, the completed program is simulated by machine tool to ensure the correctness of the program.

[0042] Step 2: Initial angle error rotation

[0043] Run the alignment program on the equipment. At this time, the initial circumferential angle of the program is B = 0°. When the tool moves to the position close to the large outer circle of the impeller, the equipment is paused and the tool position is observed. At this time, the area where the tool position is located is divided into the following two situations: A1 and A2:

[0044] A1, the tool is located entirely in Figure 4 As shown in the figure, find the inside of the fan-shaped area b between the back arc of the long blade and the inner arc of the adjacent splitter blade. At this time, the program should continue to be executed. When the tool moves completely to the inside of the large outer circle of the impeller, the equipment is stopped and the equipment reset function is started at the same time to terminate the program. At this time, the specific position of the tool is as follows Figure 5 As shown, from Figure 5 It can be found that there is no contact between the tool and the part at this time. The current angle position parameter of the equipment workbench is read and recorded as α. After the parameter is recorded, the manual function of the equipment is enabled, and the workbench is rotated clockwise. The fit between the side edge of the tool and the back arc of the long blade is detected by using a feeler gauge. When the side edge of the tool and the back arc of the long blade slowly fit together, the workbench is stopped from rotating and the current position angle parameter of the workbench is recorded as β. The specific position of the tool at this time is as follows Figure 6 As shown, the tool rotates counterclockwise relative to the impeller part, and the angular rotation difference γ generated by moving from the original α position to the current β position is γ=β-α.

[0045] A2, the tool is not completely located Figure 4 The inner sector b area between the back arc of the long blade and the inner arc of the adjacent splitter blade is shown, that is, the tool is located Figure 7 In the cases of positions ①, ②, and ③ shown in the figure, if the tool continues to feed, the tool will overcut the blade or enter area a. Overcutting will cause the part to be scrapped, and entering area a will make the tool unable to fit the back arc surface of the blade in the program. Both are undesirable. Refer to the manual rotation angle solution in A1. At this time, the equipment should be stopped and the equipment reset function should be started to terminate the program. Assume that the tool is at Figure 7At the position shown in ②, record the current angular position parameter of the equipment workbench as α1 at this time. Then rotate the workbench clockwise. When the entire tool has completely moved inside the b area relative to the impeller, stop the rotation of the workbench and record the current angular position parameter of the equipment workbench as β1. The specific position and movement of the tool are as Figure 8 shown. At this time, the angular difference γ1 of the overall rotation of the workbench is γ1 = β1 - α1.

[0046] According to the above rotation, obtain the initial angular difference γ1 of this repeated clamping of the part. Reset the initial angle B of the program from 0° to B = 0° + γ1 = γ1 = β1 - α1. Then restart the program. When the tool moves to a position close to the large outer circle of the impeller, pause the operation of the equipment and observe the position of the tool. At this time, the position where the tool is located should be as Figure 4 shown. For the subsequent steps, refer to the above A1 scheme for execution. Finally, obtain the final angular difference of the tool in the case of A2 as γ + γ1, that is, β - α + β1 - α1.

[0047] Step 3: Reset the initial angle

[0048] Reset the initial angle of the program according to the rotation angle difference obtained in the above steps, that is:

[0049] B = 0° + γ + γ1 = γ + γ1 = (β - α) + (β1 - α1)

[0050] Note: When the tool feed position is A1, β1 = α1 = 0

[0051] Step 4: Compilation and simulation of the light - seeing trial - cutting program

[0052] Refer to Figure 3 to compile the light - seeing trial - cutting program according to the new tool path of the present invention and the tool - blade profile position relationship shown in B - B. Among them, W1 = 0mm, 0 < W2 < 0.2mm. After completing the compilation, ensure the correctness of the program through machine - tool simulation.

[0053] Step 5: Fine - tuning of the initial angle

[0054] Reset the initial angle B to the angular rotation difference, that is, B = (β - α) + (β1 - α1) (Note: When the tool feed position is A1, β1 = α1 = 0). Run the light - seeing trial - cutting program to complete the trial - cutting of the back arc surface of the long blade of the impeller to be repaired. When the back arc surface is not completely visible, continue to increase the initial angle B. The specific method of increasing is as follows:

[0055] Suppose the maximum diameter of the impeller to be repaired is D, and the fixed angle for one rotation is 360°. The larger the diameter, the longer the circumference, and the longer the arc path length of the sector under the same rotation angle. That is, the thicker the cutting allowance on the surface layer where the tool is located on the back arc surface of the blade. The specific conversion relationship between the diameter and the angle is as follows:

[0056] One rotation = 360°

[0057] That is, πD = 360°,

[0058] πD*(100*0.01)=360°

[0059] 0.01mm=360 / (πD*100)

[0060] That is, for every 0.01mm of cutting into the back arc surface at the maximum outer circle, the initial angle B increases by 360 / (πD*100) degrees, that is, B=(β-α)+(β1-α1)+360 / (πD*100) (when the tool feed position is A1, β1=α1=0)

[0061] The actual feed amount is usually controlled within 0.05mm.

[0062] Note: The angle increment of the initial angle fine-tuning mainly comes from the fit error between the tool and the back arc surface of the blade during the second step of angle rotation. The method of using a feeler gauge to detect the fit will cause a slight gap between the side edge of the tool and the blade surface. Eliminating this gap through trial cutting in the light can further improve the position accuracy of the circumferential starting angle deviation initially determined in the third step, so as to achieve the purpose of making the curved surface formed by the theoretical tool path after repeated clamping fit the actual blade surface better.

[0063] Principle of the invention:

[0064] The present invention breaks through the inherent method of using the fine milling program to test cut and align the circumference of the impeller blade in traditional processing, separates the alignment program from the trial cutting program, wherein the alignment program does not participate in the trial cutting, and by setting the tool tip clearance parameter W2=5mm, the effective rotation of the workbench is achieved when the tool stops cutting into the inside of the impeller. At the same time, the distance value of the 5mm standard tool tip clearance is also convenient for on-site measurement, which can verify the correctness of the upper and lower reference parameters after repeated clamping of the parts. By setting the profile allowance W1=0mm, the fit between the tool and the back arc profile of the alignment blade is guaranteed after the tool and the workbench have a relative rotation displacement. The specific parameter position is as follows Figure 3 BB shows that the specific bonding state is as follows Figure 6 As shown in EE, the alignment program breaks through the limitation of traditional synchronous fine milling of the inner and back arc sides of the blade. According to the purpose of the program, the single-side back arc profile is selected for compilation, which simplifies programming and effectively improves the alignment efficiency. The alignment program completed by the above method combined with the above second and third steps can quickly and efficiently perform a preliminary positioning of the initial angle of the impeller circumference.

[0065] There is still a slight clearance angle error between the circumferential direction of the impeller after preliminary alignment and the final position. This error mainly comes from the small clearance reserved by the feeler gauge during the fitting of the tool and the profile in the second step. The present invention aims at the over-cutting phenomenon caused by the angle deviation during the original finish milling alignment trial cut, such as Figure 2 As shown, the machining range of the light-exposing trial cut program is accurately defined to the back arc profile of the blade. By setting the profile allowance W1 = 0 mm, the fitting degree between the spatial profile cut by the tool during the accurate circumferential position angle alignment and the solid profile of the impeller blade is ensured. By setting the tip clearance parameter 0 < W2 < 0.2 mm, while ensuring that the entire back arc profile of the blade is fully exposed in the depth direction, the necessary small clearance at the tool tip greatly reduces the influence of the tool deflection caused by the force at the tool tip on the profile milling accuracy, and ensures the accuracy of the light-exposing trial cut profile position. By the above method, the light-exposing trial cut can effectively eliminate the small angular clearance error existing in the preliminary alignment process, further improve the alignment accuracy of the impeller circumferential angle, obtain the final circumferential angle difference, and achieve the accurate circumferential alignment of the impeller.

[0066] Specifically:

[0067] The implementation of the present invention is mainly divided into the following five steps. The detailed implementation steps are illustrated by taking the circumferential alignment of the typical rotating impeller part shown in Figure 1 as an example. The specific content is as follows:

[0068] Step 1: Compilation and simulation of the quantitative alignment program for the back arc profile of the long blade

[0069] Select a suitable tool according to the original model or data of the impeller to Figure 1 complete the compilation of the initial angle circumferential alignment program with any long blade back arc machining of the impeller shown. The setting of specific programming parameters is as Figure 3 shown in B-B. The side allowance W1 of the back arc profile of the blade is 0 mm, and the tip clearance allowance W2 is 5 mm. After the program is compiled, select a conventional general simulation software to complete the program simulation. The size and positional relationship of the tooling, blank, and machine tool model involved in the simulation should be consistent with the physical object and the clamping state.

[0070] Step 2: Rotation of the starting angle error

[0071] The on-site workers complete the preparation work before impeller repair according to the tooling, tool, and tool holder used in the simulation. After the part is clamped, the axial reference is aligned to complete the preliminary establishment of the initial machining coordinate system. At the same time, the alignment program that has been simulated correctly in the first step is transferred to the corresponding five-axis equipment for repair.

[0072] After the above work is completed, the alignment program can be run on the equipment. Wait until the tool moves to Figure 4 or Figure 7When in positions ①, ②, and ③, use the equipment magnification adjustment function to pause the equipment and observe the position status of the tool:

[0073] A1. When the tool is located Figure 4 When the location type is shown:

[0074] 1) The equipment continues to run the program, and the tool will continue to feed in the idle area. When the tool runs to the inside of the large outer circle of the impeller, the equipment stops again. The specific position is as follows Figure 5 As shown, at this time, the reset function of the equipment program needs to be started, the running state of the program is completely terminated, the five-axis linkage of the equipment is canceled, the relative positions of the tool, impeller, and equipment are all static, and the angle parameter of the current position of the workbench is read on the display and recorded as α.

[0075] 2) After completing the above operations, start the manual function of the equipment, rotate the equipment workbench clockwise, and keep the other parts stationary. When the side edge of the tool is about to fit the back arc surface of the blade, reduce the manual magnification to the minimum, and use a feeler gauge to check the fit between the side edge of the tool and the back arc surface. When the feeler gauge just cannot be displaced, stop the manual rotation of the workbench immediately, read the current workbench position angle parameter on the display, and record the parameter as β. After reading the parameter, immediately rotate the workbench counterclockwise to move the tool away from the back arc surface of the blade to complete the tool retraction.

[0076] 3) At this time, the impeller circumferential starting angle difference γ is β-α, that is, the impeller initial angle deviation γ = β-α

[0077] A2. When the tool is located Figure 7 When the location type is shown:

[0078] 1) Stop the equipment, start the reset function of the equipment program, completely terminate the running state of the program, cancel the five-axis linkage of the equipment, and the relative positions of the tool, impeller, and equipment are all static. Read the angle parameter of the current position of the workbench on the display and record the parameter as α1.

[0079] 2) After completing the above operations, start the manual function of the equipment, rotate the equipment workbench clockwise, and keep the other parts stationary. When the tool moves relative to the impeller to Figure 4 The worktable can be stopped at any position in the middle of the sector-shaped area between the back arc of the long blade and the inner arc surface of the adjacent splitter blade (the specific position of the tool in the middle of the sector does not need to be accurate), and the angle parameter of the current position of the worktable is read on the display and recorded as β1. The parameter record withdraws the tool to a safe position away from the workpiece.

[0080] 3) Through the above process, it is clear that the initial rotation angle difference γ1 of the impeller circumference is (β1-α1), and γ1 is entered into the initial angle of the program, that is, B=0+γ1=β1-α1, and then the equipment is restarted to run the alignment program. When the tool moves to Figure 4 As shown in the figure, when the device is close to the outer circle of the impeller, the device magnification adjustment function is used to pause the device operation. It can be found that the current tool position is in the fan-shaped area between the back arc of the long blade in the program and the inner arc surface of the adjacent splitter blade. Then adjust the magnification and continue to run the program. When the tool moves to the inside of the large outer circle of the impeller, stop the device completely, start the reset function of the device program, completely terminate the running state of the program, cancel the five-axis linkage of the device, record the current angle position parameter α displayed on the workbench, manually rotate the workbench clockwise to make the side edge of the tool fit the back arc surface of the long blade, stop rotating and record the end angle position parameter β of the display, and rotate the workbench counterclockwise to complete the tool retraction.

[0081] 4) At this time, the total circumferential rotation angle difference of the impeller is (β1-α1)+(β-α).

[0082] Step 3: Reset the initial angle

[0083] Reset the initial angle of the program according to the rotation angle difference obtained in the above steps, that is:

[0084] B=0°+γ+γ1=γ+γ1=(β-α)+(β1-α1)

[0085] Note: When the tool feed position is A1, β1=α1=0

[0086] Step 4: Preparation and simulation of light-test cutting program

[0087] Refer to the compilation method of the first step of the alignment program, and reduce the value of the tool tip clearance margin parameter W2 from 5mm to 0.1mm, that is, the side margin of the blade back arc profile W1 = 0mm, and the tool tip clearance margin W2 = 0.1mm, thus completing the compilation of the light-seeing program. After the program is compiled, refer to the first step to perform synchronous interference collision simulation. If the simulation is correct, the preparation of the light-seeing test cutting program is completed. (Note: The light-seeing test cutting requires the overall light-seeing processing of the programmed back arc surface. If W2>0mm, there will be a knife mark at the root of the profile that affects the surface quality. Therefore, the alignment program cannot be directly used for light-seeing test cutting)

[0088] Step 5: Fine-tune the initial angle and determine the final circumferential rotation angle

[0089] Reset the initial angle B to the angle rotation difference, that is, B = (β-α) + (β1-α1) (Note: when the tool feed position is A1, β1 = α1 = 0), run the light-exposure test cutting program, and complete the back arc test cutting of the long blade of the impeller to be repaired. If the back arc surface is not completely exposed to light, the initial angle B needs to be further increased. The specific increase method is as follows:

[0090] Assuming that the maximum diameter of the impeller to be repaired is D, and the rotation angle is fixed at 360°, the larger the diameter, the longer the circumference, and the longer the fan-shaped arc path length at the same rotation angle, that is, the thickness of the surface cutting by the tool at the location of the back arc surface of the blade will be greater. The specific diameter and angle conversion relationship is as follows:

[0091] One rotation = 360°

[0092] That is, πD = 360°,

[0093] πD*(100*0.01)=360°

[0094] 0.01mm=360 / (πD*100)

[0095] That is, for every 0.01mm of cutting into the back arc surface at the maximum outer circle, the initial angle B increases by 360 / (πD*100) degrees, that is, B=(β-α)+(β1-α1)+360 / (πD*100) (when the tool feed position is A1, β1=α1=0)

[0096] The final alignment and fine-tuning of the back arc profile of the impeller long blade implemented in this plan is assumed to be 0.05mm.

[0097] According to the above method flow, the impeller circumferential starting angle B = (β-α) + (β1-α1) + 5*360 / (πD*100) is clearly defined, thereby achieving the final circumferential alignment of the impeller. During the subsequent rework program operation, the program starting angle is set according to this value to achieve repeated milling of the impeller blades.

[0098] Finally, it should be noted that the above preferred embodiments are only used to illustrate the technical solutions of the present invention rather than to limit it. Although the present invention has been described in detail through the above preferred embodiments, those skilled in the art should understand that various changes can be made in form and details without departing from the scope defined by the claims of the present invention.

Claims

1. An efficient alignment method for repeatedly clamping impeller blades, characterized in that: It includes the following steps: Step 1: Compilation and simulation of the quantitative alignment program for the back arc surface of the long blade Select a cutting tool according to the original model or data of the impeller. Take the back arc of any long blade of the impeller as the machining object, and complete the compilation of the initial angle circumferential alignment program. In the alignment program parameters, the side allowance W1 of the back arc surface of the blade is 0 mm, and the tip clearance allowance is 2 mm ≤ W2 ≤ 10 mm. Select a simulation software to complete the simulation of the alignment program; Step 2: Rotation of the starting angle error Run the alignment program on the machining equipment. At this time, the initial angle B in the circumferential direction of the program is 0°. When the cutting tool moves to be adjacent to the large outer circle of the impeller, pause the machining equipment and observe the position of the cutting tool. At this time, the area where the cutting tool is located is divided into two cases: A1 and A2: In case A1, the whole cutting tool corresponds to the fan-shaped area between the aligned back arc of the long blade and the inner arc of the adjacent splitter blade; At this time, continue to execute the alignment program. When the whole cutting tool completely moves inside the large outer circle of the impeller, stop the machining equipment. At the same time, start the reset function of the machining equipment to terminate the operation of the alignment program. At this time, there is no contact between the cutting tool and the part. Read the current angle position parameter of the workbench of the machining equipment and record this parameter as α. Enable the manual function of the machining equipment and rotate the workbench clockwise. Use a feeler gauge to detect the fit between the side edge of the cutting tool and the back arc of the long blade. When the side edge of the cutting tool fits with the back arc of the long blade, stop the rotation of the workbench and record the current position angle parameter of the workbench as β. The cutting tool rotates counterclockwise relative to the impeller part, and the angle rotation difference γ generated by moving from the original α position to the current β position is γ = β - α; In case A2, the whole cutting tool does not correspond to the fan-shaped area between the aligned back arc of the long blade and the inner arc of the adjacent splitter blade; At this time, stop the machining equipment. At the same time, start the reset function of the machining equipment to terminate the operation of the alignment program. Record the current angle position parameter of the workbench of the machining equipment at this time as α1. Then rotate the workbench clockwise until the area where the cutting tool is located reaches the situation of A1, and the workbench stops rotating. Record the current angle position parameter of the workbench of the machining equipment as β1. At this time, the overall rotation angle difference of the workbench is γ1 = β1 - α1; Set the initial angle difference of repeated clamping of this part as γ1, reset the program initial angle B to γ1, and according to case A1, run the alignment program again. Finally, the final rotation angle difference of the cutting tool in case A2 is γ + γ1, that is, β - α + β1 - α1; Step 3: Reset the initial angle Reset the initial angle of the alignment program according to the rotation angle difference of the cutting tool; Step 4: Compilation and simulation of the light exposure trial cutting program Compile the light exposure trial cutting program, where W1 = 0 mm and 0 < W2 < 0.2 mm. After the compilation is completed, simulate the program to ensure the correctness of the program.

2. The highly efficient alignment method for repeatedly clamping impeller blades according to claim 1, characterized in that: In Step 1, the tip clearance allowance W2 = 5 mm.

3. The highly efficient alignment method for repeatedly clamping impeller blades according to claim 1 is characterized in that: It also includes Step 5: Fine adjustment of the initial angle Run the light exposure trial cutting program to complete the trial cutting of the back arc surface of the long blade of the impeller to be repaired. When the back arc surface is not completely exposed to light, continue to increase the initial angle B.

4. The highly efficient alignment method for repeatedly clamping impeller blades according to claim 1 is characterized in that: The method of increasing the initial angle B is: Let the maximum diameter of the part be D. For every 0.01 mm of feed at the back arc surface at the maximum outer circle, the initial angle B increases by 360 / (πD * 100) degrees.

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