An efficient alignment method for repeatedly clamping impeller blades

Abstract

The present invention discloses an efficient alignment method for repeatedly clamping impeller blades. Through the preparation and simulation of a quantitative alignment program for a single-sided back arc surface, the preparation and simulation of a starting angle error rotation, the resetting of the initial angle, the trial cutting program in light exposure, and the fine adjustment of the initial angle, a total of five steps are used to achieve efficient circumferential alignment of the blades, thereby improving the rework efficiency and quality.

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 and milled for repair during the dynamic balancing or post-use maintenance of the product after milling. 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 profile that needs to be repaired usually has the status quo of slight stress deformation, surface roughness, local defects, etc. The surface layer of the blade profile can be used for milling repair with a smaller allowance thickness. The difficulty of traditional impeller blade repair is mainly concentrated on the circumferential alignment of the blade profile. 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 profile with slight deformation due to 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 and repeatedly passing the tool, stopping suddenly, observing and measuring. 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 off to the left or right. The specific status is as follows Figure 2 As shown in FIG, the occurrence of this state greatly reduces the processing quality of the blade surface repair, and in severe cases may even cause the parts to be scrapped.

[0006] In response to the above situation, this invention provides a new and efficient alignment method for the 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 impellers 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 quality.

[0008] The object of the present invention is achieved like this:

[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 surface

[0011] Select the tool according to the original model or data of the impeller, take the back arc of any long blade of the impeller as the processing object, complete the compilation of the initial angle circumferential alignment program, in the alignment program parameters, the side allowance of the blade back arc profile W1 = 0mm, the tool tip clearance allowance 2mm≤W2≤10mm, select the simulation software 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 adjacent 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 locate the sector 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 is completely moved 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 to 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 and 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 rotation and record the current position angle parameter of the workbench as β. The tool rotates counterclockwise relative to the impeller part. The angle rotation difference γ generated from the original α position to the current β position is β = β-α.

[0016] In case A2, the tool as a whole does not align with 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] Step 3: Reset the initial angle

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

[0021] Step 4: Compilation and simulation of the light-seeing and trial-cutting program

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

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

[0024] Preferably, it further includes Step 5: Fine-tuning of the initial angle

[0025] Run the light-seeing and 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 fully visible, continue to increase the initial angle B.

[0026] [[ID=!29]]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, and realizes the efficient alignment of any impeller circumferential direction through an efficient and regular fixed process, greatly reducing the circumferential alignment time of repeated clamping of parts and effectively improving the overall repair efficiency of parts.

[0030] 2. Improved alignment accuracy

[0031] The present invention involves determining the initial angle 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 angle directional increments, and clarifying the final impeller circumferential deviation. At the same time, the method flow of single-sided back arc surface alignment and trial cutting avoids the blade over-cutting phenomenon 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 parts. The method is concise and clear, highly versatile, and has low requirements on the personal ability of the operators or technicians involved in the parts. According to the process of this method, the parts can be quickly and accurately aligned in the circumference, avoiding the traditional irregular circumferential alignment or the problem of parts rework and scrapping due to the operator's personal ability and experience deficiency, and ensuring the stability of the quality of the parts rework. BRIEF DESCRIPTION OF THE DRAWINGS

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

[0035] Figure 2 The figure is a schematic diagram of the overcut of the blade 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 and high scrap rate in the alignment process of the circumferential direction of the blades of rotating parts that are repaired by milling using traditional irregular methods. The present invention deeply analyzes the structural characteristics of the blade profile of rotating impellers, and combines the two inherent positional relationship characteristics of line contact or point contact between the tool and the blade in conventional fine milling of blades. The method flow of the five steps of compilation and simulation of quantitative alignment program of single-sided back arc surface, rotation of starting angle error, resetting initial angle, compilation and simulation of trial cutting program in light, and fine adjustment of initial angle is successively carried out to achieve efficient alignment of the circumference of the blades. Among them, line contact is mainly for straight-grained blades, and 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 surface is selected as the object for the compilation of the alignment program, where the blade surface allowance W1 = 0, the tool tip clearance W2 = 5mm, and the specific allowance position relationship is as follows Figure 3 As shown in the figure, the completed program is simulated by the machine tool to ensure the correctness of the program.

[0042] The second step is to rotate the starting angle error

[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 close to the outer diameter of the impeller, pause the equipment and observe the tool position. The tool position area is divided into the following two situations: A1 and A2:

[0044] A1, the entire tool is located Figure 4 As shown in the figure, find the inner area of ​​the sector 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 inner part of the large outer circle of the impeller, the equipment is stopped and the reset function of the equipment is started 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. Read the current angle position parameter of the equipment workbench and record it as α. After the parameter is recorded, enable the manual function of the equipment and rotate the workbench clockwise. Use the 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 and the back arc of the long blade slowly fit together, stop the workbench rotation and record the current position angle parameter of the workbench 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 tool is located inside the sector b area between the back arc of the long blade and the inner arc of the adjacent splitter blade. Figure 7 As shown in the ①, ②, and ③ positions, 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 prevent the tool from fitting with the programmed blade back arc surface. 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 activated 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. Then rotate the workbench clockwise. When the whole 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 whole workbench rotation is γ1 = β1 - α1.

[0046] According to the above rotation, obtain the initial angular difference γ1 of the repeated clamping of this 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 tool position. At this time, the position of the tool should be as Figure 4 shown. For the subsequent steps, refer to the above A1 scheme. Finally, the final angular difference of the tool in the case of A2 is 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: Compile and simulate the light - seeing trial - cutting program

[0052] Refer to Figure 3 in the new tool - path and the tool - blade profile position relationship shown in B - B of the present invention to compile the light - seeing trial - cutting program, where W1 = 0mm, 0 < W2 < 0.2mm. After the program is compiled, 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 thickness of the cutting allowance on the surface layer where the tool is located on the back arc surface of the blade will be larger. 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 feed on 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 is mainly derived from the fit error between the tool and the blade back arc surface during the second step of angle rotation. The method of using a feeler gauge to detect the fit creates a slight gap between the tool side edge and the blade surface. Eliminating this gap through trial cutting in the presence of 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 better with the actual blade surface.

[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 when cutting into 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 surface allowance W1=0mm, the fit between the tool and the back arc surface of the alignment blade is guaranteed after the relative rotation displacement between the tool and the workbench. The specific parameter positions are as follows Figure 3 As shown in BB, the specific bonding state is as follows Figure 6 As shown in Figure EE, the simultaneous alignment program breaks through the limitations of traditional simultaneous fine milling of the inner and outer sides of the blade. Based on the program's purpose, a single-side back arc profile is selected for programming, simplifying programming while effectively improving alignment efficiency. The alignment program completed using this method, combined with the second and third steps above, can quickly and efficiently perform a preliminary positioning of the impeller's initial circumferential angle.

[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 surface in the second step. The present invention aims at the overcut phenomenon caused by the angle deviation in the original fine milling alignment and trial cutting process, such as Figure 2 As shown, the machining range of the light-exposed trial cutting program is accurately defined to the back arc surface of the blade. By setting the surface allowance W1 = 0mm, the fitting degree between the spatial surface cut by the tool during accurate circumferential position angle alignment and the solid surface of the impeller blade is ensured. By setting the tool tip clearance parameter 0 < W2 < 0.2mm, while ensuring that the entire back arc surface of the blade is completely light-exposed in the depth direction, the necessary small clearance of the tool tip greatly reduces the influence of the tool deflection phenomenon caused by the force on the tool tip on the milling accuracy of the surface, ensuring the accuracy of the light-exposed trial cutting surface position. By completing the light-exposed trial cutting through the above methods, the small angular clearance error existing in the preliminary alignment process can be effectively eliminated, further improving the alignment accuracy of the impeller circumferential angle, obtaining the final circumferential angle difference, and achieving 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 described 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 surface 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 surface of the blade is 0mm, and the tool tip clearance allowance W2 is 5mm. 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 models 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, and the preliminary establishment of the initial machining coordinate system is completed at the same time. At the same time, the alignment program that has been simulated correctly in the first step is transmitted 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 7At positions ①, ②, and ③, use the equipment magnification adjustment function to pause the equipment and observe the tool position status:

[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 moves to the inside of the impeller's large outer circle, the equipment will stop 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 move, stop the manual rotation of the workbench immediately, then read the current workbench position angle parameter on the display, record the parameter as β, and immediately rotate the workbench counterclockwise after reading the parameter 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 and start the reset function of the equipment program to completely terminate the program's running state and cancel the equipment's five-axis linkage. The relative positions of the tool, impeller, and equipment are all in a static state. 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 will retract the tool to a safe position away from the workpiece.

[0080] 3) Through the above process, the initial rotation angle difference γ1 of the impeller is determined to be (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, 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 running 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 on 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 first step of the alignment program compilation method and reduce the value of the tool tip clearance parameter W2 from 5mm to 0.1mm. That is, the blade back arc profile side margin W1 = 0mm, and the tool tip clearance margin W2 = 0.1mm. This completes the compilation of the light-seeking program. After the program is compiled, refer to the first step to perform a synchronous interference collision simulation. If the simulation is correct, the preparation work of the light-seeking test cutting program is completed. (Note: The light-seeking test cutting requires the entire back arc surface to be polished. If W2>0mm, the root of the profile will have a tool mark that affects the surface quality. Therefore, the alignment program cannot be directly applied to the light-seeking 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-seeing trial cutting program, and complete the back arc trial 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 allowance of the tool at the location of the blade back arc surface 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 feed on 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 0.05mm.

[0097] According to the above method, the impeller circumferential starting angle B = (β-α) + (β1-α1) + 5*360 / (πD*100) is clearly defined, thereby achieving the final alignment of the impeller circumference. 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 and are not limiting. 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 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 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 tool moves to be adjacent to the large outer circle of the impeller, pause the machining equipment and observe the tool position. At this time, the area where the tool position is located is divided into two cases: A1 and A2: In case A1, the whole 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 tool completely moves inside the large outer circle of the impeller, stop the machining equipment, and 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 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 tool and the back arc of the long blade. When the side edge of the 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 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 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, and 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, and then rotate the workbench clockwise until the area where the tool position 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 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 tool; Step 4: Compilation and simulation of the light-exposing trial cutting program Compile the light-exposing trial cutting program, where W1 = 0 mm, 0 < W2 < 0.2 mm. After the compilation of the program, perform simulation to ensure the correctness of the program.

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

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