Machining method for large-flow supercharger turbine shaft

Abstract

The invention discloses a processing method of a high-flow supercharger turbine shaft, which improves the processing and manufacturing efficiency of the turbine shaft and reduces the production cost in batch production. A machining method for a large-flow supercharger turbine shaft comprises the following steps that S1, a welding optical axis blank is machined, and a welding optical axis is obtained; s2, the welded turbine disc blank is machined, and the welded turbine disc is obtained; s3, the welding optical shaft and the welding turbine disc are installed and welded through friction welding, and a welding turbine shaft is obtained; and S4, the turbine shaft is machined and welded, and a turbine shaft finished product is obtained.

Description

Technical Field

[0001] The invention relates to the technical field of ship supercharger manufacturing and processing, in particular to a processing method for a turbine shaft of a large-flow supercharger. Background Art

[0002] The supercharger is a control device that relies on exhaust gas to drive the rotor to move, compress and push more air into the combustion chamber, thereby increasing the engine output power. The turbine shaft, as one of the key core components of the rotor, mainly plays the role of transmitting torque. In recent years, with the changes in the international situation, in order to meet the shipbuilding industry's demand for large-bore, large-flow marine low-speed engine turbochargers, it is necessary to break through and innovate key technologies and master their application to improve processing and manufacturing efficiency, reduce production costs, meet market changes, and consolidate market competitiveness.

[0003] The turbine shaft structure of a large-bore, large-flow marine low-speed turbocharger has a multiple-fold increase in size compared to existing products, and the turbine disc is supported by an external overhang structure. The center of gravity of the parts is concentrated at one end, showing a top-heavy distribution. The turbine shaft structure includes multi-stage shaft diameters, turbine discs, and triangular prisms. Evenly distributed tree-like mortises are provided on the circumference of the turbine disc for assembling turbine blades. The symmetry centerline of the mortise and tenon is at a certain angle to the axis of the turbine disc, and the intersection of the two-line projections is on the turbine disc. The intersection is the design center of the mortise and tenon, and has a precise positional relationship on the turbine disc. This type of structure typically has high requirements, complex structure, and great processing difficulty. The machining accuracy and quality of the mortise and tenon of the turbine shaft directly affect the basic performance and service life of the supercharger, such as airflow, working pressure ratio, etc.

[0004] There are three main methods for processing the tenon and groove of the turbine shaft: broaching, milling, and wire cutting. From the perspective of processing effect, the surface quality of the tenon and groove produced by broaching and milling is better than that produced by wire cutting; from the perspective of processing efficiency, broaching efficiency is higher than milling efficiency, and milling efficiency is higher than wire cutting efficiency. Broaching has high manufacturing efficiency and is mostly used in mass production.

[0005] The following difficulties exist in the manufacturing of turbine shafts for large-bore, high-flow marine low-speed turbochargers:

[0006] The turbine shaft has a special structure. The compression end has a longer journal section, while the turbine disc wheel back at the turbine end has only one convex circle. The center of gravity is concentrated on one side, resulting in a top-heavy distribution. The structural dimensions are doubled compared to the external dimensions of existing mature products, and the symmetry centerline of the mortise and tenon is at a certain angle to the axis of the turbine disc. During the broaching process, the forces on both sides are uneven and vary greatly, making it easy to rotate. When processing the mortise and tenon of the turbine shaft, if the long journal end of the compression end is selected for positioning and clamping, the connection space of the machine tool equipment cannot avoid the journal of the compression end of the turbine shaft, and the turbine end positioning and clamping is used. There is no reliable and firm connection and fixing structure, and there is no way to prevent rotation and limit. Summary of the invention

[0007] The purpose of the present invention is to overcome the deficiencies of the prior art and provide a method for processing a turbine shaft of a large-flow supercharger, thereby improving the processing and manufacturing efficiency of the turbine shaft and reducing production costs through batch production.

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

[0009] A method for processing a turbine shaft of a large flow supercharger comprises the following steps:

[0010] S1, processing the welding optical axis blank to obtain the welding optical axis;

[0011] S2, processing the welded turbine disk blank to obtain a welded turbine disk;

[0012] S3, welding the welded optical shaft and the welded turbine disk by friction welding to obtain a welded turbine shaft;

[0013] S4. Process and weld the turbine shaft to obtain a finished turbine shaft.

[0014] Further, step S1 includes:

[0015] S110 rough turning: Take the welding optical axis blank, clamp the outer circle with three jaws, align, and rough turn one end to remove the blank excess, and process it in place without leaving any excess;

[0016] S120 rough turning: turn around, use the three-jaw clamp to turn the outer circle, align it, and rough turn the other end to remove the excess of the blank, and process it in place without leaving any excess to obtain the welding optical axis.

[0017] Further, step S2 includes:

[0018] S210 rough turning: Take the welded turbine disk blank, clamp the outer circle with three jaws, align it, and rough turn one end to remove the large excess of the blank, leaving 1mm excess on the end face and outer circle respectively;

[0019] S220 rough turning: turn the machine, clamp the machined outer circle with three jaws, flatten the end face, align the machined outer circle, rough turn the other end to remove the large excess of the blank, and leave 1mm excess for the end face and outer circle respectively;

[0020] S230 precision turning: soft three-jaw clamping outer circle, aligning the outer circle and the machined end face within 0.05mm, precision turning the vortex end;

[0021] S240 precision turning: Soft three-jaw clamping outer circle, aligning the machined outer circle and the machined end face runout within 0.03mm, precision turning the pressure end, and obtaining the welded turbine disk.

[0022] Further, step S3 includes:

[0023] S310 welding: a. Take the welding turbine disk and welding optical axis, clean and dry their respective welding surfaces; b. Perform the first friction welding;

[0024] S320 heat treatment: stress-free annealing is performed on the welded turbine shaft after friction welding to eliminate the welding stress of the welded turbine shaft and avoid stress affecting the friction welding strength;

[0025] S330 lathe: Turn the outer circle of the weld seam of the first welded turbine shaft to facilitate weld flaw detection;

[0026] S340 flaw detection: Penetrant inspection is performed on the first welded piece, and no crack defects are allowed during the inspection;

[0027] S350 wire cutting: 4 tensile test specimens are cut from the cross section of each welded turbine shaft. The sampling positions of the 4 tensile test specimens are evenly distributed at 90° on the cross-sectional circumferential surface of the friction welding point and are located in the middle of the cross-sectional circumferential surface of the friction welding point.

[0028] S360 turning: turning the specimen to the required size;

[0029] S370 inspection: inspect the strength of the friction welding point of the first weld, including tensile strength, yield strength and elongation;

[0030] If all four tensile test specimens are qualified, repeat the S310-S320 process for batch production; if they are unqualified, repeat the S310-S370 process.

[0031] Further, step S4 includes:

[0032] S410 rough turning: a. Take the finished welded turbine shaft, clamp the outer circle with three jaws, hold the end face, align the large outer circle and end face of the turbine disk, the runout is no more than 0.03mm, and polish a section of the outer circle of the turbine shaft pressure end; b. Set up the center frame, turn the total length to the size requirements, and drill the center hole of the turbine shaft pressure end; c. Push the center hole, remove the center frame, and turn the outer circles and steps of each gear of the turbine shaft pressure end to the requirements;

[0033] S420 rough turning: turn around, clamp the outer circle with three jaws, set up a center stand, align the outer circle of the turbine disk, and make the end face runout no more than 0.05mm, process the outer circle of the turbine disk and the end face of the turbine, and drill the center hole of the turbine end of the turbine shaft;

[0034] S430 grinding: double center clamping, rough grinding of turbine disk outer circle, turbine end face and turbine shaft pressure end two-stage reference circle, used for subsequent finishing process clamping and alignment reference;

[0035] S440 precision turning: soft three-jaw clamps the large outer circle of the turbine disc, the end face is flat, the center hole is pressed, the S430 process has been recalibrated to grind the two-stage reference circle, the runout is no more than 0.02mm, and the pressure end is precision turned;

[0036] S450 finishing turning: turn around, clamp the outer circle with soft three-jaws, set up the center frame to top the center hole, align the outer circle that has been turned and the end face of the turbine disk to a value not greater than 0.05mm, and finish turning the turbine end;

[0037] S460 inspection: Penetration inspection of turbine shaft welds is performed, and no crack defects are allowed during the inspection;

[0038] S470 heat treatment: high frequency quenching of the turbine shaft quenching position;

[0039] S480 lathe: On the lathe, use carbide tips to grind the center holes at both ends of the turbine shaft to repair the center holes that are scratched or roughened during turning and testing, so as to ensure the reliability of the grinding and clamping benchmark in the subsequent process;

[0040] S490 grinding: double center clamping, fine grinding of each gear outer circle and end surface to requirements;

[0041] S4100 CNC milling: soft three-jaw clamping turbine disc outer circle, top center hole, recalibration turbine disc end face and bearing gear reference runout is not greater than 0.015mm, milling triangular pyramid to the requirements;

[0042] S4110 pliers: fit the taper protection sleeve to the triangular pyramidal part processed by S4100 process;

[0043] S4120 precision turning: clamp the large outer circle of the turbine disc with soft three-jaws, set up a center stand, align the reference outer circle of the bearing gear, the runout is no more than 0.02mm, and precision turn the threads and holes at the end of the turbine shaft pressure end to the requirements;

[0044] S4130 inspection: Penetrant flaw detection is performed on the turbine shaft pressure end, turbine end bearing block, and thrust bearing block. No crack defects are allowed during the inspection.

[0045] S4140 CNC milling: After aligning the turbine disc step outer circle runout to no more than 0.02mm, mill the U-shaped positioning groove to the requirement;

[0046] S4150 Broaching: Broach the mortise and tenon groove to the requirements;

[0047] S4160 grinding machine: double center clamping, grinding to remove the burrs on the end face of the wheel after the mortise and tenon broaching;

[0048] S4170 fine turning: clamp the outer circle with soft three-jaws, set up the center frame, find the reference circle of the bearing gear and make sure it is not more than 0.01mm, then fine turn it and polish away the quenching induction color at the quenching position;

[0049] S4180 pliers: Deburr and remove the taper protection cover.

[0050] Furthermore, in the S450 process, an external thread process stub is finely turned on the outer circle of the turbine disc journal, and the external thread process stub is used for the subsequent process of mortise and tenon broaching and connection and fixing;

[0051] A process boss is provided on the inner ring of the turbine disc wheel back at the turbine end. In the S4140 process, a U-shaped positioning anti-rotation groove is milled on the process boss. The U-shaped anti-rotation groove is used in the subsequent mortise and tenon drawing process, and cooperates with the turbine shaft mortise and tenon drawing tool for anti-rotation limiting.

[0052] In the S4170 process, the process flanges, process bosses and internal threaded holes are removed by turning and processed to the requirements.

[0053] Further, step S1 includes S130 fine turning: taking a new welding optical shaft blank, clamping it with three jaws, aligning it, processing a high-frequency quenching test bar, turning both ends around and turning them, and obtaining a turbine shaft high-frequency quenching test bar, which is required to have a structure consistent with the journal structure of the turbine shaft;

[0054] In the S470 process, a test rod is first used for trial processing. After passing the inspection and meeting the requirements, high-frequency quenching is performed on the quenching position of the turbine shaft.

[0055] Due to the adoption of the above technical solution, the present invention has the following beneficial effects:

[0056] Due to the particularity of the parts structure, in view of the problems and difficulties in the processing of the turbine shaft of the above large-bore, large-flow marine low-speed engine turbocharger, the purpose of the present invention is to overcome the shortcomings of the prior art and provide a new turbine shaft processing method in combination with the company's equipment, by setting a process boss on the inner ring of the back of the turbine end of the welded turbine disk and milling a U-shaped groove, and setting a sufficient process margin on the outer circle of the turbine end wheel disc shaft end to fine-machine M85x3 external threads as a process connection and fixing bracket, which successfully solves the problems of difficult positioning and clamping of the mortise and tenon of the turbine shaft of the large-flow supercharger by broaching, and the lack of a firm and reliable positioning, connection, and anti-rotation limiting structure.

[0057] The present invention also provides a detailed and comprehensive set of processing methods using friction welding and mortise and tenon broaching for turbine shafts of large-bore, large-flow marine low-speed engine turbochargers, and is intended to make up for the deficiencies and gaps in the prior art.

[0058] The present invention, through method innovation and reasonable design of process sequence, sets a process boss on the inner ring of the wheel back of the turbine end of the welded turbine disk and mills a U-shaped groove, and sets a sufficient process margin on the outer circle of the turbine end wheel disk shaft end to fine-machine M85x3 external threads as process connection fixing parts. The problem of difficult positioning and clamping and lack of firm and reliable positioning, connection and fixing structure in the mortise and tenon processing of the turbine shaft of a large-flow supercharger is successfully solved by broaching, thereby greatly improving the processing and manufacturing efficiency of the turbine shaft and reducing production costs through mass production.

[0059] The present invention also provides a detailed and comprehensive set of processing methods using friction welding and mortise and tenon broaching for turbine shafts of large-bore, large-flow marine low-speed engine turbochargers, and is intended to make up for the deficiencies and gaps in the prior art. BRIEF DESCRIPTION OF THE DRAWINGS

[0060] Figure 1 Schematic diagram of turbine shaft assembly structure;

[0061] Figure 2 Schematic diagram of turbine shaft structure;

[0062] Figure 3 Schematic diagram of the welding optical axis blank structure;

[0063] Figure 4 Schematic diagram of welding optical axis structure;

[0064] Figure 5 Schematic diagram of the welded turbine disk blank structure;

[0065] Figure 6 Schematic diagram of welded turbine disk structure;

[0066] Figure 7 Schematic diagram of welded turbine shaft structure;

[0067] Figure 8 Method flow chart;

[0068] Fig. 9 Figure 10 of the welding process of optical axis;

[0069] Fig.10 Figure 20 of the welding process of optical axis;

[0070] Fig.11 Figure 30 of the welding process of the optical axis;

[0071] Fig.12 Figure 10 of the process of welding turbine disk;

[0072] Fig.13 Figure 20 of the process of welding turbine disk;

[0073] Fig.14 Figure 30 of the process of welding turbine disk;

[0074] Fig.15 Figure 40 of the process of welding turbine disk;

[0075] Fig.16 Turbine shaft 10 process diagram;

[0076] Fig.17 Turbine shaft 20 process diagram;

[0077] Fig.18 Turbine shaft 30 process diagram;

[0078] Fig.19 Turbine shaft 40 process diagram;

[0079] Fig. 20Turbine shaft 50 process diagram;

[0080] Fig.21 Turbine shaft 90 process diagram;

[0081] Fig. 22 Turbine shaft 120 process diagram;

[0082] Fig.23 Turbine shaft 140 process diagram;

[0083] Fig.24 Turbine shaft 170 process diagram;

[0084] Fig.25 Schematic diagram of clamping positioning symbols. DETAILED DESCRIPTION

[0085] A method for processing a turbine shaft of a large-flow supercharger, the method flow is as follows: (1) processing a welding optical shaft blank to obtain a welding optical shaft; (2) processing a welding turbine disk blank to obtain a welding turbine disk; (3) assembling the welding optical shaft and the welding turbine disk by friction welding to obtain a welding turbine shaft; (4) processing the welding turbine shaft to obtain a turbine shaft.

[0086] Specific process steps:

[0087] S1. Welding optical axis processing steps: Figure 3 The forged welded optical shaft blank shown in the figure is processed according to the following process: 10 rough turning → 20 rough turning → 30 fine turning → 40 clamping. The specific process steps are as follows:

[0088] 1)10 Rough turning: Three-jaw clamp outer circle, align, press Fig. 9 Welding optical axis 10 process diagram Rough turning one end to remove the blank allowance, and process it in place without leaving any allowance;

[0089] 2)20 Rough turning: Turn around, use three-jaw clamp to turn the outer circle, align, press Fig.10 The welding optical axis 20 process is shown in the figure. The other end is rough-turned to remove the blank surplus, and the surplus is not left to be processed in place to obtain the welding optical axis;

[0090] 3)30 fine turning: re-use one piece Figure 3 The forged welding shaft blank is clamped with three jaws, aligned, and pressed. Fig.11The welding optical axis 30 process diagram is processed with a high-frequency quenching test bar, and the two ends are turned around to connect the car to obtain a turbine shaft high-frequency quenching test bar (because the turbine shaft must have a certain wear resistance and high hardness to meet the use requirements, the turbine shaft bearing gear must be quenched, and a certain quenching depth and hardness are required. Therefore, in order to ensure that the processed turbine shaft meets the design requirements, a turbine shaft high-frequency quenching test bar is required to be processed. The test bar structure is required to be consistent with the journal structure of the turbine shaft, but it should be noted that the outer circle of each high-frequency quenching gear has a 0.3mm grinding allowance; the high-frequency quenching test bar is used for the subsequent turbine shaft 70 heat treatment process as a high-frequency quenching specimen for quenching dissection to detect hardness and quenching depth);

[0091] 4) 40 pliers: engrave the drawing number and batch number at the illustrated position of the part and on the outer circle of the 65mm high-frequency quenching test rod.

[0092] S2. Processing steps of welding turbine disc: Figure 5 The forged welded turbine disk blank shown is processed according to the following process: 10 rough turning → 20 rough turning → 30 fine turning → 40 fine turning → 50 clamping.

[0093] The specific process steps are as follows:

[0094] 1)10 Rough turning: clamp the outer circle with claws, align, press Fig.12 Welding turbine disk 10 process diagram Rough turning one end to remove the large margin of the blank, leaving 1mm margin on the end face and outer circle;

[0095] 2)20 Rough turning: Turn around, clamp the machined outer circle with three jaws, flatten the end face, align the machined outer circle, press Fig.13 Welding turbine disk 20 process diagram Rough turning the other end to remove the large margin of the blank, leaving 1mm margin on the end face and outer circle;

[0096] 3)30 Fine turning: Soft three-jaw clamp outer circle, find the outer circle and its left end face runout within 0.05mm, press Fig.14 Welding turbine disc 30 process diagram finishing turning turbine end;

[0097] 4) 40 fine turning: Soft three-jaw clamp outer circle, align the large outer circle and the left end of the machined end face within 0.03mm, press Fig.15 Welding turbine disk 40 process diagram Precision turning the pressure end to obtain a welded turbine disk;

[0098] 5) 50 pliers: blunt the sharp edges of parts, remove burrs, and engrave part numbers and batch numbers according to the drawing requirements.

[0099] S3, welding turbine shaft processing steps: use the processed Figure 4 Welding optical axis, Figure 6The welding of turbine discs follows the following processing flow: 10 welding → 20 heat treatment → 30 turning → 40 flaw detection → 50 wire cutting → 60 turning → 70 inspection → 80 welding → 90 heat treatment.

[0100] The specific process steps are as follows:

[0101] 1) 10 Welding: a. Take out the welding turbine disk and welding optical shaft, clean the welding surfaces with acetone and dry them; b. Perform the first friction welding according to the quality and strength requirements of the turbine shaft friction welding specification and the C2500 friction welding operation instructions.

[0102] 2)20 Heat treatment: Heat treatment is carried out according to the turbine shaft friction welding specifications, and stress-free annealing is performed on the welded turbine shaft after friction welding to eliminate the welding stress of the welded turbine shaft and avoid stress affecting the friction welding strength.

[0103] 3) 30 Turning: Turn the outer diameter of the weld of the first welded turbine shaft to Ф71.2. Turning is convenient for flaw detection.

[0104] 4) 40 NDT: Perform penetration test on the first welded piece according to the NDT specification. No cracks or other defects are allowed during the test.

[0105] 5) 50 wire cutting: According to the turbine shaft friction welding specification, 4 tensile test specimens are cut from the cross section of each welded turbine shaft. The sampling positions of the 4 tensile test specimens are evenly distributed at 90° on the friction welding cross-sectional circumferential surface and in the middle of the friction cross-sectional circumferential surface. The sample size is cut according to the circular cross-section proportional sample R4 in the "GB / T228.1-2010 Metal Material Tensile Test" standard;

[0106] 6) 60 lathe: According to the standard of "GB / T228.1-2010 Tensile Test of Metal Materials", the circular cross-section proportional specimen R4 is turned to the required size;

[0107] 7) 70 inspection: Inspect the mechanical properties of the first welded piece, i.e. the strength of the friction welding point, tensile strength, yield strength and elongation, according to the turbine shaft friction welding specification requirements; if all four test samples are qualified, the first friction welded turbine shaft is qualified before 80 and subsequent processes can be carried out. If it fails, repeat processes 10-70.

[0108] 8) 80 welding: a. Take out the welded turbine disk and the welded optical shaft, clean the welding surfaces with acetone and dry them; b. Carry out batch friction welding according to the quality and strength requirements of the turbine shaft friction welding specification and the C2500 friction welding operation instructions.

[0109] 9) 90 heat treatment: heat treatment is carried out according to the turbine shaft friction welding specifications, and stress-free annealing is performed on the welded turbine shaft after friction welding to eliminate the welding stress of the welded turbine shaft.

[0110] S4, turbine shaft processing steps: use the finished Figure 7 The welding of turbine shaft follows the following processing flow: 10 rough turning → 20 rough turning → 30 grinding → 40 fine turning → 50 fine turning → 60 inspection → 70 heat treatment → 80 turning → 90 grinding → 100 CNC milling → 110 clamping → 120 fine turning → 130 inspection → 140 CNC milling → 150 broaching → 160 grinding → 170 fine turning → 180 clamping.

[0111] The specific process steps are as follows:

[0112] 1) 10 Rough turning: a. Press Fig.16 Turbine shaft 10 process drawing, three-claw clamp outer circle, hold the end face, align A circle and B surface, the runout is no more than 0.03mm, and polish a section of the outer circle; b, build a center frame, turn the total length to the size, and drill the center hole B4 / 12.5; c, push the center hole, remove the center frame, press Fig.16 Turbine shaft 10 process diagram Turn the remaining outer circle and steps to the requirements;

[0113] 2) 20 Rough turning: Turn around, clamp the outer circle with three jaws, set up the center frame, align the A circle and B surface, and make sure the runout is no more than 0.05mm. Fig.17 The turbine shaft 20 is processed as shown in the process diagram, and the center hole B4 / 12.5 is punched;

[0114] 3) 30 grinding: double center clamping, press Fig.18 The turbine shaft 30 process is roughly ground, and the end face and outer circle shown in the figure are polished for clamping and aligning the reference in the subsequent fine turning process;

[0115] 4) 40 precision turning: soft three-jaw clamp the large outer circle of the turbine disc, flatten the end face, top center hole, recalibrate the 30 process to grind two-stage reference circle, the runout is no more than 0.02mm, press Fig.19 Turbine shaft 40 process drawing finishing turning pressure end;

[0116] 5) 50 fine turning: turn the machine, clamp the outer circle with soft three-jaw, set up the center frame to top the center hole, align the outer circle and the end face of the turbine disk, and the runout should not exceed 0.05mm. Fig. 20 The attached figure of process 50 of turbine shaft shows the turbine end of fine turning. Note: In order to solve the problem of turbine shaft tenon-groove broaching and fixing connection, sufficient process margin has been reserved for the large outer circle of turbine end turbine disc when designing and processing the welded turbine disc, and the M85x3 external thread process connection scaffold is prepared for fine turning of this process. The M85x3 external thread process connection scaffold is used for the subsequent process of tenon-groove broaching and connection and fixing. The M85x3 external thread process connection scaffold successfully solves the problem of turbine shaft tenon-groove broaching using turbine end positioning without reliable and firm connection and fixing scheme;

[0117] 6) 60 inspection: Perform penetration inspection on turbine shaft welds according to the flaw detection inspection specifications. No defects such as cracks are allowed during the inspection.

[0118] 7) 70 heat treatment: perform high-frequency quenching on the turbine shaft quenching position according to the requirements of the drawing; Note: a. A 0.25mm margin is left on one side of the outer diameter of the quenching gear journal. The quenching parameters and other settings need to consider grinding to ensure that the quenching hardness and quenching depth are met; b. Before processing the genuine turbine shaft, first use the high-frequency quenching sample processed by the 30 process of fine turning during the welding optical shaft processing in the S1 process for trial processing. Only after the sample is tested and meets the requirements, can the genuine turbine shaft be processed; c. Deformation must be controlled during processing, and two ejector pins must be checked. The outer diameter runout of each gear of the turbine shaft is required to be no more than 0.06mm. max0.2X45°

[0119] 8) 80 lathe: Use a common lathe to grind the center holes at both ends of the turbine shaft with a carbide tip to repair the center holes that are scratched or roughened during turning and testing, thereby ensuring a reliable grinding and clamping benchmark for subsequent processes;

[0120] 9) 90 grinding: double center clamping, press Fig.21 Turbine shaft 90 process diagram Fine grinding of each gear outer circle and end surface to the requirements, Note: a. Turbine disc 47.606±0.05 thickness, the margin on both sides is evenly divided and ground; b. Use oilstone to remove the sharp edge produced by grinding max0.2X45;

[0121] 10) 100 CNC milling: clamp the outer circle of the turbine disc with soft three-jaws, top the center hole, recalibrate the end face of the turbine disc and the reference P and Q of the bearing gear, and the runout is not greater than 0.015mm. Mill the triangular pyramid to the requirements of the drawing;

[0122] 11) 110 pliers: put the taper protection sleeve on the triangular pyramid part after 100 process;

[0123] 12) 120 precision turning: soft three-jaw clamp the outer circle of the turbine disc, set up the center frame (support reference circle P), align the outer circle of the bearing gear reference P and Q, the runout is no more than 0.02mm, press Fig. 22 Turbine shaft 120 process diagram Finish turning the threads and holes at the pressure end of the turbine shaft to the requirements;

[0124] 13) 130 inspection: Perform penetrant inspection on the turbine shaft pressure end and turbine end bearings and thrust bearings according to the flaw detection inspection specifications. No cracks or other defects are allowed during the inspection.

[0125] 14) 140 digital milling: Position the milling tool, find the outer circle Ф239.04 (0 / -0.029) and the runout is no more than 0.02mm, press Fig.23The attached figure of process 140 of the turbine shaft shows milling of U-shaped positioning groove to the requirements. Note: In order to solve the problem that the turbine shaft tenon and groove cannot be prevented from rotating during broaching, the turbine disc is larger in diameter and thicker in thickness, and the turbine shaft is subjected to great force during broaching, resulting in abnormal deviation of the contour shape of the tenon and groove broaching. A process boss is set on the inner ring of the turbine disc wheel back during the design and processing of the welded turbine disc, and a U-shaped positioning anti-rotation groove is milled on the process boss in preparation for this process. The U-shaped anti-rotation groove is used for the subsequent process of tenon and groove broaching and the turbine shaft tenon and groove pulling tool for anti-rotation limiting, which successfully solves the abnormal rotation contour of the tenon and groove broaching parts of the turbine shaft.

[0126] 15) 150 broaching: Clamp and position the upper turbine shaft tenon and groove drawing tool, and broach the tenon and groove to the required size according to the drawing. Note: a. Before processing each batch of parts, it is necessary to first use the turbine shaft tenon and groove trial cutting pieces for trial pulling, and then project the slices to detect the tenon and groove contour. Only after passing the test can the turbine shaft tenon and groove be broached; b. When assembling and positioning the turbine shaft, the turbine shaft U-shaped positioning groove must be limited with the tooling positioning pin;

[0127] 16) 160 grinding: double center clamping, grinding to remove the burrs on the end face of the wheel after the mortise and tenon broaching. Note: the thickness of the wheel must be guaranteed;

[0128] 17) 170 fine turning: clamp the outer circle with soft three-jaw (copper pad), set up the center frame, find the reference circle of the bearing gear P and Q and the runout is no more than 0.01mm, press Fig.24 Processing diagram of turbine shaft 170: a. Fine turning, removing the process saddles and internal threaded holes on the inner ring of the turbine disc wheel back and the outer circle of the turbine disc journal to the requirements; b. Polishing and removing the quenching induction color at the quenching position shown in the figure, paying attention to protecting the grinding surface.

[0129] 18) 180 pliers: a. Engrave at the position shown in the drawing as required; b. Remove all burrs and remove the taper protection cover.

[0130] 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. A method for processing a turbine shaft of a large flow supercharger, characterized in that: The following steps are involved: S1, processing the welding optical axis blank to obtain the welding optical axis; S2, processing the welded turbine disk blank to obtain a welded turbine disk; S3, welding the welded optical shaft and the welded turbine disk by friction welding to obtain a welded turbine shaft; S4. Process and weld the turbine shaft to obtain a finished turbine shaft.

2. The method for processing a turbine shaft of a large flow supercharger according to claim 1, characterized in that: Step S1 includes: S110 rough turning: Take the welding optical axis blank, clamp the outer circle with three jaws, align, and rough turn one end to remove the blank excess, and process it in place without leaving any excess; S120 rough turning: turn around, the three-jaw clamp has turned the outer circle, align it, and rough turn the other end to remove the excess of the blank, and process it in place without leaving any excess to obtain the welding optical axis.

3. The method for processing a turbine shaft of a large flow supercharger according to claim 1, characterized in that: Step S2 includes: S210 rough turning: Take the welded turbine disc blank, clamp the outer circle with three jaws, align it, and rough turn one end to remove the large excess of the blank, leaving 1mm excess on the end face and outer circle respectively; S220 rough turning: turn the machine, clamp the machined outer circle with three jaws, flatten the end face, align the machined outer circle, and rough turn the other end to remove the large excess of the blank, leaving 1mm excess for the end face and outer circle respectively; S230 precision turning: soft three-jaw clamping outer circle, aligning the outer circle and the machined end face within 0.05mm, precision turning the vortex end; S240 precision turning: Soft three-jaw clamping outer circle, aligning the machined outer circle and the machined end face runout within 0.03mm, precision turning the pressure end, and obtaining the welded turbine disk.

4. The method for processing a turbine shaft of a large flow supercharger according to claim 1, characterized in that: Step S3 includes: S310 welding: a. Take the welding turbine disk and welding optical axis, clean and dry their respective welding surfaces; b. Perform the first friction welding; S320 heat treatment: stress-free annealing is performed on the welded turbine shaft after friction welding to eliminate the welding stress of the welded turbine shaft and avoid stress affecting the friction welding strength; S330 lathe: Turn the outer circle of the weld seam of the first welded turbine shaft to facilitate weld flaw detection; S340 flaw detection: Penetrant inspection is performed on the first welded piece, and no crack defects are allowed during the inspection; S350 wire cutting: 4 tensile test specimens are cut from the cross section of each welded turbine shaft. The sampling positions of the 4 tensile test specimens are evenly distributed at 90° on the cross-sectional circumferential surface of the friction welding point and are located in the middle of the cross-sectional circumferential surface of the friction welding point. S360 turning: turning the specimen to the required size; S370 inspection: inspect the strength of the friction welding point of the first weld, including tensile strength, yield strength and elongation; If all four tensile test specimens are qualified, repeat the S310-S320 process for batch production; if they are unqualified, repeat the S310-S370 process.

5. The method for processing a turbine shaft of a large flow supercharger according to claim 1, characterized in that: Step S4 includes: S410 rough turning: a. Take the finished welded turbine shaft, clamp the outer circle with three jaws, hold the end face, align the large outer circle and end face of the turbine disk, the runout is no more than 0.03mm, and polish a section of the outer circle of the turbine shaft pressure end; b. Set up the center frame, turn the total length to the size requirements, and drill the center hole of the turbine shaft pressure end; c. Push the center hole, remove the center frame, and turn the outer circles and steps of each gear of the turbine shaft pressure end to the requirements; S420 rough turning: turn around, clamp the outer circle with three jaws, set up a center stand, align the outer circle of the turbine disk, and make the end face runout no more than 0.05mm, process the outer circle of the turbine disk and the end face of the turbine, and drill the center hole of the turbine end of the turbine shaft; S430 grinding: double center clamping, rough grinding of turbine disk outer circle, turbine end face and turbine shaft pressure end two-stage reference circle, used for subsequent finishing process clamping and alignment reference; S440 precision turning: soft three-jaw clamps the large outer circle of the turbine disc, the end face is flat, the center hole is pressed, the S430 process has been recalibrated and the two-stage reference circle has been ground, the runout is no more than 0.02mm, and the pressure end is precision turned; S450 finishing turning: turn around, clamp the outer circle with soft three-jaws, set up the center frame to top the center hole, align the outer circle that has been turned and the end face of the turbine disk to a value not greater than 0.05mm, and finish turning the turbine end; S460 inspection: Penetration inspection of turbine shaft welds is performed, and no crack defects are allowed during the inspection; S470 heat treatment: high frequency quenching of the turbine shaft quenching position; S480 lathe: On the lathe, use carbide tips to grind the center holes at both ends of the turbine shaft to repair the center holes that are scratched or roughened during turning and testing, so as to ensure the reliability of the grinding and clamping benchmark in the subsequent process; S490 grinding: double center clamping, fine grinding of each gear outer circle and end surface to requirements; S4100 CNC milling: soft three-jaw clamping turbine disc outer circle, top center hole, recalibration turbine disc end face and bearing gear reference runout is not greater than 0.015mm, milling triangular pyramid to the requirements; S4110 pliers: fit the taper protection sleeve to the triangular pyramidal part processed by S4100 process; S4120 precision turning: clamp the large outer circle of the turbine disc with soft three-jaws, set up a center stand, align the reference outer circle of the bearing gear, the runout is no more than 0.02mm, and precision turn the threads and holes at the end of the turbine shaft pressure end to the requirements; S4130 inspection: Penetrant flaw detection is performed on the turbine shaft pressure end, turbine end bearing block, and thrust bearing block. No crack defects are allowed during the inspection. S4140 CNC milling: After aligning the turbine disc step outer circle runout to no more than 0.02mm, mill the U-shaped positioning groove to the requirement; S4150 Broaching: Broach the mortise and tenon groove to the requirements; S4160 grinding machine: double center clamping, grinding to remove the burrs on the end face of the wheel after the mortise and tenon broaching; S4170 fine turning: clamp the outer circle with soft three-jaws, set up the center frame, find the reference circle of the bearing gear and make sure it is not more than 0.01mm, then fine turn it and polish away the quenching induction color at the quenching position; S4180 pliers: Deburr and remove the taper protection cover.

6. The method for processing a turbine shaft of a large flow supercharger according to claim 5, characterized in that: In the S450 process, the outer circle of the turbine disc journal is finely machined with an external thread process, which is used for the subsequent process of mortise and tenon broaching and connection and fixation; A process boss is provided on the inner ring of the turbine disc wheel back at the turbine end. In the S4140 process, a U-shaped positioning anti-rotation groove is milled on the process boss. The U-shaped anti-rotation groove is used in the subsequent mortise and tenon drawing process, and cooperates with the turbine shaft mortise and tenon drawing tool for anti-rotation limiting. In the S4170 process, the process flanges, process bosses and internal threaded holes are removed by turning and processed to the requirements.

7. The method for processing a turbine shaft of a large flow supercharger according to claim 5, characterized in that: Step S1 includes S130 fine turning: taking a new welding optical shaft blank, clamping it with three jaws, aligning it, processing a high-frequency quenching test bar, turning the two ends around and connecting the two ends, and obtaining a turbine shaft high-frequency quenching test bar, which is required to have the same structure as the journal structure of the turbine shaft; In the S470 process, a test rod is first used for trial processing. After the test is qualified and meets the requirements, high-frequency quenching is performed on the quenching position of the turbine shaft.

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