A process method for a high-precision ultra-thin anti-overflow oil pipe of a pumped storage unit

Abstract

The application relates to a process method of a high-precision ultra-thin anti-overflow oil pipe of a pumped storage unit, and belongs to the field of pumped storage generator motor manufacturing.The application realizes the process of integrated finishing of a 20mm-thickness high-precision ultra-thin anti-overflow oil pipe and a sleeve main shaft, solves the problem of large welding deformation of the sleeve main shaft after the ultra-thin anti-overflow oil pipe is finished, solves the problem of the difficulty in supporting and fixing the sleeve on the main shaft, and solves the problem of stress concentration deformation of the ultra-thin anti-overflow oil pipe during turning processing.The process method completely breaks through the technical bottleneck of low machining precision and post-installation oil overflow of the ultra-thin anti-overflow oil pipe, greatly reduces the operation and maintenance cost of the unit during operation after installation, achieves a good effect and expectation of one-off, and obviously improves the stability of the pumped storage generator motor operation.

Description

Technical Field

[0001] This invention belongs to the field of pumped storage unit manufacturing, specifically relating to a manufacturing process for a high-precision, ultra-thin anti-overflow oil pipe. Background Technology

[0002] Currently, most pumped storage turbine projects use a two-part process to assemble the ultra-thin anti-overflow oil pipe into a single round shape. After processing, the pipe is disassembled, fitted onto the main shaft, and the welded joint surface is then ground. The advantage of this method is that it is not limited by the main shaft, and the ultra-thin anti-overflow oil pipe processing can be completed in a single piece. However, the disadvantages are: completing the process in one step leads to stress concentration, especially in thin-walled pipes, which can deform over time; the ultra-thin anti-overflow oil pipe fitted onto the main shaft requires full welding of the beveled joint surface, which can cause secondary deformation due to welding temperature; and the grinding of the joint surface can easily create uneven spots, resulting in poor roundness and perpendicularity of the ultra-thin anti-overflow oil pipe. This causes agitation of the oil flow in the oil tank, increasing the risk of overflow. Once the oil tank overflows, it contaminates the stator, rotor, upper and lower guide bearings, and water sources.

[0003] Therefore, developing a new high-precision, ultra-thin anti-overflow oil pipe manufacturing process to solve the above problems is of great practical significance. Summary of the Invention

[0004] To address the problems of low machining precision and oil spillage during use in 20mm thick ultra-thin anti-overflow oil pipes for pumped storage units, this invention provides a high-precision manufacturing process for ultra-thin anti-overflow oil pipes. The method is implemented through the following steps:

[0005] S1. Machining the joint surface of the two halves of the ultra-thin anti-overflow oil pipe: The semi-finished blank of the ultra-thin anti-overflow oil pipe is mounted at equal intervals along the X-axis in the CNC machining center, and milled at equal intervals along the Y-axis of the semi-finished blank of the ultra-thin anti-overflow oil pipe; Welding the joint plate at the joint of the ultra-thin anti-overflow oil pipe, the joint plate has a central joint hole, and the two halves of the ultra-thin anti-overflow oil pipe are combined into a whole;

[0006] S2. Machining the inner circle and upper end face of the ultra-thin anti-overflow oil pipe to the finished size, mounting the ultra-thin anti-overflow oil pipe in the CNC machining center, and turning the ultra-thin anti-overflow oil pipe by turning.

[0007] S3, a three-axis CNC machining center drills and taps 24 threaded engagement holes on the flange of an ultra-thin anti-overflow oil pipe that are associated with the generator connection; a CNC machining center drills and taps 10 threaded engagement holes on the small end cylinder wall plate of the ultra-thin anti-overflow oil pipe that are supported by the spindle.

[0008] S4. Fabricate an ultra-thin anti-overflow oil pipe and a main spindle body fixing device, weld a fixing plate and a support plate, drill 18 ultra-thin anti-overflow oil pipe connection holes on the fixing plate, and drill 9 support thread process holes on the support plate.

[0009] S5. The ultra-thin anti-overflow oil pipe sleeve is welded into the main shaft as a whole: the two ultra-thin anti-overflow oil pipe sleeves are put into the main shaft body and assembled into a whole on the shaft body; the support plate of the fixing device is used to support the main shaft body; the bevel of the oil baffle pipe parting surface is fully welded, the welded part is ground, and the joint plate is removed.

[0010] S6. Adjust the concentricity of the inner circle of the ultra-thin anti-overflow oil pipe with the spindle body, and install the small end cylinder wall support bolt of the ultra-thin anti-overflow oil pipe to firmly support the ultra-thin anti-overflow oil pipe on the spindle body.

[0011] S7. Mount the generator spindle, which is now complete with the ultra-thin anti-overflow oil pipe, onto a CNC horizontal lathe and machine the flange end face, flange outer circle, and pipe outer circle of the ultra-thin anti-overflow oil pipe by turning.

[0012] S8. Remove the support from the small end of the ultra-thin anti-overflow oil pipe, plug the process hole, and polish the weld; after processing is completed, inspect the finished product.

[0013] In the above-mentioned process for high-precision ultra-thin anti-overflow oil pipes for pumped storage units, in step S1, the CNC machining center is a three-axis CNC machining center, the cutting tool is high-speed steel, the cutting depth is 0.5mm-0.8mm, the feed rate is 20mm / min-40mm / min, and the spindle speed is 650r / min-800r / min.

[0014] In the above-mentioned process method for high-precision ultra-thin anti-overflow oil pipes for pumped storage units, step S1, which involves assembling the two ultra-thin anti-overflow oil pipes into a whole, consists of two steps:

[0015] S11. Grind the surface of the welding area to expose a metallic luster, weld the joint plate on both sides of the joint of the ultra-thin anti-overflow oil pipe, and make a 15mm fillet weld on three sides using arc welding.

[0016] S12. Insert the fitting bolts into the fitting holes of the paired joint plates and tighten them with nuts. There is no gap in the joint surface. The two ultra-thin anti-overflow oil pipes are combined into a whole.

[0017] In the above-mentioned process for high-precision ultra-thin anti-overflow oil pipes of pumped storage units, in step S2, the CNC machining center is a vertical lathe CNC machining center, the cutting tool is high-speed steel, the cutting depth is 0.8mm-1.0mm, the feed rate is 30mm / min-50mm / min, and the spindle speed is 350r / min-400r / min.

[0018] In the above-mentioned process method for high-precision ultra-thin anti-overflow oil pipes for pumped storage units, step S3, which involves drilling and tapping 10 threaded engagement holes on the small end wall plate of the ultra-thin anti-overflow oil pipe that are supported by the main shaft, is divided into two steps:

[0019] S31. The dimension L of the threaded engagement hole of the main shaft support is determined by the position of the center of gravity through equal weight balance calculation. The ultra-thin anti-overflow oil pipe has uniform thickness and density, and can be calculated by the following formula: ΔG1*ΔL1=ΔG2*ΔL2

[0020] ΔG=ΔV*ρ, ΔV=ΔL*2π*ΔR*σ

[0021] In the formula: ΔG(ΔG1,ΔG2) is the weight of the ultra-thin spill containment pipe in kilograms; ΔL(ΔL1,ΔL2) is the length of the centroid coordinate point in millimeters; ρ is the density of the steel plate of the ultra-thin spill containment pipe in kg / mm². 3 ΔV represents the solid volume of the ultra-thin anti-overflow oil pipe, in mm. 3 ; ΔH is the thickness of the ultra-thin oil spill prevention pipe plate, in millimeters; ΔR is the inner radius of the ultra-thin oil spill prevention pipe, in millimeters; σ is the thickness of the ultra-thin oil spill prevention pipe plate, in millimeters.

[0022] S32, the drilling and tapping CNC machining center is a three-axis CNC machining center. The cutting tools used are high-speed steel twist drill bits and high-speed steel machine taps. The cutting feed rate is 30mm / min-50mm / min, and the spindle speed is 450r / min-700r / min.

[0023] In the above-mentioned process for high-precision ultra-thin anti-overflow oil pipes in pumped storage units, step S4, which involves fabricating the ultra-thin anti-overflow oil pipe and the main shaft fixing device, consists of two steps:

[0024] S41. Fabricate the fixing plate and support plate;

[0025] S42, Welding fixing plates and support plates, a total of 9 sets;

[0026] S42. Drill two ultra-thin anti-overflow oil pipe connection holes on the fixed plate, and drill one support thread process hole on the support plate.

[0027] In the above-mentioned process method for high-precision ultra-thin anti-overflow oil pipes in pumped storage units, the welding of the S5 ultra-thin anti-overflow oil pipe sleeve main shaft assembly into a whole involves the following steps:

[0028] S51. Two ultra-thin anti-overflow oil pipes are fitted onto the spindle body and adjusted to the appropriate position for temporary support and fixation to prevent slippage.

[0029] S52. Insert the fitting bolts into the fitting holes of the pair of joint plates and tighten them with nuts. There is no gap in the joint surface. The two ultra-thin anti-overflow oil pipes are combined into a whole.

[0030] S53. Support the support plate of the fixing device to the main shaft body by shaft bolts;

[0031] S54, V-groove bidirectional full weld: The bevel treatment removes oxide scale, oil and other harmful impurities from the bevel and the base material surface on both sides within a range of at least 20mm (calculated from the distance from the edge of the bevel), and grinds to expose the metallic luster. Preheating temperature: 150℃~230℃. When manual arc welding, the wind speed is less than 6m / s and the relative humidity is less than 85%, the welding is carried out at a uniform speed.

[0032] S55. After grinding, polishing and cleaning the weld seam, perform UT and MT flaw detection, and finally check the quality of the weld seam of the hydrostatic liquid ultra-thin anti-overflow oil pipe for kerosene leakage.

[0033] In the above-mentioned process method for high-precision ultra-thin anti-overflow oil pipe of pumped storage unit, the step S6 of adjusting the concentricity of the inner circle of ultra-thin anti-overflow oil pipe with the main shaft body is divided into two steps:

[0034] S61. Adjust the concentricity of the inner circle of the high-precision ultra-thin anti-overflow oil pipe with the spindle shaft to 0.02mm;

[0035] S62. Use cylinder wall support bolts and shaft bolts to support and fix the high-precision ultra-thin anti-overflow oil pipe to the main shaft, and use copper sheet and steel plate to protect the shaft surface.

[0036] In the above-mentioned process method for high-precision ultra-thin anti-overflow oil pipes for pumped storage units, step S7 involves mounting the spindle, after the ultra-thin anti-overflow oil pipes are installed, onto an 18-meter horizontal CNC machining center, which is divided into the following steps:

[0037] S71. The selected CNC horizontal machining center is an 18-meter horizontal lathe machining center. The cutting tool is made of carbide steel, the cutting depth is 0.5mm-0.8mm, the feed rate is 20mm / min-40mm / min, and the spindle speed is 650r / min-800r / min.

[0038] S72. Spindle mounting and alignment: bracket mouth circular runout ≤ 0.03mm;

[0039] S73. For the flange end face, flange outer circle and pipe outer circle of the rough-machined ultra-thin anti-overflow oil pipe, in order to avoid stress concentration in the material plate and circumferential deformation after the hollow cylinder is machined, static aging for 12 hours is performed to release stress.

[0040] S74, the flange end face, flange outer circle and pipe outer circle of precision-machined ultra-thin anti-overflow oil pipe.

[0041] In the above-mentioned process method for high-precision ultra-thin anti-overflow oil pipes in pumped storage units, the steps of S8—removing the small end wall support of the ultra-thin anti-overflow oil pipe, plugging the process hole, and polishing the weld joint—are divided into two steps:

[0042] S81 Remove the support bolts on the small end of the ultra-thin anti-overflow oil pipe;

[0043] S82 plug welds fully support the threaded process hole, and the weld joint is polished.

[0044] Compared with the prior art, the present invention has the following advantages:

[0045] This invention proposes a process for manufacturing high-precision ultra-thin anti-overflow oil pipes for pumped-storage hydroelectric power units. This process achieves integrated precision machining of a 20mm thick high-precision ultra-thin anti-overflow oil pipe fitted onto the main shaft, solving the problems of large deformation during welding after precision machining of the ultra-thin anti-overflow oil pipe onto the main shaft, difficulties in supporting and fixing the ultra-thin anti-overflow oil pipe on the main shaft, and stress concentration deformation during turning of the ultra-thin anti-overflow oil pipe. This process completely overcomes the technical bottlenecks of low machining precision and oil leakage after installation of ultra-thin anti-overflow oil pipes, significantly reducing the operation and maintenance costs of the unit during post-installation operation, achieving a long-term solution and significantly improving the operational stability of the pumped-storage power generator. Attached Figure Description

[0046] Figure 1 This is a schematic diagram of a single ultra-thin anti-overflow oil pipe according to the present invention;

[0047] Figure 2 This is a schematic diagram of the spindle process for the ultra-thin anti-overflow oil pipe assembly described in this invention;

[0048] Figure 3 This is a schematic diagram showing the completed welding process after the ultra-thin anti-overflow oil pipe assembly of the present invention is installed;

[0049] The markings in the diagram are as follows: 1-Ultra-thin anti-overflow oil pipe; 2-Main shaft; 3-Seam plate; 4-Seam bolt; 5-Fixing device; 5-1-Fixing plate; 5-2-Support plate; 6-Cylinder wall support bolt; 7-Shaft bolt; 8-Weld. Detailed Implementation

[0050] To make the objectives, technical solutions, and beneficial effects of this invention clearer, further explanations and descriptions will be provided below in conjunction with the accompanying drawings and specific embodiments. However, these embodiments do not constitute a limitation of the invention. The specific embodiments described with reference to the accompanying drawings are exemplary and are only used to explain the invention, and should not be construed as limiting the invention.

[0051] Specific implementation method one: Refer to Figures 1 to 2 This embodiment describes a process for producing a high-precision, ultra-thin anti-overflow oil pipe for a pumped storage unit. The method is implemented through the following steps:

[0052] S1. Machining the two joint surfaces of the ultra-thin anti-overflow oil pipe 1: The semi-finished ultra-thin anti-overflow oil pipe blank is mounted at equal intervals along the X-axis in a CNC machining center, and milled at equal intervals along the Y-axis of the semi-finished ultra-thin anti-overflow oil pipe blank; Welding the joint plate 3 at the joint of the ultra-thin anti-overflow oil pipe, the joint plate has a central joint hole, and the two halves of the ultra-thin anti-overflow oil pipe are combined into a whole;

[0053] S2. Machining the inner circle and upper end face of the ultra-thin anti-overflow oil pipe to the finished size, mounting the ultra-thin anti-overflow oil pipe in the CNC machining center, and turning the ultra-thin anti-overflow oil pipe by turning.

[0054] S3, a three-axis CNC machining center drills and taps 24 threaded engagement holes on the flange of an ultra-thin anti-overflow oil pipe that are associated with the generator connection; a CNC machining center drills and taps 10 threaded engagement holes on the small end cylinder wall plate of the ultra-thin anti-overflow oil pipe that are supported by the spindle.

[0055] S4. Make an ultra-thin anti-overflow oil pipe and a main spindle 2 shaft fixing device 5, weld a fixing plate 5-1 and a support plate 5-2, drill 18 ultra-thin anti-overflow oil pipe connection holes on the fixing plate, and drill 9 support thread process holes on the support plate.

[0056] S5. The ultra-thin anti-overflow oil pipe sleeve is welded into a whole on the main shaft: The two ultra-thin anti-overflow oil pipe sleeves are mounted on the main shaft 2 and assembled into a whole on the shaft; the support plate 5-2 of the fixing device 5 is used to support the main shaft; the bevel of the oil-blocking pipe parting surface is fully welded to the weld seam 8, the welded part is ground, and the joint plate 3 is removed.

[0057] S6. Adjust the concentricity of the inner circle of the ultra-thin anti-overflow oil pipe 1 with the shaft of the main spindle 2, and install the small end cylinder wall support bolt 6 of the ultra-thin anti-overflow oil pipe to firmly support the ultra-thin anti-overflow oil pipe on the shaft of the main spindle 2.

[0058] S7. Mount the generator spindle, which is now complete with the ultra-thin anti-overflow oil pipe, onto a CNC horizontal lathe and machine the flange end face, flange outer circle, and pipe outer circle of the ultra-thin anti-overflow oil pipe by turning.

[0059] S8. Remove the support 6 on the small end of the ultra-thin anti-overflow oil pipe, plug the process hole, and polish the weld; after processing is completed, inspect the finished product.

[0060] In this embodiment, a high-precision, ultra-thin anti-overflow oil pipe sleeve with a thickness of 20mm was integrated into the spindle for precision machining. This solves the problems of large deformation after welding the ultra-thin anti-overflow oil pipe onto the spindle after precision machining, the difficulty in supporting and fixing the ultra-thin anti-overflow oil pipe on the spindle body, and the stress concentration deformation problem during the turning process of the ultra-thin anti-overflow oil pipe. This process completely breaks through the technical bottlenecks of low machining accuracy and oil leakage after installation of the ultra-thin anti-overflow oil pipe, greatly reducing the operation and maintenance costs of the unit during the post-installation operation period, achieving a good effect and expectation of permanent solution, and significantly improving the operational stability of the pumped storage power generation motor.

[0061] Specific Implementation Method Two: Refer to Figures 1 to 2 This embodiment further defines S1 as described in Specific Embodiment 1. In this embodiment, the CNC machining center in S1 is a three-axis CNC machining center, the cutting tool is made of high-speed steel, the cutting depth is 0.5mm-0.8mm, the feed rate is 20mm / min-40mm / min, and the spindle speed is 650r / min-800r / min.

[0062] In this embodiment, the two joint surfaces of the ultra-thin anti-overflow oil pipe are machined. First, all machined surfaces are marked with a machining allowance of 3-5mm on each side. Alignment lines and inspection lines in the X and Y directions are marked. The joint surface of the ultra-thin anti-overflow oil pipe semi-finished blank is mounted in the CNC machining center with the boring spindle body facing the machining center at equal intervals along the X-axis. The ultra-thin anti-overflow oil pipe semi-finished blank is then machined at equal intervals along the Y-axis by milling. The feed rate and boring spindle speed are strictly controlled during milling to reduce the deformation of the ultra-thin anti-overflow oil pipe caused by cutting stress.

[0063] Specific Implementation Method Three: Refer to Figures 1 to 3 This embodiment further defines S1 as described in Specific Embodiment 1. In this embodiment, S1 involves assembling the two ultra-thin anti-overflow oil pipes 1 into a whole in two steps:

[0064] S11. Grind the surface of the welding area to expose a metallic luster, weld the joint plate 3 to both sides of the joint of the ultra-thin anti-overflow oil pipe 1, and make a 15mm fillet weld on three sides using arc welding.

[0065] S12. Insert the mating bolts 4 into the mating holes of the pair of mating plates and tighten them with nuts. There is no gap in the mating surface. The two ultra-thin anti-overflow oil pipes are combined into a whole.

[0066] In this embodiment, the key technical points of welding the joint plate at the joint of the anti-overflow oil pipe are: before welding, combine the two ultra-thin anti-overflow oil pipes, ensure that there is no gap at the joint surface, align the alignment line, and weld the joint plate in pairs.

[0067] Specific Implementation Method Four: Refer to Figures 1 to 2This embodiment further defines S2 as described in Specific Embodiment 1. In this embodiment, S2 involves machining the inner circle and upper end face of the ultra-thin anti-overflow oil pipe to the finished size, mounting the ultra-thin anti-overflow oil pipe in a CNC machining center, and turning the ultra-thin anti-overflow oil pipe by turning.

[0068] In this embodiment, the inner circle and upper end face of the spill prevention pipe are aligned to the finished product dimensions, which serves as the alignment reference after being fitted onto the spindle. The CNC machining center is a vertical lathe CNC machining center, using high-speed steel cutting tools with a cutting depth of 0.8mm-1.0mm, a feed rate of 30mm / min-50mm / min, and a spindle speed of 350r / min-400r / min.

[0069] Specific Implementation Method Five: Refer to Figures 1 to 2 This embodiment further defines S3 as described in Specific Embodiment 1. In this embodiment, S3 involves drilling and tapping the 10 threaded engagement holes on the small end wall of the ultra-thin anti-overflow oil pipe 1 that are supported by the spindle, which is divided into two steps:

[0070] S31. The dimension L of the threaded engagement hole of the main shaft support is determined by the position of the center of gravity through equal weight balance calculation. The ultra-thin anti-overflow oil pipe has uniform thickness and density, and can be calculated by the following formula: ΔG1*ΔL1=ΔG2*ΔL2

[0071] ΔG=ΔV*ρ, ΔV=ΔL*2π*ΔR*σ

[0072] In the formula: ΔG(ΔG1,ΔG2) is the weight of the ultra-thin spill containment pipe in kilograms; ΔL(ΔL1,ΔL2) is the length of the centroid coordinate point in millimeters; ρ is the density of the steel plate of the ultra-thin spill containment pipe in kg / mm². 3 ΔV represents the solid volume of the ultra-thin anti-overflow oil pipe, in mm. 3 ; ΔH is the thickness of the ultra-thin oil spill prevention pipe plate, in millimeters; ΔR is the inner radius of the ultra-thin oil spill prevention pipe, in millimeters; σ is the thickness of the ultra-thin oil spill prevention pipe plate, in millimeters.

[0073] S32, the drilling and tapping CNC machining center is a three-axis CNC machining center. The cutting tools used are high-speed steel twist drill bits and high-speed steel machine taps. The cutting feed rate is 30mm / min-50mm / min, and the spindle speed is 450r / min-700r / min.

[0074] In this embodiment, the key technology is the calculation and determination of the center of gravity of the ultra-thin anti-overflow oil pipe support. The reasonable cylinder wall support position can be well matched with the end fixing device support to ensure that the turning process is stable and vibration-free, and the cylinder wall is free from deformation and tilting.

[0075] Specific Implementation Method Six: Refer to Figures 1 to 2 This embodiment further defines S4 as described in Specific Embodiment 1. In this embodiment, the fabrication of the ultra-thin anti-overflow oil pipe 1 and the spindle 2 shaft fixing device in S4 is divided into two steps:

[0076] S41. Fabricate fixing plate 5-1 and support plate 5-2

[0077] S42, welding fixing plate 5-1 and support plate 5-2, a total of 9 sets;

[0078] S43. Drill two ultra-thin anti-overflow oil pipe connection holes on the fixed plate 5-1, and drill one support thread process hole on the support plate 5-2.

[0079] In this embodiment, the fixing device is a tooling that reliably supports and fixes the oil spill prevention pipe to the spindle, which plays a crucial role in the stability of the machining after the oil spill prevention pipe is fitted onto the spindle.

[0080] Specific Implementation Method Seven: Refer to Figures 1 to 2 This embodiment further defines S5 as described in Specific Embodiment 1. In this embodiment, the welding of the ultra-thin anti-overflow oil sleeve spindle assembly into a whole in S5 involves the following steps:

[0081] S51. Two ultra-thin anti-overflow oil pipes are installed on the spindle 2 shaft and adjusted to the appropriate position for temporary support and fixation to prevent slippage.

[0082] S52. Insert the mating bolts 4 into the mating holes of the paired mating plates and tighten them with nuts. There is no gap in the mating surface. The two ultra-thin anti-overflow oil pipes are combined into a whole.

[0083] S53. The support plate 5-2 of the fixing device is supported on the main shaft by the shaft bolt 7.

[0084] S54, V-groove bidirectional full weld: The bevel treatment removes oxide scale, oil and other harmful impurities from the bevel and the base material surface on both sides within a range of at least 20mm (calculated from the distance from the edge of the bevel), and grinds to expose the metallic luster. Preheating temperature: 150℃~230℃. When manual arc welding, the wind speed is less than 6m / s and the relative humidity is less than 85%, the welding is carried out at a uniform speed.

[0085] S55. After grinding, polishing and cleaning the weld seam, perform UT and MT flaw detection, and finally check the quality of the weld seam of the hydrostatic liquid ultra-thin anti-overflow oil pipe for kerosene leakage.

[0086] Detailed Implementation Method Eight: Refer to Figures 1 to 2 This embodiment further defines S6 as described in Specific Embodiment 1. In this embodiment, S6, adjusting the concentricity of the inner circle of the ultra-thin anti-overflow oil pipe with the spindle shaft, consists of two steps:

[0087] S61. Adjust the concentricity of the inner circle of the high-precision ultra-thin anti-overflow oil pipe 1 with the spindle 2 shaft to 0.02mm;

[0088] S62. Use cylinder wall support bolts 6 and shaft bolts 7 to support and fix the high-precision ultra-thin anti-overflow oil pipe 1 to the main shaft body, and use copper sheet and steel plate to protect the shaft body surface.

[0089] In this embodiment, the inner circle of the anti-overflow oil pipe (which has been precision machined) is first adjusted to be 0.02mm concentric with the spindle shaft before final fixing and support are performed. Since the spindle shaft has been precision machined, protective pads are added to the support bolts to protect the shaft.

[0090] Specific Implementation Method Nine: Refer to Figures 1 to 2 This embodiment further defines S7 as described in Specific Embodiment 1. In this embodiment, S7 mounts the spindle 2, which is completed by fitting the ultra-thin anti-overflow oil pipe 1, onto a CNC horizontal machining center, specifically an 18-meter horizontal lathe machining center. The cutting tool used is carbide steel, with a cutting depth of 0.5mm-0.8mm, a feed rate of 20mm / min-40mm / min, and a spindle speed of 120r / min-150r / min.

[0091] Detailed Implementation Method Ten: Refer to Figures 1 to 2 This embodiment further defines S7 as described in Specific Embodiment 1. In this embodiment, S7, which uses turning to process the flange end face, flange outer circle, and pipe outer circle of the ultra-thin anti-overflow pipe, consists of two steps:

[0092] S71, spindle 2 mounting and alignment, bracket mouth circular runout ≤ 0.03mm;

[0093] S72. The flange end face, flange outer circle and pipe outer circle of the rough-machined ultra-thin anti-overflow oil pipe are subjected to static aging for 12 hours to release stress in order to avoid stress concentration in the material plate and circumferential deformation after the hollow cylinder is machined.

[0094] S73, the flange end face, flange outer circle and pipe outer circle of precision machined ultra-thin anti-overflow oil pipe 1.

[0095] In this embodiment, the key technical points are: firstly, strictly controlling the spindle speed to ensure that the temperature of the hydraulic bearing of the spindle support is less than 45°C; controlling the turning depth and feed rate to avoid deformation of the anti-overflow pipe wall; and after rough machining, ensuring sufficient time for aging to release stress before fine machining to ensure the machining accuracy of the flange end face, flange outer circle, and pipe outer circle of the anti-overflow pipe.

[0096] Detailed Implementation Method Eleven: Refer to Figures 1 to 2This embodiment further defines S8 as described in Specific Embodiment 1. In this embodiment, S8, which involves removing the support from the small end of the ultra-thin anti-overflow pipe, plugging the welding process hole, and polishing the weld joint, consists of two steps:

[0097] S81 Remove the small end cylinder wall support bolts of the ultra-thin anti-overflow oil pipe.

[0098] S82 plug welds fully support the threaded process hole, and the weld joint is polished.

[0099] In this embodiment, the key technical point is the polishing treatment of the welding area, which needs to ensure that there are no high or low points and requires grinding according to the shape.

[0100] Finally, the scope of protection of this invention is not limited to the embodiments described above. Obviously, those skilled in the art can make various modifications and variations to this invention without departing from its scope and spirit. If such modifications and variations fall within the scope of the claims of this invention and their equivalents, then this invention also intends to include such modifications and variations.

Claims

1. A process for a high-precision, ultra-thin anti-overflow oil pipe for a pumped storage unit, characterized in that: The method is implemented through the following steps: S1. Process the two joint surfaces of the ultra-thin anti-overflow oil pipe (1). The semi-finished blank of the ultra-thin anti-overflow oil pipe is mounted at equal intervals along the X-axis in the CNC machining center, and milled at equal intervals along the Y-axis of the semi-finished blank of the ultra-thin anti-overflow oil pipe. Weld the joint plate (3) at the joint of the ultra-thin anti-overflow oil pipe. The joint plate has a central joint hole, and the two halves of the ultra-thin anti-overflow oil pipe are combined into a whole. S2. Machining the inner circle and upper end face of the ultra-thin anti-overflow oil pipe to the finished size, mounting the ultra-thin anti-overflow oil pipe in the CNC machining center, and turning the ultra-thin anti-overflow oil pipe by turning. S3, a three-axis CNC machining center drills and taps 24 threaded engagement holes on the flange of an ultra-thin anti-overflow oil pipe that are associated with the generator connection; a CNC machining center drills and taps 10 threaded engagement holes on the small end cylinder wall plate of the ultra-thin anti-overflow oil pipe that are supported by the spindle. S4. Make an ultra-thin anti-overflow oil pipe and a spindle (2) shaft fixing device (5), weld a fixing plate (5-1) and a support plate (5-2), drill 18 ultra-thin anti-overflow oil pipe connection holes on the fixing plate, and drill 9 support thread process holes on the support plate. S5. The ultra-thin anti-overflow oil pipe sleeve is welded into a whole on the main shaft (2): The two ultra-thin anti-overflow oil pipe sleeves are mounted on the main shaft (2) and assembled into a whole on the shaft; the support plate (5-2) of the fixing device (5) is used to support the main shaft; the bevel of the oil-blocking pipe parting surface is fully welded (8), the welding part is ground, and the joint plate (3) is removed. S6. Adjust the concentricity of the inner circle of the ultra-thin anti-overflow oil pipe (1) with the shaft of the main shaft (2), and install the small end cylinder wall support bolt (6) of the ultra-thin anti-overflow oil pipe to firmly support the ultra-thin anti-overflow oil pipe on the shaft of the main shaft (2). S7. Mount the generator spindle, which is now complete with the ultra-thin anti-overflow oil pipe, onto a CNC horizontal lathe and machine the flange end face, flange outer circle, and pipe outer circle of the ultra-thin anti-overflow oil pipe by turning. S8. Remove the small end cylinder wall support of the ultra-thin anti-overflow oil pipe (6), plug the process hole, and polish the weld; after processing is completed, inspect the finished product.

2. The process method for a high-precision ultra-thin anti-overflow oil pipe for a pumped storage unit according to claim 1, characterized in that: In S1, the CNC machining center is a three-axis CNC machining center, the cutting tool is made of high-speed steel, the cutting depth is 0.5mm-0.8mm, the feed rate is 20mm / min-40mm / min, and the spindle speed is 650r / min-800r / min.

3. The process method for a high-precision ultra-thin anti-overflow oil pipe for a pumped storage unit according to claim 1, characterized in that: In step S1, assembling the two ultra-thin anti-overflow oil pipes (1) into a whole is divided into two steps: S11. Grind the surface of the welding area to expose the metallic luster, weld the joint plate (3) to both sides of the joint of the ultra-thin anti-overflow oil pipe (1), and make a 15mm fillet weld on three sides using electric arc welding. S12. Insert the mating bolts (4) into the mating holes of the pair of mating plates and tighten them with nuts. There is no gap in the mating surface. The two ultra-thin anti-overflow oil pipes are combined into a whole.

4. The process method for a high-precision ultra-thin anti-overflow oil pipe for a pumped storage unit according to claim 1, characterized in that: In S2, the CNC machining center is a vertical lathe CNC machining center, the cutting tool is high-speed steel, the cutting depth is 0.8mm-1.0mm, the feed rate is 30mm / min-50mm / min, and the spindle speed is 350r / min-400r / min.

5. The process method for a high-precision ultra-thin anti-overflow oil pipe for a pumped storage unit according to claim 1, characterized in that: In S3, drilling and tapping the 10 threaded engagement holes on the small end cylinder wall plate of the ultra-thin anti-overflow pipe (1) is divided into two steps: S31. The position dimension L of the threaded engagement hole of the main shaft support is determined by the position of the center of gravity through equal weight balance calculation. The thickness and density of the ultra-thin anti-overflow oil pipe are uniform. It can be calculated by the following formula: ΔG1*ΔL1=ΔG2*ΔL2. ΔG=ΔV*ρ, ΔV=ΔL*2π*ΔR*σ; In the formula: ΔG(ΔG1,ΔG2) is the weight of the ultra-thin spill containment pipe in kilograms; ΔL(ΔL1,ΔL2) is the length of the centroid coordinate point in millimeters; ρ is the density of the steel plate of the ultra-thin spill containment pipe in kg / mm². 3 ΔV represents the solid volume of the ultra-thin anti-overflow oil pipe, in mm. 3 ; ΔH is the thickness of the ultra-thin oil spill prevention pipe plate, in millimeters; ΔR is the inner radius of the ultra-thin oil spill prevention pipe, in millimeters; σ is the thickness of the ultra-thin oil spill prevention pipe plate, in millimeters; S32, the drilling and tapping CNC machining center is a three-axis CNC machining center. The cutting tools used are high-speed steel twist drill bits and high-speed steel machine taps. The cutting feed rate is 30mm / min-50mm / min, and the spindle speed is 450r / min-700r / min.

6. The process method for a high-precision ultra-thin anti-overflow oil pipe for a pumped storage unit according to claim 1, characterized in that: The fabrication of the ultra-thin anti-overflow oil pipe (1) and the main shaft (2) fixing device in S4 is divided into two steps: S41. Make the fixing plate (5-1) and the support plate (5-2); S42, Welding fixing plate (5-1) and support plate (5-2), a total of 9 sets; S43. Drill two ultra-thin anti-overflow oil pipe connection holes on the fixed plate (5-1), and drill one support thread process hole on the support plate (5-2).

7. The process method for a high-precision ultra-thin anti-overflow oil pipe for a pumped storage unit according to claim 1, characterized in that: The S5, the welding of the ultra-thin anti-oil spill sleeve spindle assembly into a whole, is carried out in the following steps: S51. Two ultra-thin anti-overflow oil pipes (1) are fitted onto the spindle (2) shaft and adjusted to the appropriate position for temporary support and fixation to prevent slippage. S52. Insert the mating bolts (4) into the mating holes of the pair of mating plates and tighten them with nuts. There is no gap in the mating surface. The two ultra-thin anti-overflow oil pipes are combined into a whole. S53. The support plate (5-2) of the fixing device is supported on the main shaft by the shaft bolt (7); S54, V-groove bidirectional full weld: The bevel treatment removes oxide scale, oil and other harmful impurities from the bevel and the base material surface on both sides within at least 20mm of the bevel, calculated from the distance from the edge of the bevel, and grinds to expose the metallic luster. Preheating temperature: 150℃~230℃. When manual arc welding, the wind speed is less than 6m / s and the relative humidity is less than 85%, and uniform speed welding is carried out. S55. After grinding, polishing and cleaning the weld seam, perform UT and MT flaw detection, and finally check the quality of the weld seam of the hydrostatic liquid ultra-thin anti-overflow oil pipe for kerosene leakage.

8. The process method for a high-precision ultra-thin anti-overflow oil pipe for a pumped storage unit according to claim 1, characterized in that: The S6 step of adjusting the concentricity of the inner circle of the ultra-thin anti-overflow oil pipe with the spindle shaft consists of two steps: S61. Adjust the concentricity of the inner circle of the high-precision ultra-thin anti-overflow oil pipe (1) with the shaft of the main spindle (2) to 0.02mm; S62. Use cylinder wall support bolts (6) and shaft bolts (7) to support and fix the high-precision ultra-thin anti-overflow oil pipe (1) on the main shaft, and use copper sheet and steel plate to protect the surface of the shaft.

9. The process method for a high-precision ultra-thin anti-overflow oil pipe for a pumped storage unit according to claim 1, characterized in that: The process of machining the flange end face, flange outer circle, and pipe outer circle of the ultra-thin anti-overflow pipe by turning is divided into two steps: S71. The selected CNC horizontal machining center is an 18-meter horizontal lathe machining center. The cutting tool is made of carbide steel, the cutting depth is 0.5mm-0.8mm, the feed rate is 20mm / min-40mm / min, and the spindle speed is 650r / min-800r / min. S72. The spindle (2) is mounted and aligned, and the circular runout of the bracket opening is ≤0.03mm; S73. For the flange end face, flange outer circle and pipe outer circle of the rough-machined ultra-thin anti-overflow oil pipe, in order to avoid stress concentration in the material plate and circumferential deformation after the hollow cylinder is machined, static aging for 12 hours is performed to release stress. S74, the flange end face, flange outer circle and pipe outer circle of the precision-machined ultra-thin anti-overflow oil pipe (1).

10. The process method for a high-precision ultra-thin anti-overflow oil pipe for a pumped storage unit according to claim 1, characterized in that: The steps of S8, namely removing the support of the small end of the ultra-thin anti-overflow pipe, plugging the welding process hole, and polishing the weld joint, are as follows: S81 Remove the support bolts on the small end of the ultra-thin anti-overflow oil pipe; S82 plug welds fully support the threaded process hole, and the weld joint is polished.

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