Nuclear power generator positioning rib assembling and welding process

Abstract

The invention provides a nuclear power generator positioning rib assembling and welding process. The nuclear power generator positioning rib assembling and welding process comprises the following steps that S1, a machine base is horizontally placed on a platform and leveled; s2, drawing a machining allowance line and knocking a sample punch; s3, the machine base is turned over, the excitation end faces downwards, and the machine base is vertically placed on a platform and leveled; and S4, a positioning rib welding tool is installed according to the pitch circle line drawn in the S2, and spot welding and fixing are conducted. And S5, steel wires are pulled at the notch positions of the positioning rib assembling and welding tools arranged at the two ends of the machine base. And S6, limiting round steel is assembled and welded. S7, removing the steel wires; and 6, hoisting positioning ribs in groups. And S8, the positioning rib welding tool is adjusted, so that the positioning rib is tightly attached to the limiting round steel. And S9, supporting blocks are assembled and fixed through spot welding. And S10, detecting the position size of the positioning rib by using a three-dimensional laser scanner, and recording the position size. And S11, welding is conducted in sequence, and flat welding is conducted on all welding seams. And S12, a weld joint is ground, and flaw detection is conducted 100%. And S13, the positioning rib assembling and welding tool is dismantled, and finally the position size of the positioning rib is detected through a three-dimensional laser scanner and recorded.

Description

TECHNICAL FIELD

[0001] The present application belongs to the technical field of generator base, and particularly relates to a nuclear power generator positioning rib assembling and welding process. BACKGROUND

[0002] In the field of nuclear power, the safety, reliability and long-life operation of the generator are almost strictly required. Any slight manufacturing defect can lead to serious consequences. The precision of the installation reference surface of the stator core directly determines the core electromagnetic performance parameters such as the uniformity of the electromagnetic field inside the generator and the symmetry of the air gap. The positioning rib in the generator base is a key basic component for fixing the stator core laminations, and the installation position and geometric precision (such as chord distance uniformity, perpendicularity and roundness) of the positioning rib have a decisive influence on the final forming quality of the core.

[0003] The traditional welding process relies on manual marking, positioning and spot welding fixation, and manual operation cannot accurately ensure the chord distance, radial position and perpendicularity of the positioning rib, which is difficult to meet the extremely high requirements of the nuclear power generator on the roundness of the core and the uniformity of the air gap. Moreover, after the positioning rib is preliminarily fixed by spot welding, if the chord distance, perpendicularity or roundness is found to be out of tolerance in subsequent detection, the original spot welding points need to be destructively removed, and the positioning and spot welding need to be re-performed, which not only reduces the efficiency but also increases the risk of deformation, damages the base material, and leads to the decline of the electromagnetic performance of the generator, the noise exceeding the standard, and the reduction of the reliability of the nuclear power generator during the operation within the designed life of several decades.

[0004] Therefore, the above problems need to be solved. SUMMARY

[0005] The present application provides a nuclear power generator positioning rib assembling and welding process, which is a turning and flat welding process, so that the base is in a vertical state for welding, the deformation of the base is controlled, the positioning ribs are hoisted in batches, the perpendicularity of the positioning ribs is ensured, and the imbalance of the base due to uneven stress during the assembly process of the positioning ribs is avoided, so as to prevent the deformation of the base. The limiting round steel provides a positioning reference for the positioning rib, improves the convenience and accuracy of assembly, adjusts the chord distance and radial size of the positioning rib in combination with the positioning rib assembling and welding tool, ensures the chord distance and roundness of the positioning rib, ensures the assembly precision of the generator, and ensures the electromagnetic performance, noise index and reliability of the generator during the long-life operation.

[0006] Technical scheme: In order to achieve the above purpose, the present application provides a nuclear power generator positioning rib assembling and welding process, which comprises the following steps: S1: horizontally placing the base on the platform and leveling the base, adjusting the levelness of the base to be less than 0.1mm and the perpendicularity of the end surface of the base to be less than 0.03mm. The base is horizontally placed on the platform, and the levelness and perpendicularity of the base are leveled by using a level, so as to ensure the levelness and perpendicularity of the base. This step is the starting point of the process, and the levelness and perpendicularity are strictly limited to ensure the assembly and welding precision.

[0007] S2: Draw the machining allowance line and knock the sample punch, draw the nodal circle line on the ring plate side wall according to the axial center of the base and knock the cross center line sample punch. The axial center of the base has a machining allowance, and the base is processed after the positioning rib and the base are welded to reduce the influence of welding deformation and ensure the chord distance, perpendicularity or roundness of the positioning rib. The axial center of the base can be determined by measuring the center of the upper and lower end plates of the base through a three-dimensional laser scanner.

[0008] S3: Turn the base upside down, place the base vertically on the platform and adjust the level, use the level to adjust the horizontal degree of the end face of the base <0.1mm, adjust the verticality of the base foot plane <0.03mm. Place the base in a vertical state to weld the positioning rib, which can reduce the influence of gravity on the positioning rib, ensure the straightness of the positioning rib, improve the positioning accuracy of the positioning rib, and reduce the difficulty of subsequent adjustment.

[0009] S4: According to the nodal circle line drawn in S2, install the positioning rib welding tooling and spot weld it. The positioning rib welding tooling includes a radial adjustment bolt group and a circumferential adjustment bolt group, the radial adjustment bolt group is used to adjust the radial size of the positioning rib, and the circumferential adjustment bolt group is used to adjust the chord distance of the positioning rib. The center of the base can be determined according to the nodal circle line drawn in S2, and the positioning rib welding tooling is installed along the nodal circle line, so that the positioning rib welding tooling is installed around the center of the base, and the distance between all positioning rib toolings and the center of the base is equal. Adjust the chord distance and radial size of the positioning rib through the radial adjustment bolt group and the circumferential adjustment bolt group, in order to avoid moving the positioning rib welding tooling, the positioning rib welding tooling and the ring plate are spot welded.

[0010] S5: Pull the steel wire at the notch position of the positioning rib welding tooling at both ends of the base. The steel wire provides a reference for subsequent welding of the limiting round steel, and the ends of the steel wire are fixed on the two ends of the base respectively and tightened using a fixing tool to reduce the deflection error.

[0011] S6: Weld the limiting round steel. The limiting round steel is arranged close to the side wall of the ring plate, the limiting round steel is arranged perpendicular to the bottom of the notch provided on the ring plate, and the end face of the limiting round steel is arranged in partial contact with the steel wire. The limiting round steel and the steel wire are in contact and welded to the side wall of the ring plate, so that the limiting round steel is arranged along the axial reference formed by the steel wire, the linear reference formed by the steel wire is converted into the surface reference formed by the limiting round steel, and an installation reference is provided for the installation of the positioning rib.

[0012] S7: Remove the steel wire, hoist the positioning rib in groups, adjust the height of the positioning rib, and make the upper end of the positioning rib flush with the inner side face of the upper end plate of the base. Hoist the positioning rib in groups to balance the stress of the base, avoid eccentric deformation, and use the positioning rib welding tooling to fix the positioning rib.

[0013] S8: Adjust the positioning rib assembly welding tool to make the positioning rib tightly adhere to the limiting round steel. Adjust the positioning rib tool to make the positioning rib tightly adhere to the limiting round steel. The gap size between the positioning rib and the limiting round steel can be detected by using a plug gauge, which is ≤0.05mm.

[0014] S9: Assemble the support block and spot weld it. The support block is used to connect the positioning rib and the ring plate, fix the positioning rib, avoid displacement of the positioning rib in the subsequent detection process, and improve the detection accuracy and efficiency.

[0015] S10: Use a three-dimensional laser scanner to detect the position size of the positioning rib, and the position size error of the positioning rib is ≤2mm, and the record is kept. The position size of the positioning rib is detected before welding to ensure the size accuracy before welding.

[0016] S11: Weld in order, and all welds are flat.

[0017] S12: Grind the weld and perform 100% flaw detection. The flaw detection is performed by magnetic particle flaw detection, and the unqualified products are repaired.

[0018] S13: Remove the positioning rib assembly welding tool, and finally use a three-dimensional laser scanner to detect the position size of the positioning rib, confirm that the position size error of the positioning rib is ≤2mm, and record it.

[0019] Further, in the above-mentioned nuclear power generator positioning rib assembly welding process, the step S2 of marking the allowance line and knocking the sample punch includes the steps of: S2-1: Mark the top support allowance line and knock the sample punch.

[0020] S2-2: Mark the allowance line of the bottom foot lower plane and knock the sample punch.

[0021] S2-3: Mark the allowance line of the bottom support and knock the sample punch.

[0022] S2-4: Draw the cross center line of the determined center line of the machine base to the outer wall end face and knock the sample punch.

[0023] S2-5: Draw the pitch circle line according to the center line of the machine base at the steam end and the excitation end respectively, and knock the cross center line sample punch.

[0024] Further, in the above-mentioned nuclear power generator positioning rib assembly welding process, the step S5 includes: suspending the steel wire in the corresponding index slot at the steam end and the excitation end, aligning the slot center, fixing and tightening the steel wire using a steel wire fixing tool, and determining the center line of the slot from the steam end to the excitation end.

[0025] Further, in the above-mentioned nuclear power generator positioning rib assembly welding process, in the step S7, the positioning rib is in diagonal four pieces as one group, and is hung into the inside of the machine base from the top of the machine base in six groups.

[0026] Further, in the positioning rib welding process of the nuclear power generator, the positioning rib welding tool in the step S8 comprises: S8-1: adjust the chord distance of the positioning rib by adjusting the circumferential adjusting bolt set of the positioning rib welding tool.

[0027] S8-2: adjust the radial size and perpendicularity of the positioning rib by adjusting the radial adjusting bolt set of the positioning rib welding tool. The radial adjusting bolt set cooperates with the wedge to adjust the radial size of the positioning rib, specifically, when the distance between the positioning rib and the center of the generator base is too large, the radial adjusting bolt is screwed, and when the distance between the positioning rib and the center of the generator base is too small, the wedge is inserted between the positioning rib and the ring plate notch.

[0028] S8-3: detect the gap between the positioning rib and the limiting round steel 7 to ensure that the positioning rib is tightly attached to the limiting round steel, and lock the radial adjusting bolt set and the circumferential bolt set.

[0029] Further, in the positioning rib welding process of the nuclear power generator, the positioning rib welding tool in the step S8 comprises: S9-1: recheck the position and size of the positioning rib, and adjust the positioning rib welding tool to make the position and size error of the positioning rib less than or equal to 2 mm.

[0030] S9-2: install the supporting block on the upper surface of the middle ring, and point weld the supporting block and the positioning rib after tightly attaching them.

[0031] Further, in the positioning rib welding process of the nuclear power generator, the step S11 comprises the steps of: S11-1: in the state that the exciting end faces downward, sequentially weld all the welds from the middle to the two ends in a flat manner. During the welding process, the welder is allowed to use wedge blocks, and after the wedge blocks are embedded in the gap, the welding process is sealed. In this step, the welding is completed, the positioning rib tool is removed, and the supporting block is welded on the upper side of all the ring plates.

[0032] S11-2: turn over the generator base, and in the state that the steam end faces downward, sequentially weld all the welds from the middle to the two ends in a flat manner. In this step, the supporting block is welded on the upper side of the ring plate. The generator base is turned over and welded, so that the generator base is always in a vertical state, and the flat welding manner ensures the penetration depth and the quality of the welds. Turning over and welding can reduce thermal deformation and control the deformation amount. Welding from the middle to the two ends can make the heat quickly spread along the welding direction, so that the steel plate has good heat dissipation effect, the accumulation of heat in the middle is reduced, the stress is uniformly distributed on both sides of the weld, the deformation caused by stress concentration is reduced, and thus the deformation degree is reduced.

[0033] S11-3: use a clamping ring to recheck the position of the screw rod at both ends of the positioning rib, and use a fire attack to finely adjust the position of the screw rod at both ends of the positioning rib. Local heating of the positioning rib releases stress and corrects the position of the screw rod. The clamping ring is an arc plate, and the arc plate is provided with through holes corresponding to the positions of the screw rods. The position accuracy between the screw rods is detected by inserting the screw rods into the through holes.

[0034] Further, the positioning rib welding process of the nuclear power generator described above, the step S11 includes the step: S11-4: adjusting the center line. The original generator base center line is determined by the step S2 reserved pitch circle line. The square steel is placed on the upper end of the base, the vertical line is bound, and the vertical line is overlapped with the original base center line to determine the actual position of the positioning rib after welding. The deviation of the present base center line and the original base center line is detected, the original base center line is adjusted to make the positioning rib position size error <2mm, and the final base center line is determined. By comparing the deviation of the original base center line and the present base center line, the original base center line is adjusted to make the positioning rib size error meet the requirements, and the adjusted original base center line is the final base center line, at this time the positioning rib distance from the final base center line size error <2mm.

[0035] Further, the positioning rib welding process of the nuclear power generator described above, the processing allowance line in the step 2 is ground to re-draw the processing allowance line with the final base center line, to provide a reference for subsequent processing, to adapt the finishing to the welding deformation, and to ensure the assembly precision.

[0036] Further, the positioning rib welding process of the nuclear power generator described above, if the deviation of the original base center line and the present base center line is <2mm, the original base center line does not need to be adjusted, and the processing allowance line does not need to be re-drawn.

[0037] Further, the positioning rib welding process of the nuclear power generator described above, if the positioning rib is difficult to adjust due to excessive error, the positioning rib welding seam is separated, the positioning rib position coordinates are adjusted using the positioning rib welding tool again, so that it meets the tolerance range, and then it is welded again.

[0038] Further, the positioning rib welding process of the nuclear power generator described above, the last positioning rib thread segment is protected, and the base is sandblasted, cleaned, and painted.

[0039] Further, the positioning rib welding process of the nuclear power generator described above, the inner side of the ring plate has a notch along the center array, the steel wire is fixed to the end plate at both ends of the base by passing through the notch and pulling the wire, and the steel wire is tightened and straightened. One end of the limiting round steel protrudes into the notch and contacts the steel wire, and the limiting round steel is spot welded to the side wall of the ring plate.

[0040] Further, the positioning rib welding process of the nuclear power generator comprises the positioning rib welding tooling, the positioning rib welding tooling comprises a bow-shaped plate, the bow-shaped plate comprises a bottom plate, and a first end plate and a second end plate are welded to two ends of the bottom plate, and the first end plate and the second end plate are respectively threadedly connected with circumferential adjusting bolts, and the circumferential adjusting bolts connected with the first end plate and the second end plate respectively abut the upper and lower sides of the positioning rib, and the circumferential adjusting bolts are screwed to adjust the chord distance of the positioning rib. The bottom plate is connected with radial adjusting bolts, a plurality of radial adjusting bolts connected with the bottom plate form a radial adjusting bolt group, the radial adjusting bolts abut the side of the positioning rib close to the center of the base, and the radial adjusting bolts adjust the distance between the positioning rib and the center line of the base. The first end plate and the second end plate are respectively provided with notches, the notches are connected with locking bolts, a ring plate is inserted into the notches, and the locking bolts abut the side wall of the ring plate to connect the positioning rib welding tooling and the ring plate.

[0041] The technical scheme can achieve the beneficial effects that the positioning rib welding process of the nuclear power generator can make the base in a vertical state for welding through twice turning and horizontal welding, control the deformation of the base, ensure the perpendicularity of the positioning rib by hoisting the positioning rib in batches, avoid the imbalance of the base caused by uneven stress during the assembly of the positioning rib, and cause the deformation of the base. The limiting round steel provides a positioning reference for the positioning rib, improves the convenience and accuracy of assembly, adjusts the chord distance and radial size of the positioning rib by the positioning rib welding tooling, ensures the chord distance and roundness of the positioning rib, ensures the assembly accuracy of the generator, and ensures the reliability of the electromagnetic performance, noise index and long-life surface operation of the generator. BRIEF DESCRIPTION OF DRAWINGS

[0042] Figure 1 The flowchart of the positioning rib welding process of the nuclear power generator.

[0043] Figure 2 The schematic diagram of the mechanism of the base.

[0044] Figure 3 The schematic diagram of the hoisting of the positioning rib into the base.

[0045] Figure 4 The installation schematic diagram of the limiting round steel.

[0046] Figure 5 The structural schematic diagram of the positioning rib welding tooling.

[0047] Figure 6 The installation schematic diagram of the positioning rib welding tooling installed on the ring plate and connected with the positioning rib.

[0048] In the figure: 1, base, 2, positioning rib, 6, steel wire, 7, limiting round steel, 8, ring plate, 81, notch, 91, bottom plate, 92, first end plate, 93, second end plate, 94, circumferential adjusting bolt, 95, radial adjusting bolt, 96, notch, 97, locking bolt. DETAILED DESCRIPTION EMBODIMENT

[0049] As Figures 1-3 shown in a kind of nuclear power generator positioning rib welding process, comprising the following steps: S1: base 1 is placed horizontally on platform and is leveled base 1, using level adjustment base 1 level <0.1mm, adjustment base 1 end surface perpendicularity <0.03mm.Base 1 is placed horizontally on platform and is leveled, ensure the level and perpendicularity of base 1, this step is the starting point of process, the level and perpendicularity are strictly limited, ensure subsequent welding precision.

[0050] S2: draw processing allowance line and knock sample punch, according to the center of base 1 axial ring plate side wall draw circle line and knock cross center line sample punch.Base 1 axial center base 1 has processing allowance, positioning rib 2 and base 1 are welded after, base 1 is processed again, reduce the influence of welding deformation, ensure the chord distance, perpendicularity or roundness of positioning rib 2.The center of base 1 axial center can be determined by three-dimensional laser scanner measuring the center of upper and lower end plate of base 1.

[0051] S3: base 1 is turned over and is excited end down, base 1 is placed vertically on platform and is leveled, using level adjustment base 1 end surface level <0.1mm, adjustment base 1 bottom plane perpendicularity <0.03mm.Base 1 is placed in vertical state and is welded positioning rib 2, can reduce the influence of gravity on positioning rib 2, ensure the straightness of positioning rib 2, improve the positioning accuracy of positioning rib 2, reduce subsequent adjustment difficulty.

[0052] S4: according to the circle line drawn in S2, install positioning rib welding tooling and spot weld fixation.The positioning rib welding tooling includes radial adjusting bolt group and circumferential adjusting bolt group, the radial adjusting bolt group is used to adjust the radial size of positioning rib 2, and the circumferential adjusting bolt group is used to adjust the chord distance of positioning rib 2.According to the circle line drawn in S2, the center of base 1 can be determined, the positioning rib welding tooling is installed along the circle line, so that the positioning rib welding tooling is arranged around the center of base 1 after installation, and the distance between all positioning rib toolings and the center of base 1 is equal.The chord distance and radial size of positioning rib 2 are adjusted by the radial adjusting bolt group and the circumferential adjusting bolt group, in order to avoid the movement of the positioning rib welding tooling, the positioning rib welding tooling and the ring plate are spot welded and fixed.

[0053] S5: The groove position of the positioning rib assembly tool is provided with a steel wire 6 at both ends of the machine base 1. The steel wire 6 provides a reference for the subsequent assembly and welding of the limiting round steel 7. The steel wire 6 is fixed at both ends of the machine base 1, and the fixed tool is used to tighten it to reduce the deflection error.

[0054] S6: The limiting round steel 7 is assembled and welded. The limiting round steel 7 is attached to the side wall of the ring plate, and the limiting round steel 7 is arranged vertically to the groove bottom of the ring plate. The end surface of the limiting round steel 7 is partially in contact with the steel wire 6. The limiting round steel 7 is in contact with the steel wire, and is welded to the side wall of the ring plate, so that the limiting round steel 7 is arranged along the axial reference formed by the steel wire, and the linear reference formed by the steel wire is converted into the surface reference formed by the limiting round steel 7, which provides an installation reference for the installation of the positioning rib 2.

[0055] S7: Remove the steel wire 6, and hoist the positioning rib 2 in groups. Adjust the height of the positioning rib 2 so that the upper end of the positioning rib 2 is flush with the inner side surface of the upper end plate of the machine base 1. Hoist the positioning rib 2 in groups to balance the stress of the machine base 1 and avoid eccentric deformation, and use the positioning rib assembly tool to fix the positioning rib 2.

[0056] S8: Adjust the positioning rib assembly tool so that the positioning rib 2 is tightly attached to the limiting round steel 7. Adjust the positioning rib tool so that the positioning rib 2 is tightly attached to the limiting round steel 7. The gap between the positioning rib 2 and the limiting round steel 7 can be detected by using a feeler gauge, and the gap size is ≤0.05mm.

[0057] S9: Assemble the supporting block and spot weld it to fix the positioning rib 2. The supporting block is used to connect the positioning rib 2 and the ring plate, and fix the positioning rib 2 to avoid displacement of the positioning rib 2 during subsequent detection, thereby improving the detection accuracy and efficiency.

[0058] S10: Use a three-dimensional laser scanner to detect the position and size of the positioning rib 2. The position and size error of the positioning rib 2 is ≤2mm, and the record is kept. The position and size of the positioning rib 2 is detected before welding to ensure the size accuracy before welding.

[0059] S11: Weld in sequence, and flat weld all the welds.

[0060] S12: Grind the welds and perform 100% flaw detection. The flaw detection is performed by magnetic particle flaw detection, and the unqualified products are repaired.

[0061] S13: Remove the positioning rib assembly tool, and finally use a three-dimensional laser scanner to detect the position and size of the positioning rib 2, and confirm that the position and size error of the positioning rib 2 is ≤2mm, and the record is kept.

[0062] The step S2 includes the steps of: S2-1: Draw the top support allowance line and knock the sample punch.

[0063] S2-2: Draw the bottom foot lower surface allowance line and knock the sample punch.

[0064] S2-3: Draw the bottom support margin line and knock the sample punch.

[0065] S2-4: Draw the cross center line of the determined shaft 1 axial center line to the outer wall end face and knock the sample punch.

[0066] S2-5: Draw the pitch circle line according to the shaft 1 axial center line at the steam end and the excitation end respectively, and knock the cross center line sample punch.

[0067] The step S5 includes: hanging a steel wire in the corresponding index slot at the steam end and the excitation end, aligning the slot center, fixing and tightening the steel wire using a steel wire fixing tool, and determining the center line of the slot from the steam end to the excitation end.

[0068] In the step S7, the positioning rib 2 is divided into 6 groups, and each group is hung into the inside of the shaft 1 from the top of the shaft 1.

[0069] In the step S8, the positioning rib assembly and welding tooling includes: S8-1: Adjust the chord distance of the positioning rib 2 by adjusting the circumferential adjustment bolt set provided on the positioning rib assembly and welding tooling.

[0070] S8-2: Adjust the radial size and perpendicularity of the positioning rib 2 by adjusting the radial adjustment bolt set provided on the positioning rib assembly and welding tooling. The radial adjustment bolt set cooperates with the wedge to adjust the radial size of the positioning rib 2, which specifically includes: when the distance between the positioning rib 2 and the center of the shaft 1 is too large, the radial adjustment bolt is screwed; when the distance between the positioning rib 2 and the center of the shaft 1 is too small, the wedge is inserted between the positioning rib and the ring plate slot.

[0071] S8-3: Detect the gap between the positioning rib 2 and the limiting round steel 7 to ensure that the positioning rib 2 is tightly attached to the limiting round steel 7, and lock the radial adjustment bolt set and the circumferential bolt set.

[0072] In the step S9, the assembly of the supporting block includes: S9-1: Recheck the position and size of the positioning rib 2, and adjust the positioning rib assembly and welding tooling to make the position and size error of the positioning rib ≤2mm.

[0073] S9-2: Install the supporting block on the upper surface of the middle ring, and then point weld the supporting block and the positioning rib 2 after pressing them.

[0074] The step S11 includes the steps of: S11-1: In the downward state of the excitation end, sequentially flat weld all the welds from the middle to both ends. During the welding process, the welder is allowed to arrange the wedge, and the wedge is inserted into the gap and then sealed. In this step, the welding is completed, the positioning rib tooling is removed, and the supporting block is assembled and welded on the upper side of all the ring plates.

[0075] S11-2: Turn the machine base 1 over, with the steam end facing downward, and perform flat welding on all welds from the middle to both ends. In this step, install a welding support block on the upper side of the ring plate. Turn the machine base 1 over for welding so that it is always in a vertical state, and use flat welding to ensure the penetration depth and weld quality. Turning over welding can reduce thermal deformation and control the amount of deformation. By welding from the middle to both ends, heat can diffuse rapidly along the welding direction, and the steel plate has a better heat dissipation effect, which reduces the accumulation of heat in the middle and makes the stress more evenly distributed on both sides of the weld, reducing deformation caused by stress concentration, thereby reducing the degree of deformation.

[0076] S11-3: Use a retaining ring to recalibrate the screw positions at both ends of rib 2. Use a fire blast to fine-tune the screw positions. Heat the rib 2 locally to release stress and correct the screw positions. The retaining ring is a curved plate with through-holes corresponding to the screw positions. Insert the screws into these through-holes to check the screw position accuracy.

[0077] The step S11 includes the steps: S11-4: adjusting the center line. The center line of the original machine base 1 is determined by the pitch circle line reserved in step S2. A square steel is placed on the upper end of the machine base 1, and a vertical line is bound to the square steel. The vertical line is overlapped with the center line of the original machine base 1, and the center line of the current machine base 1 is determined by the actual position of the positioning rib 2 after welding. The deviation between the center line of the current machine base 1 and the center line of the original machine base 1 is detected, and the center line of the original machine base 1 is adjusted so that the position size error of the positioning rib 2 is less than 2mm, and the final center line of the machine base 1 is determined. By comparing the deviation between the center line of the original machine base 1 and the center line of the current machine base 1, the center line of the original machine base 1 is adjusted so that the size error of the positioning rib 2 meets the requirements. The adjusted center line of the original machine base 1 is the final center line of the machine base 1. At this time, the size error of the positioning rib 2 from the center line of the final machine base 1 is less than 2mm.

[0078] The machining allowance line drawn in step 2 is ground off, and the machining allowance line is redrawn with the final center line of the machine base 1 to provide a reference for subsequent processing, so that the finishing can adapt to the welding deformation and ensure the assembly accuracy.

[0079] If the deviation between the original center line of machine base 1 and the current center line of machine base 1 is less than 2mm, there is no need to adjust the center line of original machine base 1 and the machining allowance line does not need to be redrawn.

[0080] If the positioning rib 2 is out of tolerance and difficult to adjust, separate the positioning rib welds, re-use the positioning rib welding fixture to adjust the positioning rib position coordinates to meet the tolerance range, and then re-weld.

[0081] Finally, the threaded section of the positioning rib 2 is protected, and the machine base 1 is subjected to processes such as sandblasting, cleaning, and painting.

[0082] like Figure 4The illustrated limiting round steel 7 is welded. Ring plate 8 has notches 81 along its inner center. Steel wire 6 is threaded through these notches and secured to the end plates of base 1. The wire 6 is tightened and straightened. One end of the limiting round steel 7 extends into the notch 81, contacting the wire 6. The limiting round steel 7 is then spot-welded to the sidewall of ring plate 8.

[0083] like Figures 5-6 The illustrated positioning rib welding fixture comprises an arched plate, which includes a base plate, and a first end plate 92 and a second end plate 93 welded to each end of the base plate 91. The first and second end plates 92 are each threadedly connected to a circumferential adjustment bolt 94. The circumferential adjustment bolts 94 connected to the first and second end plates 92, 92, respectively, constitute a circumferential adjustment bolt group. The circumferential adjustment bolts 94 connected to the first and second end plates 92, 92, respectively abut against the upper and lower sides of the positioning rib. Turning the circumferential adjustment bolts 94 adjusts the chordal distance of the positioning rib. The base plate 91 is connected to radial adjustment bolts 95. The multiple radial adjustment bolts 95 connected to the base plate 91 constitute a radial adjustment bolt group. The radial adjustment bolts 95 abut against the side of the positioning rib near the center of the machine base 1. The radial adjustment bolts 95 adjust the distance between the positioning rib and the centerline of the machine base 1. The first end plate 92 and the second end plate 92 are respectively provided with a notch 96 , and the side wall of the notch 96 is connected with a locking bolt 97 . The ring plate is inserted into the notch 96 , and the locking bolt 97 abuts against the side wall of the ring plate to connect the adjustment positioning rib welding fixture and the ring plate.

[0084] The above embodiments are illustrative and are intended to illustrate the technical concepts and features of the present invention so that those skilled in the art can understand the contents of the present invention and implement them accordingly. They are not intended to limit the scope of protection of the present invention. Any equivalent changes or modifications made based on the spirit of the present invention are intended to be covered by the scope of protection of the present invention.

Claims

1. A nuclear power generator positioning rib welding process, characterized by: The following steps are involved: S1: Place the machine base (1) horizontally on the platform and level the machine base (1). Use a spirit level to adjust the horizontality of the machine base (1) to <0.1mm and the verticality of the end face of the machine base (1) to <0.03mm. S2: Mark the machining allowance line and punch the sample, mark the pitch circle line on the side wall of the ring plate according to the axial center of the machine base (1) and punch the cross center line sample; S3: Turn the machine base (1) over so that the excitation end faces downward, place the machine base (1) upright on the platform and level it. Use a level to adjust the horizontality of the end surface of the machine base (1) to less than 0.1mm, and adjust the verticality of the bottom surface of the machine base (1) to less than 0.03mm. S4: Install the positioning rib welding fixture according to the pitch line drawn in S2 and fix it by spot welding; the positioning rib welding fixture includes a radial adjustment bolt group and a circumferential adjustment bolt group, the radial adjustment bolt group is used to adjust the radial size of the positioning rib (2), and the circumferential adjustment bolt group is used to adjust the chord distance of the positioning rib (2); S5: A steel wire (6) is pulled at the slots of the positioning rib welding fixtures provided at both ends of the machine base (1); S6: welding a limiting round steel (7); the limiting round steel (7) is attached to the side wall of the ring plate, the limiting round steel (7) is arranged perpendicular to the bottom of the notch provided on the ring plate, and the end face of the limiting round steel (7) forms a partial contact arrangement with the steel wire (6); S7: Remove the steel wire (6), hoist the positioning ribs (2) in groups, and adjust the height of the positioning ribs (2) so that the upper end of the positioning ribs (2) is flush with the inner side surface of the upper end plate of the machine base (1); S8: Adjust the positioning rib welding fixture so that the positioning rib (2) is in close contact with the limiting round steel (7); S9: Assemble the support block and fix it with spot welding; S10: Use a three-dimensional laser scanner to detect the size of the positioning rib (2). The size error of the positioning rib (2) is ≤ 2 mm, and keep a record; S11: Weld in sequence, flat welding all welds; S12: Grind the welds and perform 100% NDT inspection; S13: Remove the locating rib welding fixture, and finally use a three-dimensional laser scanner to detect the size of the locating rib (2), confirm that the size error of the locating rib (2) is ≤ 2mm, and record it.

2. The nuclear power generator positioning rib welding process according to claim 1 is characterized in that: The step S2 of marking the machining allowance line and punching the sample comprises the following steps: S2-1: Mark the top support allowance line and punch the sample; S2-2: Mark the allowance line on the bottom surface and punch it; S2-3: Draw the bottom support allowance line and punch the sample; S2-4: Draw the cross center line of the determined axial center line of the machine base (1) to the end face of the outer wall and punch it; S2-5: Draw pitch lines at the steam end and excitation end according to the axial center line of the machine base (1) and punch out cross center line samples.

3. The nuclear power generator positioning rib welding process according to claim 1, characterized in that: The step S5 comprises: hanging the steel wire (6) in the corresponding indexing slots of the steam end and the excitation end, aligning the center of the slot, fixing and tightening the steel wire using a steel wire fixing tool, and determining the center line of the slot from the steam end to the excitation end.

4. The nuclear power generator positioning rib welding process according to claim 1, characterized in that: In the step S7, the positioning ribs (2) are divided into six groups of four diagonal pieces each and are sequentially hoisted from the top of the machine base (1) into the interior of the machine base (1).

5. The nuclear power generator positioning rib welding process according to claim 1, characterized in that: In step S8, adjusting the positioning rib welding tool includes: S8-1: Adjust the circumferential adjustment bolt group provided on the positioning rib welding fixture to adjust the chord distance of the positioning rib (2); S8-2: Adjust the radial adjustment bolt group provided on the positioning rib welding fixture to adjust the radial size and verticality of the positioning rib (2); S8-3: Check the gap between the positioning rib (2) and the limiting round steel (7), ensure that the positioning rib (2) is in close contact with the limiting round steel (7), and tighten the radial adjustment bolt group and the circumferential bolt group.

6. The nuclear power generator positioning rib welding process according to claim 1, characterized in that: In step S9, assembling the support block includes: S9-1: Recheck the size of the positioning rib (2) and adjust the positioning rib welding fixture to ensure that the positioning rib size error is ≤2mm; S9-2: Install the support block on the upper surface of the middle ring, and firmly place the support block against the positioning rib (2) and then spot weld them.

7. The nuclear power generator positioning rib welding process according to claim 1, characterized in that: The step S11 includes the following steps: S11-1: With the excitation end facing downward, flat weld all the welds from the middle to both ends; S11-2: Turn the machine base (1) over with the steam end facing downwards, and weld all the welds in sequence from the middle to both ends.

8. The nuclear power generator positioning rib welding process according to claim 7, characterized in that: The step S11 comprises the following steps: S11-3: using a snap ring to re-measure the positions of the screws at both ends of the positioning rib (2), and using a fire attack to fine-tune the positions of the screws at both ends of the positioning rib (2).

9. The nuclear power generator positioning rib welding process according to claim 1, characterized in that: The step S11 includes the following steps: S11-4: Adjust the center line; determine the center line of the original machine base (1) with the pitch line reserved in step S2; place a square steel on the upper end of the machine base (1), bind a vertical line to the square steel, and make the vertical line coincide with the center line of the original machine base (1), and determine the center line of the current machine base (1) with the actual position after the positioning rib (2) is welded; detect the deviation between the center line of the current machine base (1) and the center line of the original machine base (1), adjust the center line of the original machine base (1), make the size error of the positioning rib (2) less than 2mm, and determine the center line of the final machine base (1).

10. The nuclear power generator positioning rib welding process according to claim 9, characterized in that: The machining allowance line drawn in step 2 is ground off, and the machining allowance line is redrawn with the final center line of the machine base (1).

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