A loading and unloading machine telescopic sleeve and processing method

Abstract

This invention discloses a telescopic sleeve for a loading and unloading machine and its processing method. First, the upper flange, lower flange, guide rails, mounting supports, and sleeve tube are rough-machined. Next, two rows of mounting supports are welded to the two opposite sides of the sleeve tube where the straightness is relatively small. Then, a CNC gantry milling machine is used to align and machine concave straight grooves. Next, two guide rails are welded into the two rows of concave straight grooves. Then, the upper and lower flanges are fitted onto the outer stops at both ends of the sleeve tube and positioned and welded. Finally, the entire assembly is precision-machined to complete the processing of the telescopic sleeve for the loading and unloading machine. The telescopic sleeve processed by this invention meets the requirements for straightness, symmetry, and flatness, ensuring the accuracy and tolerance requirements of the design drawings and satisfying the various functional requirements for equipment debugging.

Description

Technical Field

[0001] This invention belongs to the technical field of pressurized water reactor nuclear power plant related equipment, specifically relating to a telescopic sleeve for a loading and unloading machine and its processing method. Background Technology

[0002] The primary function of the fuel loader / unloader in a pressurized water reactor nuclear power plant is to load and unload fuel assemblies, and its safety and stability directly affect the safety and efficiency of the power plant. Furthermore, fuel loading and unloading is a critical path operation during major overhauls, requiring the equipment to be in good working order. The core component of the fuel loader / unloader, the telescopic sleeve, is 8.7 meters long and weighs approximately 620 kg. Its lower end is equipped with a fuel assembly gripper, and its upper end is connected to two steel wire ropes via a suspension head. During normal operation, the telescopic sleeve moves up and down by the extension and retraction of the steel wire ropes; when the fuel loader / unloader is not in operation, the telescopic sleeve is vertically suspended within a fixed sleeve. Because the telescopic sleeve is suspended solely by the steel wire ropes of the main lifting mechanism, without any other mechanical support structure, the overall performance and related technical indicators of the fuel loader / unloader ultimately depend on the smooth up-and-down movement of the telescopic sleeve carrying the gripper to complete the fuel assembly grabbing and release operations. Therefore, the machining precision of the telescopic sleeve itself is particularly important.

[0003] The telescopic sleeve is welded from a long, thin-walled stainless steel tube and other small stainless steel parts. The guide rails on both sides of the sleeve serve to guide the gripping / releasing of the fuel assembly, requiring extremely high machining precision (guide rail straightness 0.25mm, symmetry 0.03mm, parallelism 0.06mm). Currently, due to the extremely poor rigidity and susceptibility to deformation of these thin-walled, slender, welded stainless steel components, the straightness, symmetry, and flatness of the telescopic sleeve's tracks are prone to non-compliance. Therefore, the overall machining technology has always been a challenge in the machining industry. Summary of the Invention

[0004] The purpose of this invention is to overcome the shortcomings of the prior art and provide a telescopic sleeve for loading and unloading machines and a processing method thereof, thereby solving the technical problem of overall manufacturing and processing of the existing thin-walled stainless steel slender rod-shaped welded components - telescopic sleeves for loading and unloading machines.

[0005] To solve the technical problem, the technical solution of the present invention is: a processing method for a telescopic sleeve of a loading and unloading machine, comprising the following steps:

[0006] Step 1: Roughly machine the upper flange, lower flange, guide rail, mounting bracket, and sleeve, where there are two guide rails and multiple mounting brackets;

[0007] Step 2: Re-inspect the straightness and roundness of the sleeve, and use the two opposite sides with smaller straightness of the sleeve as the assembly and welding positions of the mounting support;

[0008] Step 3: Using one end face of the sleeve as a reference, mark the positioning dimension line of the installation support on the outer wall of the sleeve corresponding to the assembly and welding position. Use multiple gantry clamps to fix the sleeve on the construction platform and perform welding work on the installation support and the sleeve to form two rows of opposite installation supports.

[0009] Step 4: On a CNC gantry milling machine, align and machine the top surfaces and concave straight grooves of the two rows of mounting supports, ensuring that the top surfaces of the two rows of mounting supports and the groove surfaces of the concave straight grooves are on the same plane along the entire length, and that the top surfaces of the two rows of mounting supports and the groove surfaces of the concave straight grooves are symmetrical with respect to the center line of the sleeve tube.

[0010] Step 5: Place the lower end of the guide rail into the concave straight groove, adjust the reference position in the length direction of the guide rail, and weld the guide rail to the mounting bracket;

[0011] Step 6: On the CNC gantry milling machine, align and measure the length of both ends of the guide rail. Use the end face of the guide rail as a reference to determine the total length of both ends of the sleeve tube, and machine the outer stops at both ends of the sleeve tube to ensure that the outer stops at both ends are concentric.

[0012] Step 7: Fit the upper and lower flanges onto the outer stops at both ends of the sleeve pipe and weld them in place;

[0013] Step 8: Use a CNC gantry milling machine to clamp and align the components sequentially, and perform overall precision machining to complete the machining of the telescopic sleeve of the loading and unloading machine.

[0014] Preferably, the rough machining process of the upper and lower flanges in step 1 is as follows: the upper and lower flanges are machined into irregular structures with a square outer frame and a central inner circular hole, and the inner stop of the upper and lower flanges to fit with the sleeve is machined. The thickness of the upper and lower flanges, the outer frame and the central inner hole are all left for post-weld machining. All connecting threaded holes are machined after the upper and lower flanges are welded to the sleeve.

[0015] The rough machining process of the guide rail is as follows: the guide rail is machined into a long strip structure with a rectangular cross section, the lower end of the guide rail is machined into a stop type, the lower end of the guide rail is placed in a concave straight groove for welding, the top surface and two sides of the guide rail are left with post-weld machining allowance, the length of the guide rail is left with welding shrinkage and post-weld machining allowance, and the straightness of the entire length is within 0.5mm.

[0016] The rough machining process of the mounting bracket is as follows: multiple mounting brackets are machined into square structures with flat top and two side surfaces and rounded bottom surfaces. The rounded surfaces are adapted to the outer wall of the sleeve tube. The top surface of the mounting bracket is left with machining allowance after welding. The concave straight groove corresponding to the mounting bracket is not machined at this time.

[0017] The rough machining process of the sleeve is as follows: allowance is made for welding shrinkage and post-weld machining in the length direction of the sleeve, and the straightness of the entire length of the sleeve is controlled within 1.5mm.

[0018] Preferably, in step 2, the two ends of the sleeve tube need to be aligned, the two ends are concentrically machined, and the surface is flush with the light source to ensure that the two ends are perpendicular to the center of the sleeve tube.

[0019] Preferably, step 3 specifically involves: using one end face of the sleeve as a reference, marking the positioning dimension lines of the mounting supports on the outer wall of the sleeve corresponding to the assembly and welding position, accurately assembling and spot welding, and after verifying that all dimensions are correct, welding the mounting supports to the sleeve to form two opposing rows of mounting supports. During the welding process, the sleeve is placed on the construction platform along the length of the construction platform, and multiple gantry clamp fixing fixtures are used to rigidly fix the sleeve to the construction platform.

[0020] Preferably, the gantry clamp fixing fixture includes an upper clamp, a lower clamp, and two screws. The upper clamp has through holes on both sides, the upper end of the upper clamp is flat, and the lower end of the upper clamp is arc-shaped, which is adapted to the outer wall of the sleeve. The lower end of the lower clamp is flat, and the upper end of the lower clamp is arc-shaped, which is adapted to the outer wall of the sleeve. The upper surface of the construction platform is flat, and multiple sliding grooves are formed along the length of the upper surface of the construction platform. The large-diameter ends of the two screws are confined within the sliding grooves and can slide along the sliding grooves. The small-diameter ends of the two screws pass through the through holes on both sides of the upper clamp and are connected to nuts. Multiple gantry clamp fixing fixtures are evenly distributed at multiple points along the entire length of the sleeve to press the sleeve tightly, so that the sleeve is rigidly fixed on the construction platform, preventing the sleeve body from deforming due to welding heat input.

[0021] Preferably, the welding process of the guide rail and the mounting bracket in step 5 is as follows: the sleeve is placed on the construction platform along the length of the construction platform. When welding the upper guide rail, the lower side of the mounting bracket is in close contact with the construction platform. A gantry clamp fixing fixture is evenly distributed at multiple points along the entire length of the sleeve for pressing. After the upper guide rail is welded, the lower mounting bracket is turned over to become the upper mounting bracket. When welding the lower guide rail, the top surface of the original upper guide rail is in close contact with the construction platform. At the same time, a gantry clamp fixing fixture is evenly distributed at multiple points along the entire length of the sleeve for pressing, so that the sleeve is rigidly fixed on the construction platform to prevent the guide rail from warping or deforming locally, thus completing the welding of the lower guide rail.

[0022] Preferably, step 7 involves fitting the inner stops of the upper and lower flanges onto the outer stops at both ends of the sleeve pipe, positioning and welding them together. During the welding process, stainless steel tooling back plates are spot-welded to the outer end faces of the upper and lower flanges for reinforcement, reducing welding stress that could cause deformation of the inner side of the upper or lower flange.

[0023] Preferably, during steps 3 to 7, all welds undergo non-destructive surface testing, and all welds are polished after passing the test.

[0024] Preferably, in step 8, the overall precision machining consists of back-and-forth turning, small cutting amount, and multiple symmetrical machining processes, while interspersed with natural aging processes.

[0025] Preferably, a telescopic sleeve for a loading and unloading machine is manufactured by the processing method described in any one of the above claims. The telescopic sleeve includes an upper flange, a lower flange, guide rails, mounting supports, and a sleeve tube. There are two guide rails and multiple mounting supports. The upper flange and lower flange are respectively welded to both ends of the sleeve tube. The multiple mounting supports are divided into two rows. The two rows of mounting supports are respectively welded to two opposite sides of the sleeve tube with less straightness. The top surface of each row of mounting supports and the groove surface of the concave straight groove are on the same plane along the entire length of the sleeve tube. The top surface of the two rows of mounting supports and the groove surface of the concave straight groove are symmetrical with respect to the center line of the sleeve tube. The two guide rails are respectively welded into the concave straight grooves of the two rows of mounting supports.

[0026] Compared with the prior art, the advantages of the present invention are as follows:

[0027] (1) This invention discloses a processing method for a telescopic sleeve of a loading and unloading machine. First, the upper flange, lower flange, guide rail, mounting support and sleeve tube are rough processed. Then, two rows of mounting supports are welded to the two opposite sides of the sleeve tube with smaller straightness. Next, the concave straight groove is machined by using a CNC gantry milling machine. Then, the two guide rails are welded into the two rows of concave straight grooves respectively. Next, the upper flange and lower flange are respectively fitted into the outer stop at both ends of the sleeve tube, and the positioning is welded. Finally, the whole is precision machined to complete the processing of the telescopic sleeve of the loading and unloading machine. The telescopic sleeve processed by the processing method of this invention meets the requirements in terms of straightness, symmetry and flatness, ensuring the accuracy tolerance requirements of the design drawings and meeting the functional requirements of equipment debugging.

[0028] (2) In this invention, the two opposite directions with smaller straightness of the sleeve are used as the assembly and welding positions of the mounting supports. The positioning dimension lines of the mounting supports are marked on the outer wall of the sleeve corresponding to the assembly and welding positions. Multiple gantry clamps are used to fix the sleeve on the construction platform and the welding work of the mounting supports and the sleeve is carried out to form two rows of opposite mounting supports, which effectively improves the straightness.

[0029] (3) After the mounting supports are welded to the sleeve, the top surfaces and concave straight grooves of the two rows of mounting supports are machined on a CNC gantry milling machine to ensure that the top surfaces of the two rows of mounting supports and the groove surfaces of the concave straight grooves are on the same plane along the entire length. The top surfaces of the two rows of mounting supports and the groove surfaces of the concave straight grooves are symmetrical with respect to the center line of the sleeve, thus maximizing the symmetry and flatness.

[0030] (4) The present invention uses a gantry clamping fixture to press the sleeve tube at multiple points along its entire length, thereby rigidly fixing it on the construction platform, preventing the sleeve tube body from deforming due to welding heat input, and improving straightness.

[0031] (5) The present invention uses a gantry clamping fixture to press the guide rail and sleeve at multiple points along the entire length of the guide rail and sleeve, so that the guide rail is rigidly fixed on the construction platform, preventing the guide rail from warping and deforming locally, and improving the symmetry and flatness. Attached Figure Description

[0032] Figure 1 This is a schematic diagram of the structure of a telescopic sleeve for a loading and unloading machine according to the present invention;

[0033] Figure 2 for Figure 1 AA section diagram;

[0034] Figure 3 for Figure 1 View from direction B;

[0035] Figure 4 for Figure 1 The C-direction view;

[0036] Figure 5 This is a schematic diagram of the mounting support structure for a telescopic sleeve of a loading and unloading machine according to the present invention;

[0037] Figure 6 This is a schematic diagram illustrating the processing of a telescopic sleeve for a loading and unloading machine according to the present invention.

[0038] Explanation of reference numerals in the attached figures:

[0039] 1. Upper flange, 2. Lower flange, 3. Guide rail, 4. Mounting support, 5. Sleeve, 6. Construction platform, 7. Gantry clamp fixing fixture;

[0040] 4-1. Concave straight groove;

[0041] 6-1. Slide groove;

[0042] 7-1. Upper clamping plate; 7-2. Lower clamping plate; 7-3. Screw. Detailed Implementation

[0043] The specific implementation of the present invention is described below with reference to embodiments:

[0044] It should be noted that the structures, proportions, sizes, etc. shown in this specification are only used to complement the content disclosed in the specification for those skilled in the art to understand and read, and are not intended to limit the conditions under which the present invention can be implemented. Any modifications to the structure, changes in the proportions, or adjustments to the size, without affecting the effects and objectives that the present invention can produce, should still fall within the scope of the technical content disclosed in the present invention.

[0045] Furthermore, the accompanying drawings are merely illustrative diagrams of embodiments of the present invention and are not necessarily drawn to scale. The same reference numerals in the drawings denote the same or similar parts, and therefore repeated descriptions of them will be omitted. Some structural diagrams shown in the drawings are functional entities and do not necessarily correspond to physically or logically independent entities.

[0046] Example 1

[0047] like Figure 1 , 6 As shown, this invention discloses a method for processing a telescopic sleeve of a loading and unloading machine, comprising the following steps:

[0048] Step 1: Roughly machine the upper flange 1, lower flange 2, guide rail 3, mounting bracket 4 and sleeve 5, where there are two guide rails 3 and multiple mounting brackets 4;

[0049] Step 2: Re-inspect the straightness and roundness of the sleeve 5, and use the two opposite directions with smaller straightness of the sleeve 5 as the assembly and welding positions of the mounting support 4;

[0050] Step 3: Using one end face of the sleeve tube 5 as a reference, mark the positioning dimension line of the mounting support 4 on the outer wall of the sleeve tube 5 corresponding to the assembly and welding position. Use multiple gantry clamps to fix the sleeve tube 5 on the construction platform 6, and perform welding work between the mounting support 4 and the sleeve tube 5 to form two rows of opposite mounting supports 4.

[0051] Step 4: On a CNC gantry milling machine, align and machine the top surfaces of the two rows of mounting supports 4 and the concave straight grooves 4-1, ensuring that the top surfaces of the two rows of mounting supports 4 and the groove surfaces of the concave straight grooves 4-1 are on the same plane along the entire length, and that the top surfaces of the two rows of mounting supports 4 and the groove surfaces of the concave straight grooves 4-1 are symmetrical with respect to the center line of the sleeve tube 5.

[0052] Step 5: Place the lower end of the guide rail 3 into the concave straight groove 4-1, adjust the reference position of the guide rail 3 in the length direction, and weld the guide rail 3 to the mounting support 4;

[0053] Step 6: On the CNC gantry milling machine, align the two ends of the guide rail 3 and measure its length. Use the end face of the guide rail 3 as a reference to determine the total length of both ends of the sleeve tube 5, and machine the outer stops at both ends of the sleeve tube 5 to ensure that the outer stops at both ends are concentric.

[0054] Step 7: Fit the upper flange 1 and the lower flange 2 onto the outer stops at both ends of the sleeve 5, and weld them in place;

[0055] Step 8: Use a CNC gantry milling machine to clamp and align the components sequentially, and perform overall precision machining to complete the machining of the telescopic sleeve of the loading and unloading machine.

[0056] Example 2

[0057] like Figure 6 As shown, preferably, the rough machining process of the upper flange 1 and the lower flange 2 in step 1 is as follows: the upper flange 1 and the lower flange 2 are machined into an irregular structure with a square outer frame and a central inner circular hole, and the inner stop of the upper flange 1 and the lower flange 2 to fit with the sleeve tube 5 is machined. The thickness of the upper flange 1 and the lower flange 2, the outer frame and the central inner hole are all left for machining after welding. All connecting threaded holes are machined after the upper flange 1 and the lower flange 2 are welded to the sleeve tube 5.

[0058] The rough machining process of the guide rail 3 is as follows: the guide rail 3 is machined into a long strip structure with a rectangular cross section. The lower end of the guide rail 3 is machined into a stop type. The lower end of the guide rail 3 is placed in the concave straight groove 4-1 for welding. The top surface and two sides of the guide rail 3 are left with post-weld machining allowance. The length of the guide rail 3 is left with welding shrinkage and post-weld machining allowance. The straightness of the entire length is within 0.5mm.

[0059] The rough machining process of the mounting support 4 is as follows: multiple mounting supports 4 are machined into square structures with flat top and two side surfaces and rounded bottom surfaces. The rounded surfaces are adapted to the outer wall of the sleeve tube 5. The top surface of the mounting support 4 is left with machining allowance after welding. The concave straight groove 4-1 corresponding to the mounting support 4 is not machined at this time.

[0060] The rough machining process of sleeve 5 is as follows: allowance is made for welding shrinkage and post-weld machining in the length direction of sleeve 5, and the straightness of the entire length of sleeve 5 is controlled within 1.5mm.

[0061] Example 3

[0062] like Figure 6 As shown, preferably, in step 2, the two ends of the sleeve tube 5 need to be aligned, the two ends are concentrically machined, and flush with the light source to ensure that the two ends are perpendicular to the center of the sleeve tube 5.

[0063] like Figure 6As shown, preferably, step 3 specifically involves: using one end face of the sleeve tube 5 as a reference, marking the positioning dimension lines of the mounting support 4 on the outer wall of the sleeve tube 5 corresponding to the assembly and welding position, accurately assembling and spot welding, and after verifying that all dimensions are correct, performing the welding work between the mounting support 4 and the sleeve tube 5 to form two opposing rows of mounting supports 4. During the welding process, the sleeve tube 5 is placed on the construction platform 6 along the length direction of the construction platform 6, and multiple gantry clamp fixing fixtures 7 are used to rigidly fix the sleeve tube 5 on the construction platform 6.

[0064] Example 4

[0065] like Figure 6 As shown, preferably, the gantry clamp fixing fixture 7 includes an upper clamping plate 7-1, a lower clamping plate 7-2, and two screws 7-3. The upper clamping plate 7-1 has through holes on both sides. The upper end of the upper clamping plate 7-1 is flat, and the lower end is an arc surface, which fits the outer wall of the sleeve tube 5. The lower end of the lower clamping plate 7-2 is flat, and the upper end is an arc surface, which fits the outer wall of the sleeve tube 5. The upper surface of the construction platform 6 is flat. Multiple grooves 6-1 are opened along the length of the upper end face of the platform 6. The large-diameter ends of the two screws 7-3 are limited to the grooves 6-1 and can slide along the grooves 6-1. The small-diameter ends of the two screws 7-3 pass through the through holes on both sides of the upper clamping plate 7-1 and are connected to the nuts. Multiple gantry clamping plates fixing fixtures 7 are evenly distributed at multiple points along the entire length of the sleeve tube 5 to press the sleeve tube 5 tightly, so that the sleeve tube 5 is rigidly fixed on the construction platform 6, preventing the sleeve tube 5 from deforming due to welding heat input.

[0066] Example 5

[0067] like Figure 6 As shown, preferably, the welding process of guide rail 3 and mounting bracket 4 in step 5 is as follows: the sleeve tube 5 is placed on the construction platform 6 along the length of the construction platform 6. When welding the upper guide rail 3, the lower side of the mounting bracket 4 is in close contact with the construction platform 6. The gantry clamp fixing fixture 7 is evenly distributed at multiple points along the entire length of the sleeve tube 5 for pressing. After the upper guide rail 3 is welded, the lower mounting bracket 4 is turned over to become the upper mounting bracket 4. When welding the lower guide rail 3, the top surface of the original upper guide rail 3 is in close contact with the construction platform 6. At the same time, the gantry clamp fixing fixture 7 is evenly distributed at multiple points along the entire length of the sleeve tube 5 for pressing, so that the sleeve tube 5 is rigidly fixed on the construction platform 6, preventing the guide rail 3 from warping or deforming locally, thus completing the welding of the lower guide rail 3.

[0068] like Figure 6 As shown, preferably, step 7 involves fitting the inner stops of the upper flange 1 and the lower flange 2 into the outer stops at both ends of the sleeve tube 5, and then positioning and welding them together. During the welding process, stainless steel tooling back plates are spot-welded to the outer end faces of the upper flange 1 and the lower flange 2 for reinforcement, thereby reducing the deformation of the inner side of the upper flange 1 or the lower flange 2 caused by welding stress.

[0069] During steps 3 to 7, all welds undergo non-destructive surface testing, and all welds are polished after passing the test.

[0070] In step 8, the overall precision machining process consists of back-and-forth turning, small cutting amount, and multiple symmetrical machining passes, while natural aging process is interspersed.

[0071] Example 6

[0072] like Figures 1-5 As shown, preferably, a telescopic sleeve for a loading and unloading machine is manufactured by the processing method described in any one of the above-mentioned methods. The telescopic sleeve includes an upper flange 1, a lower flange 2, a guide rail 3, mounting supports 4, and a sleeve tube 5. There are two guide rails 3 and multiple mounting supports 4. The upper flange 1 and the lower flange 2 are respectively welded to the two end faces of the sleeve tube 5. The multiple mounting supports 4 are divided into two rows. The two rows of mounting supports 4 are respectively welded to two opposite sides of the sleeve tube 5 with smaller straightness. The top surface of each row of mounting supports 4 and the groove surface of the concave straight groove 4-1 are respectively on the same plane along the entire length of the sleeve tube 5. The top surface of the two rows of mounting supports 4 and the groove surface of the concave straight groove 4-1 are symmetrical with respect to the center line of the sleeve tube 5. The two guide rails 3 are respectively welded into the concave straight groove 4-1 of the two rows of mounting supports 4.

[0073] The upper flange 1 and lower flange 2 are made of stainless steel sheet, with an irregular cross-section consisting of a square outer frame and a central circular hole. The inner locating ends of the upper flange 1 and lower flange 2 are fitted and welded to the outer locating ends of the sleeve tube 5. Allowances are made for post-weld machining in terms of thickness, shape, and central hole of the upper and lower flanges. All threaded holes are machined after welding. The upper flange 1 is connected to the suspension head via locating bolts, and the lower flange 2 is connected to the grab flange via locating bolts. Therefore, the perpendicularity of the flanges at both ends of the upper flange 1 and lower flange 2 to the overall center of the sleeve tube 5 is extremely strict.

[0074] The guide rail 3 is made of stainless steel long round bar material machined into a rectangular strip. The lower end of the guide rail section is placed in a concave straight groove 4-1, and the two are fixed by welding through the side contact area. The upper three working surfaces (top surface and two side surfaces) are all left with post-weld machining allowance. The entire length of the three working surfaces of the guide rail 3 is guided by guide wheels to ensure the accurate positioning of the gripper when gripping the fuel assembly. Therefore, the machining accuracy of the entire length of the working surfaces of the guide rail 3 is of paramount importance.

[0075] The mounting bracket 4 is an arc-shaped block made of stainless steel plate, with a concave straight groove 4-1 on the top surface, flat surfaces on the left and right sides, and an arc surface on the bottom surface. The arc surface is welded to the two symmetrical sides of the outer wall of the sleeve tube 5.

[0076] The sleeve tube 5 is a finished stainless steel seamless steel pipe. As the carrier of the telescopic sleeve component, the straightness control of its entire length is very important. The two opposite directions with smaller straightness need to be used as the assembly and welding positions of the installation support. Symmetrical rectangular holes are opened at both ends of the outer wall of the sleeve tube 5 near the flange position, which are used as windows for subsequent installation and maintenance of other components.

[0077] Each individual piece is pre-welded with allowance, and intermediate processing steps sequentially meet the dimensions in the drawings. After being assembled and welded into a whole piece, it is then precision-machined. Effective process measures are taken during the process to reduce welding and machining deformation, ultimately ensuring the straightness, symmetry, flatness, and other geometric tolerances of the telescopic sleeve track.

[0078] Example 7

[0079] This invention discloses a method for processing a telescopic sleeve for a loading and unloading machine, comprising an upper flange 1 (1 piece), a lower flange 2 (1 piece), a guide rail 3 (2 pieces), a mounting support 4 (62 pieces), and a sleeve tube 5 (1 piece).

[0080] Purchase finished sleeve tube 5 (Ф219×8), allowing for welding shrinkage and post-weld machining allowance along its length. As the carrier of the telescopic sleeve component, its overall straightness must be controlled within 1.5mm.

[0081] After the sleeve tube 5 is purchased and returned to the factory, the straightness and roundness of the tube are re-inspected and the data is recorded to guide the subsequent assembly welding and machining operations. The two opposite directions with smaller straightness (90° and 270°) are used as the assembly welding positions of the mounting support 4. The subsequent manufacturing process uses this as a reference to align the two ends of the sleeve tube 5, machine the two ends concentrically, and make them flush with the light, ensuring that the end faces of both ends are perpendicular to the center of the sleeve tube.

[0082] The mounting bracket 4 is machined into a single piece with a peripheral shape and arc surface. The top surface is left with machining allowance after welding. The corresponding concave straight groove 4-1 does not need to be machined here.

[0083] Using one end face of the sleeve tube 5 as a reference, mark the positioning dimension lines for the installation support 4 on the outer wall of the sleeve tube 5 at the pre-determined assembly and welding positions (90° and 270°). Precisely assemble and spot weld, and only after verifying that all dimensions are correct can the welding work between the installation support 4 and the sleeve tube 5 proceed. During the welding process, place the sleeve tube 5 and the installation support 4 as a whole on the flat surface of the construction platform 6 along its length. Use a special gantry clamp to fix the fixture 7, evenly distributed at multiple points along the entire length, to rigidly fix it to the construction platform and prevent the cylinder body from deforming due to welding heat input.

[0084] On a CNC gantry milling machine, align and machine the top surface of the mounting supports 4 in two directions and the concave straight groove 4-1 to ensure that the top surface and groove surface of the mounting supports 4 in two directions are on the same plane along the entire length, and that the top surface and groove surface of the mounting supports in two directions are symmetrical with respect to the center line of the sleeve tube 5 (groove surface parallelism 0.06mm, groove surface straightness 0.25mm).

[0085] The guide rail 3 is machined into a long strip with a rectangular cross-section. The lower 13mm height area of ​​the cross-section is placed in the concave straight groove 4-1 for welding and is machined into a stop type. The three working surfaces at the upper end (top surface and two side surfaces) are all left with post-weld machining allowance. The length is left with welding shrinkage and post-weld machining allowance. The straightness of the entire length is within 0.5mm.

[0086] Place the lower end of the guide rail 3 section entirely into the pre-machined concave straight groove 4-1, adjust the reference position of the guide rail 3 along its length (at this time, both the guide rail 3 and the sleeve tube 5 have machining allowances in length), and weld the guide rail 3 to the mounting support 4. During the welding process, place the sleeve tube 5 and the mounting support 4 vertically on the flat construction platform 6. When welding the upper guide rail 3, ensure that the top surface of the lower mounting support 4 is flush with the platform surface (after the upper part is welded, lift the lower part to become the upper part, and when welding the original lower guide rail, ensure that the top surface of the original upper guide rail is flush with the platform surface). Use a special gantry clamping fixture 7 to evenly distribute and press it at multiple points along the entire length, so that it is rigidly fixed on the construction platform to prevent the guide rail 3 from warping or deforming locally.

[0087] On a CNC gantry milling machine, align and measure the length of both ends of the guide rail. Using the end face of guide rail 3 as a reference, determine the total length of both ends of sleeve tube 5, and machine the outer stops at both ends of sleeve tube 5 to ensure that the circles of the two ends of the stops are concentric.

[0088] Upper flange 1 and lower flange 2 are machined individually into irregular shapes with a cross-section resembling a square and a hollow circle at the center. The inner stop of the upper and lower flanges that mate with the sleeve is machined individually, with allowances made for post-weld machining in terms of thickness, shape, and central inner hole. All threaded holes are machined after welding.

[0089] The upper and lower flanges are respectively fitted onto the outer stops at both ends of the sleeve pipe, and then positioned and welded. During the welding process, stainless steel tooling back plates are spot-welded to the outer end face of the flange for reinforcement, reducing welding stress and thus reducing deformation of the inner side of the flange.

[0090] During the process, all welds underwent non-destructive surface testing, and all welds were polished after passing the test.

[0091] Using a CNC gantry milling machine, the entire guide rail is precision machined in a single setup and alignment. Through a process of "reciprocating rotation, small cutting amounts, multiple symmetrical machining passes, and natural aging interspersed throughout," stress generated during machining is released, minimizing the impact of machining stress on the overall accuracy of the guide rail.

[0092] In precision machining, factors affecting quality should be given special consideration:

[0093] a. Due to the poor rigidity of the steel pipe, its natural downward deflection and the bending amount of the steel pipe itself should be considered when clamping, and the amount of clamping should be strictly controlled. The clamping amount should be measured with a dial indicator when clamping.

[0094] b. The processing quantity should be verified before processing, and measurements should be taken intermittently during processing;

[0095] c. During each machining step, the cutting amount, rotation speed, and other machining parameters should be strictly controlled, and coolant should be used to prevent machining deformation;

[0096] d. During the processing, the clamps should be loosened periodically to observe the deformation and prevent unexpected processing deformation.

[0097] At this point, the entire machining process for the telescopic sleeve is complete.

[0098] The telescopic sleeve structure of this invention is a slender stainless steel tube with a length of nearly 8.7 meters. Upper flange 1 and lower flange 2 are welded to both ends of the tube. 31 sets (62 pieces) of mounting supports 4 are welded to the outer wall of the tube in two symmetrical straight directions. A guide rail 3 is placed in a concave straight groove 4-1 and welded to the concave straight groove 4-1 to form an integral structure. Because this structure is a slender stainless steel rod-type welded component, its overall rigidity is extremely poor. Combined with the inherent properties of the material, this makes the whole structure prone to deformation. However, the required machining precision is extremely high, making the overall machining very difficult. Integral machining technology has always been a challenge in the machining industry. This invention focuses on solving this type of integral machining technology, rather than using conventional machining methods.

[0099] The working principle of this invention is as follows:

[0100] like Figures 1-6 As shown, this invention discloses a processing method for a telescopic sleeve of a loading and unloading machine. First, the upper flange, lower flange, guide rail, mounting supports, and sleeve tube are rough-machined. Next, two rows of mounting supports are welded to the two opposite sides of the sleeve tube where the straightness is relatively small. Then, a CNC gantry milling machine is used to align and machine concave straight grooves. Next, two guide rails are welded into the two rows of concave straight grooves respectively. Then, the upper flange and lower flange are respectively fitted into the outer stops at both ends of the sleeve tube, positioned, and welded together. Finally, the entire assembly is precision-machined to complete the processing of the telescopic sleeve of the loading and unloading machine. The telescopic sleeve processed by this invention meets the requirements for straightness, symmetry, and flatness, ensuring the accuracy and tolerance requirements of the design drawings and satisfying the various functional requirements for equipment debugging.

[0101] The invention uses two opposite directions with relatively low straightness of the sleeve as the assembly and welding positions of the mounting supports. Positioning dimension lines for the mounting supports are marked on the outer wall of the sleeve corresponding to the assembly and welding positions. Multiple gantry clamps are used to fix the sleeve to the construction platform, and the welding work between the mounting supports and the sleeve is carried out to form two opposing rows of mounting supports, which effectively improves the straightness.

[0102] In this invention, after the mounting supports are welded to the sleeve, the top surfaces and concave straight grooves of the two rows of mounting supports are machined on a CNC gantry milling machine to ensure that the top surfaces of the two rows of mounting supports and the groove surfaces of the concave straight grooves are on the same plane along the entire length. The top surfaces of the two rows of mounting supports and the groove surfaces of the concave straight grooves are symmetrical with respect to the center line of the sleeve, thus maximizing the symmetry and flatness.

[0103] This invention uses a gantry clamping fixture evenly distributed at multiple points along the entire length of the sleeve to press it firmly onto the construction platform, preventing the sleeve body from deforming due to welding heat input and improving straightness.

[0104] This invention uses a gantry clamping fixture evenly distributed at multiple points along the entire length of the guide rail and sleeve tube to press them together, thus rigidly fixing them to the construction platform, preventing local warping and deformation of the guide rail, and improving symmetry and flatness.

[0105] Through technical breakthroughs, the overall dimensions of this invention ultimately meet the accuracy and tolerance requirements of the design drawings. After in-plant assembly, debugging, and testing, the relevant functional tests have confirmed that the invention meets design requirements. The entire loading and unloading machine, assembled using the telescopic sleeve manufactured according to this invention, is already in operation at a nuclear power plant with excellent results.

[0106] The preferred embodiments of the present invention have been described in detail above. However, the present invention is not limited to the above embodiments. Within the scope of knowledge possessed by those skilled in the art, various changes can be made without departing from the spirit of the present invention.

[0107] Many other changes and modifications can be made without departing from the concept and scope of this invention. It should be understood that this invention is not limited to the specific embodiments, and the scope of this invention is defined by the appended claims.

Claims

1. A method of machining a telescoping sleeve of a power and free conveyor characterized by: Includes the following steps: Step 1: Roughly machine the upper flange (1), lower flange (2), guide rail (3), mounting bracket (4) and sleeve (5), where there are two guide rails (3) and multiple mounting brackets (4); Step 2: Re-inspect the straightness and roundness of the sleeve (5), and take the two opposite sides with smaller straightness of the sleeve (5) as the assembly and welding positions of the mounting support (4); Step 3: Using the end face of one side of the sleeve (5) as a reference, mark the positioning dimension line of the mounting support (4) on the outer wall of the sleeve (5) corresponding to the assembly welding position. Use multiple gantry clamp fixing fixtures (7) to fix the sleeve (5) on the construction platform (6) and perform welding work between the mounting support (4) and the sleeve (5) to form two rows of opposite mounting supports (4). Step 4: On a CNC gantry milling machine, align and machine the top surface of the two rows of mounting supports (4) and the concave straight groove (4-1) to ensure that the top surface of the two rows of mounting supports (4) and the groove surface of the concave straight groove (4-1) are on the same plane along the entire length, and the top surface of the two rows of mounting supports (4) and the groove surface of the concave straight groove (4-1) are symmetrical with respect to the center line of the sleeve tube (5); Step 5: Place the lower end of the guide rail (3) into the concave straight groove (4-1), adjust the reference position of the guide rail (3) in the length direction, and weld the guide rail (3) to the mounting bracket (4). Step 6: On the CNC gantry milling machine, find the two ends of the machining guide rail (3) and take the length. Use the end face of the guide rail (3) as the reference to determine the total length of the two ends of the sleeve tube (5), and machine the outer stop at both ends of the sleeve tube (5) to ensure that the outer stop circles at both ends are concentric. Step 7: Fit the upper flange (1) and lower flange (2) onto the outer stops at both ends of the sleeve (5) and weld them in place; Step 8: Use a CNC gantry milling machine to clamp and align the components in sequence, and perform overall precision machining to complete the machining of the telescopic sleeve of the loading and unloading machine.

2. A method of machining a telescoping sleeve of a load handler according to claim 1, characterized in that, The rough machining process of the upper flange (1) and lower flange (2) in step 1 is as follows: the upper flange (1) and lower flange (2) are machined into irregular structures with a square outer frame and a central inner hole. The inner stop of the upper flange (1) and lower flange (2) to fit with the sleeve (5) is also machined. The thickness of the upper flange (1) and lower flange (2), the outer frame and the central inner hole are all left for machining after welding. All connecting threaded holes are machined after the upper flange (1) and lower flange (2) are welded to the sleeve (5). The rough machining process of the guide rail (3) is as follows: the guide rail (3) is machined into a long strip structure with a rectangular cross section. The lower end of the guide rail (3) is machined into a stop type. The lower end of the guide rail (3) is placed in the concave straight groove (4-1) for welding. The top surface and two sides of the guide rail (3) are left with post-weld machining allowance. The length of the guide rail (3) is left with welding shrinkage and post-weld machining allowance. The straightness of the entire length is within 0.5mm. The rough machining process of the mounting bracket (4) is as follows: multiple mounting brackets (4) are all machined into square structures with flat top and two side surfaces and rounded bottom surface. The rounded surface is adapted to the outer wall of the sleeve tube (5). The top surface of the mounting bracket (4) is left with a machining allowance after welding. The concave straight groove (4-1) corresponding to the mounting bracket (4) is not machined at this time. The rough machining process of the sleeve (5) is as follows: the length direction of the sleeve (5) is left for welding shrinkage and post-weld machining, and the straightness of the entire length of the sleeve (5) is controlled within 1.5mm.

3. The processing method of a telescopic sleeve for a loading and unloading machine according to claim 1, characterized in that: In step 2, it is also necessary to align the two ends of the sleeve (5), process the two ends concentrically, and make them flush with the light to ensure that the two ends are perpendicular to the center of the sleeve (5).

4. The processing method of a telescopic sleeve for a loading and unloading machine according to claim 1, characterized in that, Step 3 is as follows: Taking the end face of one side of the sleeve (5) as a reference, mark the positioning dimension line of the mounting support (4) on the outer wall of the sleeve (5) corresponding to the assembly and welding position, accurately assemble and spot weld, and after verifying that all dimensions are correct, carry out the welding work of the mounting support (4) and the sleeve (5) to form two rows of opposite mounting supports (4). During the welding process, place the sleeve (5) on the construction platform (6) along the length direction of the construction platform (6), and use multiple gantry clamp fixing fixtures (7) to rigidly fix the sleeve (5) on the construction platform (6).

5. The processing method of a telescopic sleeve for a loading and unloading machine according to claim 1, characterized in that, The gantry clamp fixing fixture (7) includes an upper clamp (7-1), a lower clamp (7-2), and two screws (7-3). The upper clamp (7-1) has through holes on both sides. The upper end of the upper clamp (7-1) is flat, and the lower end of the upper clamp (7-1) is arc-shaped, which is adapted to the outer wall of the sleeve (5). The lower end of the lower clamp (7-2) is flat, and the upper end of the lower clamp (7-2) is arc-shaped, which is adapted to the outer wall of the sleeve (5). The upper surface of the construction platform (6) is flat. Multiple grooves (6-1) are opened along the length of the upper end face. The large diameter ends of the two screws (7-3) are limited to the grooves (6-1) and can slide along the grooves (6-1). The small diameter ends of the two screws (7-3) pass through the through holes on both sides of the upper clamping plate (7-1) and are connected to the nuts. Multiple gantry clamping plates fixing fixtures (7) are evenly distributed at multiple points along the entire length of the sleeve (5) to press the sleeve (5) tightly, so that the sleeve (5) is rigidly fixed on the construction platform (6) to prevent the sleeve (5) from deforming due to welding heat input.

6. The processing method of a telescopic sleeve for a loading and unloading machine according to claim 1, characterized in that, The welding process of the guide rail (3) and the mounting bracket (4) in step 5 is as follows: the sleeve tube (5) is placed on the construction platform (6) along the length of the construction platform (6). When welding the upper guide rail (3), the lower mounting bracket (4) is pressed against the construction platform (6). The gantry clamp fixing fixture (7) is evenly distributed at multiple points along the entire length of the sleeve tube (5) for pressing. After the upper guide rail (3) is welded, the lower mounting bracket (4) is turned over to become the upper mounting bracket (4). When welding the lower guide rail (3), the top surface of the original upper guide rail (3) is pressed against the construction platform (6). At the same time, the gantry clamp fixing fixture (7) is evenly distributed at multiple points along the entire length of the sleeve tube (5) for pressing, so that the sleeve tube (5) is rigidly fixed on the construction platform (6) to prevent the guide rail (3) from warping and deforming locally, and the welding of the lower guide rail (3) is completed.

7. A method for processing a telescopic sleeve for a loading and unloading machine according to claim 2, characterized in that, Step 7 involves fitting the inner stop of the upper flange (1) and the lower flange (2) into the outer stop of both ends of the sleeve tube (5) for positioning and welding. During the welding process, stainless steel tooling back plates are spot-welded to the outer end faces of the upper flange (1) and the lower flange (2) for reinforcement, thereby reducing the deformation of the inner side of the upper flange (1) or the lower flange (2) caused by welding stress.

8. A method for processing a telescopic sleeve for a loading and unloading machine according to claim 1, characterized in that, During steps 3 to 7, all welds undergo non-destructive surface testing, and all welds are polished after passing the test.

9. A method for processing a telescopic sleeve for a loading and unloading machine according to claim 1, characterized in that, In step 8, the overall precision machining process consists of back-and-forth turning, small cutting amount, and multiple symmetrical machining passes, while natural aging process is interspersed.

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