Laser welding method for spent fuel storage grillwork square tube

Abstract

The invention relates to the technical field of nuclear fuel storage equipment manufacturing, in particular to a laser welding method for a spent fuel storage grillwork square tube. Two to-be-welded pipe bodies are installed on a clamping assembly, and to-be-welded weld joints of the two pipe bodies face a laser transmitter; and the to-be-welded weld joint is welded through a laser welding gun so as to be welded and machined into the square pipe. According to the arrangement, the two pipe bodies are clamped and fixed through the clamping assembly, so that it is guaranteed that the positions of the two pipe bodies meet the laser welding requirement. And then the two pipe bodies are welded through a laser welding process method, and therefore the square pipe is formed through welding. The laser welding precision is high, the generated heat input amount is small, and the welding deformation amount is reduced, so that the inner cavity size precision requirement and the form and location tolerance requirement of the square tube are met, the influence on the subsequent assembly operation of the square tube on the spent fuel storage grillwork is avoided, and the assembly precision is improved.

Description

TECHNICAL FIELD

[0001] The present disclosure relates to the technical field of nuclear fuel storage equipment manufacturing, and particularly relates to a laser welding method for a spent fuel storage rack square tube. BACKGROUND

[0002] The spent fuel storage rack is a bolted and welded metal rack with a cuboid shape. The spent fuel storage rack is composed of a whole skeleton, a square tube assembly and other auxiliary components, and is mainly used for storing spent fuel. Generally, each spent fuel storage rack contains dozens of square tubes, which are the core components for directly storing radioactive spent fuel, and are basically square cavity structures. To ensure the critical safety of spent fuel, a boron-aluminum plate is installed on each of the four side walls of the square tube. The structure of the square tube determines that it is difficult to ensure the dimensional accuracy during forming and welding, and the overall welding deformation control and post-welding dimensional control become the key points in the production process. As a spent fuel assembly storage chamber, it is required to have high inner cavity dimensional accuracy and shape tolerance. If the traditional argon arc welding process is used, the heat input during welding is large, which is easy to cause welding deformation, and it is difficult to control the dimensional accuracy of the square tube after welding, which affects the subsequent assembly of the square tube in the spent fuel storage rack.

[0003] Therefore, it is necessary to provide a laser welding method for a spent fuel storage rack square tube to at least partially solve the problems in the prior art. SUMMARY

[0004] The present disclosure aims to at least solve one of the technical problems in the prior art or related art.

[0005] To this end, the present disclosure provides a laser welding method for a spent fuel storage rack square tube.

[0006] Therefore, according to the embodiments of the present disclosure, a laser welding method for a spent fuel storage rack square tube is provided, which comprises:

[0007] Placing the clamping assembly on the workbench;

[0008] Installing the two pipe bodies to be welded on the clamping assembly, and making the weld seams to be welded of the two pipe bodies face the laser emitter;

[0009] Welding the weld seams to be welded by the laser welding gun to process the square tube.

[0010] In a feasible embodiment, the clamping assembly comprises:

[0011] An outer clamping tool for clamping the outer side walls of the two pipe bodies;

[0012] An inner supporting tool for expanding the inner side walls of the two pipe bodies.

[0013] In an embodiment, the step of mounting the two pipe bodies to be welded to the clamping assembly and orienting the weld seams to be welded of the two pipe bodies towards the laser emitter comprises:

[0014] preliminarily positioning the two pipe bodies to be welded by the outer clamping tool and the inner supporting tool;

[0015] secondarily positioning the two pipe bodies by adjusting the position of the outer clamping tool and the position of the inner supporting tool, so that the assembly accuracy of the two pipe bodies meets the preset requirement.

[0016] In an embodiment, the inner supporting tool comprises:

[0017] a support base;

[0018] a plate assembly arranged in the support base, and a placement space formed in the plate assembly;

[0019] a pull rod inserted into the support base and rotatably connected to the support base through a bearing;

[0020] a mandrel arranged in the placement space and connected to the pull rod;

[0021] a telescopic mechanism arranged on the circumferential side of the mandrel and used for telescoping in the radial direction of the mandrel;

[0022] wherein, when the pull rod rotates in a first direction, the telescopic mechanism extends to drive the plate assembly to move away from the mandrel to tighten the inner side wall of the pipe body; when the pull rod rotates in a second direction, the telescopic mechanism retracts to drive the plate assembly to move towards the mandrel to leave the inner side wall of the pipe body; and the first direction and the second direction are opposite.

[0023] In an embodiment, the length of the inner supporting tool is greater than the length of the pipe bodies to be welded.

[0024] In an embodiment, the step of preliminarily positioning the two pipe bodies to be welded by the outer clamping tool and the inner supporting tool comprises:

[0025] mounting the two pipe bodies to be welded into the inner cavity of the outer clamping tool, and adjusting the two pipe bodies so that the weld seams to be welded are oriented towards the laser emitter;

[0026] sliding the inner supporting tool into the inner cavities of the two pipe bodies;

[0027] The outer clamping tool is fixed on the workbench by the pressing plate, and the inner supporting tool is adjusted to contact the inner sidewalls of the two pipe bodies.

[0028] In an embodiment, the step of adjusting the position of the outer clamping tool and the position of the inner supporting tool to position the two pipe bodies again so that the assembly accuracy of the two pipe bodies meets the preset requirement comprises:

[0029] The degree of the outer clamping tool pressing the outer sidewalls of the two pipe bodies and the degree of the inner supporting tool pressing the inner sidewalls of the two pipe bodies are adjusted by adjusting the pressing plate until the assembly accuracy of the two pipe bodies meets the preset requirement.

[0030] The preset requirement includes that the gap of the to-be-welded weld seams of the two pipe bodies is less than or equal to 0.05 mm, and / or the misalignment of the to-be-welded weld seams of the two pipe bodies is less than or equal to 0.05 mm.

[0031] In an embodiment, the step of welding the to-be-welded weld seams by the laser welding gun to process the square pipe comprises:

[0032] Adjusting the power of the laser emitter of the laser welding gun to a preset power;

[0033] Adjusting the focal length of the laser emitter to a preset focal length;

[0034] Passing protective gas into the torch of the laser welding gun through the laser emitter, and passing protective gas into the inner supporting tool;

[0035] Starting the laser welding gun to weld the to-be-welded weld seams to process the square pipe.

[0036] In an embodiment, the preset power is 900 W to 1050 W;

[0037] The preset focal length is 182 mm to 185 mm;

[0038] The welding speed of the laser welding gun is 18 mm / s to 22 mm / s.

[0039] In an embodiment, the laser welding method of the spent fuel storage grid square pipe further comprises:

[0040] After the welding is completed, the pressing plate is removed and the inner supporting tool is retracted so that the inner supporting tool is away from the inner sidewalls of the square pipe;

[0041] The inner supporting tool is extracted from the square pipe, and the welded square pipe is taken out from the outer clamping tool.

[0042] Compared with the prior art, the present disclosure at least includes the following beneficial effects: the laser welding method of the spent fuel storage rack square tube provided by the embodiment of the present disclosure places the clamping assembly on the workbench; installs two pipe bodies to be welded on the clamping assembly, and makes the weld seams to be welded of the two pipe bodies face the laser emitter; and welds the weld seams to be welded by the laser welding gun to process a square tube. In this way, the two pipe bodies are clamped and fixed by the clamping assembly to ensure that the positions of the two pipe bodies meet the requirements of laser welding. Then, the two pipe bodies are welded by the process method of laser welding, so as to form a square tube. The laser welding has high precision, small heat input, and small welding deformation, so as to meet the requirements of the inner cavity size precision and the shape and position tolerance of the square tube, thereby avoiding affecting the subsequent assembly operation of the square tube in the spent fuel storage rack and improving the assembly precision. BRIEF DESCRIPTION OF DRAWINGS

[0043] Various other advantages and benefits will become apparent to those of ordinary skill in the art upon reading the following detailed description of the exemplary embodiments. The accompanying drawings are included to provide a description of the exemplary embodiments and are not intended to limit the scope of the present disclosure. Moreover, like reference numerals designate like parts throughout the several views in the drawings. In the drawings:

[0044] Figure 1 A schematic flow chart of a laser welding method of a spent fuel storage rack square tube of an embodiment provided by the present disclosure;

[0045] Figure 2 An assembly schematic diagram of a clamping assembly and a pipe body of an embodiment provided by the present disclosure;

[0046] Figure 3 A schematic structural diagram of one angle of an inner support tool of an embodiment provided by the present disclosure;

[0047] Figure 4 A schematic structural diagram of another angle of an inner support tool of an embodiment provided by the present disclosure;

[0048] Figure 5 A schematic structural diagram of a telescopic structure of an embodiment provided by the present disclosure.

[0049] Wherein, Figures 2 to 5 The correspondence between the reference signs and the component names in the drawings is as follows:

[0050] 200 clamping assembly, 210 outer clamping tool, 220 inner supporting tool, 221 supporting seat, 222 plate assembly, 223 pull rod, 224 mandrel, 225 telescopic mechanism, 2251 shaft sleeve, 2252 connecting rod, 2253 screw, 2254 connecting block, 226 bearing, 230 workbench, 240 pipe body, 250 laser welding gun, a weld. DETAILED DESCRIPTION

[0051] The application will be further described below in conjunction with the accompanying drawings and specific embodiments. It should be noted that the description of these embodiments is used to help understand the application, but does not constitute a limitation of the application. The specific structure and functional details disclosed herein are only used to describe the example embodiments of the application. However, the application can be embodied in many alternative forms, and should not be understood as limited in the embodiments described herein.

[0052] As Figure 1 shown, the laser welding method for the square tube of the spent fuel storage rack according to the embodiments of the present disclosure comprises:

[0053] Step S110: placing the clamping assembly 200 on the workbench 230; Step S120: installing the two pipe bodies 240 to be welded on the clamping assembly 200, and making the welds to be welded of the two pipe bodies 240 face the laser emitter; Step S130: welding the welds to be welded by the laser welding gun 250 to process a square tube.

[0054] It can be understood that the laser welding method for the square tube of the spent fuel storage rack provided by the embodiments of the present disclosure places the clamping assembly 200 on the workbench 230; installs the two pipe bodies 240 to be welded on the clamping assembly 200, and makes the welds to be welded of the two pipe bodies 240 face the laser emitter; and welds the welds to be welded by the laser welding gun 250 to process a square tube. By clamping and fixing the two pipe bodies 240 by the clamping assembly 200, the position of the two pipe bodies 240 can meet the requirements of laser welding. Then, the two pipe bodies 240 are welded by the process of laser welding, so as to form a square tube. The laser welding has high precision and small heat input, which reduces the welding deformation, so as to meet the requirements of the inner cavity size precision and the shape and position tolerance of the square tube, thereby avoiding affecting the subsequent assembly of the square tube in the spent fuel storage rack and improving the assembly precision.

[0055] It should be noted that the square tube obtained by the laser welding method for the square tube of the spent fuel storage rack provided by the embodiments of the present disclosure has a perpendicularity of less than or equal to 0.6 mm relative to the bottom surface. The two pipe bodies 240 are both C-shaped pipes, which are welded to form a square tube.

[0056] In some examples, asFigure 2 As shown, the clamping assembly 200 includes an outer clamping tool 210 for clamping the outer sidewalls of the two pipe bodies 240, and an inner supporting tool 220 for expanding the inner sidewalls of the two pipe bodies 240.

[0057] It can be understood that the clamping assembly 200 can be provided with the outer clamping tool 210 and the inner supporting tool 220. The outer clamping tool 210 can clamp the outer sidewalls of the two pipe bodies 240 to be welded, and at the same time, the inner supporting tool 220 expands the inner sidewalls of the two pipe bodies 240 to be welded, so as to fix the inner and outer sides of the pipe bodies 240, thereby further reducing the welding deformation amount generated by laser welding, improving the size precision control of the square pipe after welding, and improving the reliability.

[0058] Exemplarily, when the clamping assembly 200 is stored, the inner supporting tool 220 can be expanded in the outer clamping tool 210 to reduce the storage volume, and when used, the clamping assembly 200 can be hoisted to the workbench 230 by a crane, and the inner supporting tool 220 can be retracted and taken out of the outer clamping tool 210.

[0059] In some examples, the step of installing the two pipe bodies 240 to be welded on the clamping assembly 200 and making the weld seams of the two pipe bodies 240 to be welded face the laser emitter includes: preliminarily positioning the two pipe bodies 240 to be welded by the outer clamping tool 210 and the inner supporting tool 220; adjusting the position of the outer clamping tool 210 and the position of the inner supporting tool 220 to secondarily position the two pipe bodies 240, so that the assembly precision of the two pipe bodies 240 meets the preset requirement.

[0060] It can be understood that when the two pipe bodies 240 are clamped and fixed, the outer clamping tool 210 can be preliminarily pressed and fixed to the outer wall of the housing, and the inner supporting tool 220 can be adjusted so that the inner supporting tool 220 contacts the inner wall of the pipe body 240, so as to preliminarily position the two pipe bodies 240, reduce the movement of the pipe bodies 240, facilitate further adjustment of the clamping assembly 200, and improve the reliability. After the preliminary positioning is completed, the pressure and position of the outer clamping tool 210 on the outer walls of the two pipe bodies 240 can be finely adjusted, and the pressure and position of the inner supporting tool 220 on the inner walls of the two pipe bodies 240 can be finely adjusted according to the preset requirement of the assembly precision of the two pipe bodies 240, so that the positions of the two pipe bodies 240 are fixed and meet the requirements of subsequent laser welding.

[0061] In some examples, as Figure 3 and Figure 4As shown, the inner support tool 220 comprises a support base 221, a plate body assembly 222 arranged in the support base 221, the plate body assembly 222 is internally formed with a placing space, a pull rod 223 inserted in the support base 221 and rotatably connected to the support base 221 through a bearing 226, a mandrel 224 arranged in the placing space, the mandrel 224 is connected to the pull rod 223, and a telescopic mechanism 225 arranged on the circumferential side of the mandrel 224 and used for telescoping in the radial direction of the mandrel 224. In the case that the pull rod 223 rotates in a first direction, the telescopic mechanism 225 is extended to drive the plate body assembly 222 to move away from the mandrel 224 to tighten the inner side wall of the pipe body 240. In the case that the pull rod 223 rotates in a second direction, the telescopic mechanism 225 is retracted to drive the plate body assembly to move close to the mandrel 224 to move away from the inner side wall of the pipe body 240. The first direction and the second direction are opposite.

[0062] It can be understood that the inner support tool 220 can be provided with the support base 221, the plate body assembly 222, the pull rod 223, the mandrel 224 and the telescopic mechanism 225. Specifically, the support base 221 is arranged on the side of the plate body assembly 222 to support the plate body assembly 222. The plate body assembly 222 can be provided with four, corresponding to the four inner side walls of the structure surrounded by the two pipe bodies 240. The pull rod 223 is inserted into the support base 221 and rotatably connected to the support base 221 through the bearing 226, which ensures smooth rotation. The mandrel 224 is arranged in the placing space, the mandrel 224 is arranged in the placing space, and the mandrel 224 is threadedly connected to the pull rod 223. The circumferential side of the mandrel 224 is provided with the telescopic mechanism 225, and each plate body of the plate body assembly 222 is connected to one telescopic mechanism 225. In this way, in the case that the pull rod 223 rotates in a first direction, the pull rod 223 drives the mandrel 224 to move axially through the threaded connection, so that the telescopic mechanism 225 extends in the radial direction of the mandrel 224 to drive the plate body assembly 222 to move away from the mandrel 224 to press and tighten the inner side wall of the pipe body 240. In the case that the pull rod 223 rotates in a second direction, the pull rod 223 drives the mandrel 224 to move axially through the threaded connection, so that the telescopic mechanism 225 retracts in the radial direction of the mandrel 224 to drive the plate body assembly 222 to move close to the mandrel 224 to move away from the inner side wall of the pipe body 240, so as to facilitate the removal of the inner support tool 220 from the pipe body 240. By operating the pull rod 223, the inner wall of the pipe body 240 can be fixed, which is convenient to operate.

[0063] Exemplarily, as Figure 5As shown, the telescopic mechanism 225 can be provided with a sleeve 2251, a connecting rod 2252, a screw 2253 and a connecting block 2254. The sleeve 2251 is sleeved on the mandrel 224, and the outer side of the sleeve 2251 is provided with a boss. The connecting rod 2252 can swing relative to the boss around the screw 2253, and the side of the connecting block 2254 can be connected to the connecting rod 2252 by another screw 2253 to drive the connecting block 2254 to swing by the connecting rod 2252, and the top of the connecting block 2254 is connected to the plate body. In this way, the connecting rod 2252 and the screw 2253 can constitute a cam mechanism. In the case that the sleeve 2251 is driven by the mandrel 224 to move along the axial direction of the mandrel 224, the connecting rod 2252 drives the connecting block 2254 to swing, so that the connecting block 2254 drives the plate body to move radially along the sleeve 2251, thereby making the plate body close to or away from the mandrel 224.

[0064] In some examples, the length of the inner support tooling 220 is greater than the length of the pipe 240 to be welded.

[0065] It can be understood that the length of the inner support tooling 220 should be greater than the length of the pipe 240 to be welded, so that the length of the pipe 240 is within the effective range of the inner support tooling 220, and the constraint effect of the inner support tooling 220 on the inner wall of the pipe 240 is ensured.

[0066] In some examples, the step of preliminarily positioning the two pipes 240 to be welded by the outer clamping tooling 210 and the inner support tooling 220 includes: loading the two pipes 240 to be welded into the inner cavity of the outer clamping tooling 210, adjusting the two pipes 240 to make the welds to be welded face the laser emitter; sliding the inner support tooling 220 into the inner cavities of the two pipes 240; fixing the outer clamping tooling 210 to the workbench 230 by the pressing plate, and adjusting the inner support tooling 220 to make the inner support tooling 220 contact the inner side walls of the two pipes 240.

[0067] It can be understood that when the two pipes 240 to be welded are preliminarily positioned by the outer clamping tooling 210 and the inner support tooling 220, the two pipes 240 to be welded can be loaded into the inner cavity of the outer clamping tooling 210, and the angles of the two pipes 240 to be welded are adjusted to make the welds to be welded of the two pipes 240 face the laser emitter. Then the inner support tooling 220 is slid into the inner cavities of the two pipes 240 to complete the preliminary assembly. Then the screw of the pressing plate is adjusted to press the outer clamping tooling 210, so that the outer clamping tooling 210 is fixed to the workbench 230. At the same time, the inner support tooling 220 is adjusted to make the inner support tooling 220 contact the inner side walls of the pipes 240, so that the clamping assembly 200 preliminarily fixes and constrains the two pipes 240, facilitating subsequent positioning operations.

[0068] In some examples, the step of adjusting the position of the outer clamping tool 210 and the position of the inner supporting tool 220 to reposition the two pipe bodies 240 to ensure that the assembly accuracy of the two pipe bodies 240 meets the preset requirement includes: adjusting the pressing plate to adjust the degree of pressing the outer clamping tool 210 against the outer sidewalls of the two pipe bodies 240 and adjusting the degree of pressing the inner supporting tool 220 against the inner sidewalls of the two pipe bodies 240 until the assembly accuracy of the two pipe bodies 240 meets the preset requirement; wherein the preset requirement includes that the gap between the to-be-welded weld seams of the two pipe bodies 240 is less than or equal to 0.05 mm, and / or the misalignment of the to-be-welded weld seams of the two pipe bodies 240 is less than or equal to 0.05 mm.

[0069] It can be understood that when the two pipe bodies 240 are repositioned, the pressing plate can be adjusted to press the outer clamping tool 210, so as to adjust the degree of pressing the outer clamping tool 210 against the outer sidewalls of the two pipe bodies 240 and ensure the fixing effect of the outer clamping tool 210 on the outer sidewalls of the two pipe bodies 240. Then, the degree of pressing the inner supporting tool 220 against the inner sidewalls of the two pipe bodies 240 is adjusted to tighten the inner sidewalls of the two pipe bodies 240 by the inner supporting tool 220, so as to ensure the fixing effect of the inner supporting tool 220 on the inner sidewalls of the two pipe bodies 240. Thus, the repositioning effect of the clamping assembly 200 on the two pipe bodies 240 ensures that the assembly accuracy of the two pipe bodies 240 meets the preset requirement. The preset requirement is that the gap between the to-be-welded weld seams of the two pipe bodies 240 is less than or equal to 0.05 mm, and the misalignment of the to-be-welded weld seams of the two pipe bodies 240 is less than or equal to 0.05 mm. In this way, the subsequent laser welding effect is ensured, the welding deformation is reduced, the inner cavity size accuracy and the shape and position tolerance requirements of the square tube are met, and the subsequent assembly operation of the square tube in the spent fuel storage rack is avoided, thereby improving the assembly accuracy.

[0070] In some examples, the step of welding the to-be-welded weld seams by the laser welding gun 250 to process the square tube includes: adjusting the power of the laser emitter of the laser welding gun 250 to a preset power; adjusting the focal length of the laser emitter to a preset focal length; introducing protective gas into the laser welding gun 250 through the laser emitter and introducing protective gas into the inner supporting tool 220; and starting the laser welding gun 250 to weld the to-be-welded weld seams to process the square tube.

[0071] It can be understood that when the laser welding gun 250 is used to weld the to-be-welded weld, the power of the laser emitter of the laser welding gun 250 can be adjusted to a preset power, and the focal length of the laser emitter can be adjusted to a preset focal length. The protective gas is introduced into the welding gun of the laser welding gun 250 through the laser emitter, and the protective gas is introduced into the inner supporting tool 220, and the molten pool is protected by gas during the welding process, so that a high-quality laser welding weld is formed. Then, the laser welding gun 250 is aligned with the position of the to-be-welded weld, and the laser welding gun 250 is started to perform welding work to obtain a square tube. The laser welding can ensure the welding precision, and the heat input is small, so as to reduce the welding deformation, and the outer clamping tool 210 and the inner supporting tool 220 can further reduce the welding deformation, so as to meet the size precision requirement and the shape and position tolerance requirement of the inner cavity of the square tube, avoid affecting the subsequent assembly work of the square tube in the spent fuel storage rack, and improve the assembly precision. Exemplarily, the above laser welding can be applied to a square tube with a thickness of 1.5 mm to 4.0 mm.

[0072] In some examples, the preset power is 900 W to 1050 W; the preset focal length is 182 mm to 185 mm; and the welding speed of the laser welding gun 250 is 18 mm / s to 22 mm / s.

[0073] It can be understood that the preset power of the laser emitter can be 900 W to 1050 W, the preset focal length of the laser emitter can be 182 mm to 185 mm, and the welding speed of the laser welding gun 250 can be 18 mm / s to 22 mm / s, so as to ensure the laser welding effect.

[0074] In some examples, the laser welding method of the square tube of the spent fuel storage rack further includes: after the welding is completed, the pressing plate is removed, and the inner supporting tool 220 is retracted, so that the inner supporting tool 220 is away from the inner side wall of the square tube; the inner supporting tool 220 is extracted from the square tube, and the welded square tube is taken out from the outer clamping tool 210.

[0075] It can be understood that after the laser welding work is completed, the pressing plate can be removed to release the outer clamping tool 210, and the inner supporting tool 220 is retracted to make the inner supporting tool 220 away from the inner side wall of the welded square tube, so as to remove the pressure of the inner supporting tool 220 to the square tube. Then, the inner supporting tool 220 can be separated from the square tube, and the welded square tube can be taken out from the outer clamping tool 210, so as to detect the size and the weld of the square tube.

[0076] It should be understood that the terms first, second, etc. are used to identify different descriptive elements, but not to indicate or imply relative importance. Although the terms first, second, etc. can be used herein to describe various elements, these elements should not be limited by these terms. These terms are used only to distinguish one element from another. For example, a first element could be termed a second element, and, similarly, a second element could be termed a first element, without departing from the scope of example embodiments of the present application.

[0077] It should be understood that the term "and / or" in this text merely describes an association relationship of associated objects, which means that there can be three relationships, for example, A and / or B can mean that A exists alone, B exists alone, and A and B exist together. The term " / and" in this text describes another association relationship of associated objects, which means that there can be two relationships, for example, A / and B can mean that A exists alone and A and B exist together. In addition, the character " / " in this text generally means that the associated objects before and after are in an "or" relationship.

[0078] It should be understood that in the description of the present application, the orientation or position relationship indicated by the terms "upper", "vertical", "inner", "outer" and the like is the orientation or position relationship when the disclosed product is commonly placed or the orientation or position relationship commonly understood by those skilled in the art, and is only for the convenience of describing the present application and simplifying the description, and does not indicate or imply that the device or element referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as a limitation on the present application.

[0079] In the description of the present application, it should also be noted that, unless otherwise explicitly specified and limited, the terms "arrangement", "installation", "connection" should be understood broadly, for example, it can be fixedly connected, or it can be detachably connected, or integrally connected; it can be directly connected, or indirectly connected through an intermediate medium, or it can be the communication inside two elements. For those skilled in the art, the specific meaning of the above terms in the present application can be understood according to the specific circumstances.

[0080] The terms used herein are used only to describe specific embodiments and are not intended to limit example embodiments of the present application. As used herein, the singular forms "a", "an" and "the" are intended to include plural forms, unless the context clearly indicates otherwise. It should also be understood that the terms "comprise", "comprises", "include", and / or "includes" when used in this text specify the existence of the declared features, integers, steps, operations, units and / or components, and do not exclude the existence or addition of one or more other features, quantities, steps, operations, units, components and / or combinations thereof.

[0081] In the following description, specific details are set forth to provide a thorough understanding of the example embodiments. However, persons having ordinary skill in the art will understand that the example embodiments can be practiced without incorporating these particular details. In other instances, well-known processes, structures and techniques have not been shown in detail in order not to obscure the understanding of this description.

[0082] The above summary of the present application is provided to introduce some concepts of the application. A further appreciation of other aspects of the application can be obtained by attending to the following detailed description and appended claims.

[0083] It should be noted that information disclosed in this Background section was in fact known prior to the filing date of this patent document and thus does not necessarily constitute prior art against the present application. However, the information can constitute part of the common general knowledge.

Claims

1. A laser welding method for spent fuel storage grid square tubes, characterized in that: include: Place the clamping assembly on the workbench; Install the two pipes to be welded on the clamping assembly, and make the weld seams of the two pipes face the laser emitter; The weld to be welded is welded by a laser welding gun to form a square tube.

2. The laser welding method for spent fuel storage grid square tubes according to claim 1, characterized in that: The clamping assembly comprises: An external clamping tool, used for clamping the outer side walls of the two tube bodies; The inner support tool is used for tightening the inner side walls of the two tube bodies.

3. The laser welding method for spent fuel storage grid square tubes according to claim 2, characterized in that: The step of installing the two pipes to be welded on the clamping assembly and making the weld seams of the two pipes face the laser emitter includes: Preliminary positioning of the two pipe bodies to be welded is performed by using the outer clamping fixture and the inner supporting fixture; The position of the outer clamping fixture and the position of the inner supporting fixture are adjusted, and the two tube bodies are re-positioned so that the assembly accuracy of the two tube bodies meets the preset requirements.

4. The laser welding method for spent fuel storage grid square tubes according to claim 3, characterized in that: The inner support tooling comprises: Support seat; A plate assembly is arranged on the support seat, and a placement space is formed inside the plate assembly; A pull rod is inserted into the support seat and is rotatably connected to the support seat via a bearing; a core shaft, disposed in the placement space, the core shaft being connected to the pull rod; a telescopic mechanism, provided on the circumferential side of the core shaft, for telescoping along the radial direction of the core shaft; When the pull rod rotates in a first direction, the telescopic mechanism extends to drive the plate assembly to move away from the core shaft to tighten the inner side wall of the tube body; when the pull rod rotates in a second direction, the telescopic mechanism retracts to drive the pressure plate assembly to move toward the core shaft to leave the inner side wall of the tube body; The first direction and the second direction are opposite.

5. The laser welding method for spent fuel storage grid square tubes according to claim 3, characterized in that: The length of the inner support tool is greater than the length of the tube body to be welded.

6. The laser welding method for spent fuel storage grid square tubes according to claim 3, characterized in that: The step of performing preliminary positioning of the two pipe bodies to be welded by using the outer clamping fixture and the inner supporting fixture comprises: Install the two tubes to be welded into the inner cavity of the outer clamping tool, and adjust the two tubes so that the weld to be welded faces the laser emitter; Sliding the inner support fixture into the inner cavities of the two tube bodies; The outer clamping tool is fixed to the workbench by a pressing plate, and the inner supporting tool is adjusted so that the inner supporting tool is in contact with the inner side walls of the two tube bodies.

7. The laser welding method for spent fuel storage grid square tubes according to claim 6, characterized in that: The step of adjusting the position of the outer clamping fixture and the position of the inner supporting fixture to perform secondary positioning on the two tube bodies so that the assembly accuracy of the two tube bodies meets the preset requirements includes: By adjusting the pressing plate, the degree to which the outer clamping tool presses the outer side walls of the two tube bodies is adjusted, and the degree to which the inner support tool presses the inner side walls of the two tube bodies is adjusted, until the assembly accuracy of the two tube bodies meets the preset requirements; The preset requirements include that the gap between the weld seams of the two pipe bodies to be welded is less than or equal to 0.05 mm, and / or the misalignment of the weld seams of the two pipe bodies to be welded is less than or equal to 0.05 mm.

8. The laser welding method for spent fuel storage grid square tubes according to any one of claims 1 to 7, characterized in that: The step of welding the weld to be welded by a laser welding gun to form a square tube includes: Adjusting the power of the laser emitter of the laser welding gun to a preset power; Adjusting the focal length of the laser transmitter to a preset focal length; Supplying shielding gas to the welding gun of the laser welding gun through the laser emitter, and supplying shielding gas to the inner support tooling; The laser welding gun is started to weld the weld to be welded, so as to form the square tube by welding.

9. The laser welding method for spent fuel storage grid square tubes according to claim 8, characterized in that: The preset power is 900W to 1050W; The preset focal length is 182mm to 185mm; The welding speed of the laser welding gun is 18 mm / s to 22 mm / s.

10. The laser welding method for spent fuel storage grid square tubes according to claim 7, characterized in that: Also includes: After welding is completed, the pressing plate is removed and the inner support fixture is retracted so that the inner support fixture leaves the inner side wall of the square tube; The inner support fixture is pulled out from the square tube, and the welded square tube is taken out from the outer clamping fixture.

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