A column welding structure, a positioning tool for assembly welding, and a processing and using method

Abstract

This invention discloses a column welding structure, a welding positioning fixture, and a processing and usage method, including a fork-shaped plate (1) and four columns (2). The fork-shaped plate (1) has a circular hole (1-1) in the center and slots (1-2) at the four corners. The upper sides of the four columns (2) are welded into the four slots (1-2) of the fork-shaped plate (1), and the axial direction of the four columns (2) is perpendicular to the plane of the fork-shaped plate (1). A deep cylindrical through hole (2-1) is opened at the axial center of the column (2).

Description

Technical Field

[0001] This invention belongs to the technical field of welded structures, specifically relating to a column welded structure, a welding positioning fixture, and a processing and usage method. Background Technology

[0002] The loading and unloading equipment is one of the key pieces of equipment in the nuclear power plant's fuel handling and storage system. Since the entire equipment ultimately completes the task of grabbing and releasing nuclear fuel assemblies by operating grippers, the relevant technical performance indicators are all centered around the grippers, so the precision requirements for the grippers are extremely high.

[0003] The wedge-type self-locking gripper is a new type of gripper with a novel structure. The welded column structure serves as the mounting carrier for the entire gripper component. Existing welded column structures have a rather unique structure and cannot be well integrated with other components.

[0004] In addition, existing welded column structures have weak overall rigidity due to the lack of rigid fixation and mutual restraint during welding. This makes them prone to irregular deformation (inward contraction, outward expansion, or twisting) during the welding process, resulting in serious dimensional deviations and scrapping after welding. Furthermore, due to the combined effects of rigidity and welding stress, machining deformation occurs during the machining process, thereby losing the original machining accuracy.

[0005] Therefore, it is necessary to develop a new type of column welded structure, as well as a welding positioning fixture for the column welded structure, and to adopt a new process method to control and prevent the deformation of this welded component, so as to ensure the dimensional stability of the overall component and the accuracy of the final machining precision. Summary of the Invention

[0006] The purpose of this invention is to overcome the shortcomings of the prior art and provide a column welding structure, welding positioning fixtures, processing and usage methods.

[0007] To solve the technical problem, the technical solution of the present invention is: a column welding structure, including a fork-shaped plate and four columns. The fork-shaped plate has a circular hole in its center and slots at its four corners. The upper sides of the four columns are welded into the four slots of the fork-shaped plate, and the axial direction of the four columns is perpendicular to the plane of the fork-shaped plate. A deep cylindrical through hole is formed in the axial center of each column.

[0008] Preferably, the fork-shaped plate has an irregularly symmetrical "X" structure, the included angle between two adjacent slots of the fork-shaped plate is 90°, a protrusion is provided between two adjacent slots of the fork-shaped plate, and a circular hole is provided on the fork-shaped plate between the slot and the circular hole, and the slot is a right-angle slot.

[0009] Preferably, the cross-section of the column is a cave-shaped cross-section with three straight sides and one semi-circular side, and the center of the cross-section is a deep cylindrical through hole. The three straight sides of the column are adapted to the slot, and the three straight sides of the column are clamped and welded into the slot. Stepped holes are respectively opened on the upper and lower sides of the deep cylindrical through hole.

[0010] Preferably, a welding positioning fixture for a column welding structure includes a fixture clamp plate, ferrules, and screws. The fixture clamp plate has a process hole at its center, the diameter of which is the same as the diameter of the circular hole in the fork-shaped plate. The fixture clamp plate has clamp slots at its four corners. The lower side of the column is installed in the clamp slot. The ferrules are connected to the clamp slots by four sets of screws, fixing the lower side of the column in the clamp slot.

[0011] Preferably, the clamp slot is a right-angled slot, and the center of the sleeve is provided with a semi-circular groove. The space formed by the right-angled slot of the clamp slot and the semi-circular groove of the sleeve is adapted to the cross-section of the column.

[0012] Preferably, a method for processing a welded column structure includes the following steps:

[0013] Step 1: Design and manufacture the welding positioning fixture for the column welding structure.

[0014] Step 2: Insert the welding positioning fixture of the column welding structure into the lower part of the column, adjust the posture to ensure that each column is perpendicular to the fixture plate, then use the clamp to rigidly fix the fixture plate and tighten the screws.

[0015] Step 3: Low-temperature stress relief heat treatment. Fit the fork-shaped plate into the upper part of the column. Insert the cylindrical leveling block into the round hole of the fork-shaped plate and the process hole of the tooling fixture plate to ensure that the fork-shaped plate is perpendicular to each column. Weld the fork-shaped plate to the column. During the welding process, use the left-right staggered and symmetrical welding process to reduce welding deformation.

[0016] Step 4: Place the entire column welded structure together with the welding positioning fixture on the trolley-type heat treatment electric furnace platform, heat to 320±20℃, hold for 120~150min, and then air cool.

[0017] Step 5: Vibration aging treatment: Vibration impact is applied to the weld area to induce plastic deformation in the weld area by utilizing the variable load stress generated by stable resonance.

[0018] Step 6: After vibration aging is completed, place the entire column welded structure and the welding positioning fixture of the column welded structure statically on the platform for natural aging.

[0019] Step 7: After natural aging, the overall machining begins. The upper and lower end faces of each column and the deep cylindrical through holes are precision machined using a CNC machining center.

[0020] Step 8: Use the CNC coordinate positioning of the CNC machining center to inspect the various dimensions of the welded column structure after machining, and issue an inspection report.

[0021] Preferably, in step 4, the heating rate is ≤220℃ / h and the heating temperature is 320±20℃.

[0022] Preferably, in step 5, the vibration frequency is 4500 r / min and the vibration acceleration is 20.0 to 40.0 m / s².

[0023] Preferably, the natural aging time in step 6 is 24 hours.

[0024] Preferably, a method for using a welded column structure, wherein the welded column structure serves as an installation carrier for a gripper component, wherein springs are installed in the upper stepped holes of the four columns of the welded column structure, and cold-fit copper sleeves are installed in the lower stepped holes, and guide pins, positioning pins, and support pins are longitudinally inserted into the deep cylindrical through holes from the lower end, with the heads of the guide pins, positioning pins, and support pins being positioned and connected to the upper flange, the circular holes being used for the control sleeve of the gripper component to pass through and move up and down, the protrusions being used to install wedges, and the circular holes being used for the manual emergency operating lever to pass through.

[0025] Compared with the prior art, the advantages of the present invention are as follows:

[0026] (1) This invention discloses a column welding structure, including a fork-shaped plate and columns. The upper sides of the four columns are respectively welded into the four slots of the fork-shaped plate, and the axial direction of the four columns is perpendicular to the plane of the fork-shaped plate. The circular hole of the column welding structure of this invention is used for the control sleeve of the gripper component to pass through and move up and down. The protrusion is used to install the wedge block. The circular hole is used to pass through the manual emergency operation rod. The deep cylindrical through hole is used to install three kinds of four slender rod pins with different functions. The upper stepped hole is used to install the spring, and the lower stepped hole is used to install the cold-fit copper sleeve. The column welding structure of this invention has a simple structure and is perfectly matched with other components of the gripper component.

[0027] (2) This invention discloses a welding positioning fixture for a column welded structure. The fixture slot of the fixture plate of the welding positioning fixture adopts the same positioning size as the fork-shaped plate slot of the column welded structure. It is tightened with a sleeve with the same arc surface as the semi-circular column, so that the upper and lower references of the entire column welded structure are unified. This can ensure that the column does not deform in all directions during the welding process and ensure accurate positioning. It also facilitates the disassembly of the welding positioning fixture after stress relief after the overall machining is completed, making it easy to disassemble and assemble.

[0028] (3) The column welded structure of the present invention undergoes three different stress relief processes. Through overall low-temperature stress relief heat treatment, the deformation of the workpiece is reduced, which can eliminate 80% to 90% of the welding stress. Then, vibration impact is applied to the weld area. The variable load stress generated by stable resonance causes plastic deformation in the weld area, achieving the purpose of eliminating 10% of the residual stress. Then, natural aging is carried out, which basically eliminates the internal welding stress and greatly improves the overall dimensional stability. This creates good conditions for the overall machining of the column welded structure and improves the dimensional stability.

[0029] (4) The column welding structure of the present invention adopts CNC machining center, coordinate positioning, precision machining, accurate accuracy, stable quality, meets the high and strict requirements of the column welding structure in terms of dimensional accuracy, and CNC precision machining ensures stable and reliable quality.

[0030] (5) The column welded structure of the present invention is positioned by the assembly welding positioning fixture, and stress is eliminated by the processing technology to control and prevent the deformation of the column welded structure, thereby ensuring the dimensional stability of the column welded structure and the accuracy of the final machining precision. The assembly welding positioning fixture of the column welded structure is simple, reasonable, compact and easy to install and disassemble. When applied to specific project products, the overall dimensional accuracy of each part is guaranteed to meet the requirements of the design drawings, and the overall performance of the loading and unloading machine equipment is directly improved. Attached Figure Description

[0031] Figure 1 A schematic diagram of the structure of a welded column structure according to the present invention;

[0032] Figure 2 A cross-sectional schematic diagram of a welding positioning fixture for a column welding structure according to the present invention;

[0033] Figure 3 A schematic diagram of the assembly structure of a column welding structure and a welding positioning fixture according to the present invention;

[0034] Figure 4 A top view schematic diagram of the assembly structure of a column welding structure and a welding positioning fixture according to the present invention;

[0035] Figure 5 This invention Figure 4 A sectional view along line AA.

[0036] Explanation of reference numerals in the attached figures:

[0037] 1. Fork-shaped plate, 2. Column, 3. Tooling fixture plate, 4. Sleeve, 5. Screw;

[0038] 1-1, round hole; 1-2, slot; 1-3, protrusion; 1-4, round hole;

[0039] 2-1. Deep cylindrical through hole; 2-2. Stepped hole;

[0040] 3-1. Process hole; 3-2. Fixture slot;

[0041] 4-1. Semi-circular groove. Detailed Implementation

[0042] The specific implementation of the present invention is described below with reference to embodiments:

[0043] 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.

[0044] Example 1

[0045] like Figure 1 , 3 As shown in Figure 4, the present invention discloses a column welding structure, including a fork-shaped plate 1 and four columns 2. The fork-shaped plate 1 has a circular hole 1-1 in the center and slots 1-2 in the four corners of the fork-shaped plate 1. The upper sides of the four columns 2 are respectively welded into the four slots 1-2 of the fork-shaped plate 1, and the axial direction of the four columns 2 is perpendicular to the plane of the fork-shaped plate 1. The column 2 has a deep cylindrical through hole 2-1 in the center of its axial direction.

[0046] Example 2

[0047] like Figure 1 , 3 As shown in Figure 4, the fork-shaped plate 1 has an irregularly symmetrically distributed "X" structure. The included angle between two adjacent slots 1-2 of the fork-shaped plate 1 is 90°. A protrusion 1-3 is provided between two adjacent slots 1-2 of the fork-shaped plate 1. A circular hole 1-4 is provided on the fork-shaped plate 1 between the slot 1-2 and the circular hole 1-1. The slot 1-2 is a right-angle slot.

[0048] The sides of the protrusions 1-3 are used to install wedges (product parts), and the engagement and release of the gripper hooks rely on the self-locking positioning of the wedges.

[0049] The circular holes 1-4 are used to pass through the manual emergency operating lever (product part).

[0050] The fork-shaped plate 1 is made of 18.8mm thick stainless steel plate. The center of the plate surface has a round hole, and the surrounding area has an irregularly symmetrical "X" structure. Right-angle slots are set at four 45° angles.

[0051] The circular hole 1-1 is used for the control sleeve (product part) of the gripper component to pass through the circular hole and move up and down during the assembly of the column welding structure.

[0052] like Figure 1 , 3 As shown in Figures 4 and 5, the cross-section of the column 2 is a cave-shaped cross-section with three straight sides and one semi-circular side. The center of the cross-section is a deep cylindrical through hole 2-1. The three straight sides of the column 2 are adapted to the slot 1-2. The three straight sides of the column 2 are clamped and welded into the slot 1-2. The deep cylindrical through hole 2-1 has stepped holes 2-2 on the upper and lower sides respectively.

[0053] The column 2 has a cave-like cross-section with three straight sides and one semi-circular side. The center of the cross-section is a deep cylindrical cavity (through hole), and the wall thickness at the thinnest point of the hole is 2.75mm.

[0054] The deep cylindrical through hole 2-1 is used to install three different types of four slender rod pins (product parts) with different functions.

[0055] Example 3

[0056] like Figure 2 As shown, a welding positioning fixture for a column welding structure includes a fixture clamp plate 3, a sleeve 4, and screws 5. The fixture clamp plate 3 has a process hole 3-1 in the center, and the diameter of the process hole 3-1 is the same as the diameter of the circular hole 1-1 of the fork-shaped plate 1 of the column welding structure. The fixture clamp plate 3 has clamp slots 3-2 at its four corners. The lower side of the column 2 is installed in the clamp slots 3-2. The sleeve 4 is connected to the clamp slots 3-2 by screws 5 to fix the lower side of the column 2 in the clamp slots 3-2.

[0057] The tooling fixture plate 3 is a square plate with a Ф120 process hole in the center, with chamfered planes and threaded holes at the four 45° corners, and a fixture slot 3-2.

[0058] The diameter of the process hole 3-1 is Ф120. The four 45° corners of the tooling fixture plate 3 have the same position and size as the slots 1-2 of the fork-shaped plate 1 of the column welding structure.

[0059] The process hole 3-1 is used to reduce weight on the one hand, and to align the entire structure during subsequent processing on the other hand, by using a cylindrical leveling block that passes through the process hole 3-1 and the round hole 1-1.

[0060] like Figure 2 As shown, the clamp slot 3-2 is a right-angled slot, and the center of the sleeve 4 is provided with a semi-circular groove 4-1. The space formed by the right-angled slot of the clamp slot 3-2 and the semi-circular groove 4-1 of the sleeve 4 is adapted to the cross section of the column 2.

[0061] The ferrule 4 has an arc-shaped boss cross section.

[0062] Screw 5 is an M6 screw, which conforms to the GB / T5783-2016 standard.

[0063] Example 4

[0064] like Figure 3 , 4 As shown, a method for processing a welded column structure includes the following steps:

[0065] Step 1: Design and fabricate the welding positioning fixture for the column welding structure;

[0066] Step 2: Insert the welding positioning fixture of the column welding structure into the lower part of the column 2, adjust the posture to ensure that each column 2 is perpendicular to the fixture plate 3, and then use the clamp 4 to rigidly fix the fixture plate 3 and tighten the screws 5.

[0067] Step 3: Fit the fork-shaped plate 1 onto the upper part of the column 2, insert the cylindrical leveling block into the round hole 1-1 of the fork-shaped plate 1 and the process hole 3-1 of the tooling fixture plate 3 to ensure that the fork-shaped plate 1 is perpendicular to each column 2, and weld the fork-shaped plate 1 to the column 2. During the welding process, the left and right staggered and symmetrical welding process is adopted to reduce welding deformation.

[0068] Step 4: Low-temperature stress relief heat treatment. The entire column welded structure, along with the welding positioning fixture, is placed on a special platform of a trolley-type heat treatment electric furnace. It is heated to 320±20℃, held for 120~150min, and then air-cooled. Through the overall low-temperature stress relief heat treatment, the deformation of the workpiece is reduced, and 80%~90% of the welding stress can be eliminated.

[0069] Step 5: Vibration aging treatment: Vibration impact is applied to the weld area, and the variable load stress generated by stable resonance is used to induce plastic deformation in the weld area, thereby eliminating 10% of the residual stress.

[0070] Step 6: After vibration aging is completed, place the entire column welded structure and the welding positioning fixture of the column welded structure statically on the platform for natural aging.

[0071] Step 7: After natural aging, the overall machining begins. The upper and lower end faces of each column 2 and the deep cylindrical through holes 2-1 are precision machined using a CNC machining center. The entire machining process adopts a roughing-to-finishing approach, with real-time monitoring of the machining deformation state. Based on this, the chip amount and cutting speed are adjusted to reduce thermal deformation of the machined surface.

[0072] Step 8: Use the CNC coordinate positioning of the CNC machining center to inspect the various dimensions of the welded column structure after machining, and issue an inspection report.

[0073] Preferably, in step 4, the heating rate is ≤220℃ / h and the heating temperature is 320±20℃.

[0074] Preferably, in step 5, the vibration frequency is 4500 r / min and the vibration acceleration is 20.0–40.0 m / s². 2 .

[0075] Preferably, the natural aging time in step 6 is 24 hours.

[0076] Example 5

[0077] Preferably, a method of using a column welded structure, wherein the column welded structure serves as the mounting carrier for the gripper component, wherein springs are installed in the upper stepped holes 2-2 of the four columns 2 of the column welded structure, and cold-fit copper sleeves are installed in the lower stepped holes 2-2, and guide pins, positioning pins, and support pins are longitudinally inserted into the deep cylindrical through holes 2-1 from the lower end, with the heads of the guide pins, positioning pins, and support pins being positioned and connected to the upper flange, the circular hole 1-1 is used for the control sleeve of the gripper component to pass through and move up and down, the protrusion 1-3 is used to install wedges, and the gripper hook engagement and release rely on the wedges for positioning and self-locking, and the circular hole 1-4 is used for the manual emergency operating lever to pass through.

[0078] Two guide pins are arranged diagonally to guide the positioning of the gripper and the fuel assembly; there is one positioning pin to prevent the gripper from being mispositioned on the fuel assembly and to ensure the correct positioning direction; there is one support pin to support the balance between the gripper and the fuel assembly.

[0079] The gripper assembly consists of an upper flange, a welded column structure, a U-shaped block, a wedge, a gripping hook, a guide pin, a positioning pin, a support pin, and a control sleeve. The upper flange and the welded column structure are the main mounting carriers. When the upper flange is not in contact with the welded column structure, the spring springs up, inserting the wedge into the "release" / "engage" groove of the gripping hook, and the gripper is in an ungripping / gripping state. When the upper flange is in contact with the welded column structure, the spring is compressed, the wedge disengages from the "release" / "engage" groove of the gripping hook, and the gripper is in a self-locking open state.

[0080] Operating procedures for gripper components:

[0081] (1) The gripper is in the released state and is positioned on the fuel assembly or temporary support structure. The upper flange moves downward and contacts the welded structure of the column, releasing the self-locking state of the gripper hook.

[0082] (2) Confirm that the gripper's self-locking function has been released, press the gripper engagement button, and the gripper hook will change from the released state to the engaged state.

[0083] (3) Lift the gripper to separate the upper flange from the welded structure of the column and complete the self-locking of the gripper hook. Continue to lift the gripper so that the gripper carries the fuel assembly up to complete the gripping operation.

[0084] (4) The gripper is in the engaged state and the fuel assembly is suspended; the fuel assembly is placed in the position, the upper flange moves downward and contacts the welded structure of the column, and the self-locking state of the gripper is released.

[0085] (5) Confirm that the gripper’s self-locking function has been released, press the gripper release button, and the gripper hook will change from the engaged state to the released state.

[0086] (6) Lift the gripper to disengage the upper flange from the welded structure of the column and complete the self-locking of the gripper hook. Continue to lift the gripper to complete the release of the gripped object.

[0087] Example 6

[0088] The specific steps for processing the welded column structure using the processing method described in this invention are as follows:

[0089] Step 1: Design and manufacture the welding positioning fixture for the column welding structure. The column welding structure includes a fork-shaped plate 1 and a column 2. The welding positioning fixture includes a fixture clamp plate 3, a sleeve 4 and a screw 5. The round hole 1-1 of the fork-shaped plate 1 has the same size as the process hole 3-1 of the fixture clamp plate 3. The four slots 1-2 of the fork-shaped plate 1 correspond to the four clamp slots 3-2 of the fixture clamp plate 3.

[0090] Step 2: Insert the welding positioning fixture of the column welding structure into the lower part of the column 2, adjust the posture to ensure that each column 2 is perpendicular to the fixture plate 3, and then use the clamp 4 to rigidly fix the fixture plate 3 and tighten the screws 5.

[0091] Step 3: Fit the fork-shaped plate 1 onto the upper part of the column 2, insert the cylindrical leveling block into the round hole 1-1 of the fork-shaped plate 1 and the process hole 3-1 of the tooling fixture plate 3 to ensure that the fork-shaped plate 1 is perpendicular to each column 2, and weld the fork-shaped plate 1 to the column 2. During the welding process, the left and right staggered and symmetrical welding process is adopted to reduce welding deformation.

[0092] Step 4: Low-temperature stress relief heat treatment. The entire column welded structure, along with the welding positioning fixture, is placed on a special platform of a trolley-type heat treatment electric furnace. It is heated to 320℃, held for 120 minutes, and then air-cooled. Through the overall low-temperature stress relief heat treatment, the deformation of the workpiece is reduced, and 80% to 90% of the welding stress can be eliminated.

[0093] Step 5: Vibration aging treatment: Vibration impact is applied to the weld area, and the variable load stress generated by stable resonance is used to induce plastic deformation in the weld area, thereby eliminating 10% of the residual stress.

[0094] Step 6: After vibration aging is completed, the entire column welded structure and the welding positioning fixture of the column welded structure are placed statically on the platform for natural aging. After natural aging, a small amount of stress remains.

[0095] Step 7: After natural aging, the overall machining begins. The upper and lower end faces of each column 2 and the deep cylindrical through holes 2-1 are precision machined using a CNC machining center. The entire machining process adopts a roughing-to-finishing approach, with real-time monitoring of the machining deformation state. Based on this, the chip amount and cutting speed are adjusted to reduce thermal deformation of the machined surface.

[0096] Step 8: Use the CNC coordinate positioning of the CNC machining center to inspect the various dimensions of the welded column structure after machining, and issue an inspection report.

[0097] The stress test data for the welded column structure after post-weld processing are as follows:

[0098] Since the stress values ​​vary depending on the location of the inspection on the workpiece, only one inspection range value is given.

[0099] The residual stress before post-weld heat treatment is 180–230 MPa;

[0100] The residual stress after heat treatment is 30–50 MPa;

[0101] The residual stress after vibration aging is 20-25 MPa.

[0102] The working principle of this invention is as follows:

[0103] like Figures 1-4As shown, this invention discloses a column welding structure and a welding positioning fixture. The column welding structure includes a fork-shaped plate 1 and columns 2. The fork-shaped plate 1 has a circular hole 1-1 at its center and slots 1-2 at its four corners. The upper sides of the four columns 2 are welded into the four slots 1-2 of the fork-shaped plate 1. The axial direction of the four columns 2 is perpendicular to the plane of the fork-shaped plate 1. A deep cylindrical through hole 2-1 is formed at the center of the axial direction of each column 2. The welding positioning fixture includes a fixture clamping plate 3, a clamping sleeve 4, and screws 5. The fixture clamping plate 3 has a process hole 3-1 at its center, which has the same diameter as the circular hole 1-1. The four corners are provided with clamp slots 3-2. During welding, the lower sides of the four columns 2 are installed in the clamp slots 3-2. The sleeve 4 is connected to the clamp slots 3-2 by screws 5, fixing the lower sides of the columns 2 in the clamp slots 3-2. After the four columns 2 are fixed, the four slots 1-2 of the fork plate 1 are engaged with the four columns 2. The cylindrical leveling block is inserted into the round hole 1-1 and the process hole 3-1 to ensure that the fork plate 1 is perpendicular to the four columns 2. Then the fork plate 1 is welded to the columns 2. During the welding process, the left and right staggered and symmetrical welding process is adopted to reduce welding deformation. The welded column structure can be perfectly matched with other components of the gripper.

[0104] This invention discloses a column welding structure, including a fork-shaped plate and four columns. The upper sides of the four columns are respectively welded into four slots in the fork-shaped plate, and the axial direction of the four columns is perpendicular to the plane of the fork-shaped plate. The circular hole of the column welding structure is used for the control sleeve of the gripper component to pass through and move up and down. The protrusion is used to install the wedge block. The circular hole is used to pass through the manual emergency operating rod. The deep cylindrical through hole is used to install three kinds of four slender rod pins with different functions. A spring is installed in the upper stepped hole, and a cold-fit copper sleeve is installed in the lower stepped hole. The column welding structure of this invention has a simple structure and fits perfectly with other components of the gripper component.

[0105] This invention discloses a welding positioning fixture for a column welded structure. The fixture's clamping slots on the fixture plate have the same positioning dimensions as the fork-shaped plate slots of the column welded structure. It is tightened with a clamping sleeve that has the same arc surface as the semi-circular column, so that the upper and lower references of the entire column welded structure are unified. This not only ensures that the column does not deform in all directions during the welding process and ensures accurate positioning, but also facilitates the disassembly of the welding positioning fixture after stress relief after the overall machining is completed, making it easy to assemble and disassemble.

[0106] The welded column structure of this invention undergoes three different stress-relief processes. First, overall low-temperature stress-relief heat treatment reduces workpiece deformation, eliminating 80%–90% of welding stress. Next, vibration impact is applied to the weld area, utilizing the variable load stress generated by stable resonance to induce plastic deformation in the weld area, achieving the goal of eliminating 10% of residual stress. Finally, natural aging is performed, essentially eliminating the internal welding stress and significantly improving the overall dimensional stability. This creates favorable conditions for the overall machining of the welded column structure, further enhancing dimensional stability.

[0107] The column welding structure of this invention is manufactured using a CNC machining center with coordinate positioning and precision machining, resulting in accurate precision and stable quality. This meets the stringent requirements for high dimensional accuracy in column welding structures, and the CNC precision machining ensures stable and reliable quality.

[0108] The welded column structure of this invention is positioned using a welding positioning fixture. Stress is eliminated through processing technology, and deformation of the welded column structure is controlled and prevented, ensuring the dimensional stability and final machining accuracy of the welded column structure. The welding positioning fixture for the welded column structure is simple, reasonable, compact, and easy to install and disassemble. When applied to specific projects, the overall dimensional accuracy of the welded column structure meets the requirements of the design drawings, directly improving the overall performance of the loading and unloading equipment.

[0109] 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.

[0110] 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 columnar welded structure, characterized by: The application relates to a column welding structure body, which comprises a fork-shaped plate (1) and four columns (2). A circular hole (1-1) is formed in the center of the fork-shaped plate (1), and clamping grooves (1-2) are formed at four corners of the fork-shaped plate (1). The upper sides of the four columns (2) are respectively welded into the four clamping grooves (1-2) of the fork-shaped plate (1), and the axial directions of the four columns (2) are perpendicular to the plane where the fork-shaped plate (1) is located. A longitudinal deep cylindrical through hole (2-1) is formed in the axial center of the column (2). The fork-shaped plate (1) is an "X" structure with heterogeneous symmetry, the included angle between the adjacent two clamping grooves (1-2) of the fork-shaped plate (1) is 90 degrees, a protrusion (1-3) is arranged between the adjacent two clamping grooves (1-2) of the fork-shaped plate (1), a circular hole (1-4) is formed in the fork-shaped plate (1) between the clamping groove (1-2) and the circular hole (1-1), and the clamping groove (1-2) is a right-angle clamping groove. The cross section of the column (2) is a cave type cross section with three straight edges and one semicircle, the cross section center is the longitudinal deep cylindrical through hole (2-1), the three straight edges of the column (2) are matched with the clamping groove (1-2), the three straight edges of the column (2) are clamped and welded into the clamping groove (1-2), and step holes (2-2) are respectively formed in the upper side and the lower side of the longitudinal deep cylindrical through hole (2-1).

2. A tack-welding positioning jig for use in the column-welded structure according to claim 1, characterized by: The application further relates to a column welding structure body assembly positioning tool, which comprises a tool clamp plate (3), a clamping sleeve (4) and a screw (5). A process hole (3-1) is formed in the center of the tool clamp plate (3), the diameter of the process hole (3-1) is the same as the diameter of the circular hole (1-1) of the fork-shaped plate (1) of the column welding structure body, clamping grooves (3-2) are formed at four corners of the tool clamp plate (3), the lower sides of the columns (2) are mounted into the clamping grooves (3-2), the clamping sleeve (4) is connected with the clamping grooves (3-2) through the screw (5), and the lower sides of the columns (2) are fixed into the clamping grooves (3-2).

3. The tack weld positioning fixture of claim 2, wherein: The clamping groove (3-2) is a right-angle clamping groove, the clamping sleeve (4) is provided with a semicircular groove (4-1) in the center, the right-angle clamping groove of the clamping groove (3-2) is connected with the semicircular groove (4-1) of the clamping sleeve (4) to form a space matched with the cross section of the column (2).

4. A method of processing a column welded structure, characterized by, The application further relates to a column welding structure body assembly positioning tool, which comprises the following steps: Step 1: a column welding structure body assembly positioning tool is designed and manufactured according to the column welding structure body of claim 1 and the column welding structure body of claim 2 or 3; Step 2: the column welding structure body assembly positioning tool is sleeved on the lower part of the column (2), the posture is adjusted, the columns (2) are ensured to be perpendicular to the tool clamp plate (3), the tool clamp plate (3) is rigidly fixed by the clamping sleeve (4), and the screw (5) is tightened; Step 3: the fork-shaped plate (1) is sleeved on the upper part of the column (2), a cylindrical leveling block is inserted into the circular hole (1-1) of the fork-shaped plate (1) and the process hole (3-1) of the tool clamp plate (3), the fork-shaped plate (1) is ensured to be perpendicular to the columns (2), the fork-shaped plate (1) is welded with the columns (2), a left-right staggered and symmetrical welding process method is adopted in the welding process to reduce welding deformation. Step 4: low temperature stress relief heat treatment, the whole column welded structure and the column welded structure of the group welding positioning tool are placed on the platform of the trolley type heat treatment electric furnace, heated to 320±20℃, and then air cooled after holding for 120-150min; Step 5: vibration aging treatment: vibration impact is carried out on the weld area, and plastic deformation is generated in the weld area by using the variable load stress generated by stable resonance; Step 6: after the vibration aging is completed, the whole column welded structure and the column welded structure of the group welding positioning tool are placed on the platform and subjected to natural aging; Step 7: after the natural aging is completed, the whole column (2) upper and lower end faces and longitudinal deep cylindrical through hole (2-1) are precisely machined by using a numerical control machining center; Step 8: the sizes of the column welded structure after machining are inspected by using the numerical control coordinate positioning of the numerical control machining center, and a detection report is issued.

5. The method of claim 4, wherein: The heating speed in step 4 is ≤220℃ / h, and the heating temperature is 320±20℃.

6. The method of claim 4, wherein: The vibration frequency in step 5 is 4500 r / min, and the vibration acceleration is 20.0-40.0 m / s 2 .

7. The method of claim 4, wherein: The natural aging time in step 6 is 24h.

8. A method of using a column weldment structure, characterized by: The column welded structure is a mounting carrier of a grabber component, and when used, springs are mounted in the upper end step holes (2-2) of the four columns (2) of the column welded structure of claim 1, copper sleeves are mounted in the lower end step holes (2-2), guide pins, positioning pins and support pins are longitudinally inserted into the longitudinal deep cylindrical through hole (2-1) from the lower end, the heads of the guide pins, positioning pins and support pins are connected with the upper flange positioning, the round hole (1-1) is used for the control sleeve of the grabber component to pass through and run up and down, the protrusion (1-3) is used for mounting a wedge block, and the circular hole (1-4) is used for passing through a manual emergency operating rod.

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