Telescopic arm arm cylinder manufacturing process method

Abstract

The application discloses a telescopic arm barrel manufacturing process method, comprising the following steps: S1, double-side surface shot blasting of plate material raw material; S2, plate material raw material leveling; S3, plate material raw material blanking, to obtain a first rough flat plate and a second rough flat plate; S4, beveling of the first rough flat plate and the second rough flat plate respectively; S5, part pressing through pre-pressing and re-pressing; S6, part reverse deformation treatment; S7, arm barrel assembly; S8, on a welding tool, segmented base welding of two side bevels of the arm barrel to be welded is simultaneously carried out; S9, the arm barrel after segmented base welding is separated from the welding tool, and cover welding of the two side bevels is carried out; S10, bench work treatment; S11, welding deformation detection and correction; S12, arm barrel accessory parts are assembled and welded; and S13, the arm barrel is subjected to re-shot blasting. The application can improve arm barrel finished product qualification rate, reduce repair workload, and improve arm barrel production efficiency.

Description

Technical Field

[0001] This invention relates to the field of engineering machinery manufacturing technology, and specifically to a manufacturing process for a telescopic boom barrel. Background Technology

[0002] Telescopic booms are load-bearing structural components of cranes, truck-mounted cranes, and other construction machinery. Their dimensional accuracy, structural strength, and welding stability affect the overall load-bearing capacity and service life of the machine. Currently, the construction machinery industry commonly uses BS700 series high-strength cold-formed steel plates to manufacture telescopic booms. This series of steel has advantages such as high yield strength, good lightweight effect, and strong structural load-bearing capacity, making it the mainstream material for high-end boom structural components.

[0003] However, since BS700 high-strength steel is formed using a controlled rolling and cooling fine-grain strengthening process, the material has high hardness, low plasticity reserve, large springback, and obvious tendency to harden during welding. In actual industrial production, the forming and welding processes of the boom cylinder are prone to quality defects such as large springback deviation during bending and severe deformation after welding. Large springback deviation and severe deformation after welding cannot be corrected mechanically and can only be corrected by conventional high-temperature flame, which can easily damage the metallographic structure of the base material, resulting in a low finished product qualification rate. Summary of the Invention

[0004] In view of this, the purpose of the present invention is to provide a manufacturing process for a telescopic boom barrel that can improve the yield rate of finished boom barrels, reduce rework workload, and improve boom barrel production efficiency.

[0005] A manufacturing process for a telescopic boom barrel according to the present invention includes the following steps:

[0006] S1. Shot blasting of both sides of the raw material sheet;

[0007] S2, Leveling of raw material boards;

[0008] S3. Cut the sheet material to obtain the first blank plate and the second blank plate;

[0009] S4. Perform beveling on the first blank plate and the second blank plate respectively;

[0010] S5. Parts are formed by pre-pressing and re-pressing: The first blank plate and the second blank plate are pre-formed by bending. After the pre-formed bending is completed, the first U-shaped part and the second U-shaped part are obtained by re-pressing with a bending machine.

[0011] S6. Parts reverse deformation treatment: symmetrically bend the two groove sidewalls of each U-shaped part, so that the two groove sidewalls of the U-shaped part are inclined, and the distance between the two groove sidewalls gradually increases along the direction from the root to the opening.

[0012] S7. Boom assembly: The first U-shaped piece and the second U-shaped piece are fixedly connected by the inner support component and the welding fixture to form the boom to be welded. The inner support component is set in the inner cavity of the first and second ends of the boom, and the welding fixture is used to fix the outer side of the boom.

[0013] S8. On the welding fixture, perform segmented root pass welding on both sides of the boom to be welded simultaneously. After welding, place for a preset time to perform weld flaw detection. If the flaw detection is unqualified, rework until qualified; if the flaw detection is qualified, proceed to the next step.

[0014] S9. Separate the boom cylinder that has completed the segmented root weld from the welding fixture, and perform cover weld on both sides of the bevel.

[0015] S10. Fitter processing: After the weld has cooled, remove the inner support components inside the boom cylinder and perform post-weld processing.

[0016] S11. Welding deformation detection and correction;

[0017] S12, Welding boom and auxiliary components;

[0018] S13. Perform shot blasting on the boom again.

[0019] Furthermore, in step S2, the sheet material is leveled at least three times, and after each leveling, it is left for a certain period of time to release its internal stress.

[0020] Furthermore, in step S3, micro-connected laser cutting is used to cut the sheet material to control the side bending deformation of the first blank plate and the second blank plate in the width direction.

[0021] Furthermore, step S5 also includes: detecting the root width, opening width, total height, flatness, and perpendicularity of the first U-shaped part and the second U-shaped part. If they are not qualified, mechanical correction is performed after pressing. If they are qualified, proceed to step S6.

[0022] Furthermore, in step S6, after completing the reverse deformation process, the U-shaped part is inverted onto the calibration platform with its opening facing downwards. The tilt angles of the two sidewalls of the U-shaped part are detected by the calibration plate. The calibration plate includes two detection arms that are at an angle to each other. The angle between the two detection arms corresponds to the required tilt angle of the reverse deformation of the sidewalls of the sidewalls. During the detection, one detection arm abuts against the bottom wall of the U-shaped part's groove, and the other detection arm abuts against the sidewall of the U-shaped part's groove. Multiple detections are performed at intervals along the length of the U-shaped part.

[0023] Furthermore, in step S8, the two bevels on both sides of the arm cylinder in the width direction are the welding positions. Multiple first parts to be welded are provided at intervals along the length direction of the arm cylinder on both sides. A second part to be welded and a third part to be welded are provided at intervals between two adjacent first parts to be welded.

[0024] On the welding fixture, the segmented root pass welding of both sides of the bevel simultaneously includes the following steps: First, weld each first part to be welded in sequence along the length of the boom; then, weld each second part to be welded in sequence along the length of the boom; finally, weld each third part to be welded in sequence along the length of the boom.

[0025] Furthermore, in step S8, the parameters for the root pass welding of the first, second, and third parts to be welded include: current: 130-180A, voltage: 16-23V, gas: CO2, gas flow rate: 15-20L / min, the length of the single-segment root pass weld of the first, second, and third parts to be welded is no more than 250mm, and the weld leg is no more than 3mm.

[0026] Furthermore, in step S9, the arm cylinder that has completed the segmented root pass welding is separated from the welding fixture and transferred to the welding robot station, where the welding robot performs cover welding on both sides of the bevel.

[0027] Furthermore, in step S9, the parameters for the welding robot to perform the cover welding include: welding speed of 30-35 cm / min, current of 210-230 A, voltage of 25-28 V, gas of CO2, and gas flow rate of 15-20 L / min; it is required that the cover welding of the single-sided bevel be completed continuously in one go.

[0028] Furthermore, in step S10, the post-weld treatment specifically includes: cleaning welding spatter, grinding high points of the weld, and not allowing grinding of the weld bead.

[0029] The beneficial effects of this invention are:

[0030] 1. This invention is designed to match the springback characteristics of BS700 high-strength steel with bending processes. By pre-pressing and re-pressing, the parts are formed and reverse-deformed, which together ensure that the dimensional deviation of the boom cylinder is small after forming and improve the processing accuracy of the boom cylinder body.

[0031] 2. The present invention performs segmented and staggered root pass welding before the cover pass welding, which can reduce welding thermal deformation and reduce the amount of deformation and twisting in the one-time forming of the cover pass welding.

[0032] 3. The step-by-step forming process of this invention reduces deviations caused by springback deformation, resulting in higher dimensional accuracy after processing. The smaller dimensional deviations allow for mechanical correction without the need for high-temperature flame straightening. Using mechanical straightening instead of traditional high-temperature flame straightening avoids damage to the metallographic structure of the cold-rolled steel in the BS700 controlled-roll hole, preserving the original mechanical properties of the base material and eliminating the risk of fatigue fracture in the boom.

[0033] 4. The entire process is logically connected, which can improve the qualification rate of the boom, reduce the amount of rework, and improve the production efficiency of the boom. Attached Figure Description

[0034] To make the objectives, technical solutions, and beneficial effects of this invention clearer, the following figures are provided for illustration:

[0035] Figure 1 This is a schematic diagram of the process of the present invention;

[0036] Figure 2 This is a schematic diagram of the structure of the first U-shaped part and the second U-shaped part after part forming processing according to the present invention;

[0037] Figure 3 This is a schematic diagram illustrating the working principle of the present invention for inspecting U-shaped parts after reverse deformation treatment;

[0038] Figure 4 This is a schematic diagram of the connection between the boom cylinder, the inner support component, and the welding fixture of the present invention;

[0039] Figure 5 This is a front view of the connection between the boom cylinder, the inner support component, and the welding fixture of the present invention;

[0040] Figure 6 This is a schematic diagram of the welding sequence for the segmented root pass welding of the present invention;

[0041] Figure 7 This is a schematic diagram of the welding sequence for the cover weld of the present invention.

[0042] The following labels are shown in the attached diagram:

[0043] 101 - Tank sidewall, 102 - Tank bottomwall;

[0044] 201 - Calibration platform; 202 - Calibration card;

[0045] 300 - Internal support component;

[0046] 400-Welding fixture, 401-Support platform, 402-Detachable fixed frame, 4021-Upper pressure plate component, 4022-Modible pressure plate component, 4023-Fixed support component. Detailed Implementation

[0047] The technical solution of the present invention will be described in detail below with reference to the accompanying drawings and embodiments.

[0048] like Figures 1-2As shown, a telescopic boom is a retractable working device mounted on engineering machinery. A telescopic boom typically consists of several sections. A certain type of telescopic boom's boom cylinder is categorized into fixed boom, movable boom, and movable inner boom, all made of BS700 series high-strength steel. Taking a fixed boom with a length dimension of 5000mm, a width dimension of 388mm, and a height dimension of 484mm as an example, it includes a first U-shaped member and a second U-shaped member with openings facing each other. Both the first and second U-shaped members have a width dimension of 388mm, a height dimension of 242mm, and a thickness of 7mm. A 15mm radius radius rounded corner is provided at the base of the U-shaped member, where the base refers to both sides of the bottom wall 102 of the groove (i.e., the side furthest from the opening). The manufacturing process of the telescopic boom cylinder will be described in detail below using the manufacturing process of this fixed boom as an example.

[0049] A telescopic boom cylinder manufacturing process method in this embodiment includes the following steps:

[0050] S1. Shot blasting of both sides of the raw material sheet.

[0051] After the boom is welded, its length dimension is large, forming a long chamber structure. It is difficult to perform shot blasting on the inner surface of the chamber and the quality of the treatment cannot be guaranteed. Therefore, shot blasting is performed on both sides of the plate material to remove rust and oxide scale from both sides. The inner surface of the boom chamber has rust, oxide scale, etc.

[0052] S2, Leveling of raw material boards.

[0053] In this step, the board material is leveled three times, and after each leveling, it is left to stand for at least 48 hours to ensure that the stress of the board material is fully released, which can reduce the impact of lateral bending and flatness after forming, and control the flatness requirement to within 1mm.

[0054] S3. Cut the raw material from the sheet to obtain the first blank plate and the second blank plate.

[0055] In this step, micro-connected laser cutting is used to cut the raw material from the sheet. Multiple small connection points are reserved at intervals along the laser cutting path to control the side bending deformation of the first and second blank plates in the width direction to within 2mm.

[0056] S4. Perform beveling on the first blank plate and the second blank plate respectively.

[0057] The bevel is located at the opening of the sidewall 101 of the two grooves, and the bevel machining retains a 1mm blunt edge.

[0058] S5. Part forming through pre-pressing and re-pressing: The first and second blank flat plates are pre-formed by bending. After the pre-formation is completed, a bending machine is used for re-pressing to obtain the first and second U-shaped parts. The root width, opening width, total height, flatness, and perpendicularity of the first and second U-shaped parts are inspected. If they are not up to standard, mechanical correction is performed after forming. If they are up to standard, proceed to S6.

[0059] First, the blank flat plate is roughly shaped and bent into a near-U-shaped contour, and then it is precision shaped to the required size by repressing. This step-by-step forming process reduces deviations caused by springback deformation, resulting in higher dimensional accuracy after processing. If the dimensions are not up to standard, mechanical correction is performed, which involves tapping to correct them. This process does not damage the metallographic structure of the base material, preserves the original mechanical properties of the base material, and eliminates the risk of fatigue fracture of the boom.

[0060] like Figure 2 As shown, the first and second U-shaped parts have the same dimensional requirements, with a root width requirement of 3880. + 1 mm, opening width requirement is 3880 +1 mm, meaning the allowable upper deviation for the root width and opening width is 1mm, and the allowable lower deviation is 0mm; the height dimension requirement is 242. -1 0 mm, the allowable upper deviation of the height dimension is 0mm, and the allowable lower deviation is -1mm; the flatness and verticality deviation of the groove sidewalls 101 on both sides of the opening shall not exceed 1mm.

[0061] S6. Part Reverse Deformation Processing: Symmetrically bend the two groove sidewalls 101 of each U-shaped part, so that the two groove sidewalls 101 of the U-shaped part are inclined, and the distance between the two groove sidewalls 101 gradually increases along the direction from the root to the opening.

[0062] The fixed arm has a single-sided deformation of 3mm, and the two symmetrical groove sidewalls 101 extend outward by a total of 6mm, that is: the root width is 388mm and the opening width is 392mm.

[0063] like Figure 3 As shown, after the anti-deformation process is completed, the U-shaped part is inverted onto the calibration platform 201 with the opening facing downwards. The tilt angle of the two groove sidewalls 101 of the U-shaped part is detected by the calibration plate 202. The calibration plate 202 includes two detection arms that are at an angle to each other. The angle between the two detection arms corresponds to the anti-deformation tilt angle requirement of the groove sidewall 101. During the detection, one detection arm abuts against the bottom wall 102 of the groove of the U-shaped part, and the other detection arm abuts against the groove sidewall 101 of the U-shaped part. Multiple detections are performed at intervals along the length of the U-shaped part.

[0064] The fixed arm is 5m long, and each U-shaped part is inspected every 1m along the length direction to improve the inspection accuracy.

[0065] Inward shrinkage deformation at the weld bead is an inevitable phenomenon during the welding process. To address this deformation, by reserving a counter-deformation amount, the dimensional deviation of the boom after welding can be reduced.

[0066] S7. Boom assembly: The first U-shaped piece and the second U-shaped piece are fixedly connected by the inner support member 300 and the welding fixture 400 to form the boom to be welded. The inner support member 300 is set in the inner cavity of the first and second ends of the boom, and the welding fixture 400 is used to fix the outer side of the boom.

[0067] like Figure 4 and Figure 5 As shown, the welding fixture 400 is equipped with a support platform 401. Multiple detachable fixed frames 402 are spaced apart along the length of the support platform 401. The upper pressure plate component 4021 of each detachable fixed frame 402 is detachable. A movable pressure plate component 4022 is provided on one side in the width direction, and a fixed support component 4023 is provided on the other side in the width direction. In use, the upper pressure plate component 4021 is first disassembled, and the position of the movable pressure plate component 4022 is adjusted to move it away from the fixed support component 4023. Then, the second U-shaped piece is hoisted and placed on the support platform 401 with its opening facing upwards. On 01, one side of the width direction abuts against the fixed support member 4023. Then, the two inner support members 300 are respectively set at the beginning and end of the groove of the second U-shaped part. Next, the opening direction of the first U-shaped part is downward, and it is hoisted above the second U-shaped part and connected. At this time, the two inner support members 300 are respectively set in the inner cavity between the first U-shaped part and the second U-shaped part, which can provide support for the first U-shaped part. Finally, the position of the movable pressure plate member 4022 is adjusted so that it abuts against the outer surface of the first U-shaped part and the second U-shaped part, and the pressure plate member 4021 is installed to press the first U-shaped part.

[0068] Multiple detachable fixing frames 402 are spaced apart along the length direction, with the bevels on both sides basically exposed, which facilitates subsequent root welding.

[0069] S8. On the welding fixture 400, perform segmented root pass welding on both sides of the boom cylinder to be welded simultaneously. After welding, place it for a preset time to perform weld flaw detection. If the flaw detection is unqualified, rework until qualified; if the flaw detection is qualified, proceed to the next step.

[0070] In this step, the two bevels on both sides of the boom barrel in the width direction are the welding positions. Multiple first parts to be welded are arranged at intervals along the length direction of the boom barrel on both sides. A second part to be welded and a third part to be welded are arranged at intervals between two adjacent first parts to be welded.

[0071] On welding fixture 400, the segmented root pass welding of both bevels is performed simultaneously, including the following steps: First, weld each first part to be welded sequentially along the length of the boom; then, weld each second part to be welded sequentially along the length of the boom; finally, weld each third part to be welded sequentially along the length of the boom. Figure 6 As shown, first, according to Figure 6 Weld the first parts to be welded in sequence according to the direction of the middle arrow, corresponding to numbers 1-5, and then press... Figure 6 Weld the second part to be welded in sequence according to the direction of the middle arrow, number 6. Finally, press... Figure 6 Weld the third parts to be welded in sequence according to the direction of the middle arrow, corresponding to numbers 10-13.

[0072] The parameters for the root pass welding of the first, second, and third parts to be welded include: current: 130-180A, voltage: 16-23V, gas: CO2, gas flow rate: 15-20L / min, the length of the single-segment root pass weld of the first, second, and third parts to be welded is no more than 250mm, and the weld leg is no more than 3mm.

[0073] This intermittent, staggered welding method reduces welding thermal deformation. Welding both bevels simultaneously ensures symmetry even with minor thermal deformation on both sides. Performing a root pass before the cover pass serves two purposes: firstly, it fixes the relative positions of the first and second U-shaped parts, facilitating subsequent cover pass welding by a welding robot; secondly, the root pass reduces the amount of deformation and twisting during the single-pass cover pass welding.

[0074] S9. Separate the boom cylinder, after completing the segmented root pass welding, from the welding fixture 400, and perform cover pass welding on both sides of the bevel. For example... Figure 7 As shown, first press Figure 7 Weld the cap weld on side 1 (number 1) in the direction of the middle arrow in one go, then press... Figure 7 The cap weld on the side of serial number 2 is welded in one go in the direction of the middle arrow.

[0075] After the segmented root pass welding is completed, the boom is separated from the welding fixture 400 and transferred to the welding robot station. The welding robot then performs capping welding on both bevels. The parameters for the welding robot's capping welding include: welding speed of 30-35 cm / min, current of 210-230 A, voltage of 25-28 V, gas of CO2, and gas flow rate of 15-20 L / min. The capping welding of each bevel must be completed continuously in one pass.

[0076] The welding robot station is equipped with a welding platform. The boom and welding fixture 400 are placed separately on the welding platform, which can prevent the detachable fixing frame 402 of the welding fixture 400 from affecting the operation of the welding robot.

[0077] Welding robots can achieve continuous and rapid welding, ensuring that a 5m long weld can be completed in one continuous operation within a specified time. The movements are smooth and the parameters are stable, and the weld formation and quality are more uniform than those of a human hand.

[0078] S10. Fitter's work: After the weld has cooled, remove the inner support component 300 from the boom cylinder for post-weld processing. Post-weld processing specifically includes: cleaning welding spatter, grinding high points of the weld, and not grinding the weld bead.

[0079] S11. Welding Deformation Detection and Correction. Use tools such as jacks, right-angle rulers, height gauges, and scribers to inspect the dimensions of the boom after welding.

[0080] S12. Welding boom sleeve auxiliary components, such as pads, local reinforcing ribs, mounting bases and other small auxiliary parts.

[0081] S13. Perform shot blasting on the boom barrel again to ensure the surface quality of the boom barrel.

[0082] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit it. Although the present invention has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions can be made to the technical solutions of the present invention without departing from the spirit and scope of the technical solutions of the present invention, and all such modifications or substitutions should be covered within the scope of the claims of the present invention.

Claims

1. A manufacturing process for a telescopic boom barrel, characterized in that, Includes the following steps: S1. Shot blasting of both sides of the raw material sheet; S2, Leveling of raw material boards; S3. Cut the sheet material to obtain the first blank plate and the second blank plate; S4. Perform beveling on the first blank plate and the second blank plate respectively; S5. Parts are formed by pre-pressing and re-pressing: The first blank plate and the second blank plate are pre-formed by bending. After the pre-formed bending is completed, the first U-shaped part and the second U-shaped part are obtained by re-pressing with a bending machine. S6. Parts reverse deformation treatment: symmetrically bend the two groove sidewalls of each U-shaped part, so that the two groove sidewalls of the U-shaped part are inclined, and the distance between the two groove sidewalls gradually increases along the direction from the root to the opening. S7. Boom assembly: The first U-shaped piece and the second U-shaped piece are fixedly connected by the inner support component and the welding fixture to form the boom to be welded. The inner support component is set in the inner cavity of the first and second ends of the boom, and the welding fixture is used to fix the outer side of the boom. S8. On the welding fixture, perform segmented root pass welding on both sides of the boom to be welded simultaneously. After welding, place for a preset time to perform weld flaw detection. If the flaw detection is unqualified, rework until qualified; if the flaw detection is qualified, proceed to the next step. S9. Separate the boom cylinder that has completed the segmented root weld from the welding fixture, and perform cover weld on both sides of the bevel. S10. Fitter processing: After the weld has cooled, remove the inner support components inside the boom cylinder and perform post-weld processing. S11. Welding deformation detection and correction; S12, Welding boom and auxiliary components; S13. Perform shot blasting on the boom again.

2. The manufacturing process of the telescopic boom barrel according to claim 1, characterized in that: In step S2, the plate material is leveled at least three times, and after each leveling, it is left for a certain period of time to release its internal stress.

3. The manufacturing process of the telescopic boom barrel according to claim 1, characterized in that: In step S3, micro-connected laser cutting is used to cut the sheet material to control the side bending deformation of the first blank plate and the second blank plate in the width direction.

4. The manufacturing process of the telescopic boom barrel according to claim 1, characterized in that: Step S5 also includes: detecting the root width, opening width, total height, flatness, and perpendicularity of the first U-shaped part and the second U-shaped part. If they are not qualified, mechanical correction is performed after pressing. If they are qualified, proceed to S6.

5. The manufacturing process of the telescopic boom barrel according to claim 1, characterized in that: In step S6, after the reverse deformation process is completed, the U-shaped part is inverted onto the calibration platform with the opening facing downwards. The tilt angles of the two groove sidewalls of the U-shaped part are detected by the calibration plate. The calibration plate includes two detection arms that are at an angle to each other. The angle between the two detection arms corresponds to the required tilt angle of the reverse deformation of the groove sidewalls. During the detection, one detection arm abuts against the bottom wall of the groove of the U-shaped part, and the other detection arm abuts against the sidewall of the groove of the U-shaped part. Multiple detections are performed at intervals along the length of the U-shaped part.

6. The manufacturing process of the telescopic boom barrel according to claim 1, characterized in that: In step S8, the two bevels on both sides of the arm cylinder in the width direction are the welding positions. Multiple first parts to be welded are provided at intervals along the length direction of the arm cylinder on both sides. A second part to be welded and a third part to be welded are provided at intervals between two adjacent first parts to be welded. On the welding fixture, the segmented root pass welding of both bevels is carried out simultaneously in the following steps: First, weld each first part to be welded in sequence along the length of the boom, then weld each second part to be welded in sequence along the length of the boom, and finally weld each third part to be welded in sequence along the length of the boom.

7. The manufacturing process of the telescopic boom barrel according to claim 6, characterized in that: In step S8, the parameters for the root pass welding of the first, second, and third parts to be welded include: current: 130-180A, voltage: 16-23V, gas: CO2, gas flow rate: 15-20L / min; the length of the single-segment root pass weld of the first, second, and third parts to be welded is no more than 250mm, and the weld leg is no more than 3mm.

8. The manufacturing process of the telescopic boom barrel according to claim 1, characterized in that: In step S9, the arm cylinder that has completed the segmented root pass welding is separated from the welding fixture and transferred to the welding robot station, where the welding robot performs cover welding on both sides of the bevel.

9. The manufacturing process of the telescopic boom barrel according to claim 8, characterized in that: In step S9, the parameters for the welding robot to perform cover welding include: welding speed of 30-35 cm / min, current of 210-230 A, voltage of 25-28 V, gas of CO2, and gas flow rate of 15-20 L / min; the cover welding of the single-sided bevel is required to be completed continuously in one go.

10. The manufacturing process of the telescopic boom barrel according to claim 1, characterized in that: In step S10, the post-weld treatment specifically includes: cleaning welding spatter, grinding high points of the weld, and not allowing grinding of the weld bead.

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