阅读说明：本技术 一种轻质合金中厚板焊后预应力校形及强化方法 (Method for correcting and strengthening prestress of welded light alloy medium and heavy plates ) 是由 谈正晓 于 2020-11-25 设计创作，主要内容包括：本发明公开了一种轻质合金中厚板焊后预应力校形及强化方法,属于焊接校形及强化的技术领域,所述方法包括如下部分步骤：步骤S1：焊接件加工,采用焊接工艺参数对轻质合金中厚板进行单面焊接双面成型,焊接后保持工件处于夹持状态固定并冷却。本发明中,利用撞针式超声波喷丸设备进行校形及强化,通过更换不同大小的多撞针式工作头,实现校形和强化功能,操作方便,且高效,能够同步完成打磨以及焊接工作,通过进行打磨使得焊接面呈斜面形结构,便于对较厚的轻质合金中厚板进行焊接处理,且通过利用打磨低温刚结构所产生的热能对其进行预热,在实现节能的基础上,可降低焊缝产生的概率,并削弱应力的影响。(The invention discloses a method for correcting and strengthening the pre-stress of a light alloy medium and heavy plate after welding, which belongs to the technical field of welding correction and strengthening and comprises the following steps: step S1: and (3) processing a welded part, namely performing single-side welding and double-side forming on the light alloy medium plate by adopting welding process parameters, and keeping the workpiece in a clamping state, fixing and cooling after welding. According to the invention, the shape correction and strengthening are carried out by utilizing the striker type ultrasonic shot blasting equipment, the shape correction and strengthening functions are realized by replacing the multi-striker type working heads with different sizes, the operation is convenient and efficient, the grinding and welding work can be synchronously completed, the welding surface is in an inclined plane structure by grinding, the welding treatment on a thicker light alloy medium and thick plate is convenient, the heat energy generated by grinding the low-temperature steel structure is utilized to preheat the medium and thick plate, the probability of generating a welding seam is reduced on the basis of realizing energy conservation, and the influence of stress is weakened.)

1. A method for correcting and strengthening the welded prestress of a light alloy medium and heavy plate is characterized by comprising the following steps:

step S1: processing a welding part, namely performing single-side welding and double-side forming on the light alloy medium plate by adopting welding process parameters, and after welding, keeping the workpiece in a clamping state, fixing and cooling;

step S2: analyzing welding residual stress and deformation, and comprehensively calculating and analyzing the stress state of the welded workpiece and the deformation after releasing welding constraint according to welding heat input, a welding sequence and the workpiece constraint condition;

step S3: designing a prestress shot blasting path and a load, applying unreleased residual stress as a prestress load according to the calculated deformation, and calculating and analyzing an ultrasonic shot blasting load and a shot blasting path required by workpiece correction;

step S4: performing ultrasonic shot blasting shape correction, namely selecting a firing pin with a certain diameter, and performing shot blasting shape correction on the welding seam and the peripheral area of the welding seam according to set amplitude and coverage rate by using ultrasonic shot blasting equipment;

step S5: checking the appearance, supplementing and correcting the shape, disassembling a welding tool, placing a workpiece on the checking tool to check the fitting degree of the workpiece, and supplementing manual shape correction to a local deformation area by using ultrasonic shot blasting equipment;

step S6: ultrasonic strengthening of the surface of the welding seam, selecting a striker with a small diameter, and carrying out uniform impact on the surface of the welding seam after shape correction and a root area, so that the coverage rate of the surface of the welding seam is controlled between 100% and 150%, wherein the root area comprises the welding seam and a heat affected zone.

2. The method for correcting and strengthening the post-weld prestress of the light alloy medium and heavy plate according to claim 1, characterized in that the welding equipment applied in the welding process comprises a base (1), a side plate seat (2) is fixedly connected to the edge of the top of the base (1), a pressing type fixed seat (3) is arranged on the inner side of the side plate seat (2), a hydraulic lifting device (7) is fixedly connected to the side of the base (1), a top seat (8) is fixedly connected to the surface of the hydraulic lifting device (7) corresponding to the position of the base (1), a second threaded rod (9) is arranged above the top seat (8), a through hole (18) is formed in the top of the top seat (8) corresponding to the position of the second threaded rod (9), a second threaded cylinder (14) is connected to the surface of the second threaded rod (9) in a threaded manner, and the bottom of the second threaded cylinder (14) is fixedly connected to the top of the first connecting seat (15), the dust collector is characterized in that the first connecting seat (15) is connected in the through hole (18) in a sliding mode, the bottom of the first connecting seat (15) is fixedly connected with a shell (23), the top of the shell (23) is communicated with one end, close to the dust collection pipe (19), of the shell (23), a grinding roller (24) is arranged inside the shell (23), a third threaded cylinder (16) is connected to the surface of the second threaded rod (9) in a threaded mode, a second connecting seat (17) is fixedly connected to the bottom of the third threaded cylinder (16), the second connecting seat (17) is connected in the through hole (18) in a sliding mode, a welding head (21) is fixedly connected to the bottom of the second connecting seat (17), and a movable type extrusion positioning device (22) is fixedly connected to the surface of the welding.

3. The method for pre-stress shape correction and strengthening of the light alloy medium plate after welding according to claim 1, characterized in that a first bearing (4) is clamped on the surface of the side plate seat (2) at a position corresponding to the extrusion type fixed seat (3), a first threaded barrel (5) is sleeved in the first bearing (4), a first threaded rod (6) is connected in the first threaded barrel (5) in a threaded manner, the end part of the first threaded rod (6) is fixedly connected with one side close to the extrusion type fixed seat (3), the end part of the second threaded rod (9) is fixedly connected with a transfer shaft (10), a second bearing (11) is sleeved on the end part of one transfer shaft (10), the second bearing (11) is clamped on the surface of a bearing seat (12), the bottom of the bearing seat (12) is fixedly connected with the top of the top seat (8), and the end part of the other transfer shaft (10) is fixedly connected with the end part of the output shaft of the first motor (13), the bottom of the body of the first motor (13) is fixedly connected with the top of the top seat (8) through a damping seat.

4. The method for pre-stress sizing and strengthening the welded lightweight alloy medium and heavy plates according to claim 1, wherein the other end of the dust suction pipe (19) is communicated with an input port of an air pump (20), the dust suction pipe (19) is positioned in the through hole (18), the bottom of the body of the air pump (20) is fixedly connected with the bottom of the top seat (8) through a shock absorption seat, the grinding roller (24) is fixedly connected to the surface of the rotating shaft (25), the surface of the rotating shaft (25) is sleeved with a third bearing (26), the third bearing (26) is clamped to the surface of the shell (23), the end of the rotating shaft (25) is fixedly connected with the end of an output shaft of a second motor (27), and the surface of the body of the second motor (27) is fixedly connected with the surface of the shell (23) close to the surface of the shell (23) through the shock absorption seat.

5. The method for pre-stress shape correction and reinforcement of the welded light alloy medium and thick plate according to claim 1 is characterized in that a telescopic groove (28) is formed in the bottom of the shell (23), a sealing sleeve (29) is sleeved in the telescopic groove (28), the top of the sealing sleeve (29) is fixedly connected with the top of the inner side of the telescopic groove (28) through a second supporting spring (30), a sliding panel (31) is fixedly connected with the bottom of the sealing sleeve (29), the cross section of the side view of the grinding roller (24) is of a diamond structure, and the model of the grinding roller (24) can be adaptively changed according to the thickness of the light alloy medium and thick plate to be machined.

6. The method for pre-stress shape correction and strengthening of the light alloy medium and heavy plate after welding according to claim 1, wherein the movable extrusion positioning device (22) comprises a roller (221), a sleeve (222) is fixedly connected to the top of the roller (221), a bevel groove (223) is formed in the top of the sleeve (222), a bevel rod (224) is sleeved in the bevel groove (223), a connecting ring (225) is fixedly connected to the surface of the bevel rod (224), the connecting ring (225) is fixedly connected to the opposite surface of the roller (221) through a first supporting spring (226), the first supporting spring (226) is sleeved on the surfaces of the bevel rod (224) and the sleeve (222), the top of the bevel rod (224) is fixedly connected to the surface of the welding head (21) close to the welding head through a bridge-type connecting frame (227), and the bevel of the end of the bevel rod (224) corresponding to the bevel groove (223) is also set as a bevel, and the inclination angle of the inclined surface rod (224) is smaller than that of the inclined surface groove (223).

7. The method for pre-stress sizing and strengthening of the light alloy medium and heavy plates after welding according to claim 1, wherein the cross section of the sealing sleeve (29) in a plan view is a rectangular structure, the cross section of the through hole (18), the first connecting seat (15) and the second connecting seat (17) in a plan view is a rectangular structure, and the outer diameter of the first connecting seat (15) and the outer diameter of the second connecting seat (17) are matched with the inner diameter of the through hole (18).

8. The method as claimed in claim 1, wherein a striker diameter of 1.2mm, 2mm, 3mm or 4mm, a striker amplitude of 0-100%, a striker coverage of 20-80% and a database of the relationship between material thickness and test plate longitudinal and transverse deformation curvature are established before step S3, and a striker diameter of 1.2mm or 2mm, a striker amplitude of 0-100%, a coverage of 100-150% and a database of the relationship between material thickness and test plate fatigue performance are established before step S6.

9. The method as claimed in claim 1, wherein the ultrasonic peening device used in step S4 is a multi-firing pin type working head, the multi-firing pin type working head can be replaced by a multi-firing pin type working head to select different firing pins with different diameters, the multi-firing pin type working head is cooled by circulating cooling water, the peening performed in step S4 selects a firing pin with a diameter of 2mm, the range of the firing pin is 0-50%, and the impact angle is 90 °.

10. The method for pre-stress shaping and strengthening the heavy and medium light alloy plate after welding according to claim 1, wherein the welding method adopted by the welding head (21) in the welding process comprises friction stir welding, laser welding or arc welding.

Technical Field

The invention belongs to the technical field of welding shape correction and strengthening, and particularly relates to a method for correcting and strengthening the pre-stress of a light alloy medium-thickness plate after welding.

Background

The welding of light aluminum alloy or titanium alloy medium and thick plates is an indispensable key process in the field of aerospace, but after welding, parts are deformed due to expansion with heat and contraction with cold at welding seams, and excessive welding deformation affects the dimensional accuracy of products, reduces the bearing capacity of the products and shortens the service life, so that the deformation after welding needs to be corrected.

The tool can be disassembled after welding for thin-wall parts, deformation correction can be realized in the directions of laser shot blasting, portable shot blasting or stamping and the like, but the stress released after welding of large-size medium-thickness plate parts is overlarge, the welding seam cracking can be caused by stamping correction, the laser shot blasting or portable shot blasting correction efficiency is lower, on the other hand, the stress released after welding is larger, so whether the part of stress can be fully utilized or not is judged, the correction efficiency and the correction quality are improved, and the tool has very important significance for practical engineering application.

The light alloy medium plate is larger in welding process and control welding deformation, in order to improve welding quality, the light alloy medium plate needs to be preheated before welding, the cost is higher, meanwhile, the welding efficiency of the light alloy medium plate can be reduced to a certain degree, in the past, when a certain light alloy plate with larger thickness is welded, a welding surface is usually required to be polished, a vertical plane structure is converted into an inclined plane structure, after polishing work is completed, welding treatment is carried out, and in the stage, because the polished surface is easy to oxidize, certain influence is easily caused on the welding quality.

Disclosure of Invention

The invention aims to: in order to solve the problems that after welding, the part is deformed due to expansion with heat and contraction with cold at the welding seam, the excessive welding deformation affects the dimensional precision of the product, but also can reduce the bearing capacity and shorten the service life, and the light alloy medium plate has larger deformation in the welding process and the welding control, in order to improve the welding quality, the light alloy medium and heavy plates need to be preheated before welding, the cost is high, meanwhile, the welding efficiency of the light alloy medium and heavy plates is reduced to a certain extent, and when some light alloy plates with larger thickness are welded, it is usually necessary to grind the bonding surface, convert the vertical plane structure into the inclined plane structure, after finishing the polishing work, welding treatment is carried out, and in this stage, the polishing surface is easy to oxidize and easy to have certain influence on the welding quality, so the method for correcting and strengthening the prestress of the welded light alloy medium and thick plate is provided.

In order to achieve the purpose, the invention adopts the following technical scheme:

a method for correcting and strengthening the welded prestress of a light alloy medium and heavy plate comprises the following steps:

step S1: processing a welding part, namely performing single-side welding and double-side forming on the light alloy medium plate by adopting welding process parameters, and after welding, keeping the workpiece in a clamping state, fixing and cooling;

step S2: analyzing welding residual stress and deformation, and comprehensively calculating and analyzing the stress state of the welded workpiece and the deformation after releasing welding constraint according to welding heat input, a welding sequence and the workpiece constraint condition;

step S3: designing a prestress shot blasting path and a load, applying unreleased residual stress as a prestress load according to the calculated deformation, and calculating and analyzing an ultrasonic shot blasting load and a shot blasting path required by workpiece correction;

step S4: performing ultrasonic shot blasting shape correction, namely selecting a firing pin with a certain diameter, and performing shot blasting shape correction on the welding seam and the peripheral area of the welding seam according to set amplitude and coverage rate by using ultrasonic shot blasting equipment;

step S5: checking the appearance, supplementing and correcting the shape, disassembling a welding tool, placing a workpiece on the checking tool to check the fitting degree of the workpiece, and supplementing manual shape correction to a local deformation area by using ultrasonic shot blasting equipment;

step S6: ultrasonic strengthening of the surface of the welding seam, selecting a striker with a small diameter, and carrying out uniform impact on the surface of the welding seam after shape correction and a root area, so that the coverage rate of the surface of the welding seam is controlled between 100% and 150%, wherein the root area comprises the welding seam and a heat affected zone.

As a further description of the above technical solution:

the welding equipment applied in the welding process comprises a base, a side plate seat is fixedly connected to the edge of the top of the base, an extrusion type fixed seat is arranged on the inner side of the side plate seat, a hydraulic lifting device is fixedly connected to the side face of the base, a top seat is fixedly connected to the surface of the hydraulic lifting device corresponding to the position of the base, a second threaded rod is arranged above the top seat, a through hole is formed in the top of the top seat corresponding to the position of the second threaded rod, a second threaded cylinder is connected to the surface of the second threaded rod in a threaded manner, the bottom of the second threaded cylinder is fixedly connected to the top of a first connecting seat, the first connecting seat is connected to the through hole in a sliding manner, a shell is fixedly connected to the bottom of the first connecting seat, the top of the shell is communicated with one end, close to a dust suction pipe, a grinding roller is arranged in the shell, and a third threaded cylinder is, the bottom of the third threaded cylinder is fixedly connected with a second connecting seat, the second connecting seat is connected in the through hole in a sliding mode, the bottom of the second connecting seat is fixedly connected with a welding head, and the surface of the welding head is fixedly connected with a movable type extrusion positioning device.

As a further description of the above technical solution:

the utility model discloses a bearing, including curb plate seat, extrusion formula fixing base, first threaded barrel internal thread connection, the tip of first threaded rod and the similar one side fixed connection of extrusion formula fixing base, the tip fixedly connected with switching axle of second threaded rod, and the tip of one of them switching axle has cup jointed the second bearing, the second bearing joint is on the surface of bearing frame, the bottom of bearing frame and the top fixed connection of footstock, and the tip of another switching axle and the tip fixed connection of first motor output shaft, the top fixed connection of shock attenuation seat and footstock is passed through to the bottom of first motor fuselage.

As a further description of the above technical solution:

the other end of dust absorption pipe is linked together with the input port of air pump to the dust absorption pipe is located the perforation, the bottom fixed connection of shock mount and footstock is passed through to the bottom of air pump fuselage, grinding roller fixed connection is on the surface of pivot, the third bearing has been cup jointed on the surface of pivot, the third bearing joint is on the surface of casing, the tip of pivot and the tip fixed connection of second motor output shaft, the one side fixed connection that the surface of second motor fuselage is close with the casing through the shock mount.

As a further description of the above technical solution:

the utility model discloses a polishing roller, including casing, flexible inslot, second supporting spring and flexible inslot side, flexible inslot has seted up flexible groove, the seal cover has been cup jointed in the flexible groove, the top of seal cover is through the top fixed connection of second supporting spring with flexible inslot side, the bottom fixedly connected with slip sheet of seal cover, the cross-sectional shape that the polishing roller looked sideways at is the rhombus structure, just the model of polishing roller can carry out the suitability according to the thickness of waiting to process light alloy medium thickness and change.

As a further description of the above technical solution:

the movable type extrusion positioning device comprises a roller, a sleeve is fixedly connected to the top of the roller, an inclined plane groove is formed in the top of the sleeve, an inclined plane rod is arranged in the inclined plane groove in a sleeved mode, a connecting ring is fixedly connected to the surface of the inclined plane rod, the connecting ring is fixedly connected with the opposite surface of the roller through a first supporting spring, the first supporting spring is sleeved on the surface of the inclined plane rod and the surface of the sleeve, one fixed connection end, close to a welding head, of the bridge-type connecting frame is arranged at the top of the inclined plane rod, the inclined plane of the end portion of the inclined plane rod, corresponding to the inclined plane groove, is also arranged to be an inclined plane, and the inclined angle of the.

As a further description of the above technical solution:

the seal cover is cross-sectional shape that overlooks is the rectangle structure, the cross-sectional shape that perforation, first connecting seat and second connecting seat overlook is the rectangle structure to the external diameter size of first connecting seat and second connecting seat all matches with fenestrate internal diameter size.

As a further description of the above technical solution:

before the step S3, a database of relationships between the striker diameter and the test panel longitudinal and transverse deformation curvatures, the striker diameter being 1.2mm, 2mm, 3mm or 4mm, the striker amplitude being in the range of 0 to 100%, and the striker coverage being in the range of 20 to 80%, and the material thickness, and a database of relationships between the test panel longitudinal and transverse deformation curvatures, and before the step S6, a database of relationships between the striker diameter and the test panel fatigue characteristics, the striker diameter being 1.2mm or 2mm, the striker amplitude being in the range of 0 to 100%, and the coverage being in the range of 100 to 150%, are established.

As a further description of the above technical solution:

the ultrasonic peening device used in step S4 is a multi-striker type working head, and the multi-striker type working head can select strikers of different diameters by replacing the multi-striker type working head, and the striker type working head is cooled by circulating cooling water, and the peening performed in step S4 selects a striker with a diameter of 2mm, the range of the striker is 0% to 50%, and the impact angle is 90 °.

As a further description of the above technical solution:

the welding method adopted by the welding head in the welding process comprises friction stir welding, laser welding or arc welding.

In summary, due to the adoption of the technical scheme, the invention has the beneficial effects that:

1. in the invention, the shape correction and strengthening are carried out by utilizing the striker type ultrasonic shot blasting equipment, the shape correction and strengthening functions are realized by replacing the multi-striker type working heads with different sizes, the operation is convenient and efficient, the polishing and welding work can be synchronously completed, the welding surface is in an inclined plane structure by polishing, so that the thicker light alloy medium plate can be conveniently welded, and the heat energy generated by polishing the low-temperature steel structure is utilized to preheat the thick light alloy medium plate, on the basis of realizing energy conservation, the probability of generating welding seams can be reduced, the influence of stress is weakened, the strength, the rigidity and the hardness of the light alloy medium plate product are improved, the safety of the light alloy medium plate product in use is ensured, the harm of welding stress is greatly reduced, the structural deformation is greatly reduced, thereby improving the stability of the light alloy medium plate and ensuring the mechanical property of the light alloy medium plate product.

2. In the invention, after the weldment is cooled, unreleased residual stress is used as prestress load to be applied, so that the energy required by shape correction can be greatly reduced, meanwhile, the damage to the surface of the material caused by shape correction in a high-temperature state is avoided, and the method is particularly suitable for the control treatment of the welding deformation of the light high-strength material after heat treatment strengthening.

3. According to the invention, through the designed side plate seat, the extrusion type fixed seat, the first bearing, the first threaded cylinder and the first threaded rod, the first threaded cylinder is rotated in the first bearing to rotate, and under the combined effect of the torque force and the thread occlusion force, the extrusion type fixed seat can be driven to move towards the direction away from or close to the side plate seat, and through extrusion and fixation of the two light alloy medium plates to be welded, the light alloy medium plates can be prevented from displacing in the welding and polishing processes, and the welding quality is improved.

4. According to the invention, the running state of the hydraulic lifting device is controlled through the designed hydraulic lifting device, and the hydraulic lifting device is used for adjusting the height difference of the grinding roller and the welding head relative to the base through controlling the height of the top seat.

5. According to the invention, the operation of the first motor is controlled through the designed first motor, the second threaded cylinder, the second threaded rod, the third threaded cylinder, the first connecting seat, the second connecting seat, the transfer shaft, the second bearing and the bearing seat, the first motor can apply a torsion force to the second threaded rod through the corresponding transfer shaft in the working process, and in the process, the second threaded rod can drive the other transfer shaft to rotate in the second bearing so as to improve the load capacity of the second threaded rod and ensure the stability of the second threaded rod, and in the rotating process of the second threaded rod, under the combined effect of the torsion force and the thread biting force, the first connecting seat and the second connecting seat can be simultaneously driven to slide in the through hole in the same direction.

6. In the invention, through the designed first connecting seat, the shell, the polishing roller, the second motor, the sliding panel, the telescopic groove, the sealing sleeve, the third bearing and the rotating shaft, the first connecting seat controls the second motor to operate in the process of sliding in the through hole, the second motor can drive the polishing roller to perform polishing operation through the rotating shaft in the working process, simultaneously, the parts to be welded of the two light alloy medium plates to be processed are polished, after polishing, the two light alloy medium plates to be processed are inclined planes in side view, and are V-shaped or trapezoidal in shape, on one hand, the shell, the sliding panel and the sealing sleeve can apply pressure on the light alloy medium plate to be processed, is used for weakening vibration energy generated by grinding, on the other hand, can prevent grinding materials generated by grinding from scattering around, in the polishing process, the to-be-welded surface of the light alloy medium-thickness plate has higher temperature due to the action of friction force.

7. According to the invention, through the designed dust suction pipe, the air pump and the shell, the first connecting seat controls the air pump to operate in the process of sliding in the through hole, and the air pump can apply suction force to the bottom of the shell through the dust suction pipe in the working process and is used for rapidly guiding grinding materials generated by grinding out of the shell.

8. According to the invention, through the designed welding head, the second connecting seat controls the welding head to work in the process of sliding in the through hole, and in the welding process of the welding head, the part to be welded is preheated in a grinding mode, and the welding surface is in an inclined plane structure through grinding, so that the thicker light alloy medium and thick plate can be conveniently welded.

9. According to the invention, through the designed movable extrusion positioning device, the welding head can be driven to synchronously move in the process of moving welding under the driving of the second connecting seat, and due to the two inclined planes, two opposite rollers can generate moving extrusion force between the two rollers, and meanwhile, the first supporting spring can be used for applying downward pressure, so that the stability between the two light alloy medium plates to be welded can be ensured.

Drawings

FIG. 1 is a schematic perspective view of a method for post-weld pre-stress shape correction and strengthening of a light alloy medium and heavy plate according to the present invention;

FIG. 2 is an enlarged structural diagram of a method A for post-weld pre-stress shape correction and strengthening of a light alloy medium and heavy plate according to the present invention;

FIG. 3 is a schematic perspective view of a movable extrusion positioning device in a welding device for light alloy medium and heavy plates based on a cooling tower according to the present invention;

FIG. 4 is a schematic perspective view of a housing of a welding device for light alloy medium and heavy plates based on a cooling tower according to the present invention;

FIG. 5 is a schematic cross-sectional view of a sleeve of a welding device for light alloy medium and heavy plates based on a cooling tower according to the present invention;

FIG. 6 is a schematic perspective view of a telescopic groove in a welding device for light alloy medium and heavy plates based on a cooling tower according to the present invention;

FIG. 7 is a sectional view schematically illustrating a front view of a housing of a welding apparatus for a light alloy medium plate based on a cooling tower according to the present invention;

FIG. 8 is a schematic cross-sectional view of a left side view of a shell of a welding device for light alloy medium and heavy plates based on a cooling tower according to the present invention;

FIG. 9 is a schematic view of a cooling tower-based welding device for light alloy medium and heavy plates according to the present invention before welding in a state of releasing the constraint of the light alloy medium and heavy plates;

FIG. 10 is a schematic diagram of deformation after welding of a light alloy medium plate in a welding device for a light alloy medium plate based on a cooling tower according to the present invention in a state of constraint and release of the light alloy medium plate;

FIG. 11 is a schematic diagram of a welding device for light alloy medium and heavy plates based on a cooling tower before ultrasonic shot peening shape correction;

FIG. 12 is a schematic view of the cooling tower-based welding device for light alloy medium and heavy plates after ultrasonic peening for shape correction;

FIG. 13 is a flow chart of the post-welding pre-stress shape correction and strengthening in the welding device for light alloy medium and heavy plates based on the cooling tower according to the present invention;

FIG. 14 is a schematic view of a multi-striker ultrasonic peening head in a welding device for light alloy medium and heavy plates based on a cooling tower.

Illustration of the drawings:

1. a base; 2. a side plate seat; 3. an extrusion type fixed seat; 4. a first bearing; 5. a first threaded barrel; 6. a first threaded rod; 7. a hydraulic lifting device; 8. a top seat; 9. a second threaded rod; 10. a transfer shaft; 11. a second bearing; 12. a bearing seat; 13. a first motor; 14. a second threaded barrel; 15. a first connecting seat; 16. a third threaded barrel; 17. a second connecting seat; 18. perforating; 19. a dust collection pipe; 20. an air pump; 21. welding a head; 22. a mobile extrusion positioning device; 221. a roller; 222. a sleeve; 223. an inclined plane groove; 224. a beveled rod; 225. a connecting ring; 226. a first support spring; 227. a bridge-type connecting frame; 23. a housing; 24. grinding a roller; 25. a rotating shaft; 26. a third bearing; 27. a second motor; 28. a telescopic groove; 29. sealing sleeves; 30. a second support spring; 31. a sliding panel.

Detailed Description

The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

Referring to fig. 1-14, the present invention provides a technical solution: a method for correcting and strengthening the welded prestress of a light alloy medium and heavy plate comprises the following steps:

step S1: processing a welding part, namely performing single-side welding and double-side forming on the light alloy medium plate by adopting welding process parameters, and after welding, keeping the workpiece in a clamping state, fixing and cooling;

step S2: analyzing welding residual stress and deformation, and comprehensively calculating and analyzing the stress state of the welded workpiece and the deformation after releasing welding constraint according to welding heat input, a welding sequence and the workpiece constraint condition;

step S3: designing a prestress shot blasting path and a load, applying unreleased residual stress as a prestress load according to the calculated deformation, and calculating and analyzing an ultrasonic shot blasting load and a shot blasting path required by workpiece correction;

step S4: performing ultrasonic shot blasting shape correction, namely selecting a firing pin with a certain diameter, and performing shot blasting shape correction on the welding seam and the peripheral area of the welding seam according to set amplitude and coverage rate by using ultrasonic shot blasting equipment;

step S5: checking the appearance, supplementing and correcting the shape, disassembling a welding tool, placing a workpiece on the checking tool to check the fitting degree of the workpiece, and supplementing manual shape correction to a local deformation area by using ultrasonic shot blasting equipment;

step S6: ultrasonic strengthening of the surface of the welding seam, selecting a striker with a small diameter, and carrying out uniform impact on the surface of the welding seam after shape correction and a root area, so that the coverage rate of the surface of the welding seam is controlled between 100% and 150%, wherein the root area comprises the welding seam and a heat affected zone.

Specifically, as shown in fig. 1, the welding equipment applied in the welding process comprises a base 1, a side plate seat 2 is fixedly connected to the edge of the top of the base 1, an extrusion type fixed seat 3 is arranged on the inner side of the side plate seat 2, a hydraulic lifting device 7 is fixedly connected to the side of the base 1, the running state of the hydraulic lifting device 7 is controlled through the designed hydraulic lifting device 7, the running state is used for adjusting the height difference of a grinding roller 24 and a welding head 21 relative to the base 1 through controlling the height of the top seat 8, the top seat 8 is fixedly connected to the surface of the hydraulic lifting device 7 corresponding to the position of the base 1, a second threaded rod 9 is arranged above the top seat 8, a through hole 18 is formed in the top of the top seat 8 corresponding to the position of the second threaded rod 9, a second threaded cylinder 14 is connected to the surface of the second threaded rod 9 through a thread, the bottom of the second threaded, the first connecting seat 15 is slidably connected in the through hole 18, a shell 23 is fixedly connected at the bottom of the first connecting seat 15, and the top of the shell 23 is communicated with one end close to the dust suction pipe 19, the grinding roller 24 is arranged inside the shell 23, the surface of the second threaded rod 9 is in threaded connection with a third threaded cylinder 16, the bottom of the third threaded cylinder 16 is fixedly connected with a second connecting seat 17, the second connecting seat 17 is in sliding connection in the through hole 18, the bottom of the second connecting seat 17 is fixedly connected with a welding head 21, by the arranged welding head 21, the second connecting seat 17 controls the welding head 21 to work in the process of sliding in the through hole 18, in the welding process of the welding head 21, the part to be welded is preheated by grinding, and the welding surface is in an inclined plane structure by polishing, so that the thicker light alloy medium and thick plate can be conveniently welded, and the surface of the welding head 21 is fixedly connected with a movable extrusion positioning device 22.

Specifically, as shown in fig. 2, a first bearing 4 is clamped on the surface of the side plate base 2 corresponding to the position of the extrusion type fixed base 3, a first threaded barrel 5 is sleeved in the first bearing 4, a first threaded rod 6 is connected in the first threaded barrel 5 in a threaded manner, the end part of the first threaded rod 6 is fixedly connected with one side close to the extrusion type fixed base 3, a transfer shaft 10 is fixedly connected with the end part of the second threaded rod 9, a second bearing 11 is sleeved on the end part of one transfer shaft 10, the second bearing 11 is clamped on the surface of a bearing seat 12, the bottom of the bearing seat 12 is fixedly connected with the top of a top base 8, the end part of the other transfer shaft 10 is fixedly connected with the end part of an output shaft of a first motor 13, and by designing the side plate base 2, the extrusion type fixed base 3, the first bearing 4, the first threaded barrel 5 and the first threaded rod 6, the first threaded barrel 5 is rotated in the first bearing, receive under the combined action effect of torsion and screw thread occlusive force, alright drive extrusion formula fixing base 3 to deviating from or being close to the direction removal of curb plate seat 2, extrude fixedly through treating two welded light alloy medium plates, can prevent to remove at welding and the in-process light alloy medium plate of polishing, improved welding quality, the top fixed connection of shock mount and footstock 8 is passed through to the bottom of first motor 13 fuselage.

Specifically, as shown in fig. 1, the other end of the dust suction pipe 19 is communicated with the input port of the air pump 20, the dust suction pipe 19 is located in the through hole 18, the bottom of the body of the air pump 20 is fixedly connected with the bottom of the top seat 8 through a shock absorption seat, the polishing roller 24 is fixedly connected to the surface of the rotating shaft 25, the surface of the rotating shaft 25 is sleeved with the third bearing 26, the third bearing 26 is clamped on the surface of the housing 23, the end of the rotating shaft 25 is fixedly connected with the end of the output shaft of the second motor 27, the surface of the body of the second motor 27 is fixedly connected with the surface of the housing 23 close to the housing 23 through the shock absorption seat, the first motor 13 is controlled to operate through the designed first motor 13, the second threaded cylinder 14, the second threaded rod 9, the third threaded cylinder 16, the first connection seat 15, the second connection seat 17, the adapter shaft 10, the second bearing 11 and the bearing seat 12, the first motor 13 can apply torsion on the second threaded rod 9 through the corresponding, in the process, the second threaded rod 9 can drive the other adapter shaft 10 to rotate in the second bearing 11, so that the loading capacity of the second threaded rod 9 is improved, and the stability of the second threaded rod 9 is ensured, and in the rotating process of the second threaded rod 9, under the combined effect of the torque force and the thread engagement force, the first connecting seat 15 and the second connecting seat 17 can be driven to slide in the through hole 18 in the same direction.

Specifically, as shown in fig. 1, a telescopic groove 28 is formed in the bottom of the shell 23, a sealing sleeve 29 is sleeved in the telescopic groove 28, the top of the sealing sleeve 29 is fixedly connected with the top of the inner side of the telescopic groove 28 through a second supporting spring 30, a sliding panel 31 is fixedly connected to the bottom of the sealing sleeve 29, the cross section of the side view of the polishing roller 24 is of a diamond structure, and the model of the polishing roller 24 can be adaptively changed according to the thickness of a light alloy medium-thickness plate to be processed.

Specifically, as shown in fig. 8, the movable type extrusion positioning device 22 includes a roller 221, a sleeve 222 is fixedly connected to the top of the roller 221, a bevel groove 223 is formed in the top of the sleeve 222, a bevel rod 224 is sleeved in the bevel groove 223, a connection ring 225 is fixedly connected to the surface of the bevel rod 224, a dust suction pipe 19, an air pump 20 and a housing 23 are designed, during the sliding process of the first connection seat 15 in the through hole 18, the operation of the air pump 20 is controlled, during the working process of the air pump 20, the dust suction pipe 19 applies suction to the bottom of the housing 23 to quickly guide grinding materials generated by grinding out of the housing 23, the connection ring 225 is fixedly connected to the opposite surface of the roller 221 through a first support spring 226, the first support spring 226 is sleeved on the surfaces of the bevel rod 224 and the sleeve 222, the top of the bevel rod 224 is fixedly connected to the surface of the welding head 21 through a bridge type connection frame 227, through the designed first connecting seat 15, the shell 23, the grinding roller 24, the second motor 27, the sliding panel 31, the telescopic groove 28, the sealing sleeve 29, the third bearing 26 and the rotating shaft 25, the second motor 27 is controlled to operate in the process that the first connecting seat 15 slides in the through hole 18, the second motor 27 can drive the grinding roller 24 to carry out grinding operation through the rotating shaft 25 in the working process, meanwhile, the parts to be welded of the two light alloy medium plates to be processed are ground, after grinding, the side-looking cross-sectional shapes of the two light alloy medium plates to be processed are inclined planes and form a V shape or a trapezoid shape, and the shell 23, the sliding panel 31 and the sealing sleeve 29 can apply pressure on the light alloy medium plates to be processed to weaken the vibration energy generated by grinding on the one hand, and on the other hand, the grinding materials generated by grinding can be prevented from drifting around, and in the grinding process due to the action of friction force, the to-be-welded surface of the light alloy medium and heavy plate may have a higher temperature, the end of the slope bar 224 corresponding to the slope of the slope groove 223 is also set as a slope, and the slope angle of the slope bar 224 is smaller than the slope angle of the slope groove 223.

Specifically, as shown in fig. 7, the cross-sectional shape of the sealing sleeve 29 viewed from above is a rectangular structure, the cross-sectional shapes of the through hole 18, the first connecting seat 15, and the second connecting seat 17 viewed from above are all rectangular structures, and the outer diameters of the first connecting seat 15 and the second connecting seat 17 are both adapted to the inner diameter of the through hole 18, through the designed movable pressing and positioning device 22, the welding head 21 can drive the movable pressing and positioning device 22 to perform synchronous motion in the process of moving and welding under the driving of the second connecting seat 17, and due to the two inclined planes, the two opposite rollers 221 can generate moving pressing force therebetween, and meanwhile, the first supporting spring 226 can apply downward pressure, so that the stability between the two light alloy medium plates to be welded can be ensured.

Specifically, as shown in fig. 13, a database of relationships between the diameter of the striker and the longitudinal and transverse deformation curvatures of the test panel is established before step S3, the amplitude of the striker is in the range of 0 to 100%, the coverage of the striker is in the range of 20% to 80%, and the thickness of the material is in the range of 100% to 150%, and a database of relationships between the thickness of the material and the fatigue properties of the test panel is established before step S6.

Specifically, as shown in fig. 13, the ultrasonic peening apparatus used in step S4 is a multi-striker type working head, and the multi-striker type working head can select a striker with a different diameter by replacing the multi-striker type working head, and the striker type working head is cooled by circulating cooling water, and the shape correction of the peening performed in step S4 selects a striker with a diameter of 2mm, and the range of the striker is 0% to 50%, and the impact angle is 90 °.

Specifically, as shown in fig. 13, the welding method used by the welding head 21 in the welding process includes friction stir welding, laser welding, or arc welding.

Fig. 9 and 10 are schematic diagrams illustrating deformation before and after welding in a constraint release state, and it can be seen that the welding part generates obvious angular deformation, and two sides are tilted upwards.

Fig. 11 and 12 are schematic diagrams of ultrasonic shot peening deformation, and the deformation trend of the ultrasonic shot peening deformation is opposite to that of the deformation after welding, so that the deformation after welding can be corrected by using an ultrasonic shot peening method in a constraint unreleased state, and efficient and low-cost deformation correction is realized.

Referring to fig. 13, fig. 13 shows a flow chart of the post-weld pre-stress shape correction and reinforcement in the present invention, which includes the following steps:

step s 1: processing a welding part of the medium plate, performing single-side welding and double-side forming on the aluminum-clad plate gold with the thickness of 8mm by adopting an MIG welding process, and after welding, keeping a workpiece in a clamping state, fixing and cooling;

step s 2: analyzing welding residual stress and deformation, namely calculating and analyzing the stress state of the welded workpiece and the deformation after the welding constraint is released by utilizing finite element analysis software according to welding parameters, a welding sequence and the workpiece constraint condition;

step s 3: designing a prestress shot blasting path and a load, applying unreleased residual stress as a prestress load according to the calculated welding deformation, and calculating and analyzing the diameter, amplitude, coverage rate and shot blasting path of an ultrasonic shot blasting load striker required by workpiece correction;

step s 4: performing ultrasonic shot blasting shape correction, namely selecting a firing pin with the diameter of 2mm, and performing shot blasting shape correction on the welding seam and the peripheral area of the welding seam according to the set amplitude of 80% and the set coverage rate of 50% by utilizing a working head diagram 14 of ultrasonic shot blasting equipment;

step s 5: checking the appearance, supplementing and correcting the shape, disassembling a welding tool, placing a workpiece on the checking tool to check the fitting degree of the workpiece, and supplementing manual shape correction to a local deformation area by using ultrasonic shot blasting equipment;

step s 6: ultrasonic strengthening of the surface of the welding seam, selection of a small-diameter firing pin, and uniform impact on the surface of the corrected welding seam and the root area including the welding seam and a heat affected zone, so that the coverage rate of the surface of the welding seam is controlled to be 100-120%.

The working principle is as follows: when the device is used, firstly, a welding part is processed, single-side welding and double-side forming are carried out on the light alloy medium plate by adopting welding process parameters, a workpiece is kept in a clamping state and is fixed and cooled after welding, when the device is used for welding the light alloy medium plate, the first thread cylinder 5 is rotated to rotate in the first bearing 4, under the combined action of torsion and thread occlusion force, the extrusion type fixing seat 3 can be driven to move towards the direction away from or close to the side plate seat 2, the light alloy medium plate can be prevented from moving in the welding and polishing processes by extruding and fixing the two light alloy medium plates to be welded, the welding quality is improved, the operation state of the hydraulic lifting device 7 is controlled, the device is used for controlling the operation of the first motor 13 by controlling the height difference between the grinding roller 24 and the welding head 21 relative to the base 1 through the height adjustment of the top seat 8, the first motor 13 can apply torsion to the second threaded rod 9 through the corresponding adapter shaft 10 in the working process, and in the process, the second threaded rod 9 can drive the other adapter shaft 10 to rotate in the second bearing 11 to improve the load capacity of the second threaded rod 9 and ensure the stability of the second threaded rod 9, while the second threaded rod 9 can simultaneously drive the first connecting seat 15 and the second connecting seat 17 to slide in the through hole 18 in the same direction under the combined action effect of the torsion and the thread engagement force in the rotating process, the first connecting seat 15 controls the second motor 27 to operate in the process of sliding in the through hole 18, the second motor 27 can drive the grinding roller 24 to perform grinding operation through the rotating shaft 25 in the working process, and simultaneously perform grinding operation on to-be-welded parts of two to-be-machined light alloy medium plates, and after grinding, the cross-sectional shapes of the two light alloy medium plates to be processed are inclined planes which are in a V shape or a trapezoid shape, on one hand, the shell 23, the sliding panel 31 and the sealing sleeve 29 can apply pressure on the light alloy medium plates to be processed to weaken vibration energy generated by grinding, on the other hand, grinding materials generated by grinding can be prevented from floating around, in the grinding process, due to the action of friction force, the to-be-welded surfaces of the light alloy medium plates have higher temperature, the air pump 20 is controlled to operate, in the working process, the air pump 20 can apply suction to the bottom of the shell 23 through the dust suction pipe 19 to quickly guide out the grinding materials generated by grinding from the shell 23, in the sliding process of the second connecting seat 17 in the through hole 18, the welding joint 21 is controlled to work, in the welding process, the to-be-welded parts are preheated in a grinding mode, the welding surface is made to be an inclined surface structure by polishing, which is convenient for welding thicker light alloy medium and heavy plates, the welding head 21 can drive the movable extrusion positioning device 22 to synchronously act in the process of moving welding under the drive of the second connecting seat 17, and because of the two inclined surfaces, two opposite rollers 221 can generate moving extrusion force between the two, meanwhile, the first supporting spring 226 can be used for applying downward pressure, so that the stability between the two light alloy medium and heavy plates to be welded can be ensured, then the residual stress and deformation analysis is carried out, the stress state of the welded workpiece and the deformation after the release of welding constraint are comprehensively calculated and analyzed according to the welding heat input, the welding sequence and the workpiece constraint condition, and the prestress shot blasting path and load design are carried out according to the prestress analysis result, according to the calculated deformation, applying unreleased residual stress as a prestress load, calculating and analyzing an ultrasonic shot blasting load and a shot blasting path required by workpiece correction, performing ultrasonic shot blasting shape correction, selecting a firing pin with a certain diameter, performing shot blasting shape correction on a weld joint and a weld joint peripheral region according to set amplitude and coverage rate by using ultrasonic shot blasting equipment, performing shape inspection and supplementary shape correction, disassembling a welding tool, placing the workpiece on the inspection tool to inspect the joint degree of the workpiece, performing supplementary manual shape correction on a local deformation region by using the ultrasonic shot blasting equipment, finally performing ultrasonic reinforcement on the surface of the weld joint, selecting a firing pin with a small diameter, and performing uniform impact on the corrected weld joint surface and a root region to control the coverage rate of the weld joint surface between 100% and 150%, wherein the root region comprises the weld joint and a heat affected zone.

The above description is only for the preferred embodiment of the present invention, but the scope of the present invention is not limited thereto, and any person skilled in the art should be able to cover the technical scope of the present invention and the equivalent alternatives or modifications according to the technical solution and the inventive concept of the present invention within the technical scope of the present invention.