阅读说明：本技术 一种提高回转体零件焊缝力学性能的装置与方法 (Device and method for improving mechanical property of welding seam of revolving body part ) 是由 任旭东 陈嘉男 周王凡 童照鹏 顾嘉阳 刘怀乐 孙禺州 胡文景 于 2019-08-05 设计创作，主要内容包括：本发明涉及一种提高回转体零件焊缝力学性能的装置与方法。包括激光冲击强化系统、PLC控制系统与夹具装置,滚珠丝杠机构与伺服电机相连来调整工件高度,喷水装置给激光冲击强化焊缝时提供流水作为约束层；回转体零件被位于两端的机械手加紧,机械手与步进电机相连可通过PLC控制系统控制转动角度,步进电机下方的转动机构调整工件倾斜角度,使得光斑能冲击到焊缝的不同位置,达到冲击强化的目的。本发明可加工回转体零件范围广,焊缝位置不限,冲击诱导的高温等离子产生高压冲击波作用在焊缝上,可以产生较深的残余应力并细化晶粒,表面产生纳米晶,能够显著提升焊缝的力学性能,延长其使用寿命。(The invention relates to a device and a method for improving the mechanical property of a welding seam of a revolving body part. The device comprises a laser shock peening system, a PLC control system and a clamp device, wherein a ball screw mechanism is connected with a servo motor to adjust the height of a workpiece, and a water spraying device provides flowing water as a restraint layer for laser shock peening of a welding seam; the revolving body part is clamped by the mechanical arms positioned at the two ends, the mechanical arms are connected with the stepping motor, the rotating angle can be controlled by the PLC control system, and the rotating mechanism below the stepping motor adjusts the inclination angle of the workpiece, so that light spots can impact different positions of a welding line, and the purpose of impact reinforcement is achieved. The invention has wide range of machinable revolving body parts, unlimited welding seam position, deeper residual stress and refined crystal grains under the action of high-pressure shock waves generated by impact-induced high-temperature plasma on the welding seam, nanocrystalline generated on the surface, remarkably improved mechanical property of the welding seam and prolonged service life.)

1. The device for improving the mechanical property of the welding seam of the revolving body part is characterized by comprising a laser generating device and a guide rail (17), wherein a first servo motor (16) is arranged on the right side of the guide rail (17), a second servo motor (20) is arranged on the left side of the guide rail (17), the first servo motor (16) controls a first workbench (15) to move left and right on the guide rail (17), and the second servo motor (20) controls a second workbench (19) to move left and right on the guide rail (17); the first workbench (15) is connected with a third servo motor (14), and the third servo motor (14) is connected with the first ball screw mechanism (9) through a first coupler (13);

the first ball screw mechanism (9) is connected with the first connecting plate (12) on a ball nut; a first rotating mechanism (11) is arranged on the first connecting plate (12); the first rotating mechanism (11) is connected with the first stepping motor (10) at the bottom; the first stepping motor (10) is connected with the first manipulator (8); a fourth servo motor (18) is connected to the second workbench (19), and the fourth servo motor (18) is connected with a second ball screw mechanism (22) through a second coupler (21);

the second ball screw mechanism (22) is connected with a second connecting plate (23) on a ball nut; a second rotating mechanism (24) is arranged on the second connecting plate (23); the second rotating mechanism (24) is connected with a second stepping motor (25) at the bottom; the second stepping motor (25) is connected with a second mechanical arm (27).

2. The device for improving the mechanical property of the welding seam of the revolving body part according to claim 1, wherein the first servo motor (16), the second servo motor (20), the third servo motor (14), the fourth servo motor (18), the first stepping motor (10), the second stepping motor (25), the first rotating mechanism (11) and the second rotating mechanism (24) are connected with a PLC control system (26) through data connecting lines (28).

3. The device for improving the mechanical property of the welding line of the revolving body part according to claim 1 or 2, characterized in that the laser generating device comprises a laser generator (1), and a beam expanding lens (2) is positioned right at the right side of the laser generator (1) and is used for expanding the incident high-energy laser into a parallel laser beam (3); the light guide system (4) reflects the parallel laser beams (3) to a focusing lens (5), and the focusing lens (5) focuses the parallel laser beams (3) into light spots.

4. The device for improving the mechanical property of the welding seam of the rotary body part according to the claim 1 or 2, characterized by further comprising a water spraying device (6).

5. A method for improving mechanical properties of welding seams of revolving body parts comprises the following steps:

s1: cleaning the welding seam of the revolving body workpiece (7) to remove dirt and burrs on the surface;

s2: coating ethyl silicate black paint on the welding seam, and adjusting various parameters of the laser;

s3: after the ethyl silicate black paint is cured, the first servo motor (16) and the second servo motor (20) are controlled to work by the PLC control system (26) so that the first workbench (15) and the second workbench (19) are separated by a proper distance,

s4: the PLC control system (26) controls the third servo motor (14) and the fourth servo motor (18) to work, and drives the first ball screw (9) and the second ball screw mechanism (22) to move up and down, so that the first connecting plate (12) and the second connecting plate (23) are kept horizontal;

the PLC control system (26) controls the first rotating mechanism (11) and the second rotating mechanism (24) to rotate and keep the first manipulator (8) and the second manipulator (27) horizontal;

s5: clamping a revolving body workpiece (7) by using a first manipulator (8) and a second manipulator (27), controlling a first rotating mechanism (11) and a second rotating mechanism (24) to rotate by using a program in a PLC (programmable logic controller) control system (26), and controlling a third servo motor (14) and a fourth servo motor (18) to work so that a first ball screw (9) and a second ball screw mechanism (22) move up and down to be matched with the rotation of the first rotating mechanism (11) and the second rotating mechanism (24), so that a welding seam of the revolving body workpiece (7) is positioned on a plane vertical to laser;

s6: the first servo motor (16) and the second servo motor (20) are controlled to work through a PLC (programmable logic controller) control system (26), so that the first workbench (15) and the second workbench (19) synchronously move, and light spots are aligned to welding seams; opening the water flowing device (6) and taking flowing water as a laser shock strengthened restraint layer;

s7: the first servo motor (16) and the second servo motor (20) are controlled to work simultaneously through a program in a PLC control system (26), so that the first working table (15) and the second working table (19) synchronously move to enable laser to carry out impact strengthening from left to right from the left edge of a welding seam, the movement speed is ensured to be 0.5mm/s, the overlapping rate of light spots is controlled to be 50 percent by a program, when the light spot reaches the right edge, the PLC control system (26) controls the first stepping motor (10) and the second stepping motor (25) to synchronously rotate clockwise for 2.5 degrees, the first servo motor (16) and the second servo motor (20) are controlled to work simultaneously through the program of a PLC control system (26), the first workbench (15) and the second workbench (19) move reversely and synchronously, so that the laser is subjected to impact strengthening from right to left from the edge of the right side of the welding seam, and other parameters are ensured to be unchanged;

repeating the steps in sequence until all welding seam areas are impacted, and finishing the first impact strengthening process;

s8: turning off the laser generator (1), turning off the water spraying device (6), taking down the revolving body workpiece (7), cleaning the ethyl silicate black paint, and recoating; repeating the steps, and performing secondary impact reinforcement;

s9: repeating the above steps to perform a third impact reinforcement;

s10: after the impact strengthening is finished, a welding seam area is polished by using precise sand paper, so that the surface roughness improvement caused by the laser impact strengthening is reduced.

Technical Field

The invention belongs to the technical field of laser processing, and particularly relates to a device and a method for specially improving the mechanical property of a revolving body weld joint.

Background

Welding is the most common processing mode in the current industrial field, and welding methods can be divided into three categories, namely fusion welding, pressure welding and brazing according to the state of metal in a welding process and the characteristics of the process. The processes are widely applied to the fields of shipbuilding, aerospace, automobiles, electronics and the like, and can be seen to occupy an important position in national economy by welding. Compared with the common connection mode, extra materials are mostly consumed, 15% -20% of materials can be saved by welding parts, workpieces with complex structures cannot be directly processed by casting, forging and other methods, and the production period can be greatly saved by adopting the welding mode.

However, the welding part inevitably has certain defects, and the welding residual stress, the low micro-hardness and the existence of coarse microstructure caused by welding heat greatly weaken the mechanical property, the corrosion resistance and the like of the welding seam of the welding part.

Conventional methods such as rolling, explosive impact or heat treatment may be used to increase the strength of the weld in the area of weakness, but these methods are often impractical or undesirable. Therefore, what kind of novel method is adopted to improve the mechanical property of the welding seam at the welding position becomes a problem to be solved urgently by those in the technical field at present.

The laser shock peening technology is an advanced high-strain peening technology with high efficiency, local peening can be performed on a certain specific area of a workpiece, and high-energy shock waves generated by explosion of a laser irradiation absorption layer can be applied to the surface of a base metal

And a residual compressive stress layer with a certain depth is excited, the residual tensile stress on the surface of the welding seam of the welding part is effectively reduced or eliminated, meanwhile, the coarse microstructure on the surface of the welding seam and the coarse microstructure in the welding seam area can be refined, the generation of crack sources is inhibited, and the mechanical property at the welding seam of the welding part is greatly improved.

General enterprises use a multi-axis manipulator to perform laser shock peening treatment on a welding part, but the method has poor positioning accuracy and high requirement on the deflection of a slender part. The slight shaking can be generated when the laser impact of the slender part is processed, which is not beneficial to generating good strengthening effect.

Disclosure of Invention

The invention aims to provide a device and a method for improving the mechanical property of a welding seam of a revolving body part, which are used for prolonging the service life of the revolving body part and being used for more severe working conditions.

In order to achieve the aim, the technical scheme adopted by the invention is that the device for improving the mechanical property of the welding seam of the revolving body part comprises a laser generating device and a guide rail, wherein a first servo motor is arranged on the right side of the guide rail, a second servo motor is arranged on the left side of the guide rail, the first servo motor controls a first workbench to move left and right on the guide rail, and the second servo motor controls a second workbench to move left and right on the guide rail; and the first workbench is connected with a third servo motor, and the third servo motor is connected with the first ball screw mechanism through a first coupler. The first ball screw mechanism is connected with the first connecting plate on the ball nut; the first connecting plate is provided with a first rotating mechanism; the first rotating mechanism is connected with the first stepping motor at the bottom; the first stepping motor is connected with the first manipulator; and a fourth servo motor is connected to the second workbench and is connected with the second ball screw mechanism through a second coupler. The second ball screw mechanism is connected with the second connecting plate on a ball nut; the second rotating mechanism is arranged on the second connecting plate; the second rotating mechanism is connected with the second stepping motor at the bottom; and the second stepping motor is connected with the second manipulator.

In the above scheme, the first servo motor, the second servo motor, the third servo motor, the fourth servo motor, the first stepping motor, the second stepping motor, the first rotating mechanism and the second rotating mechanism are connected with the PLC control system through data connecting lines.

In the above scheme, the laser generating device comprises a laser generator, and the beam expanding lens is positioned right to the right of the laser generator and is used for expanding incident high-energy laser into parallel laser beams; and the light guide system reflects the parallel laser beams onto a focusing lens, and the focusing lens focuses the parallel laser beams into light spots.

In the above scheme, the device further comprises a water spraying device.

The invention also provides a method for improving the mechanical property of the welding line of the revolving body part, which comprises the following steps: s1: cleaning the welding seam of the revolving body workpiece to remove dirt and burrs on the surface; s2: coating ethyl silicate black paint on the welding seam, and adjusting various parameters of the laser; s3: after the ethyl silicate black paint is cured, controlling the first servo motor and the second servo motor to work through a PLC control system, so that the first workbench and the second workbench are away from each other by a proper distance, S4: the PLC control system controls the third servo motor and the fourth servo motor to work and drives the first ball screw and the second ball screw mechanism to move up and down, so that the first connecting plate and the second connecting plate are kept horizontal. The PLC control system controls the first rotating mechanism and the second rotating mechanism to rotate to keep the first manipulator and the second manipulator horizontal; s5: clamping a revolving body workpiece by using a first manipulator and a second manipulator, controlling a first rotating mechanism and a second rotating mechanism to rotate by a program in a PLC control system, and controlling a third servo motor and a fourth servo motor to work so that a first ball screw and a second ball screw mechanism move up and down to be matched with the rotation of the first rotating mechanism and the second rotating mechanism, so that a welding seam of the revolving body workpiece is positioned on a plane vertical to laser; s6: the first servo motor and the second servo motor are controlled to work through the PLC control system, so that the first workbench and the second workbench move synchronously, and light spots are aligned to welding seams; opening the water flowing device to take flowing water as a laser shock strengthened constraint layer; s7: the first servo motor and the second servo motor are controlled to work simultaneously through a program in the PLC control system, so that the first workbench and the second workbench move synchronously, the laser is enabled to impact-reinforce from left to right at the edge of the left side of a welding seam, the movement speed is guaranteed to be 0.5mm/s, the overlapping rate of light spots is controlled to be 50% through the program, when the light spots reach the edge of the right side, the first stepping motor and the second stepping motor are controlled to synchronously rotate clockwise for 2.5% through the PLC control system, the first servo motor and the second servo motor are controlled to work simultaneously through the program of the PLC control system, the first workbench and the second workbench move reversely and synchronously, the laser is enabled to impact-reinforce from right to left at the edge of the right side of the welding seam, and other parameters are guaranteed to be unchanged. Repeating the steps in sequence until all welding seam areas are impacted, and finishing the first impact strengthening process; s8: turning off the laser generator, turning off the water spraying device, taking down the revolving body workpiece, cleaning the ethyl silicate black paint, and recoating; repeating the steps, and performing secondary impact reinforcement; s9: repeating the above steps to perform a third impact reinforcement; s10: after the impact strengthening is finished, a welding seam area is polished by using precise sand paper, so that the surface roughness improvement caused by the laser impact strengthening is reduced.

The invention has the beneficial effects that: the invention has the advantages of wide range of machinable revolving body parts, unlimited welding seam position, simple structure and convenient operation, high-temperature plasma induced by multiple times of laser impact on the welding seam coated with the ethyl silicate black paint generates high-pressure shock waves to act on the welding seam, deeper residual stress can be generated, crystal grains can be refined, nanocrystalline is generated on the surface, the mechanical property of the welding seam can be obviously improved, and the service life of the welding seam is prolonged.

Drawings

Fig. 1 is a schematic diagram of the structure of the present invention.

Fig. 2 is a schematic view of a rotary workpiece.

In the figure: 1. a laser generator; 2. a beam expanding lens; 3. a parallel laser beam; 4. a light guide system; 5. a focusing lens; 6. a water spraying device; 7. a revolving body workpiece; 8. a first manipulator; 9. a first ball screw mechanism; 10. a first stepper motor; 11. a first rotating mechanism; 12. a first connecting plate; 13. a first coupling; 14. a third servo motor; 15. a first table; 16. a first servo motor; 17. a guide rail; 18. a fourth servo motor; 19. a second table; 20. a second servo motor; 21. a second coupling; 22. a second ball screw mechanism; 23. a second connecting plate; 24. a second rotating mechanism; 25. a second stepping motor; a PLC control system; 27. a second manipulator; 28. and a data connecting line.

Detailed Description

The invention is described in further detail below with reference to the examples of the drawings.

As shown in fig. 1, a beam expanding lens 2 is located right and right of a laser generator 1, and is configured to expand incident high-energy laser into a parallel laser beam 3; the light guide system 4 reflects the parallel laser beams 3 to the focusing lens 5, and the focusing lens 5 focuses the parallel laser beams 3 into a light spot. A first servo motor 16 is arranged on the right side of the guide rail 17, a second servo motor 20 is arranged on the left side of the guide rail 17, the first servo motor 16 controls the first workbench 15 to move left and right on the guide rail 17, and the second servo motor 20 controls the second workbench 19 to move left and right on the guide rail 17. And a third servo motor 14 is connected to the first workbench 15, and the third servo motor 14 is connected with the first ball screw mechanism 9 through a first coupler 13. The first ball screw mechanism 9 is connected with the first connecting plate 12 on a ball nut; the first connecting plate 12 is provided with a first rotating mechanism 11; the first rotating mechanism 11 is connected with the first stepping motor 1) at the bottom; the first stepping motor 10 is connected with the first manipulator 8; and a fourth servo motor 18 is connected to the second workbench 19, and the fourth servo motor 18 is connected with a second ball screw mechanism 22 through a second coupler 21. The second ball screw mechanism 22 is connected with the second connecting plate 23 on a ball nut; a second rotating mechanism 24 is arranged on the second connecting plate 23; the second rotating mechanism 24 is connected with a second stepping motor 25 at the bottom; the second stepping motor 25 is connected to a second robot 27. The first servo motor 16, the second servo motor 20, the third servo motor 14, the fourth servo motor 18, the first stepping motor 10, the second stepping motor 25, the first rotating mechanism 11 and the second rotating mechanism 24 are connected with a PLC control system 26 through a data connection line 28.

The method for improving the mechanical property of the welding line of the revolving body part by utilizing the novel method comprises the following steps: s1: cleaning the welding seam of the revolving body workpiece 7 (the specific shape is shown in figure 2), and removing dirt and burrs on the surface; s2: coating ethyl silicate black paint on the welding seam, and adjusting various parameters of the laser; s3: after the ethyl silicate black paint is cured, controlling the first servo motor 16 and the second servo motor 20 to work through the PLC control system 26, so that the first workbench 15 and the second workbench 19 are spaced at a proper distance, S4: the PLC control system 26 controls the third servo motor 14 and the fourth servo motor 18 to work, and drives the first ball screw 9 and the second ball screw mechanism 22 to move up and down, so that the first connecting plate 12 and the second connecting plate 23 are kept horizontal. The PLC control system 26 controls the first and second rotating mechanisms 11 and 24 to rotate, and keeps the first and second manipulators 8 and 27 horizontal. S5: clamping a revolving body workpiece 7 by using a first manipulator 8 and a second manipulator 27, controlling a first rotating mechanism 11 and a second rotating mechanism 24 to rotate by using a program in a PLC (programmable logic controller) control system 26, and controlling a third servo motor 14 and a fourth servo motor 18 to work so that a first ball screw 9 and a second ball screw mechanism 22 move up and down to be matched with the rotation of the first rotating mechanism 11 and the second rotating mechanism 24, so that the revolving body workpiece 7 is in a proper angle; s6: the first servo motor 16 and the second servo motor 20 are controlled to work by the PLC control system 26, so that the first workbench 15 and the second workbench 19 move synchronously to align the light spot with the welding seam. And opening the water flowing device 6 to enable flowing water to be used as a restraint layer for laser shock strengthening. S7: the first servo motor 16 and the second servo motor 20 are controlled to work simultaneously through a program in the PLC control system 26, so that the first workbench 15 and the second workbench 19 move synchronously, the laser is enabled to impact and strengthen from left to right on the left side edge of a welding seam, the movement speed is guaranteed to be 0.5mm/s, the overlapping rate of a light spot is controlled to be 50% through the program, when the light spot reaches the right side edge, the first stepping motor 10 and the second stepping motor 25 are controlled to rotate clockwise for 2.5 degrees synchronously through the PLC control system 26, the first servo motor 16 and the second servo motor 20 are controlled to work simultaneously through the program of the PLC control system 26, the first workbench 15 and the second workbench 19 move reversely and synchronously, the laser is enabled to impact and strengthen from right to left on the right side edge of the welding seam, and other parameters are guaranteed to be unchanged. And repeating the steps in sequence until all the welding seam areas are impacted, and finishing the first impact strengthening process. S8: turning off the laser generator 1, turning off the water spraying device 6, taking down the revolving body workpiece 7, cleaning the ethyl silicate black paint, and recoating; repeating the steps and carrying out secondary impact reinforcement. S9: repeating the above steps, performing the third impact reinforcement, S10: after the impact strengthening is finished, a welding seam area is polished by using precise sand paper, so that the surface roughness improvement caused by the laser impact strengthening is reduced.