A coaxial wire powder welding device and welding method with zoned control of welding heat input

Abstract

This invention discloses a wire-powder coaxial welding device and method with zoned control of welding heat input, belonging to the field of welding technology. The wire-powder coaxial welding device with zoned control of welding heat input includes a laser head and a nozzle. Inside the laser head housing is a beam-splitting mechanism for splitting the laser beam. Behind the beam-splitting mechanism is an intensity adjustment mechanism for adjusting the power of each laser beam individually. Behind the intensity adjustment mechanism is a focusing structure for focusing each laser beam. Inside the housing is a wire feed tube, which is coaxial with the powder feed tube on the nozzle. By using the wire-powder coaxial welding device and method with zoned control of welding heat input described in this invention, a single laser beam is divided into multiple beams by the beam-splitting mechanism, and the power of each laser beam is adjusted by the intensity adjustment mechanism, achieving zoned adjustment of laser power, which is beneficial for improving weld quality.

Description

Technical Field

[0001] This invention relates to the field of welding technology, and in particular to a wire-powder coaxial welding device and welding method with zoned control of welding heat input. Background Technology

[0002] Laser welding is a precision machining technique that uses a high-power-density laser beam as a heat source to melt and join materials (usually metals or thermoplastics). The high-intensity laser beam generated by the laser is focused onto the workpiece surface through an optical system (such as lenses or mirrors), forming a very small and highly concentrated spot of light. This high energy density causes the material to rapidly heat up to above its melting point in a very short time, thus achieving localized melting. Current laser welding methods mostly use a single light source, concentrating energy on the tip of the welding wire and the weld area, causing the metal to melt and then solidify, forming a continuous weld. Single light sources have the following problems: 1. For aluminum alloys, laser welding exhibits severe fluctuations, resulting in an unstable welding process and welding defects such as porosity; 2. For various alloy materials, the single beam cannot control the heat in small areas of the weld; 3. The energy distribution required for the simultaneous feeding of wire and powder is large, and the irradiation area of ​​a single light source is limited, resulting in poor melting and forming effects.

[0003] Existing patent 202411098871.1 discloses an ultrasonic-assisted ring laser coaxial wire feeding welding device and method. A clamping mechanism is installed above a support frame, a vibration mechanism is installed on the support frame, and a welding mechanism is installed above the support frame. The welding mechanism is connected to a robotic arm and includes an ultrasonic mechanism. A connecting tube is located at the center of the welding mechanism's fixed base, and a wire feeding tube is installed inside the connecting tube. Several lasers are evenly arranged on the fixed base, and an entrance channel for the lasers to pass through the fixed base is provided inside. The circle containing the lasers is coaxial with the wire feeding tube. A nozzle is located below the fixed base, and a cavity is provided inside the nozzle for the wire feeding tube and lasers to pass through the nozzle. The aforementioned ultrasonic-assisted ring laser coaxial wire feeding welding device and method can solve the problems of poor adaptability and poor ultrasonic processing effect of existing welding devices. The patent, by setting multiple lasers and adjusting the power of different lasers, can achieve control of the intensity of different zones. However, setting multiple lasers not only increases the size of the welding device but also increases the cost. Summary of the Invention

[0004] The purpose of this invention is to provide a wire-powder coaxial welding device and welding method with zoned control of welding heat input. By setting a beam splitting mechanism to divide a laser beam into multiple beams, and by adjusting the power of each laser beam through an intensity adjustment mechanism, the laser power can be zoned and adjusted, which is beneficial to improving the weld quality; it also reduces the number of lasers, which is beneficial to reducing the size of the laser head and simplifying the laser head structure.

[0005] To achieve the above objectives, the present invention provides a wire-powder coaxial welding device with zoned control of welding heat input, comprising a laser head and a nozzle. One end of the laser head is connected to a laser generator via an optical fiber, and the other end of the laser head is connected to the nozzle. The laser head includes a housing, inside which is a beam-splitting mechanism for splitting the laser beam. Behind the beam-splitting mechanism is an intensity adjustment mechanism for adjusting the power of each laser beam. Behind the intensity adjustment mechanism is a focusing structure for focusing each laser beam. Inside the housing is a wire feeding tube, and the circumference formed by the wire feeding tube and the powder feeding tube on the nozzle is coaxial.

[0006] Preferably, the beam splitting mechanism includes a plane lens located below the mounting base. The optical fiber is fixed on the mounting base. A first reflecting mirror is disposed below the plane lens to reflect the optical fiber. Behind the first reflecting mirror are a first flat-top beam shaping mirror and a second flat-top beam shaping mirror to shape the laser beam. Behind the second flat-top beam shaping mirror is a beam splitter to uniformly split the laser beam. Around the beam splitter are second reflecting mirrors to reflect each of the split laser beams. The second reflecting mirrors correspond one-to-one with the split laser beams. An intensity adjustment mechanism is located behind the second reflecting mirror. The laser beam adjusted by the intensity adjustment mechanism is misaligned with the wire feeding tube.

[0007] Preferably, the intensity adjustment mechanism includes a mounting plate, on which intensity adjustment units corresponding to the laser beams are provided; the intensity adjustment unit includes a mounting hole on the mounting plate, a neutral density filter is rotatably disposed in the mounting hole, and the mounting plate is provided with an angle adjustment structure for adjusting the angle of the neutral density filter. By changing the angle of the neutral density filter, the thickness of the laser passing through the neutral density filter is changed, thereby adjusting the intensity of the laser.

[0008] Preferably, the angle adjustment structure includes a sliding plate, and the mounting plate is provided with a sliding structure that drives the sliding plate to slide horizontally; the sliding plate is provided with a connecting rod, the connecting rod is located on both sides of the central density filter, the connecting rod is provided with a long strip-shaped sliding groove, one end of the central density filter is provided with a fixing block, the fixing block is provided with a pin, the pin is located in the sliding groove and is slidably connected to the sliding groove;

[0009] The sliding structure includes a lead screw, which is rotatably connected to a mounting plate. The slide plate is threadedly connected to the lead screw. A micro motor that drives the lead screw to rotate is provided on the mounting plate. A fixed plate is provided on one side of the mounting plate. The fixed plate is connected to the mounting plate through a guide rod. The guide rod is parallel to the lead screw. A guide hole is provided on the slide plate for the guide rod to pass through. The lead screw is rotatably connected to the fixed plate.

[0010] Preferably, the center density filter is a wedge-shaped block, with a rotating shaft on both sides of the center density filter. A slot for placing the rotating shaft is provided on the mounting plate, and a fixing seat is provided on one side of the mounting plate. The fixing seat has a semi-circular groove that matches the slot. The rotating shaft is located in the circular cavity formed by the slot and the semi-circular groove. The rotating shaft is rotatably connected to the mounting plate and the fixing seat.

[0011] Preferably, the housing is provided with an insertion hole for inserting the mounting plate, the insertion hole is provided with a clearance hole for avoiding the micro motor and the fixing plate, the inner wall of the housing is provided with a slot for inserting the mounting plate, the top of the mounting plate is provided with a limiting plate, the limiting plate is located outside the housing, the top of the limiting plate is provided with a handle, and the limiting plate is connected to the housing by a locking structure.

[0012] Preferably, the locking structure includes connecting posts disposed on the lower surface of the limiting plate, the connecting posts being located on both sides of the mounting plate, connecting holes for inserting the connecting posts being provided on the housing, through holes for passing through the side walls of the connecting holes, the locking pin being perpendicular to the connecting posts, and locking holes for inserting the locking pin being provided on the connecting posts, a fixing sleeve being provided on the side walls of the housing, a handle being slidably disposed inside the fixing sleeve, the handle being connected to the locking pin via a guide post, a positioning plate being provided inside the fixing sleeve, a hole for passing through the positioning plate, and a spring being provided between the positioning plate and the locking pin for inserting the locking pin into the locking hole; a guide groove being provided on the inner wall of the fixing sleeve along the axial direction of the fixing sleeve, an arc-shaped groove being provided at the outer end of the guide groove along the circumference of the fixing sleeve, and a guide block being provided on the side wall of the handle, the guide block being located in the guide groove and slidably connected to both the guide groove and the arc-shaped groove.

[0013] Preferably, the focusing structure includes a third reflecting mirror, and a focusing mirror is disposed below the third reflecting mirror. Both the third reflecting mirror and the focusing mirror are provided with through holes for the wire feeding tube to pass through.

[0014] Preferably, the nozzle includes a body, the top of which is fixedly connected to the bottom of the housing. The body has an internal cavity with a powder feeding pipe located at the center of the cavity. A sleeve with a bottom opening is provided outside the powder feeding pipe. The sleeve is connected to an external protective gas cylinder via an air inlet pipe at the bottom of the housing. Several powder feeding pipes are provided on the side wall of the body and are connected to an external welding powder box. Several air supply pipes are also provided on the side wall of the body and are connected to an external protective gas cylinder. The air supply pipes are located outside the powder feeding pipes. A flow equalization plate is provided at the bottom of the air supply pipes, with several air vents evenly distributed on the flow equalization plate. An annular air outlet chamber is provided at the bottom of the body, connected to the air supply pipes via air vents. The air vents have a funnel-shaped structure with a small top opening and a large bottom opening.

[0015] The welding method of the above-mentioned wire powder coaxial welding device with zoned control of welding heat input includes the following steps:

[0016] S1. Insert the pin of the neutral density filter into the slide groove, put the rotating shaft of the neutral density filter into the slot, place the fixing seat on one side of the mounting plate, and fix the fixing seat to the mounting plate with screws to complete the installation of the neutral density filter on the mounting plate.

[0017] S2. Pull the locking pin outward by the handle, the spring is compressed, and the guide block on the handle slides into the arc groove along the guide groove. Rotate the handle to lock the guide block in the arc groove. Insert the mounting plate into the slot through the insertion hole, insert the connecting post into the connecting hole, rotate the handle in the opposite direction, and the guide block slides from the arc groove into the guide groove. The spring returns to its original position, and the spring drives the locking pin to insert into the lock hole, locking the connecting post in the connecting hole.

[0018] S3. Mount the laser head on the robotic arm and set the laser generator power and welding speed. Turn on the laser generator. The laser beam from the laser generator enters the laser head through an optical fiber. After passing through a plane lens, the laser beam is reflected by the first reflecting mirror. The reflected laser beam then passes through the first and second flat-top light shaping mirrors and enters the beam splitter. The beam splitter evenly splits the laser beam into multiple beams. The split laser beam is reflected by the second reflecting mirror and enters the neutral density filter for intensity adjustment. Then, after being reflected by the third reflecting mirror, it exits the laser head through the focusing mirror and irradiates the weld seam for heating.

[0019] S4. The micro motor drives the lead screw to rotate, and the lead screw drives the slide plate to slide through the thread engagement. The slide plate drives the connecting rod to move synchronously. The connecting rod drives the neutral density filter to rotate around the rotating shaft through the pin. The pin slides along the slide groove, changing the propagation length of the laser in the neutral density filter, thereby adjusting the intensity of each laser beam, and then adjusting the intensity of each area of ​​the laser spot irradiating the weld.

[0020] S5. The temperature and morphology of the molten pool are detected in real time by an industrial camera and an infrared thermal imager mounted on a robotic arm or laser head, and the detection results are sent to an external control system. The control system adjusts the intensity of each laser beam zone according to the real-time temperature distribution.

[0021] The advantages and positive effects of the wire-powder coaxial welding device and welding method with zoned control of welding heat input described in this invention are as follows:

[0022] 1. The present invention has a beam splitting mechanism inside the housing, which splits a laser beam into several uniform laser beams, reducing the number of laser generators and helping to reduce costs.

[0023] 2. The present invention has an intensity adjustment mechanism inside the housing. The intensity adjustment mechanism adjusts each laser beam independently, thereby independently adjusting the intensity of each zone in the laser spot to meet the welding temperature requirements of different welding powders, welding wires and base materials, which is beneficial to improving the weld quality. Furthermore, different laser powers result in different temperature gradients in the molten pool. Different weld structures can be obtained under different temperature gradients, thereby achieving controllable weld micro-region structure and improving welding performance.

[0024] 3. This invention uses a micro motor to drive a lead screw to rotate. The lead screw adjusts the distance between the sliding plate and the mounting plate, thereby driving the neutral density filter to rotate along the shaft via a pin. This adjusts the length of the laser light passing through the neutral density filter. The longer the laser light passes through the neutral density filter, the more its intensity attenuates. The length of the laser light passing through the neutral density filter is adjusted by rotating the neutral density filter, making the operation convenient.

[0025] 4. This invention features several powder feeding pipes on the side wall of the main body. These pipes allow for the delivery of welding powder of different compositions to the weld seam, enabling control of the weld composition based on the base material and weld requirements, thus improving weld quality. The combination of the powder feeding pipes and the zoned laser beam allows for the formulation of welding parameters as needed, further enhancing welding quality.

[0026] The technical solution of the present invention will be further described in detail below with reference to the accompanying drawings and embodiments. Attached Figure Description

[0027] Figure 1 This is a schematic diagram of the cross-sectional structure of an embodiment of the present invention;

[0028] Figure 2 This is a three-dimensional structural diagram of an embodiment of the present invention;

[0029] Figure 3 This is a schematic diagram of the shell cross-section structure according to an embodiment of the present invention;

[0030] Figure 4 This is a schematic diagram of the front structure of the mounting plate according to an embodiment of the present invention;

[0031] Figure 5 This is a schematic diagram of the back structure of the mounting plate according to an embodiment of the present invention;

[0032] Figure 6 This is a schematic diagram of the strength adjustment mechanism structure according to an embodiment of the present invention;

[0033] Figure 7 for Figure 6 Enlarged view of A in the middle;

[0034] Figure 8 This is a schematic diagram of the neutral density filter structure according to an embodiment of the present invention;

[0035] Figure 9 This is a schematic diagram of the mounting plate structure according to an embodiment of the present invention;

[0036] Figure 10 This is a schematic diagram of the locking structure according to an embodiment of the present invention;

[0037] Figure 11 This is a schematic diagram of the fixing sleeve structure according to an embodiment of the present invention;

[0038] Figure 12 This is a schematic diagram of the nozzle structure according to an embodiment of the present invention;

[0039] Figure 13 for Figure 12 Enlarged view of B in the middle;

[0040] Figure 14 This is a macroscopic diagram of the weld microstructure of TC4 titanium alloy in an embodiment of the present invention;

[0041] Figure 15 for Figure 14 Enlarged view of region C1;

[0042] Figure 16 for Figure 14 Enlarged view of area C2 in the middle;

[0043] Figure 17 for Figure 14 Enlarged view of C3 area.

[0044] Figure Labels

[0045] 1. Laser head; 11. Housing; 12. Mounting base; 13. Plane lens; 14. First reflecting mirror; 15. First flat-top beam shaping mirror; 16. Second flat-top beam shaping mirror; 17. Beam splitter; 18. Second reflecting mirror; 19. Third reflecting mirror; 110. Focusing mirror; 111. Wire feed tube; 112. Mounting plate; 113. Limiting plate; 114. Insertion hole; 115. Clearance hole; 116. Slot; 117. Mounting hole; 118. Neutral density filter; 119. Fixing base; 120. Slot; 12 1. Shaft; 122. Slide plate; 123. Connecting rod; 124. Slide groove; 125. Pin; 126. Fixing block; 127. Fixing plate; 128. Lead screw; 129. Guide rod; 130. Micro motor; 131. Handle; 132. Connecting column; 133. Connecting hole; 134. Locking pin; 135. Fixing sleeve; 136. Guide column; 137. Positioning plate; 138. Handle; 139. Spring; 140. Guide block; 141. Guide groove; 142. Arc groove; 143. Sleeve; 144. Air inlet pipe;

[0046] 2. Nozzle; 21. Body; 22. Cavity; 23. Powder delivery pipe; 24. Air delivery pipe; 25. Air outlet chamber; 26. Flow equalization plate; 27. Vent hole. Detailed Implementation

[0047] In the description of this invention, it should be noted that the terms "upper," "lower," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, or the orientation or positional relationship commonly used when the product is in use. They are used only for the convenience of describing the invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on the invention. In the description of this invention, it should also be noted that, unless otherwise explicitly specified and limited, the terms "set," "install," and "connect" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal communication between two components. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0048] In this application, unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application pertains. In case of any inconsistency, the meaning as set forth in this specification or derived from the content described herein shall prevail. Furthermore, the terminology used herein is for the purpose of describing embodiments of this application only and is not intended to limit this application. To accurately describe the technical content of this application and to accurately understand the invention, the following explanations or definitions of the terms used in this specification are provided before describing specific embodiments:

[0049] The embodiments of the present invention will now be described in detail with reference to the accompanying drawings.

[0050] like Figure 1 , Figure 2 As shown, a coaxial wire-powder welding device with zoned control of welding heat input includes a laser head 1 and a nozzle 2. One end of the laser head 1 is connected to a laser generator via an optical fiber, and the other end of the laser head 1 is connected to the nozzle 2. The laser head 1 is fixed to an existing six-axis robotic arm, which moves the laser head 1 to weld the workpiece.

[0051] The laser head 1 includes a housing 11. Inside the housing 11 is a beam-splitting mechanism that divides the laser beam into several uniform beams. Behind the beam-splitting mechanism is an intensity adjustment mechanism that adjusts the power of each laser beam independently. This intensity adjustment mechanism allows for independent adjustment of the intensity of each zone within the laser spot, meeting the welding temperature requirements of different welding powders, welding wires, and base materials, thus improving weld quality. Different laser powers result in different temperature gradients in the molten pool, leading to different weld microstructures and enabling controllable weld microstructure, thereby improving welding performance. Behind the intensity adjustment mechanism is a focusing structure that focuses each laser beam. Inside the housing 11 is a wire feed tube 111, which is coaxial with the powder feed tube 23 on the nozzle 2, enabling coaxial powder feeding welding.

[0052] The beam splitting mechanism includes a plane lens 13, which is located directly below the mounting base 12. The mounting base 12 is located at the top of the housing 11, and the optical fiber is fixed to the mounting base 12. Below the plane lens 13, a first reflecting mirror 14 is provided to reflect the optical fiber, thereby changing the direction of the laser. Behind the first reflecting mirror 14, a first flat-top beam shaping mirror 15 and a second flat-top beam shaping mirror 16 are provided to shape the laser beam. Behind the second flat-top beam shaping mirror 16, a beam splitter 17 is provided to uniformly split the laser beam. After being shaped by the first flat-top beam shaping mirror 15 and the second flat-top beam shaping mirror 16, the laser beam can enter the beam splitter 17 in parallel, improving the uniformity of the laser beam splitting by the beam splitter 17. Around the beam splitter 17, second reflecting mirrors 18 are provided to reflect each of the split laser beams, with each second reflecting mirror 18 corresponding to a separate split laser beam. The intensity adjustment mechanism is located behind the second reflector 18. The laser beam adjusted by the intensity adjustment mechanism is misaligned with the wire feeding tube 111 to avoid interference between the wire feeding tube 111 and the laser beam.

[0053] In this embodiment, the beam splitter 17 splits the laser into four laser beams. Four second reflectors 18 are provided, and the four laser beams are located on both sides of the wire feed tube 111. After being reflected by the third reflector 19, the four laser beams are focused by the focusing lens 110 to form a near-circular laser spot composed of four laser zones. The intensity of the four laser zones of the laser spot can be adjusted by the intensity adjustment mechanism, thereby adjusting the laser according to the composition of the welding powder, welding wire and base material, which is beneficial to improving the welding quality.

[0054] like Figure 4 , Figure 5 , Figure 6 , Figure 7 , Figure 9As shown. The intensity adjustment mechanism includes a mounting plate 112, on which intensity adjustment units corresponding to the laser beams are provided. Each intensity adjustment unit includes a mounting hole 117 on the mounting plate 112, within which a neutral density filter 118 is rotatably mounted. The neutral density filter 118 attenuates light of different wavelengths at the same proportion, thereby adjusting the laser energy. The mounting plate 112 is provided with an angle adjustment structure to adjust the angle of the central density filter. By changing the angle of the central density filter, the thickness of the laser passing through the central density filter is changed, thereby adjusting the laser intensity.

[0055] The angle adjustment structure includes a sliding plate 122, and a sliding structure on the mounting plate 112 for driving the sliding plate 122 to slide horizontally. A connecting rod 123 is fixedly mounted on the sliding plate 122, and the connecting rod 123 is located on both sides of the center density filter. The connecting rod 123 is provided with a long strip-shaped sliding groove 124, and a fixing block 126 is fixedly mounted on one end of the center density filter. A pin 125 is fixedly mounted on the fixing block 126, and the pin 125 is located in the sliding groove 124 and slidably connected to the sliding groove 124.

[0056] The sliding structure includes a lead screw 128, which is rotatably connected to a mounting plate 112 via bearings. A sliding plate 122 is threadedly connected to the lead screw 128. A micro motor 130, which drives the lead screw 128 to rotate, is mounted on the mounting plate 112. A fixing plate 127 is mounted on one side of the mounting plate 112, and the fixing plate 127 is fixedly connected to the mounting plate 112 via a guide rod 129. The guide rod 129 is parallel to the lead screw 128, and a guide hole is provided on the sliding plate 122 for the guide rod 129 to pass through. The guide rod 129 guides and limits the sliding of the sliding plate 122. The lead screw 128 is rotatably connected to the fixing plate 127.

[0057] The micro motor 130 drives the lead screw 128 to rotate, and the lead screw 128 adjusts the distance between the slide plate 122 and the mounting plate 112. This, in turn, drives the neutral density filter 118 to rotate along the rotating shaft 121 via the pin, thereby adjusting the length of the laser passing through the neutral density filter 118. The longer the laser passes through the neutral density filter 118, the more its intensity is attenuated. The length of the laser passing through the neutral density filter 118 can be adjusted by rotating the neutral density filter 118, which is convenient to operate.

[0058] like Figure 8As shown. The center density filter is a wedge-shaped block, with rotating shafts 121 fixedly mounted on both sides. A mounting plate 112 has a slot 120 for holding the rotating shaft 121, and a fixing seat 119 is provided on one side of the mounting plate 112. The fixing seat 119 has a semi-circular groove that matches the slot 120. The rotating shaft 121 is located within the circular cavity formed by the slot 120 and the semi-circular groove. The rotating shaft 121 is rotatably connected to the mounting plate 112 and the fixing seat 119. The fixing seat 119 is detachably connected to the mounting plate 112 by screws, facilitating the replacement of the center density filter.

[0059] The center density filter can also be configured as a rectangle, circle or other structure of equal thickness as needed.

[0060] like Figure 3 As shown. The housing 11 has an insertion hole 114 for inserting the mounting plate 112, and an obstacle hole 115 for avoiding the micro motor 130 and the fixing plate 127. The inner wall of the housing 11 has a slot 116 for inserting the mounting plate 112, which limits the mounting plate 112 and improves its stability during installation within the housing 11. A limiting plate 113 is fixedly installed at the top of the mounting plate 112, located outside the housing 11. A handle 131 is fixedly installed at the top of the limiting plate 113.

[0061] like Figure 10 , Figure 11 As shown. The limiting plate 113 and the housing 11 are connected by a locking structure. The locking structure includes connecting posts 132 fixedly disposed on the lower surface of the limiting plate 113, with the connecting posts 132 located on both sides of the mounting plate 112. The housing 11 is provided with connecting holes 133 for inserting the connecting posts 132. The side wall of the connecting hole 133 is provided with a through hole for passing a locking pin 134, which is perpendicular to the connecting post 132. The connecting post 132 is provided with a locking hole for inserting the locking pin 134. A fixing sleeve 135 is fixedly disposed on the side wall of the housing 11, and a handle 138 is slidably disposed inside the fixing sleeve 135. The handle 138 is fixedly connected to the locking pin 134 via a guide post 136. A positioning plate 137 is provided inside the fixing sleeve 135, and the positioning plate 137 is provided with a hole for passing the guide post 136. A spring 139 is provided between the positioning plate 137 and the locking pin 134 to allow the locking pin 134 to be inserted into the lock hole. The spring 139 is sleeved on the outside of the guide post 136, and the two ends of the spring 139 are fixedly connected to the positioning plate 137 and the locking pin 134 respectively.

[0062] The inner wall of the fixing sleeve 135 is provided with a guide groove 141 along the axial direction of the fixing sleeve 135, and the outer end of the guide groove 141 is provided with an arc-shaped groove 142 along the circumference of the fixing sleeve 135. A guide block 140 is fixedly provided on the side wall of the handle 138. The guide block 140 is located in the guide groove 141 and is slidably connected to both the guide groove 141 and the arc-shaped groove 142. The arc-shaped groove 142 and the guide block 140 can be used to position the locking pin 134 after it is pulled out of the lock hole, which facilitates the installation and removal of the mounting plate 112.

[0063] The focusing structure includes a third reflecting mirror 19, and a focusing mirror 110 is disposed below the third reflecting mirror 19. Both the third reflecting mirror 19 and the focusing mirror 110 are provided with through holes for the wire feeding tube 111 to pass through.

[0064] like Figure 12 , Figure 13 As shown. The nozzle 2 includes a body 21, the top of which is fixedly connected to the bottom of the housing 11 by threads. A cavity 22 is provided inside the body 21, and the powder feeding pipe 23 is located at the center of the cavity 22. A sleeve 143 with an open bottom is provided outside the powder feeding pipe 23. The sleeve 143 is connected to an external protective gas cylinder through an air inlet pipe 144 at the bottom of the housing 11, thereby protecting the welding wire with protective gas and improving the protective effect of the welding wire.

[0065] Several powder feeding pipes 23 are provided on the side wall of the main body 21. The powder feeding pipes 23 are connected to the external welding powder box. Different types of welding powder can be delivered to the weld through the powder feeding pipes 23. The composition of the weld can be adjusted according to the base material and the requirements of the weld, which is beneficial to improving the quality of the weld.

[0066] Several gas supply pipes 24 are provided on the side wall of the main body 21. The gas supply pipes 24 are connected to the external protective gas cylinder. The gas supply pipes 24 are located outside the powder supply pipe 23. A flow equalization plate 26 is provided at the bottom end of the gas supply pipe 24. Several air vents 27 are evenly arranged on the flow equalization plate 26. An annular air outlet chamber 25 is provided at the bottom end of the main body 21. The air outlet chamber 25 is connected to the gas supply pipe 24 through the air vents 27. The air vents 27 are funnel-shaped structures with a small opening at the top and a large opening at the bottom.

[0067] The welding method of the above-mentioned wire powder coaxial welding device with zoned control of welding heat input includes the following steps:

[0068] S1. Insert the pin 125 of the neutral density filter 118 into the slide groove 124, put the rotating shaft 121 of the neutral density filter 118 into the slot 120, place the fixing seat 119 on one side of the mounting plate 112, and fix the fixing seat 119 on the mounting plate 112 with screws to complete the installation of the neutral density filter 118 on the mounting plate 112.

[0069] S2. Pull the locking pin 134 outward through the handle 138, compressing the spring 139. The guide block 140 on the handle 138 slides into the arc-shaped groove 142 along the guide groove 141. Rotate the handle 138 to lock the guide block 140 into the arc-shaped groove 142. Insert the mounting plate 112 into the slot 116 through the insertion hole 114, and insert the connecting post 132 into the connecting hole 133. Rotate the handle 138 in the opposite direction, and the guide block 140 slides from the arc-shaped groove 142 into the guide groove 141. The spring 139 returns to its original position, and the spring 139 drives the locking pin 134 to insert into the lock hole, locking the connecting post 132 into the connecting hole 133.

[0070] S3. Mount the laser head 1 on the robotic arm and set the laser generator power and welding speed. Turn on the laser generator. The laser beam from the laser generator enters the laser head 1 through the optical fiber. After passing through the plane lens 13, the laser beam is reflected by the first reflecting mirror 14. The reflected laser beam then passes through the first flat-top light shaping mirror 15 and the second flat-top light shaping mirror 16 before entering the beam splitter 17. The beam splitter 17 evenly splits the laser beam into multiple beams. The split laser beam is reflected by the second reflecting mirror 18 and then enters the neutral density filter 118 for intensity adjustment. After being reflected by the third reflecting mirror 19, it exits the laser head 1 through the focusing mirror 110 and irradiates the weld seam for heating.

[0071] S4. The micro motor 130 drives the lead screw 128 to rotate. The lead screw 128 drives the slide plate 122 to slide through the thread engagement. The slide plate 122 drives the connecting rod 123 to move synchronously. The connecting rod 123 drives the neutral density filter 118 to rotate around the rotating shaft 121 through the pin 125. The pin 125 slides along the slide groove 124, changing the propagation length of the laser in the neutral density filter 118, thereby adjusting the intensity of each laser beam, and then adjusting the intensity of each area of ​​the laser spot irradiating the weld seam respectively.

[0072] S5. The temperature and morphology of the molten pool are monitored in real time by an industrial camera and an infrared thermal imager mounted on the robotic arm or laser head 1, and the monitoring results are sent to an external control system. The control system adjusts the intensity of each laser beam zone according to the real-time temperature distribution. The electrical connection between the industrial camera, infrared thermal imager, micro motor 130 and the control system can adopt existing technologies as needed.

[0073] The welding apparatus described in this invention is used to weld TC4 titanium alloy base material, and the macrostructure of the weld is as follows: Figure 14 As shown, Figure 14 The magnified microstructure images of regions C1, C2, and C3 are shown below. Figure 15 , Figure 16 , Figure 17As shown in the figure, the welding device described in this invention can adjust the laser intensity in different weld zones, thereby obtaining different grain sizes in different weld structures and achieving zoned control of the weld structure.

[0074] Therefore, the wire-powder coaxial welding device and welding method with zoned control of welding heat input described in this invention can divide a laser beam into multiple beams by setting a beam splitting mechanism and adjust the power of each laser beam by an intensity adjustment mechanism, thereby achieving zoned adjustment of laser power, which is beneficial to improving weld quality; it also reduces the number of lasers, which is beneficial to reducing the size of the laser head and simplifying the laser head structure.

[0075] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and not to limit them. 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 still be made to the technical solutions of the present invention, and these modifications or equivalent substitutions cannot cause the modified technical solutions to deviate from the spirit and scope of the technical solutions of the present invention.

Claims

1. A wire powder coaxial welding device with zoned control of welding heat input, characterized in that: The device includes a laser head and a nozzle. One end of the laser head is connected to a laser generator via an optical fiber, and the other end of the laser head is connected to the nozzle. The laser head includes a housing, inside which is a beam splitting mechanism for splitting the laser beam. Behind the beam splitting mechanism is an intensity adjustment mechanism for adjusting the power of each laser beam. Behind the intensity adjustment mechanism is a focusing structure for focusing each laser beam. Inside the housing is a wire feeding tube, which is coaxial with the circumference formed by the wire feeding tube and the powder feeding tube on the nozzle. The intensity adjustment mechanism includes a mounting plate, on which intensity adjustment units corresponding to the laser beams are provided. Each intensity adjustment unit includes a mounting hole on the mounting plate, in which a neutral density filter is rotatably disposed. The mounting plate is provided with an angle adjustment structure for adjusting the angle of the neutral density filter. By changing the angle of the neutral density filter, the thickness of the laser passing through the neutral density filter is changed, thereby adjusting the intensity of the laser. The center density filter is a wedge-shaped block; The angle adjustment structure includes a sliding plate, and a sliding structure that drives the sliding plate to slide horizontally is provided on the mounting plate; a connecting rod is provided on the sliding plate, the connecting rod is located on both sides of the central density filter, and a long strip-shaped sliding groove is provided on the connecting rod; a fixing block is provided at one end of the central density filter, and a pin is provided on the fixing block, the pin is located in the sliding groove and is slidably connected to the sliding groove. The sliding structure includes a lead screw, which is rotatably connected to a mounting plate. The slide plate is threadedly connected to the lead screw. A micro motor that drives the lead screw to rotate is provided on the mounting plate. A fixed plate is provided on one side of the mounting plate. The fixed plate is connected to the mounting plate through a guide rod. The guide rod is parallel to the lead screw. A guide hole is provided on the slide plate for the guide rod to pass through. The lead screw is rotatably connected to the fixed plate. The center density filter has a rotating shaft on both sides, a slot for placing the rotating shaft on the mounting plate, a fixed seat on one side of the mounting plate, and a semi-circular groove on the fixed seat that matches the slot. The rotating shaft is located in the circular cavity formed by the slot and the semi-circular groove. The rotating shaft is rotatably connected to the mounting plate and the fixed seat.

2. The wire powder coaxial welding device with zoned control of welding heat input according to claim 1, characterized in that: The beam splitting mechanism includes a planar lens located below the mounting base. An optical fiber is fixed on the mounting base. Below the planar lens is a first reflecting mirror that reflects the optical fiber. Behind the first reflecting mirror are a first flat-top beam shaping mirror and a second flat-top beam shaping mirror that shape the laser beam. Behind the second flat-top beam shaping mirror is a beam splitter that evenly splits the laser beam. Around the beam splitter are second reflecting mirrors that reflect each of the split laser beams. Each of the second reflecting mirrors corresponds to a split laser beam. An intensity adjustment mechanism is located behind the second reflecting mirror. The laser beam adjusted by the intensity adjustment mechanism is misaligned with the wire feeding tube.

3. The wire powder coaxial welding device with zoned control of welding heat input according to claim 2, characterized in that: The housing is provided with an insertion hole for inserting the mounting plate, and the insertion hole is provided with a clearance hole to avoid the micro motor and the fixing plate. The inner wall of the housing is provided with a slot for inserting the mounting plate. The top of the mounting plate is provided with a limit plate, which is located outside the housing. The top of the limit plate is provided with a handle. The limit plate is connected to the housing by a locking structure.

4. The wire powder coaxial welding device with zoned control of welding heat input according to claim 3, characterized in that: The locking structure includes connecting posts disposed on the lower surface of the limiting plate, the connecting posts being located on both sides of the mounting plate, connecting holes for inserting the connecting posts being provided on the housing, through holes for passing through the side walls of the connecting holes, the locking pin being perpendicular to the connecting posts, and locking holes for inserting the locking pin being provided on the connecting posts, a fixing sleeve being provided on the side walls of the housing, a handle being slidably disposed inside the fixing sleeve, the handle being connected to the locking pin via a guide post, a positioning plate being provided inside the fixing sleeve, a hole for passing through the positioning plate, and a spring being provided between the positioning plate and the locking pin for inserting the locking pin into the locking hole; a guide groove being provided on the inner wall of the fixing sleeve along the axial direction of the fixing sleeve, an arc-shaped groove being provided at the outer end of the guide groove along the circumference of the fixing sleeve, and a guide block being provided on the side wall of the handle, the guide block being located within the guide groove and slidably connected to both the guide groove and the arc-shaped groove.

5. The wire powder coaxial welding device with zoned control of welding heat input according to claim 4, characterized in that: The focusing structure includes a third reflecting mirror, and a focusing mirror is disposed below the third reflecting mirror. Both the third reflecting mirror and the focusing mirror are provided with through holes for the wire feeding tube to pass through.

6. The wire powder coaxial welding device with zoned control of welding heat input according to claim 5, characterized in that: The nozzle includes a body, the top of which is fixedly connected to the bottom of the housing. The body has an internal cavity with a powder feeding pipe located at the center. A sleeve with a bottom opening is provided outside the powder feeding pipe. The sleeve is connected to an external protective gas cylinder via an air inlet pipe at the bottom of the housing. Several powder feeding pipes are provided on the side wall of the body, and these pipes are connected to an external welding powder box. Several air supply pipes are also provided on the side wall of the body, and these air supply pipes are connected to an external protective gas cylinder. The air supply pipes are located outside the powder feeding pipes. A flow equalization plate is provided at the bottom of the air supply pipes, and several air vents are evenly distributed on the flow equalization plate. An annular air outlet chamber is provided at the bottom of the body, and the air outlet chamber is connected to the air supply pipes via air vents. The air vents have a funnel-shaped structure with a small opening at the top and a large opening at the bottom.

7. A welding method based on the wire powder coaxial welding device with zoned control of welding heat input as described in claim 6, characterized in that, Includes the following steps: S1. Insert the pin of the neutral density filter into the slide groove, put the rotating shaft of the neutral density filter into the slot, place the fixing seat on one side of the mounting plate, and fix the fixing seat to the mounting plate with screws to complete the installation of the neutral density filter on the mounting plate. S2. Pull the locking pin outward by the handle, the spring is compressed, and the guide block on the handle slides into the arc groove along the guide groove. Rotate the handle to lock the guide block in the arc groove. Insert the mounting plate into the slot through the insertion hole, insert the connecting post into the connecting hole, rotate the handle in the opposite direction, and the guide block slides from the arc groove into the guide groove. The spring returns to its original position, and the spring drives the locking pin to insert into the lock hole, locking the connecting post in the connecting hole. S3. Mount the laser head on the robotic arm and set the laser generator power and welding speed. Turn on the laser generator. The laser beam from the laser generator enters the laser head through an optical fiber. After passing through a plane lens, the laser beam is reflected by the first reflecting mirror. The reflected laser beam then passes through the first and second flat-top light shaping mirrors and enters the beam splitter. The beam splitter evenly splits the laser beam into multiple beams. The split laser beam is reflected by the second reflecting mirror and enters the neutral density filter for intensity adjustment. Then, after being reflected by the third reflecting mirror, it exits the laser head through the focusing mirror and irradiates the weld seam for heating. S4. The micro motor drives the lead screw to rotate, and the lead screw drives the slide plate to slide through the thread engagement. The slide plate drives the connecting rod to move synchronously. The connecting rod drives the neutral density filter to rotate around the rotating shaft through the pin. The pin slides along the slide groove, changing the propagation length of the laser in the neutral density filter, thereby adjusting the intensity of each laser beam, and then adjusting the intensity of each area of ​​the laser spot irradiating the weld. S5. The temperature and morphology of the molten pool are detected in real time by an industrial camera and an infrared thermal imager mounted on a robotic arm or laser head, and the detection results are sent to an external control system. The control system adjusts the intensity of each laser beam zone according to the real-time temperature distribution.

Images