Wire powder coaxial welding device with welding heat input partitioned regulation and control function and welding method

Abstract

The invention discloses a wire powder coaxial welding device with welding heat input partitioned regulation and control and a welding method, and belongs to the technical field of welding. A wire powder coaxial welding device with welding heat input regulated and controlled in a partition mode comprises a laser head and a nozzle, a beam splitting mechanism for splitting laser beams is arranged in a shell of the laser head, and an intensity adjusting mechanism for adjusting the power of each laser beam is arranged behind the beam splitting mechanism. A focusing structure for focusing each laser beam is arranged behind the intensity adjusting mechanism; a wire feeding pipe is arranged in the shell, and the wire feeding pipe is coaxial with the circumference defined by the powder feeding pipe on the nozzle. According to the wire powder coaxial welding device capable of regulating and controlling the welding heat input in the partitioned mode and the welding method, one laser beam is divided into multiple laser beams through the beam splitting mechanism, the power of all the laser beams is adjusted through the intensity adjusting mechanism, partitioned adjustment of the laser power is achieved, and the welding seam quality can be improved easily.

Description

Technical Field

[0001] The present invention relates to the field of welding technology, and particularly to a wire-powder coaxial welding device and a welding method for regulating welding heat input in zones. Background Art

[0002] Laser welding is a precision machining technology 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 surface of the workpiece through an optical system (such as a lens or a mirror), forming a very small and highly energy-concentrated light spot. This high energy density causes the material to rapidly heat up above the melting point in an extremely short time, thereby achieving local melting. Most existing laser welding uses a single light source, with the energy concentratedly irradiating the end of the welding wire and the weld zone, causing the metal to melt and then solidify to form a continuous weld. The single light source has the following problems: 1. For aluminum alloy materials, laser welding has severe fluctuations, the welding process is unstable, and there are welding defects such as pores; 2. For various alloy materials, the beam is single, and it is impossible to regulate the heat in the tiny area of the weld; 3. The energy distribution required for the synchronous feeding process of the wire and powder is relatively large, the irradiation area of the single light source is limited, and the melting and forming effect is poor.

[0003] The existing patent 202411098871.1 discloses an ultrasonic-assisted ring laser coaxial wire feeding welding device and a welding method. A clamping mechanism is arranged above the support frame, a vibration mechanism is arranged on the support frame, a welding mechanism is arranged above the support frame, the welding mechanism is connected to a robotic arm, and an ultrasonic mechanism is arranged on the welding mechanism. A connecting pipe is arranged at the center of the fixed seat of the welding mechanism, a wire feeding pipe is arranged inside the connecting pipe, several lasers are evenly arranged on the fixed seat, a light inlet channel for the laser to pass through the fixed seat is arranged inside the fixed seat, the circle where the lasers are located is coaxial with the wire feeding pipe, a nozzle is arranged below the fixed seat, and a cavity for the wire feeding pipe and the laser to pass through the nozzle is arranged inside the nozzle. The above ultrasonic-assisted ring laser coaxial wire feeding welding device and welding method can solve the problems of poor adaptability of the existing welding device and poor ultrasonic treatment effect. By arranging multiple lasers in the above patent, different zone intensities can be controlled by adjusting the powers of different lasers. However, arranging multiple lasers not only increases the volume of the welding device but also increases the cost. Summary of the Invention

[0004] The object of the present invention is to provide a wire-powder coaxial welding device and a welding method for regulating welding heat input in zones. By arranging a beam splitting mechanism to split a beam of laser into multiple beams and adjusting the powers of each beam of laser through an intensity adjustment mechanism, the zonal adjustment of the laser power is realized, which is beneficial to improving the weld quality; the number of lasers is reduced, which is beneficial to reducing the volume of the laser head and simplifying the structure of the laser head.

[0005] To achieve the above object, the present invention provides a wire and powder coaxial welding device for regulating the welding heat input in zones, which includes a laser head and a nozzle. One end of the laser head is connected to a laser generator through an optical fiber, and the other end of the laser head is connected to the nozzle. The laser head includes a housing, and inside the housing, there is a beam splitting mechanism for splitting the laser beam. Behind the beam splitting mechanism, there is an intensity adjustment mechanism for adjusting the power of each laser beam respectively. Behind the intensity adjustment mechanism, there is a focusing structure for focusing each laser beam. Inside the housing, there 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 plano-convex lens, which is located below the mounting seat. The optical fiber is fixed on the mounting seat. Below the plano-convex lens, there is a first reflector for reflecting the optical fiber. Behind the first reflector, there is a first flat-top beam shaping mirror and a second flat-top beam shaping mirror for shaping the laser beam. Behind the second flat-top beam shaping mirror, there is a beam splitter for evenly splitting the laser beam. Around the beam splitter, there are second reflectors for reflecting each split laser beam. The second reflectors correspond to the split laser beams one by one. The intensity adjustment mechanism is located behind the second reflectors, and the laser beam adjusted by the intensity adjustment mechanism is arranged offset from the wire feeding tube.

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

[0008] Preferably, the angle adjustment structure includes a sliding plate. On the mounting plate, there is a sliding structure for driving the sliding plate to slide horizontally. On the sliding plate, there are connecting rods located on both sides of the center density filter. On the connecting rods, there are long strip-shaped sliding grooves. One end of the center density filter is provided with a fixing block, and on the fixing block, there is a pin column, which 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 the mounting plate. The sliding plate is threadedly connected to the lead screw. On the mounting plate, there is a micro-motor for driving the lead screw to rotate. On one side of the mounting plate, there is a fixing plate, which is connected to the mounting plate through a guide rod. The guide rod is parallel to the lead screw. The sliding plate is provided with a guide hole for the guide rod to pass through, and the lead screw is rotatably connected to the fixing plate.

[0010] Preferably, the central density filter is a wedge-shaped block. Rotating shafts are arranged on both sides of the central density filter. A clamping groove for placing the rotating shafts is arranged on the mounting plate. A fixed seat is arranged on one side of the mounting plate. A semi-circular groove adapted to the clamping groove is arranged on the fixed seat. The rotating shafts are located in the circular cavity formed by the clamping groove and the semi-circular groove, and the rotating shafts are rotatably connected to both the mounting plate and the fixed seat.

[0011] Preferably, the housing is provided with an insertion hole for inserting the mounting plate. An avoidance hole for avoiding the micro-motor and the fixing plate is arranged on the insertion hole. A slot for inserting the mounting plate is arranged on the inner wall of the housing. A limiting plate is arranged at the top end of the mounting plate. The limiting plate is located outside the housing. A handle is arranged at the top end of the limiting plate. The limiting plate and the housing are connected through a locking structure.

[0012] Preferably, the locking structure includes connecting columns arranged on the lower surface of the limiting plate. The connecting columns are located on both sides of the mounting plate. The housing is provided with connecting holes for inserting the connecting columns. Through holes for the locking pins to pass through are arranged on the side walls of the connecting holes. The locking pins are perpendicular to the connecting columns. Locking holes for inserting the locking pins are arranged on the connecting columns. A fixed sleeve is arranged on the side wall of the housing. A pull handle is slidably arranged inside the fixed sleeve. The pull handle is connected to the locking pin through a guide post. A positioning plate is arranged inside the fixed sleeve. A hole for the guide post to pass through is arranged on the positioning plate. A spring for inserting the locking pin into the locking hole is arranged between the positioning plate and the locking pin; Guide grooves along the axial direction of the fixed sleeve are arranged on the inner wall of the fixed sleeve. An arc-shaped groove along the circumferential direction of the fixed sleeve is arranged at the outer end of the guide groove. A guide block is arranged on the side wall of the pull handle. The guide block is located in the guide groove and is slidably connected to both the guide groove and the arc-shaped groove.

[0013] Preferably, the focusing structure includes a third reflecting mirror. A focusing lens is arranged below the third reflecting mirror. Through holes for the wire feeding tube to pass through are arranged on both the third reflecting mirror and the focusing lens.

[0014] Preferably, the nozzle includes a body. The top end of the body is fixedly connected to the bottom end of the housing. A cavity is arranged inside the body. The powder feeding tube is located at the center of the cavity. A sleeve with an open bottom is arranged outside the powder feeding tube. The sleeve is connected to an external protective gas bottle through an air inlet pipe at the bottom end of the housing. A plurality of powder feeding tubes are arranged on the side wall of the body. The powder feeding tubes are connected to an external powder welding box; A plurality of air supply tubes are arranged on the side wall of the body. The air supply tubes are connected to an external protective gas bottle. The air supply tubes are located outside the powder feeding tubes. A flow equalizing plate is arranged at the bottom end of the air supply tube. A plurality of air permeable holes are evenly arranged on the flow equalizing plate. An annular air outlet cavity is arranged at the bottom end of the body. The air outlet cavity is connected to the air supply tube through the air permeable holes. The air permeable holes are of a trumpet-shaped structure with a small top opening and a large bottom opening.

[0015] The welding method of the wire and powder coaxial welding device for regulating the welding heat input in zones includes the following steps:

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

[0017] S2. Pull the locking pin outwards through the handle, the spring compresses, the guide block on the handle slides along the guide groove into the arc groove, rotate the handle, and lock the guide block in the arc groove; insert the mounting plate into the slot through the jack, insert the connecting column into the connecting hole, rotate the handle in the reverse direction, the guide block slides from the arc groove into the guide groove, the spring resets, and the spring drives the locking pin to insert into the lock hole to lock the connecting column in the connecting hole;

[0018] S3. Install the laser head on the robot arm, set the power of the laser generator and the welding speed; turn on the laser generator, the laser of the laser generator enters the laser head through the optical fiber, the laser passes through the plano-convex lens and then is reflected by the first mirror, the reflected laser passes through the first flat-top beam shaper and the second flat-top beam shaper in sequence and then enters the beam splitter, the beam splitter evenly divides a beam of laser into multiple beams of laser, the split laser is reflected by the second mirror and then enters the neutral density filter for intensity adjustment, and then is reflected by the third mirror and passes through the focusing lens to emit from the laser head and irradiate on the weld for heating;

[0019] S4. Drive the lead screw to rotate through the micro-motor, the lead screw drives the slide plate to slide through 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 column, the pin column slides along the chute, changes the propagation length of the laser in the neutral density filter, thereby adjusts the intensity of each beam of laser, and further adjusts the intensity of each area of the laser spot irradiated on the weld;

[0020] S5. Use the industrial camera and infrared thermal imager set on the robot arm or the laser head to respectively detect the temperature and morphology of the molten pool in real time, and send the detection results to the external control system, and the control system adjusts the intensity of each laser beam partition according to the temperature distribution detected in real time.

[0021] The advantages and positive effects of the wire-powder coaxial welding device and welding method for regulating the welding heat input partition of the present invention are as follows:

[0022] 1. The present invention is provided with a beam splitting mechanism in the housing, and the beam splitting mechanism divides a beam of laser into several uniform beams of laser, reducing the number of laser generators and being beneficial to cost reduction.

[0023] 2. The housing of the present invention is provided with an intensity adjustment mechanism, which independently adjusts each beam of laser, thereby independently adjusting the intensity of each partition in the laser spot, meeting the requirements of different welding powders, welding wires and base materials for welding temperature, and being beneficial to improving the weld quality. Moreover, different laser powers result in different temperature gradients in the molten pool, and different weld microstructures can be obtained under different temperature gradients, thereby realizing controllability of the weld microzone microstructure and improving the welding performance.

[0024] 3. In the present invention, a micro-motor drives a lead screw to rotate, and the lead screw adjusts the distance between the sliding plate and the mounting plate. Thus, a pin shaft drives a neutral density filter to rotate along a rotating shaft, and further adjusts the length of the laser passing through the neutral density filter. The longer the length of the laser passing through the neutral density filter, the more the intensity decays. Adjusting the length of the laser passing through the neutral density filter is achieved by rotating the neutral density filter, and the operation is convenient.

[0025] 4. The side wall of the main body of the present invention is provided with a plurality of powder feeding pipes. Different components of welding powder can be conveyed to the weld through the powder feeding pipes, and the composition of the weld can be regulated according to the requirements of the base material and the weld, which is beneficial to improving the weld quality. The combination of the powder feeding pipes and the partitioned laser beams can set welding parameters according to needs, which is beneficial to improving the welding quality.

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

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

[0028] Figure 2 It is a schematic three-dimensional structure diagram of an embodiment of the present invention;

[0029] Figure 3 It is a schematic cross-sectional structure diagram of the housing of an embodiment of the present invention;

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

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

[0032] Figure 6 It is a schematic structure diagram of the intensity adjustment mechanism of an embodiment of the present invention;

[0033] Figure 7 It is Figure 6 the enlarged view of A in

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

[0035] Figure 9 Schematic diagram of the mounting plate structure according to an embodiment of the present invention;

[0036] Figure 10 Schematic diagram of the locking structure according to an embodiment of the present invention;

[0037] Figure 11 Schematic diagram of the fixed sleeve structure according to an embodiment of the present invention;

[0038] Figure 12 Schematic diagram of the nozzle structure according to an embodiment of the present invention;

[0039] Figure 13 is Figure 12 enlarged view of B in;

[0040] Figure 14 Macrograph of the weld microstructure of TC4 titanium alloy in an embodiment of the present invention;

[0041] Figure 15 is Figure 14 enlarged view of area C1 in;

[0042] Figure 16 is Figure 14 enlarged view of area C2 in;

[0043] Figure 17 is Figure 14 enlarged view of area C3 in.

[0044] Reference numerals

[0045] 1. Laser head; 11. Housing; 12. Mounting base; 13. Planar lens; 14. First reflector; 15. First flat-top light shaping mirror; 16. Second flat-top light shaping mirror; 17. Beam splitter; 18. Second reflector; 19. Third reflector; 110. Focusing lens; 111. Wire feeding tube; 112. Mounting plate; 113. Limiting plate; 114. Insertion hole; 115. Avoidance hole; 116. Slot; 117. Mounting hole; 118. Neutral density filter; 119. Fixed seat; 120. Card slot; 121. Rotating shaft; 122. Slide plate; 123. Connecting rod; 124. Slide groove; 125. Pin; 126. Fixed block; 127. Fixed plate; 128. Lead screw; 129. Guide rod; 130. Micro motor; 131. Handle; 132. Connecting column; 133. Connecting hole; 134. Locking pin; 135. Fixed sleeve; 136. Guide post; 137. Positioning plate; 138. Pull 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 feeding tube; 24. Air supply tube; 25. Air outlet cavity; 26. Flow equalizing plate; 27. Vent hole. Detailed implementation mode

[0047] In the description of the present invention, it should be noted that the orientation or positional relationship indicated by the terms "upper", "lower", "inner", "outer", etc. is based on the orientation or positional relationship shown in the drawings, or the orientation or positional relationship in which the product of the present invention is usually placed during use. It is only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be construed as a limitation to the present invention. In the description of the present invention, it should also be noted that unless otherwise clearly specified and defined, the terms "set", "installed", "connected" should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be directly connected or indirectly connected through an intermediate medium, and it can be the communication inside two elements. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to specific situations.

[0048] In this application, unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by those of ordinary skill in the technical field to which this application belongs. In case of inconsistency, it shall be subject to the meaning stated in this specification or the meaning derived from the content recorded in this specification. In addition, the terms used herein are only for the purpose of describing the embodiments of this application and are not intended to limit this application. In order to accurately describe the technical content in this application and to accurately understand the present invention, the following explanations or definitions of the terms used in this specification are given before describing the specific implementation mode:

[0049] The following will describe the embodiments of the present invention in detail with reference to the drawings.

[0050] As Figure 1 、 Figure 2 shown. A wire and powder coaxial welding device for regulating the welding heat input in zones includes a laser head 1 and a nozzle 2. One end of the laser head 1 is connected to a laser generator through an optical fiber, and the other end of the laser head 1 is connected to the nozzle 2. The laser head 1 is fixed on an existing six-axis robot, and the robot drives the laser head 1 to move, thereby welding the workpiece.

[0051] The laser head 1 includes a housing 11. Inside the housing 11, there is a beam splitting mechanism for splitting the laser beam. Through the beam splitting mechanism, a single laser beam is divided into several uniform laser beams. Behind the beam splitting mechanism, there is an intensity adjustment mechanism for separately adjusting the power of each laser beam. Through the intensity adjustment mechanism, each laser beam is independently adjusted, so as to independently adjust the intensity of each zone in the laser spot, meet the requirements of different welding powders, welding wires and base materials for the welding temperature, and is beneficial to improving the weld quality. Different laser powers result in different temperature gradients in the molten pool. Under different temperature gradients, different weld microstructures can be obtained, thereby realizing the controllability of the weld microzone microstructure and improving the welding performance. Behind the intensity adjustment mechanism, there is a focusing structure for focusing each laser beam. Inside the housing 11, there is a wire feeding tube 111. The wire feeding tube 111 is coaxial with the circumference formed by the powder feeding tube 23 on the nozzle 2, realizing coaxial powder feeding welding.

[0052] The beam splitting mechanism includes a plano - lens 13. The plano - lens 13 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 on the mounting base 12. Below the plano - lens 13, there is a first reflecting mirror 14 for reflecting the optical fiber, which changes the direction of the laser beam through the first reflecting mirror 14. Behind the first reflecting mirror 14, there are a first flat - top beam shaping mirror 15 and a second flat - top beam shaping mirror 16 for shaping the laser beam. Behind the second flat - top beam shaping mirror 16, there is a beam splitter 17 for uniformly splitting the laser beam. After being shaped by the first flat - top beam shaping mirror 15 and the second flat - top beam shaping mirror 16, it is convenient for the laser to 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, there are second reflecting mirrors 18 for reflecting each split laser beam. The second reflecting mirrors 18 correspond one - to - one with the split laser beams. The intensity adjustment mechanism is located behind the second reflecting mirrors 18. The laser beam adjusted by the intensity adjustment mechanism is arranged offset from 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 beam into four laser beams. Four second reflecting mirrors 18 are provided. The four laser beams are respectively located on both sides of the wire feeding tube 111. After being reflected by the third reflecting mirror 19, the four laser beams are focused by the focusing lens 110 to form a quasi - circular laser spot composed of four laser zones. The intensities of the four laser zones of the laser spot can be respectively adjusted by the intensity adjustment mechanism, so as to adjust the laser beam specifically according to the welding powder, welding wire composition and base material composition, which is beneficial to improving the welding quality.

[0054] Such as Figure 4 、 Figure 5 、 Figure 6 、 Figure 7 、 Figure 9As shown in the figure. The intensity adjustment mechanism includes a mounting plate 112, and intensity adjustment units corresponding to the laser beams one by one are arranged on the mounting plate 112. The intensity adjustment unit includes a mounting hole 117 arranged on the mounting plate 112, and a neutral density filter 118 is rotatably arranged in the mounting hole 117. The neutral density filter 118 attenuates light of different wavelengths in the same proportion, thereby adjusting the energy of the laser. An angle adjustment structure for adjusting the angle of the central density filter is arranged on the mounting plate 112. By changing the angle of the central density filter, the thickness of the laser passing through the central density filter is changed, and further the intensity of the laser is adjusted.

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

[0056] The sliding structure includes a lead screw 128, and the lead screw 128 is rotatably connected with the mounting plate 112 through a bearing. The sliding plate 122 is threadedly connected with the lead screw 128. A micro-motor 130 for driving the lead screw 128 to rotate is arranged on the mounting plate 112. A fixing plate 127 is arranged on one side of the mounting plate 112, and the fixing plate 127 is fixedly connected with the mounting plate 112 through a guide rod 129. The guide rod 129 is parallel to the lead screw 128, and a guide hole for the guide rod 129 to pass through is arranged on the sliding plate 122. The guide rod 129 has a guiding and limiting effect on the sliding of the sliding plate 122. The lead screw 128 is rotatably connected with 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 sliding plate 122 and the mounting plate 112, thereby driving the neutral density filter 118 to rotate along the rotating shaft 121 through the pin shaft, and further adjusting the length of the laser passing through the neutral density filter 118. The longer the length of the laser passing through the neutral density filter 118, the more the intensity decays. By rotating the neutral density filter 118, the adjustment of the length of the laser passing through the neutral density filter 118 is realized, and the operation is convenient.

[0058] Such as Figure 8As shown in the figure. The central density filter is a wedge-shaped block, and rotating shafts 121 are fixedly arranged on both sides of the central density filter. A card slot 120 for placing the rotating shaft 121 is arranged on the mounting plate 112. A fixed seat 119 is arranged on one side of the mounting plate 112. A semi-circular groove adapted to the card slot 120 is arranged on the fixed seat 119. The rotating shaft 121 is located in the circular cavity formed by the card slot 120 and the semi-circular groove, and the rotating shaft 121 is rotatably connected to both the mounting plate 112 and the fixed seat 119. The fixed seat 119 and the mounting plate 112 are detachably connected by screws, which is convenient for replacing the central density filter.

[0059] The central density filter can also be set into a rectangular, circular or other structure with equal thickness according to needs.

[0060] As Figure 3 shown in the figure. A jack 114 for inserting the mounting plate 112 is arranged on the housing 11. An avoidance hole 115 for avoiding the micro-motor 130 and the fixing plate 127 is arranged on the jack 114. A slot 116 for inserting the mounting plate 112 is arranged on the inner wall of the housing 11. The mounting plate 112 is limited by the slot 116, which improves the stability of the mounting plate 112 installed in the housing 11. A limiting plate 113 is fixedly arranged at the top end of the mounting plate 112, and the limiting plate 113 is located outside the housing 11. A handle 131 is fixedly arranged at the top end of the limiting plate 113.

[0061] As Figure 10 、 Figure 11 shown in the figure. The limiting plate 113 and the housing 11 are connected by a locking structure. The locking structure includes a connecting column 132 fixedly arranged on the lower surface of the limiting plate 113, and the connecting column 132 is located on both sides of the mounting plate 112. A connecting hole 133 for inserting the connecting column 132 is arranged on the housing 11. A through hole for the locking pin 134 to pass through is arranged on the side wall of the connecting hole 133, and the locking pin 134 is perpendicular to the connecting column 132. A locking hole for inserting the locking pin 134 is arranged on the connecting column 132. A fixed sleeve 135 is fixedly arranged on the side wall of the housing 11. A pull handle 138 is slidably arranged inside the fixed sleeve 135, and the pull handle 138 is fixedly connected to the locking pin 134 through a guide post 136. A positioning plate 137 is arranged inside the fixed sleeve 135, and a hole for the guide post 136 to pass through is arranged on the positioning plate 137. A spring 139 for inserting the locking pin 134 into the locking hole is arranged between the positioning plate 137 and the locking pin 134. The spring 139 is sleeved outside the guide post 136, and both ends of the spring 139 are fixedly connected to the positioning plate 137 and the locking pin 134 respectively.

[0062] On the inner wall of the fixed sleeve 135, a guide groove 141 along the axis of the fixed sleeve 135 is provided, and an arc-shaped groove 142 along the circumferential direction of the fixed sleeve 135 is provided at the outer end of the guide groove 141. A guide block 140 is fixedly arranged 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. Through the arc-shaped groove 142 and the guide block 140, the positioning of the locking pin 134 after being pulled out from the lock hole can be realized, which is convenient for the installation and disassembly of the mounting plate 112.

[0063] The focusing structure includes a third reflector 19. A focusing lens 110 is arranged below the third reflector 19. Through holes for the wire feeding tube 111 to pass through are provided on both the third reflector 19 and the focusing lens 110.

[0064] As Figure 12 、 Figure 13 shown. The nozzle 2 includes a body 21. The top end of the body 21 is fixedly connected to the bottom end of the housing 11 by a thread. A cavity 22 is arranged inside the body 21. The powder feeding tube 23 is located at the center of the cavity 22. A sleeve 143 with an open bottom is arranged outside the powder feeding tube 23. The sleeve 143 is connected to an external protective gas cylinder through an air inlet pipe 144 at the bottom end of the housing 11. The wire is protected by the protective gas, improving the protection effect of the wire.

[0065] A plurality of powder feeding tubes 23 are arranged on the side wall of the body 21. The powder feeding tubes 23 are connected to an external powder box. Different components of powder can be conveyed to the weld through the powder feeding tubes 23, and the composition of the weld can be adjusted according to the requirements of the base material and the weld, which is beneficial to improving the weld quality.

[0066] A plurality of air supply tubes 24 are arranged on the side wall of the body 21. The air supply tubes 24 are connected to an external protective gas cylinder. The air supply tubes 24 are located outside the powder feeding tubes 23. A flow equalizing plate 26 is arranged at the bottom end of the air supply tubes 24. A plurality of ventilation holes 27 are evenly arranged on the flow equalizing plate 26. An annular air outlet cavity 25 is arranged at the bottom end of the body 21. The air outlet cavity 25 is connected to the air supply tubes 24 through the ventilation holes 27. The ventilation holes 27 are of a flared structure with a small top opening and a large bottom opening.

[0067] The welding method of the wire and powder coaxial welding device for regulating the welding heat input in zones includes the following steps:

[0068] S1. Insert the pin 125 of the neutral density filter 118 into the sliding groove 124, place the rotating shaft 121 of the neutral density filter 118 into the clamping groove 120. Place the fixed seat 119 on one side of the mounting plate 112, and fix the fixed 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 outwards through the handle 138. The spring 139 is compressed, and 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 in the arc-shaped groove 142. Insert the mounting plate 112 into the slot 116 through the jack 114, and insert the connecting column 132 into the connecting hole 133. Rotate the handle 138 in the reverse direction. The guide block 140 slides from the arc-shaped groove 142 into the guide groove 141, the spring 139 resets, and the spring 139 drives the locking pin 134 to insert into the lock hole, locking the connecting column 132 in the connecting hole 133.

[0070] S3. Install the laser head 1 on the robot arm, and set the power of the laser generator and the welding speed. Turn on the laser generator. The laser of the laser generator enters the laser head 1 through the optical fiber. After passing through the plano lens 13, the laser is reflected by the first reflecting mirror 14. The reflected laser passes through the first flat-top light shaping mirror 15 and the second flat-top light shaping mirror 16 in sequence and then enters the beam splitter 17. The beam splitter 17 evenly divides a beam of laser into multiple beams of laser. The split laser is reflected by the second reflecting mirror 18 and then enters the neutral density filter 118 for intensity adjustment, and then is reflected by the third reflecting mirror 19 and emitted from the laser head 1 through the focusing lens 110, irradiating on the weld to heat it.

[0071] S4. Drive the lead screw 128 to rotate through the micro-motor 130. The lead screw 128 drives the slide plate 122 to slide through 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 chute 124, changing the propagation length of the laser in the neutral density filter 118, thereby adjusting the intensity of each beam of laser, and further adjusting the intensity of each area of the laser spot irradiated on the weld.

[0072] S5. Use the industrial camera and the infrared thermal imager set on the robot arm or the laser head 1 to respectively detect the temperature and morphology of the molten pool in real time, and send the detection results to an external control system. The control system adjusts the intensity of each laser beam partition according to the temperature distribution detected in real time. The electrical connection methods of the industrial camera, the infrared thermal imager, and the micro-motor 130 with the control system can adopt existing technologies according to needs.

[0073] When welding the TC4 titanium alloy base material using the welding device of the present invention, the macroscopic structure of the weld is as Figure 14 shown, Figure 14 and the enlarged micrographs of the microstructures in regions C1, C2, and C3 in Figure 15 , Figure 16 , Figure 17As shown. It can be seen from the figure that the laser intensity in different weld zones can be adjusted by the welding device of the present invention, so as to obtain different grain sizes at different weld microstructures, achieving zonal control of the weld microstructure.

[0074] Therefore, by using the wire-powder coaxial welding device and welding method for zonal control of welding heat input of the present invention, a beam of laser is divided into multiple beams by setting a beam splitting mechanism, and the power of each beam of laser is adjusted by an intensity adjusting mechanism, realizing zonal adjustment of the laser power, which is beneficial to improving the weld quality; reducing the number of lasers is beneficial to reducing the volume of the laser head and simplifying the structure of the laser head.

[0075] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit them. Although the present invention has been described in detail with reference to the preferred embodiments, those of ordinary skill in the art should understand that they can still modify or equivalently replace the technical solutions of the present invention, and these modifications or equivalent replacements cannot make the modified technical solutions deviate from the spirit and scope of the technical solutions of the present invention.

Claims

1. A silk-powder coaxial welding device with zoned control of welding heat input, characterized in that: It includes a laser head and a nozzle, one end of the laser head is connected to the laser generator through an optical fiber, and the other end of the laser head is connected to the nozzle; the laser head includes a shell, the interior of the shell is provided with a beam splitting mechanism for splitting the laser, the rear of the beam splitting mechanism is provided with an intensity adjustment mechanism for adjusting the power of each laser beam respectively, and the rear of the intensity adjustment mechanism is provided with a focusing structure for focusing each laser beam; a wire feeding tube is provided inside the shell, and the wire feeding tube is coaxial with the circumference surrounded by the powder feeding tube on the nozzle.

2. The silk-powder coaxial welding device with zoned control of welding heat input according to claim 1, characterized in that: The beam splitting mechanism includes a plane lens, which is located below a mounting seat, on which the optical fiber is fixed, a first reflector for reflecting the optical fiber is arranged below the plane lens, a first flat-top light shaping mirror and a second flat-top light shaping mirror for shaping the laser are arranged behind the first reflector, a beam splitter for evenly splitting the laser is arranged behind the second flat-top light shaping mirror, a second reflector for reflecting each beam of split laser is arranged around the beam splitter, the second reflector corresponds to the split laser one by one, an intensity adjustment mechanism is located behind the second reflector, and the laser beam adjusted by the intensity adjustment mechanism is staggered with the wire feeding tube.

3. The silk-powder coaxial welding device with zoned control of welding heat input according to claim 1, characterized in that: The intensity adjustment mechanism includes a mounting plate, on which are arranged intensity adjustment units corresponding to the laser beams one by one; the intensity adjustment unit includes a mounting hole arranged on the mounting plate, in which a neutral density filter is rotatably arranged, and an angle adjustment structure for adjusting the angle of the center density filter is arranged on the mounting plate. By changing the angle of the center density filter, the thickness of the laser passing through the center density filter is changed, thereby adjusting the intensity of the laser.

4. The silk-powder coaxial welding device with zoned control of welding heat input according to claim 3, characterized in that: The angle adjustment structure comprises a slide plate, and a sliding structure for driving the slide plate to slide horizontally is arranged on the mounting plate; a connecting rod is arranged on the slide plate, and the connecting rod is located on both sides of the center density filter, and a long strip slide groove is arranged on the connecting rod; a fixing block is arranged at one end of the center density filter, and a pin is arranged on the fixing block, and the pin is located in the slide groove and is slidably connected to the slide groove; The sliding structure includes a screw rod, which is rotatably connected to a mounting plate, a slide plate is threadedly connected to the screw rod, a micro motor for driving the screw rod to rotate is arranged on the mounting plate, a fixed plate is arranged 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 screw rod, a guide hole for the guide rod to pass through is arranged on the slide plate, and the screw rod is rotatably connected to the fixed plate.

5. The silk-powder coaxial welding device with zoned control of welding heat input according to claim 4, characterized in that: The center density filter is a wedge-shaped block, with rotating shafts on both sides of the center density filter, a slot for placing the rotating shaft is provided on the mounting plate, a fixing seat is provided on one side of the mounting plate, a semicircular groove matched with the slot is provided on the fixing seat, the rotating shaft is located in a circular cavity surrounded by the slot and the semicircular groove, and the rotating shaft is rotatably connected to the mounting plate and the fixing seat.

6. The silk-powder coaxial welding device with zoned control of welding heat input according to claim 5, characterized in that: The shell is provided with a socket for inserting the mounting plate, the socket is provided with an avoidance hole for avoiding the micromotor and the fixing plate, the inner wall of the shell is provided with a slot for inserting the mounting plate, the top of the mounting plate is provided with a limit plate, the limit plate is located outside the shell, the top of the limit plate is provided with a handle, and the limit plate and the shell are connected by a locking structure.

7. The silk-powder coaxial welding device with zoned control of welding heat input according to claim 6, characterized in that: The locking structure includes a connecting column arranged on the lower surface of the limiting plate, the connecting column is located on both sides of the mounting plate, a connecting hole for inserting the connecting column is arranged on the shell body, a through hole for passing the locking pin is arranged on the side wall of the connecting hole, the locking pin is perpendicular to the connecting column, a locking hole for inserting the locking pin is arranged on the connecting column, a fixing sleeve is arranged on the side wall of the shell body, a handle is slidably arranged inside the fixing sleeve, the handle is connected to the locking pin through a guide column, a positioning plate is arranged inside the fixing sleeve, a hole for passing the guide column is arranged on the positioning plate, and a spring for inserting the locking pin into the locking hole is arranged between the positioning plate and the locking pin; a guide groove along the axial direction of the fixing sleeve is arranged on the inner wall of the fixing sleeve, an arc groove along the circumference of the fixing sleeve is arranged at the outer end of the guide groove, and a guide block is arranged on the side wall of the handle, the guide block is located in the guide groove and is slidably connected to both the guide groove and the arc groove.

8. The silk-powder coaxial welding device with zoned control of welding heat input according to claim 7, characterized in that: The focusing structure comprises a third reflector, a focusing mirror is arranged below the third reflector, and both the third reflector and the focusing mirror are provided with through holes for the wire feeding tube to pass through.

9. The silk-powder coaxial welding device with zoned control of welding heat input according to claim 8, characterized in that: The nozzle includes a main body, the top of the main body is fixedly connected to the bottom of the shell, a cavity is arranged inside the main body, a powder feeding tube is located at the center of the cavity, a sleeve with a bottom opening is arranged outside the powder feeding tube, the sleeve is connected to an external protective gas bottle through an air inlet pipe at the bottom of the shell, a plurality of powder feeding tubes are arranged on the side wall of the main body, and the powder feeding tubes are connected to an external welding powder box; a plurality of air supply pipes are arranged on the side wall of the main body, the air supply pipes are connected to an external protective gas bottle, the air supply pipes are located outside the powder supply pipe, a flow equalizing plate is arranged at the bottom end of the air supply pipe, a plurality of air holes are evenly arranged on the flow equalizing plate, an annular air outlet cavity is arranged at the bottom end of the main body, the air outlet cavity is connected to the air supply pipe through the air holes, and the air holes are a trumpet-shaped structure with a small opening at the top and a large opening at the bottom.

10. A welding method based on the silk-powder coaxial welding device with zoned control of welding heat input according to claim 9, characterized in that: The following steps are involved: S1. Insert the pin of the neutral density filter into the slide slot, put the rotating shaft of the neutral density filter into the card slot, place a fixing seat on one side of the mounting plate, fix the fixing seat on the mounting plate with screws, and complete the installation of the neutral density filter on the mounting plate; S2. Pull the locking pin outward through the handle, the spring is compressed, the guide block on the handle slides into the arc groove along the guide groove, rotate the handle, and clamp the guide block in the arc groove; insert the mounting plate into the slot through the jack, insert the connecting column into the connecting hole, rotate the handle in the opposite direction, the guide block slides from the arc groove into the guide groove, the spring is reset, and the spring drives the locking pin to insert into the lock hole, locking the connecting column in the connecting hole; S3. Install the laser head on the manipulator, set the laser generator power and welding speed; turn on the laser generator, the laser of the laser generator enters the laser head through the optical fiber, the laser passes through the plane lens and then is reflected by the first reflector, the reflected laser passes through the first flat top light shaping mirror and the second flat top light shaping mirror in sequence and then enters the beam splitter, the beam splitter evenly divides a laser beam into multiple laser beams, the split laser beam is reflected by the second reflector and then enters the neutral density filter for intensity adjustment, then is reflected by the third reflector and then emitted from the laser head through the focusing mirror, and irradiates the weld for heating; S4. The micromotor drives the lead screw to rotate, the lead screw drives the slide plate to slide through the threaded 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, and the propagation length of the laser in the neutral density filter is changed, so as to adjust the intensity of each laser beam, and then adjust the intensity of each area of ​​the laser spot irradiated on the weld respectively; S5. The temperature and morphology of the molten pool are detected in real time by the industrial camera and infrared thermal imager installed on the manipulator or laser head, and the detection results are sent to the external control system. The control system adjusts the intensity of each laser beam partition according to the real-time detected temperature distribution.

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