Multi-wavelength light source arc composite laser processing head and method for coaxial wire and powder delivery

Abstract

The present invention discloses a multi-wavelength light source arc composite laser processing head and method for coaxial wire and powder delivery. The laser processing head includes a control module, a wire drawing mechanism and a multi-beam laser head; the control module includes a sensor for detecting whether the welding wire passes through; in the wire drawing mechanism, the wire drawing assembly is driven by a wire drawing motor to draw and retract the welding wire between two axially opposite wire drawing nozzles; the multi-beam laser head includes a wire guide sleeve, two access blocks with accommodating cavities, one or more groups of mirror group adjustment modules and corresponding protective mirror modules; a replaceable nozzle is provided at the end of the wire guide sleeve; and two inner and outer double cavities are provided in the nozzle. The laser processing head of the present invention can realize controllable heating of the welding wire; and can judge the laser light emission timing according to the corresponding signal. The laser processing head can be installed at the end of various motion mechanisms to realize high surface quality laser welding / additive, multi-wavelength laser composite welding / additive, laser fuse / powder delivery / wire and powder delivery welding / additive.

Description

Technical Field

[0001] The invention relates to a multi-wavelength light source arc composite laser processing head and method for coaxial wire-powder co-feeding welding / material adding, belonging to the technical field of laser processing. Background Art

[0002] At present, when it comes to laser metal additive technology, the more widely known is powder bed fusion (PBF) technology. In addition to PBF technology, laser metal additive has another important technical branch: laser directed energy deposition DED-LB. Although PBF technology is mature and widely used, it also has some inherent defects compared with DED-LB technology. Its iconic powder bed structure brings many limitations to it, such as: the molding size is limited to the powder spreading mechanism; the material utilization rate is low; the external axis displacement cannot be used; it is not suitable for repair operations.

[0003] In the early days, DED-LB generally used metal powder spraying or side-axis wire feeding. Compared with powder feeding, wire feeding can bring higher deposition rate and molding quality, and is very suitable for heterogeneous isomorphic additive manufacturing. It also has great advantages in economy. The coaxial wire feeding method is even better than side-axis wire feeding, and can bring better isotropic uniformity to workpiece molding. Through reasonable layout, it is also possible to achieve simultaneous feeding of wire and powder. On the basis of coaxial wire feeding, the composition of the deposition layer can be adjusted with the help of powder, and additive manufacturing of uncommon materials can be achieved at a lower cost, while having the functions of separate wire feeding / powder feeding.

[0004] At present, the coaxial wire feeding scheme can be divided into three types according to its implementation method: multi-beam coaxial technology, multi-beam integrated coaxial technology, and ring-beam coaxial technology. Among them, multi-beam integrated coaxial technology has the advantages of simple optical path, relatively compact structure, and low cost. Since each light source of multi-beam integrated coaxial technology is independent, it is proposed that different wavelengths of laser combination can be used according to process requirements to achieve the effect of multi-wavelength light source compounding.

[0005] Multi-wavelength composite lasers can optimize the deposition process. Currently, there are studies on composite welding of red laser and blue laser. The composite of red and blue laser can promote the absorption of red light by high reflectivity metals, which increases the melting depth on the one hand. On the other hand, blue lasers are currently expensive and have relatively low maximum power. Composite with red laser can achieve the same output power at a lower cost. Summary of the invention

[0006] The technical problem to be solved by the present invention is to overcome the defects of the prior art and provide a multi-wavelength light source arc composite laser processing head specially used for coaxial wire powder co-feeding additive / welding.

[0007] In order to solve the above technical problems, the technical solution adopted by the present invention is as follows:

[0008] A multi-wavelength light source composite laser processing head for coaxial wire and powder feeding additive materials, comprising a control module, a wire drawing mechanism and a multi-beam laser head;

[0009] The control module includes a sensor for detecting whether the welding wire passes through;

[0010] In the wire drawing mechanism, the wire drawing motor drives the wire drawing assembly to draw and retract the welding wire between two axially opposite wire drawing nozzles;

[0011] The multi-beam laser head includes a wire guide sleeve coaxial with the wire drawing nozzle in the wire drawing mechanism and capable of accommodating the welding wire to pass through, two access blocks with accommodating cavities sleeved on one end of the outer side of the wire guide sleeve, one or more groups of mirror group adjustment modules and corresponding protective mirror modules arranged around the wire guide sleeve; a replaceable nozzle is arranged at the end of the wire guide sleeve; the nozzle has two inner and outer double cavities formed by respectively penetrating the access blocks.

[0012] Furthermore, it also includes a conductive module interface, one end of which is connected to the welding wire through a conductive component, and the other end is connected to an external power source to realize a variety of laser composite processes.

[0013] Furthermore, it also includes a welding wire quick-insert port arranged outside, wherein the welding wire quick-insert port axially cooperates with the welding wire quick-insert port and the first welding wire quick-insert port joint in the control module and the second welding wire quick-insert port joint in the wire drawing mechanism to form a pluggable welding wire passage;

[0014] Furthermore, the control module includes an elastic movable pair for elastically stopping the groove on the first welding wire quick-plug connector.

[0015] Furthermore, the wire drawing assembly includes an active wire drawing wheel and a follower wire drawing wheel arranged on both sides of the axis of the two wire drawing nozzles; it also includes an active spring moving pair for elastically stopping the groove on the second welding wire quick-plug connector and a wire pressing screw pair for adjusting the wire pressing of the follower wire drawing wheel.

[0016] Furthermore, a protective gas nozzle is arranged in the nozzle, and the protective gas nozzle sleeve is installed on the wire guide tube clamping sleeve at the other end of the outside of the wire guide sleeve; the external space formed by the protective gas nozzle and the nozzle is connected with one of the access blocks to form an external cavity for outputting compressed air; the internal space between the protective gas nozzle and the wire guide tube clamping sleeve is connected with another access block to form an internal cavity for outputting inert protective gas.

[0017] Furthermore, the multi-beam laser head also includes a conductive nozzle with one end passing through the nozzle to clamp the welding wire, and the other end of the conductive nozzle is connected to the conductive rod in the wire drawing mechanism through the conductive component;

[0018] When the conductive rod is connected to one pole of the external hot wire power supply, the substrate is connected to the other pole of the hot wire power supply, and the welding wire held by the conductive nozzle touches the substrate, an electrical circuit is formed to electrically heat the welding wire;

[0019] When the conductive rod is connected to one pole of an external arc welding power source and the substrate is connected to the other pole of the arc welding power source, an arc is formed between the welding wire and the substrate through the cooperation of the wire drawing mechanism, and the welding wire is melted to realize arc laser hybrid welding / additive manufacturing.

[0020] Furthermore, the replaceable nozzle is a powder delivery nozzle, and the powder delivery nozzle is provided with a loop or multiple powder delivery channels.

[0021] Further, the lens group adjustment module comprises a tilt adjustment plate, a lens group mounting seat, a lens group mounted in the lens group mounting seat, and a precision thread pair for adjusting the lens group mounting seat and the lens group;

[0022] The precision thread pair is threadedly mounted on the tilt adjustment plate, with the end resting on the lens group mounting seat; a tension spring for applying tension is arranged between the tilt adjustment plate and the lens group mounting seat, and a steel ball is clamped between the tilt adjustment plate and the lens group mounting seat as an adjustment fulcrum.

[0023] Furthermore, the mirror group adjustment module also includes an annular water cooling block and a side water cooling block;

[0024] The annular water cooling block passes through the tilt adjustment plate and is clamped into the lens group mounting seat through a rubber ring; a side water cooling block is installed on the side of the lens group mounting seat;

[0025] The water inlet and outlet of the annular water cooling block and the side water cooling block are equipped with quick-connect connectors.

[0026] Furthermore, the protective mirror module includes a protective mirror and a protective mirror compartment for accommodating the protective mirror;

[0027] A pan-seal ring and a protective lens pressure ring are respectively arranged on both sides of the protective lens.

[0028] Furthermore, it also includes an ultrasonic transducer, which is arranged between the wire drawing mechanism and the multi-beam laser head, and the welding wire is ultrasonically vibrated by the ultrasonic transducer.

[0029] The control method of the multi-wavelength light source composite laser processing head for coaxial wire and powder feeding additive material according to any one of the above items comprises the following steps:

[0030] Step 1: When receiving the laser command, start recording the time when the welding wire touches the substrate;

[0031] Step 2: The annular proximity sensor detects whether there is a signal of welding wire passing through; when welding wire passes through, the wire drawing motor is controlled to rotate continuously to push the welding wire out for wire feeding;

[0032] Step 3: The welding wire touch detection module detects whether there is a detection voltage or current signal on the substrate;

[0033] When the welding wire touch detection module detects a detection voltage or current signal on the substrate, it sends a "welding wire ready" signal to the PLC. At the same time, the wire feeding of the wire drawing motor is paused, and the welding wire touch detection module disconnects from the welding wire electrical circuit; then the PLC controls the laser to emit light.

[0034] When the welding wire touch detection module does not detect the detection voltage or current signal on the substrate, it is determined whether the time currently recorded that the welding wire touches the substrate exceeds the preset time value. If it exceeds the preset time value, a "welding wire is not ready" alarm signal is issued to terminate the laser action; if it does not exceed the preset time value, it returns to step 2.

[0035] The beneficial effects achieved by the present invention are:

[0036] The laser processing head of the present invention can be installed at the end of various motion mechanisms and can be used for integrated additive manufacturing of complex metal components with high surface quality requirements.

[0037] The mirror adjustment module is independently set up and can be quickly disassembled and connected to the external optical fiber to quickly build working conditions with different wavelengths. The mirror adjustment module can be fine-tuned to facilitate multi-beam focusing.

[0038] Through the coordination and connection between the conductive rod, conductive block, contact block and conductive nozzle for holding the welding wire, an external hot wire power supply is used to connect the two poles to the substrate and the conductive rod respectively. When the welding wire touches the substrate, an electric circuit can be formed, and the current can be conducted to the welding wire through the conductive nozzle, so that the controllable heating of the welding wire can be realized. At the same time, the voltage / current generated on the substrate by the detection circuit can also be used as a condition to determine whether the laser emits laser.

[0039] When the conductive rod is connected to one pole of the external MIG or MAG welding power source, and the substrate is connected to the other pole of the MIG or MAG welding power source, an arc is formed between the welding wire and the substrate through the cooperation of the wire drawing mechanism, and the welding wire is melted to achieve MIG or MAG welding. This process can act simultaneously with the laser light source to achieve the effect of auxiliary laser fuse or process compounding.

[0040] The timing of laser light emission is determined by signals such as whether the wire feeder is producing wire, the operating signal fed back by the motor, the presence of welding wire signals detected by the sensor, and whether the welding wire touches the substrate, so as to determine the transition state of the molten pool in the additive process.

[0041] The present invention can select a combination of laser light sources of different wavelengths according to the requirements of materials and processes, achieve the effect of multi-wavelength light source composite, and realize high surface quality laser additive / welding, multi-wavelength laser composite additive / welding, laser fuse / powder delivery / wire and powder co-delivery additive / welding; it has a wide range of application scenarios in scientific research, product proofing and high-end manufacturing. BRIEF DESCRIPTION OF THE DRAWINGS

[0042] Figure 1 is a schematic diagram of a laser processing head in this embodiment (optical fiber is not shown in the figure);

[0043] Figure 2 yes Figure 1 Right view of;

[0044] Figure 3 yes Figure 1 The control module outline diagram in FIG.

[0045] Figure 4 yes Figure 3 The control module exploded diagram in the figure;

[0046] Figure 5 yes Figure 1 Outline drawing of the wire drawing mechanism;

[0047] Figure 6 yes Figure 5 Exploded diagram of wire drawing mechanism;

[0048] Figure 7 yes Figure 5 A magnified view of the assembly position of the wire drawing components inside the wire drawing mechanism and the welding wire quick-insert mounting plate;

[0049] Figure 8 yes Figure 5 A magnified view of the assembly position of the wire drawing components and the movable spring moving pair inside the wire drawing mechanism (the welding wire quick-insert mounting plate is hidden);

[0050] Fig. 9 yes Figure 1 The appearance diagram of the multi-beam laser head in FIG.

[0051] Fig.10 yes Fig. 9 Exploded diagram of the multi-beam laser head;

[0052] Fig.11 yes Fig.10 Outline drawing of the mirror adjustment module in FIG.

[0053] Fig.12 yes Fig.11 Exploded diagram of the mirror adjustment module;

[0054] Fig.13 yes Fig.10The protective mirror module outline diagram in the figure;

[0055] Fig.14 yes Fig.13 Exploded diagram of protective mirror module;

[0056] Fig.15 It is a flow logic diagram of the control method. DETAILED DESCRIPTION

[0057] The present invention will be further described below in conjunction with the accompanying drawings. The following embodiments are only used to more clearly illustrate the technical solution of the present invention, and cannot be used to limit the protection scope of the present invention.

[0058] Example 1

[0059] Combination Figure 1 and Figure 2 As shown, the multi-wavelength light source arc composite laser processing head for coaxial wire powder feeding disclosed in this embodiment mainly includes the following components:

[0060] Cable corrugated tube 1: used for cable bundling.

[0061] Control module 2: mainly includes gas circuit switch control elements, control buttons, cable connectors, etc., which control some important conditions of the laser wire filling cladding process.

[0062] Wire drawing mechanism 3: It is composed of a wire drawing wheel driven by a servo motor, located at the upper end of the multi-beam laser head 6, and can draw and retract the welding wire. It is equipped with a hot wire power cable access port.

[0063] Wire quick connector 4: The wire path can be connected manually and quickly.

[0064] Optical fiber 5: the main transmission carrier of laser, which loads the laser onto the mirror group in the multi-beam laser head 6.

[0065] Multi-beam laser head 6: A laser processing head composed of 6 single-wavelength or multi-wavelength mixed lasers, integrating air positive pressure protection and inert gas molten pool protection. By replacing the lower end nozzle, wire feeding inside the laser and powder feeding outside the laser can be achieved.

[0066] Optical fiber bracket 7: used to fix the optical fiber to avoid damage to the optical fiber.

[0067] Installation base plate 8: used to fix the wire drawing mechanism 3, the control module 2 and to be mounted on the end axis of the six-axis robot, and to achieve application in multiple scenarios by adding flanges and other means.

[0068] Combination Figure 3 and Figure 4As shown, the control module 2 includes a welding wire quick-plug 21, an insulated welding wire detection protection shaft 22, an annular proximity sensor 23, a bellows mounting cover 24, a support 25, a welding wire detection mounting base plate 26, a welding wire connection transition piece 27, a welding wire quick-plug connector 28, an insulating mounting plate 29, a mounting sheet metal 210 and an outer cover shell 212.

[0069] The welding wire quick plug-in unit 21 is used for manually and quickly connecting the welding wire pipeline, and a hollow insulating welding wire detection protection shaft 22 made of plastic material is installed on it. The welding wire can pass through the insulating welding wire detection protection shaft 22, and the insulating welding wire detection protection shaft 22 is inserted into the annular proximity sensor 23. The annular proximity sensor 23 is used to detect whether there is welding wire passing through the insulating welding wire detection protection shaft 22.

[0070] The bellows installation cover plate 24 is arranged at the upper end of the installation base plate 8 and the outer cover shell 212, and covers the installation space for accommodating the control module 2 at the upper end. The cable bellows 1 is connected to the bellows installation cover plate 24.

[0071] One end of the pillar 25 is installed on the mounting base plate 8, and the other end is installed on the welding wire detection mounting base plate 26. The welding wire detection mounting base plate 26 is elevated and supported in the mounting space formed by the outer cover shell 212 and the mounting base plate 8, so as to facilitate the line arrangement in the internal space formed between the mounting base plate 8 and the welding wire detection mounting base plate 26.

[0072] The welding wire plug transition piece 27 is installed on the welding wire detection installation base plate 26 through the insulating installation plate 29 to play an insulating role. The welding wire plug transition piece 27 is installed with a spring pressure cover 271, a spring 272 and a stop pin 273 to form an elastic moving pair, which elastically stops the groove 281 on the welding wire quick plug connector 28, which is conducive to quick plugging and pulling.

[0073] The welding wire quick-insertion plug 281 is installed on the welding wire quick-insertion connector 28 to fix the external wire guide tube of the welding wire.

[0074] The outer cover shell 212 is installed on the installation base plate 8 to form an installation space for accommodating the control module 2 .

[0075] The mounting sheet metal 210 is disposed on the mounting base plate 8 and adjacent to the outer cover shell 212 . The mounting sheet metal 210 and the outer cover shell 212 jointly protect the control module 2 .

[0076] A button 211 connected to the PLC is installed on the button installation sheet 210, which is used to control wire drawing, wire drawing, protective gas supply, and switching the laser teaching red light.

[0077] Combination Figure 5 , Figure 6 , Figure 7 and Figure 8As shown, the wire drawing mechanism 3 includes a driving structure 31 installed on the mounting base plate 8, a wire drawing wheel mounting plate 32, a wire drawing assembly 33 driven by the driving structure 31 for drawing, a welding wire quick-insertion mounting plate 34, a movable spring moving pair 35, a wire pressing screw pair 36, a conductive rod 37, and a welding wire quick-insertion connector 38.

[0078] The driving structure 31 includes a wire drawing machine motor housing 311 , a wire drawing motor 312 , and a driving wheel mounting drive shaft 313 .

[0079] One end of the wire drawing machine motor housing 311 is mounted on the mounting base plate 8, which plays the role of fixing the entire wire drawing mechanism. A wire drawing wheel mounting plate 32 is mounted on the other end of the wire drawing machine motor housing 311. The wire drawing motor 312 is arranged inside the wire drawing machine motor housing 311 and mounted on the wire drawing wheel mounting plate 32. One end of the driving wheel mounting drive shaft 313 is connected to the rotating end of the wire drawing motor 312, and the other end is connected to the wire drawing assembly 33, and the wire drawing assembly is driven by the wire drawing motor 312 as a wire drawing power source.

[0080] The wire drawing assembly 33 includes a driving wire drawing wheel 331 , a driven wire drawing wheel 332 , a wire drawing wheel pressure arm 333 , an insulating sleeve 334 and a wire pressing member rotating shaft 335 .

[0081] The active wire drawing wheel 331 is mounted on the rotating end of the wire drawing motor 312 through the active wheel mounting drive shaft 313, and is driven by the wire drawing motor 312 as a wire drawing power source.

[0082] The follower wire drawing wheel 332 and its insulating sleeve 334 are rotatably mounted on the wire drawing wheel pressure arm 333 , and the wire drawing wheel pressure arm 333 is rotatably disposed on the wire drawing wheel mounting plate 32 via a wire pressing member rotating shaft 335 .

[0083] The wire drawing pressure arm stop pin 3331 and the wire drawing screw pressure arm stop pin 3332 are both installed on the wire drawing wheel pressure arm 333 .

[0084] The welding wire quick plug mounting plate 34 is fixedly mounted on the wire drawing wheel mounting plate 32. The welding wire quick plug mounting plate 34 is equipped with a movable spring moving pair 35 composed of a pin cap 351, a spring 352, a quick plug pin insulating sleeve 353, a quick plug pin end insulating sleeve 354 and a quick plug pin 355. The quick plug welding wire is realized by the movable spring moving pair 35. A wire pressing screw pair 36 composed of a pressing screw 361, a stop arm, a spring and a wire drawing screw ring 362 is also installed. The wire drawing wheel pressing arm 333 is pressed by the wire pressing screw pair 36, so that the main and follower wire drawing wheels are pressed against the welding wire and exert pressure on the clamped welding wire, thereby realizing wire drawing.

[0085] The conductive rod 37 is inserted into the drawing wheel mounting plate 32 through the upper and lower conductive rod insulating sleeves 371, and one end can be electrically connected to the cable connector in the control module 2 through the hot wire power cable access port, and the other end passes through the drawing wheel mounting plate 32 to be connected to the conductive block 67 in the multi-beam laser head 6, and the electric heating of the welding wire can be controlled by PLC.

[0086] A mounting hole coaxial with the welding wire quick plug connector 28 is provided on the surface of the welding wire quick plug connector 34 facing the control module 2, and the welding wire quick plug connector 38 can be inserted into the mounting hole. Two sets of plastic bearings 341 coaxial with the mounting hole and capable of accommodating the welding wire quick plug connector 38 are provided inside the welding wire quick plug connector 34, which facilitates the insertion and removal of the welding wire quick plug connector 38 and also serves as an insulation function.

[0087] The other end of the welding wire quick plug-in connector 38 can be connected to a wire drawing outlet nozzle 381 , and the other end of the wire drawing outlet nozzle 381 is installed with a wire drawing plastic outlet nozzle 382 .

[0088] A wire drawing outlet tube mounting block 39 is also mounted on the wire drawing wheel mounting plate 32, and a wire drawing outlet tube 391 axially connected to the welding wire quick plug-in connector 38 is mounted on the wire drawing outlet tube mounting block 39, and a wire drawing outlet plastic nozzle 392 opposite to the wire drawing plastic nozzle 382 is mounted on the wire drawing outlet tube 391 at one end facing the wire drawing plastic outlet nozzle 382. The other end of the wire drawing outlet tube 391 is connected to the wire guide sleeve 682 in the multi-beam laser head 6.

[0089] An active wire drawing wheel 331 and a follower wire drawing wheel 332 are arranged on both sides of the axis between the wire drawing plastic wire outlet nozzle 382 and the wire drawing plastic wire outlet nozzle 392, so that the active wire drawing wheel 331 and the follower wire drawing wheel 332 can be movably clamped on the side wall of the welding wire between the wire drawing plastic wire outlet nozzle 382 and the wire drawing plastic wire outlet nozzle 392.

[0090] A wire drawing outer cover 321 is installed on the side of the wire drawing wheel mounting plate 32, and a wire drawing front cover 322 is installed on the end of the wire drawing wheel mounting plate 32 facing the control module 2, which can protect the wire drawing assembly 33, welding wire quick-insertion mounting plate 34, movable spring moving pair 35, wire pressing screw pair 36 and welding wire quick-insertion connector 38 in the enclosed internal space, and facilitate disassembly, assembly and maintenance.

[0091] Combination Fig. 9 and Fig.10 As shown, the multi-beam laser head 6 includes a mounting body 61, a conductive component mounting seat 62 arranged on the mounting body 61, a protective gas access block 63, an air access block 64, an insulating docking block 66, an electric contact docking block 65, a conductive block 67, a guide wire assembly 68, a spraying assembly 69, a mirror group adjustment module 610 and a protective mirror module 620.

[0092] The conductive component mounting seat 6 is sleeved in the protective gas access block 63 and is sleeved in the air access block 64 together to form an inner and outer double cavity for passing protective gas and compressed air.

[0093] The air access block 64 is mounted on the mounting flange 641 and is mounted on the mounting body 61 through the mounting flange 641 for accessing gas.

[0094] The conductive block 67 is mounted on the conductive assembly mounting seat 62, disposed between the wire drawing mechanism 3 and the multi-beam laser head 6, and in contact with the conductive rod 37 in the wire drawing mechanism 3. The conductive block 67 is separated from the entire multi-beam laser head 6 by upper and lower conductive block insulating pads 671 and conductive assembly insulating pads 672.

[0095] An insulating docking block 66 is disposed in the conductive component mounting seat 62 , and an electric contact docking block 65 is disposed in the insulating docking block 66 .

[0096] The guide wire assembly 68 includes a guide wire tube transition piece 681 , a guide wire sleeve 682 , a guide wire tube clamping sleeve 683 and an insulating sleeve 684 .

[0097] One end of the wire guide tube transition piece 681 is inserted into the electric contact docking block 65. The other end of the wire guide tube transition piece 681 is inserted into the wire guide tube clamping sleeve 683. One end of the wire guide tube clamping sleeve 683 is installed on the installation body 61 through an insulating sleeve 684 sleeved thereon. The other end of the wire guide tube clamping sleeve 683 is sleeved with a protective gas nozzle 691.

[0098] A wire guide sleeve 682 connected to the wire drawing outlet tube 391 is provided through the wire guide tube transition piece 681 . The welding wire passing through the wire drawing outlet tube 391 can axially pass through the wire guide sleeve 682 and extend to the conductive nozzle 693 .

[0099] The spraying assembly 69 includes a protective gas nozzle 691 , a conductive nozzle 693 , a nozzle 692 or a four-way powder delivery nozzle 694 .

[0100] The shielding gas nozzle 691 is sleeved and installed on the wire guide tube clamping sleeve 683 to shape the shielding gas flow.

[0101] The nozzle 692 is mounted on the mounting body 61 and surrounds the outside of the shielding gas nozzle 691, and is used to receive compressed air to play an internal positive pressure role to prevent external dust from returning to contaminate the protective mirror. The inner space between the shielding gas nozzle 691 and the wire guide tube clamping sleeve 683 is connected to the shielding gas access block 63 to carry inert shielding gas, which plays an anti-oxidation protection role for the molten welding wire / powder during the cladding process; the outer space formed by the shielding gas nozzle 691 and the nozzle 692 is connected to the air access block 64 to carry compressed air to protect the protective mirror 623 in the protective mirror module 620 from contamination.

[0102] The conductive nozzle 693 is installed on the wire guide tube clamping sleeve 683 to clamp the contact welding wire, facilitate the straightening of the welding wire, and is connected to the wire guide tube transition piece 681, connected to the electric contact docking block 65 through the wire guide tube transition piece 681, and then connected to the conductive rod 37 through the conductive block 67.

[0103] It also includes a conductive module interface, one end of which is connected to the welding wire through a conductive component, and the other end is connected to an external power source to achieve a variety of laser composite processes. The external power source can be a hot wire power source or an arc welding power source.

[0104] In this embodiment, the external hot wire power source has one pole connected to the substrate and the other pole connected to the conductive rod 37. The conductive nozzle clamps the welding wire. When the welding wire touches the substrate, an electrical circuit is formed. The current can be conducted to the welding wire through the conductive nozzle to heat the welding wire. At the same time, the voltage / current of the circuit can also be detected as a condition for judging whether the laser emits laser.

[0105] In other embodiments, when the conductive rod is connected to one pole of an external arc welding power source and the substrate is connected to the other pole of the arc welding power source, an arc can be formed between the welding wire and the substrate through the cooperation of the wire drawing mechanism, and the welding wire is melted to achieve arc welding. The above process can act simultaneously with the laser light source to achieve the effect of auxiliary laser fuse or process combination. Arc welding can be MIG welding or MAG welding.

[0106] In other embodiments, the nozzle may be replaced by a powder delivery nozzle, which is provided with a loop or multiple powder delivery channels, such as a four-way powder delivery nozzle.

[0107] One or more mirror adjustment modules 610 and corresponding protective mirror modules 620 are also installed on the installation body 61 .

[0108] The lens group adjustment module 610 mainly performs the shaping and focusing function of the laser beam, and uses the XY dual-axis fine-tuning structure to achieve fine-tuning of the laser focus. The protective mirror module 620 protects the collimating and focusing lenses in the lens group to prevent external dust pollution and scattered light. At the same time, by replacing the lens group adjustment module 610, it is possible to achieve free switching of multi-wavelength lasers, forming a variety of different usage scenarios of a single wavelength or a mixture of multiple wavelengths, and maximally accommodate laser cladding operations of different materials.

[0109] Combination Fig.11 and Fig.12 As shown, the lens group adjustment module 610 includes a tilt adjustment plate 613 , a lens group mounting seat 616 , a lens group 6161 mounted in the lens group mounting seat 616 , and a precision thread pair 614 for adjusting the lens group mounting seat 616 and the lens group 6161 .

[0110] The precision thread pair 614 is threadedly mounted on the tilt adjustment plate 613, and is pushed down on the lens assembly mounting seat 616 to fine-tune the XY tilt of the tilt adjustment plate 613, thereby achieving the adjustment of the lens assembly mounting seat 616 and the lens assembly 6161. Among them, the steel ball 617 is clamped between the tilt adjustment plate 613 and the lens assembly mounting seat 616 as an adjustment fulcrum, the tension spring 615 applies tension between the tilt adjustment plate 613 and the lens assembly mounting seat 616, and the pin is used to fix the two ends of the tension spring on the tilt adjustment plate 613 and the lens assembly mounting seat 616 respectively. The tension spring 615, the pin and the steel ball 617 form a multi-point support between the tilt adjustment plate 613 and the lens assembly mounting seat 616, and the adjustment is achieved by rotating the precision thread pair 614 through the thread. The fine adjustment of the lens assembly can facilitate the focusing of multiple beams.

[0111] The center of the tilt adjustment plate 613 has a through hole, which can accommodate the annular water cooling block 6121. The annular water cooling block 6121 is inserted into the lens assembly mounting seat 616 through the rubber ring 618 to prevent dust. A side water cooling block 6122 is installed on the side of the lens assembly mounting seat 616.

[0112] The quick-plug connector 611 is installed on the annular water-cooling block 6121 and the side water-cooling block 6122 to form the water inlet and outlet. Water passes through the quick-plug connector 611 and enters the annular water-cooling block 6121 and the side water-cooling block 6122 through the inlet, and then flows through the outlet for water cooling and temperature adjustment to adjust the mirror group mounting seat 616 and the mirror group 6161.

[0113] The O-ring 6191 is located between the protective mirror cover plate 619 and the mirror assembly mounting seat 616 , and acts as a seal to prevent dust from entering the mirror assembly mounting seat 616 .

[0114] The captive screws 6192 are used to fasten the protective mirror cover plate 619 to the mirror assembly mounting seat 616, making it easy to disassemble and install.

[0115] The mirror group adjustment module 610 is independently arranged and can be quickly disassembled. The optical fiber 5 is externally arranged and can be connected to the mirror groups 6161 in the mirror group adjustment module 610 respectively, so as to quickly build a working condition of compounding different wavelengths.

[0116] Combination Fig.13 and Fig.14 As shown, the protective mirror module 620 includes a protective mirror 623 located on the same center line as the corresponding mirror group 6161 and a protective mirror chamber 625 for accommodating the protective mirror 623 .

[0117] The protective lens 623 is placed on the universal seal ring 624 and pressed down into the protective lens chamber 625 by the protective lens pressing ring 621. The universal seal ring 624 is elastic and can clamp the protective lens 623 firmly in the middle.

[0118] A protective mirror pressing ring 622 is embedded in the protective mirror pressing ring 621, which can press the protective mirror 623 without damaging the protective mirror 623.

[0119] The protective mirror chamber 625 is fixed to the mounting body 61 by a captive screw 626 for easy replacement and disassembly.

[0120] An installation position is also reserved on the multi-beam laser head 6, which is convenient for adding a molten pool detection camera, a weld detection or an external atmosphere shield to form a low-oxygen environment for cladding operations on active metals.

[0121] The laser processing head of this product can be installed at the end of various motion mechanisms. The molding size mainly depends on the size of the motion mechanism. It can be used for integrated additive manufacturing of complex metal components with high surface quality requirements. Different laser light source combinations can be selected according to material and process requirements. The silk and powder co-feeding function can also meet the manufacturing needs of uncommon standard grades of materials. It has a wide range of application scenarios in scientific research, product proofing and high-end manufacturing.

[0122] Example 2

[0123] Based on Example 1, this example discloses a method for controlling a multi-wavelength light source arc composite laser processing head for coaxial wire powder delivery. Fig.15 shown.

[0124] The annular proximity sensor 23 in the control module is used to detect whether a welding wire passes through.

[0125] The wire drawing motor in the wire drawing mechanism 3 feeds back the operation signal to the PLC. The wire drawing motor can be controlled by the PLC to run, and can also be started and stopped manually.

[0126] The welding wire touch detection module is used to detect whether there is a detection voltage / current signal on the substrate, as a condition for judging whether the laser emits laser. When one pole of the external hot wire power supply is connected to the substrate and the other pole is connected to the conductive rod 37, and the conductive nozzle 693 clamps the welding wire to touch the substrate to form an electrical circuit, the welding wire touch detection module can detect the detection voltage or current signal generated on the substrate.

[0127] The timing of laser light emission is determined by the operation signal fed back by the wire drawing motor, the signal of the presence of welding wire detected by the annular proximity sensor, and the signal of whether the welding wire touches the substrate detected by the welding wire touch detection module, so as to determine the transition state of the molten pool in the additive process.

[0128] When feeding the wire for the first time, the welding wire is usually inserted into the laser processing head manually, and the wire drawing motor is started to feed the wire.

[0129] The specific control methods are as follows:

[0130] Step 1: PLC receives the light-emitting instruction from the host computer;

[0131] Start recording the time when the welding wire touches the substrate;

[0132] Step 2: The annular proximity sensor 23 detects a signal indicating whether there is a welding wire passing through; when the welding wire passes through, the wire drawing motor is controlled to rotate continuously to push the welding wire out for wire feeding; when no welding wire passes through, it indicates that the wire reel is empty, and the wire reel can be replaced and the wire can be fed again; at the same time, the wire drawing motor can be paused to avoid idling;

[0133] Step 3: The welding wire touch detection module detects whether there is a detection voltage or current signal on the substrate.

[0134] When the welding wire touch detection module detects a detection voltage or current signal on the substrate, it means that the welding wire has been fed to the substrate to form an electrical circuit. The welding wire touch detection module feeds back a "welding wire ready" signal to the PLC. At the same time, the wire feeding of the wire drawing motor is suspended (to ensure that the light is emitted first and then the wire is continuously output to prevent the front welding wire from not melting). The welding wire touch detection module disconnects from the welding wire electrical circuit to protect the welding wire touch detection module from being damaged by the hot welding wire. Then, the PLC controls the laser to emit light.

[0135] When the welding wire touch detection module does not detect the detection voltage or current signal on the substrate, it is determined whether the time currently recorded that the welding wire touches the substrate exceeds the preset time value. If it exceeds the preset time value, a "welding wire is not ready" alarm signal is issued to terminate the light emitting action; if it does not exceed the preset time value, it returns to execute step 2.

[0136] Until the work is completed.

[0137] Example 3

[0138] On the basis of Example 1, the laser processing head of this embodiment further includes an ultrasonic transducer, which is arranged between the wire drawing mechanism and the multi-beam laser head. The ultrasonic transducer can make the welding wire ultrasonically vibrate in the molten pool, improve the internal grains of the metal after solidification, improve the mechanical properties, refine the grains at the microscopic level, and stir the molten pool at the macroscopic level to reduce the porosity of the weld.

[0139] The above is only a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the technical principles of the present invention. These improvements and modifications should also be regarded as the scope of protection of the present invention.

Claims

1. A multi-wavelength light source arc composite laser processing head with coaxial wire and powder delivery, characterized in that: It includes a control module, a wire drawing mechanism and a multi-beam laser head; The control module includes a sensor for detecting whether the welding wire passes through; In the wire drawing mechanism, the wire drawing motor drives the wire drawing assembly to draw and retract the welding wire between two axially opposite wire drawing nozzles; The multi-beam laser head is a laser processing head composed of multi-wavelength mixed lasers; The multi-beam laser head also includes a conductive nozzle with one end extending out of the nozzle to clamp the welding wire, and the other end of the conductive nozzle is connected to the conductive rod in the wire drawing mechanism through the conductive component; When the conductive rod is connected to one pole of the external hot wire power supply, the substrate is connected to the other pole of the hot wire power supply, and the welding wire held by the conductive nozzle touches the substrate, an electrical circuit is formed to electrically heat the welding wire; When the conductive rod is connected to one pole of an external arc welding power source and the substrate is connected to the other pole of the arc welding power source, an arc is formed between the welding wire and the substrate through the cooperation of the wire drawing mechanism, and the welding wire is melted to realize arc laser hybrid welding / additive manufacturing; The multi-beam laser head comprises a wire guide sleeve coaxial with the wire drawing outlet nozzle in the wire drawing mechanism and capable of accommodating the welding wire to pass through, two access blocks with accommodating cavities sleeved on one end of the outer side of the wire guide sleeve, one or more mirror group adjustment modules arranged around the wire guide sleeve and a corresponding protective mirror module; a replaceable nozzle is arranged at the end of the wire guide sleeve; the nozzle has two inner and outer double cavities respectively connected with the access block to form; the nozzle is used to access compressed air to prevent external dust from returning to contaminate the protective mirror module; the replaceable nozzle is a powder feeding nozzle, and a loop or multi-channel powder feeding channel is arranged on the powder feeding nozzle; A protective gas nozzle is arranged in the nozzle, and the protective gas nozzle sleeve is installed on the wire guide tube clamping sleeve at the other end of the outside of the wire guide sleeve; the outer space formed by the protective gas nozzle and the nozzle is connected with one of the access blocks to form an outer cavity for outputting compressed air; the inner space between the protective gas nozzle and the wire guide tube clamping sleeve is connected with the other access block to form an inner cavity for outputting inert protective gas.

2. The multi-wavelength light source arc composite laser processing head with coaxial wire and powder feeding according to claim 1 is characterized in that: It also includes a conductive module interface, one end of which is connected to the welding wire through a conductive component, and the other end is connected to an external power source to realize a variety of laser composite processes.

3. The multi-wavelength light source arc composite laser processing head with coaxial wire and powder feeding according to claim 1 is characterized in that: It also includes a welding wire quick socket arranged outside, which is axially matched with the welding wire quick plug-in unit and the first welding wire quick plug-in unit joint in the control module and the second welding wire quick plug-in unit joint in the wire drawing mechanism to form a pluggable welding wire passage.

4. The multi-wavelength light source arc composite laser processing head with coaxial wire and powder feeding according to claim 3 is characterized in that: The control module comprises an elastic movable pair for elastically stopping the groove on the first welding wire quick-insert connector.

5. The multi-wavelength light source arc composite laser processing head with coaxial wire and powder feeding according to claim 3 is characterized in that: The wire drawing assembly includes an active wire drawing wheel and a follower wire drawing wheel arranged on both sides of the axis of the two wire drawing nozzles; it also includes a movable spring moving pair for elastically stopping the groove on the second welding wire quick-plug connector and a wire pressing screw pair for adjusting the wire pressing of the follower wire drawing wheel.

6. The multi-wavelength light source arc composite laser processing head with coaxial wire and powder feeding according to claim 1 is characterized in that: The control module includes a welding wire quick plug-in, an insulated welding wire detection protection shaft, and an annular proximity sensor; The welding wire quick plug-in unit is used for manually and quickly connecting the welding wire pipeline, and is provided with the hollow insulating welding wire detection protection shaft made of plastic material, and the welding wire can pass through the insulating welding wire detection protection shaft, and the insulating welding wire detection protection shaft is inserted into the annular proximity sensor, and the annular proximity sensor is used for detecting whether the welding wire passes through the insulating welding wire detection protection shaft.

7. The multi-wavelength light source arc composite laser processing head with coaxial wire and powder feeding according to claim 6 is characterized in that: Also included are cable bellows and mounting base plate; The control module also includes a bellows mounting cover plate, a support column, a welding wire detection mounting base plate, an insulating mounting plate and an outer cover shell; The bellows installation cover is arranged at the upper ends of the installation base plate and the outer cover shell, and covers the installation space accommodating the control module at the upper end; One end of the support is mounted on the mounting base plate, and the other end is mounted on the welding wire detection mounting base plate, so that the welding wire detection mounting base plate is elevated and supported in the mounting space formed by the outer cover shell and the mounting base plate.

8. The multi-wavelength light source arc composite laser processing head with coaxial wire and powder feeding according to claim 1 is characterized in that: The lens group adjustment module comprises a tilt adjustment plate, a lens group mounting seat, a lens group mounted in the lens group mounting seat, and a precision thread pair for adjusting the lens group mounting seat and the lens group; The precision thread pair is threadedly mounted on the tilt adjustment plate, with the end resting on the lens group mounting seat; a tension spring for applying tension is arranged between the tilt adjustment plate and the lens group mounting seat, and a steel ball is clamped between the tilt adjustment plate and the lens group mounting seat as an adjustment fulcrum.

9. The multi-wavelength light source arc composite laser processing head for coaxial wire and powder feeding according to claim 8 is characterized in that: The lens group adjustment module also includes an annular water cooling block and a side water cooling block; The annular water cooling block passes through the tilt adjustment plate and is clamped into the lens group mounting seat through a rubber ring; a side water cooling block is installed on the side of the lens group mounting seat; The water inlet and outlet of the annular water cooling block and the side water cooling block are equipped with quick-connect connectors.

10. The multi-wavelength light source arc composite laser processing head with coaxial wire and powder feeding according to claim 1 is characterized in that: The protective lens module comprises a protective lens and a protective lens compartment for accommodating the protective lens; A pan-seal ring and a protective lens pressure ring are respectively arranged on both sides of the protective lens.

11. The multi-wavelength light source arc composite laser processing head with coaxial wire and powder feeding according to claim 1 is characterized in that: It also includes an ultrasonic transducer, which is arranged between the wire drawing mechanism and the multi-beam laser head, and the ultrasonic transducer is used to make the welding wire ultrasonically vibrate.

12. A control method for a multi-wavelength light source arc composite laser processing head with coaxial wire and powder feeding according to any one of claims 1 to 11, characterized in that: The following steps are involved: Step 1: When receiving the laser command, start recording the time when the welding wire touches the substrate; Step 2: The annular proximity sensor detects whether there is a signal of welding wire passing through; when welding wire passes through, the wire drawing motor is controlled to rotate continuously to push the welding wire out for wire feeding; Step 3: The welding wire touch detection module detects whether there is a detection voltage or current signal on the substrate; When the welding wire touch detection module detects a detection voltage or current signal on the substrate, it sends a "welding wire ready" signal to the PLC. At the same time, the wire feeding of the wire drawing motor is paused, and the welding wire touch detection module is disconnected from the welding wire electrical circuit; then the PLC controls the laser to emit light; When the welding wire touch detection module does not detect the detection voltage or current signal on the substrate, it determines whether the time the welding wire currently touches the substrate exceeds the preset time value. If it exceeds the preset time value, it sends out a "welding wire is not ready" alarm signal and stops the laser action; If the preset time value is not exceeded, return to step 2.

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