Laser welding head and laser welding device

Abstract

The invention provides a laser welding head and a laser welding device. The laser welding head comprises a light guide part and a plurality of pressing rod assemblies. A light guide channel is arranged in the light guide part and is used for allowing a laser beam to pass through; the light guide channel penetrates to the light emitting end of the light guide part; the multiple pressing rod assemblies are distributed around the axis of the light guide channel, and each pressing rod assembly is configured to elastically stretch out and draw back independently, so that the end, exceeding the light outlet end of the light guide piece, of each pressing rod assembly can elastically abut against a welding workpiece. When the laser welding head is pressed on the surface of a workpiece, the laser welding head can automatically adapt to unevenness or height difference of the surface of the workpiece, pressure on the workpiece is kept, the position of the welded workpiece is kept, and therefore the welding effect is improved.

Description

Technical Field

[0001] This invention relates to the field of laser welding technology, and more specifically to a laser welding head and a laser welding device. Background Technology

[0002] Plastic welding, as a core technology for joining polymer materials, has been widely used in the automotive, electronics, medical, and aerospace industries.

[0003] In related technologies, when welding workpieces, the tooling fixtures cannot apply pressure to irregularly shaped parts effectively. When there are height differences in the plastic parts to be welded, the compressive load around the welding position is different, which leads to a deterioration in the tooling effect and makes it difficult to control the spacing between plastic parts, thus affecting the welding effect. Summary of the Invention

[0004] An embodiment of the present invention provides a laser welding head, the portion of which abuts against a workpiece is capable of elastic deformation to adapt to the clamping of workpieces with height differences, thereby improving the quality of welding.

[0005] According to one aspect of this application, a laser welding head is provided, including a light guide and a plurality of pressure rod assemblies; a light guide channel is provided in the light guide for a laser beam to pass through; the light guide channel extends to the light-emitting end of the light guide; the plurality of pressure rod assemblies are distributed around the axis of the light guide channel, one end of each pressure rod assembly is limited on the light guide, and the other end extends beyond the light-emitting end of the light guide; each pressure rod assembly is configured to be able to elastically expand and contract independently, such that the end of each pressure rod assembly extending beyond the light-emitting end can elastically abut against the workpiece to be welded.

[0006] In some embodiments of this application, the light-emitting end of the light guide is provided with a limiting channel; the pressure rod assembly includes a buffer rod and an elastic element; the buffer rod includes a limiting section and a pressing section; the limiting section is slidably inserted in the limiting channel along a straight line, and the elastic element extends out of the light-emitting end; the elastic element is disposed between the light guide and the limiting section so as to drive the pressing section to press against the workpiece.

[0007] In some embodiments of this application, a limiting hole is formed on the end face of the buffer rod facing away from the abutting section; the elastic element passes through the limiting hole, and the two ends of the elastic element abut against the light guide and the buffer rod respectively.

[0008] In some embodiments of this application, the end of the abutment section is provided with rotatable or rollable balls.

[0009] In some embodiments of this application, the ball bearing is provided with a rotating shaft; the rotating shaft passes through the ball bearing and the buffer rod, so that the ball bearing can rotate relative to the buffer rod.

[0010] In some embodiments of this application, a limiting groove is formed on the buffer rod, and the rotating shaft is disposed in the limiting groove; the limiting groove extends along the length direction of the buffer rod, and the rotating shaft can be adjusted to a position within the limiting groove along the extension direction of the limiting groove.

[0011] In some embodiments of this application, the axes of multiple rotating shafts on multiple buffer rods are arranged in parallel.

[0012] In some embodiments of this application, the peripheral sidewall of the limiting channel is provided with a foolproof groove, and the opening direction of the foolproof grooves of the multiple limiting channels is consistent; a foolproof protrusion is formed on the outer periphery of the buffer rod, the foolproof protrusion is limited in the foolproof groove, and can move along the length direction of the buffer rod in the foolproof groove.

[0013] In some embodiments of this application, the radial cross-section of the limiting channel is a non-circular structure, and the outer periphery of the buffer rod is adapted to the inner periphery of the limiting channel.

[0014] In some embodiments of this application, a plurality of exhaust ducts are provided on the peripheral sidewall of the light guide, and the plurality of exhaust ducts are spaced apart along the extension direction of the light guide channel; the two ends of each exhaust duct extend to the outer side of the light guide and the light guide channel, respectively.

[0015] In some embodiments of this application, the light guide is provided with an air inlet channel and an air inlet for each of the exhaust ducts; the air inlet is located at one end of the air inlet channel; the other end of the air inlet channel is opposite to the exhaust duct.

[0016] According to another aspect of this application, this application provides a laser welding apparatus, including a laser generator and the aforementioned laser welding head; the laser generator is used to generate and emit a laser beam; the laser generator is fixed on the light guide.

[0017] In some embodiments of this application, the laser generator is a thulium-doped fiber laser capable of emitting a wavelength of 1940 nm.

[0018] The above-mentioned technical features have at least the following advantages and beneficial effects: Multiple pressure rod assemblies are distributed around the axis of the light guide channel. Each pressure rod assembly is configured to elastically expand and contract independently, allowing the end of each assembly extending beyond the light-emitting end of the light guide to elastically abut against the workpiece. When the laser welding head presses against the workpiece surface, it can automatically adapt to unevenness or height differences on the workpiece surface, maintaining pressure on the workpiece and keeping the workpiece in position, thereby improving the welding effect. Attached Figure Description

[0019] To more clearly illustrate the technical solutions in the embodiments of the present invention, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0020] Figure 1 This is a schematic diagram of the laser welding apparatus shown in this application.

[0021] Figure 2 This is a schematic diagram of the structure of a laser welding head shown in an embodiment of this application.

[0022] Figure 3 This is a cross-sectional schematic diagram of a laser welding head shown in an embodiment of this application.

[0023] Figure 4 This is a schematic diagram of the structure of the light guide shown in the embodiment of this application.

[0024] Figure 5 This is a cross-sectional schematic diagram of the light guide component shown in the embodiments of this application.

[0025] Figure 6 This is a schematic diagram of the structure of the pressure bar assembly shown in the embodiment of this application.

[0026] Figure 7 This is a cross-sectional schematic diagram of the pressure bar assembly shown in an embodiment of this application.

[0027] Figure 8 This is a partial schematic diagram of the pressure bar assembly shown in an embodiment of this application.

[0028] Explanation of reference numerals in the attached figures: 10. Laser welding head; 20. Laser generator; 100. Light guide; 101. Light output end; 110. Light guide channel; 120. Limiting channel; 130. Pressure plate; 140. Smoke exhaust duct; 150. Air inlet channel; 160. Air inlet; 200. Pressure rod assembly; 210. Buffer rod; 211. Limiting hole; 212. Limiting groove; 220. Elastic element; 230. Ball bearing; 240. Rotating shaft; 250. Bearing. Detailed Implementation

[0029] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention. Furthermore, it should be understood that the specific embodiments described herein are only for illustration and explanation of the present invention and are not intended to limit the present invention. In the present invention, unless otherwise stated, directional terms such as "upper" and "lower" generally refer to the upper and lower positions of the device in actual use or operation, specifically the drawing directions in the accompanying drawings; while "inner" and "outer" refer to the outline of the device.

[0030] In related technologies, when welding workpieces, the tooling fixtures cannot apply pressure to irregularly shaped parts effectively. When there are height differences in the plastic parts to be welded, the compressive load around the welding position is different, which leads to a deterioration in the tooling effect and makes it difficult to control the spacing between plastic parts, thus affecting the welding effect.

[0031] One concept of this application is to provide a laser welding apparatus that can adaptively press against the surface of a workpiece with a height difference, thereby improving the quality of the weld.

[0032] For ease of description and understanding, in this application, the direction in which the welding device touches the workpiece is the downward direction, and the direction away from the downward direction is the upward direction.

[0033] Figure 1 This is a schematic diagram of the laser welding apparatus shown in this application.

[0034] See Figure 1 This application provides a laser welding apparatus, including a laser welding head 10 and a laser generator 20. The laser generator 20 is used to generate and emit a laser beam. The laser generator 20 is connected to the light guide channel 110 of the laser welding head 10 through a transmission optical fiber or other optical path system to provide a high-energy laser beam to the laser welding head 10.

[0035] The laser welding head 10 is used for guiding the laser beam to obtain a high-energy-density spot at the output end 101. The high-energy spot acts on the workpiece to melt and weld it. In one example, the laser welding head 10 can also be used for focusing the laser beam.

[0036] The laser welding head 10 can also press against and clamp onto the workpiece to maintain its position during welding, preventing it from moving and thus improving the quality of the weld.

[0037] In one embodiment, the laser welding apparatus further includes a motion unit, to which the laser welding head 10 is fixed so that it can move under the drive of the motion unit. The motion unit can be a robotic arm or other three-dimensional motion structure.

[0038] In one embodiment, the laser generator 20 is a thulium-doped fiber laser capable of emitting a wavelength of 1940 nm.

[0039] The fundamental frequency vibrational absorption lines of chemical bonds (especially CH and OH bonds) in the molecular structure of commonly used plastics (such as polypropylene PP, polyethylene PE, polyamide PA nylon, polycarbonate PC, and PMMA acrylic) are located near the wavelength of 1940 nm. This means that the photon energy at this wavelength can be efficiently and directly absorbed by plastic molecules and rapidly converted into thermal vibrational energy.

[0040] In related technologies, semiconductor lasers with wavelengths of 915nm or 980nm are commonly used in plastic laser welding. The absorption of these near-infrared wavelengths by plastics is mainly achieved through intrinsic absorption, i.e., by adding absorbers such as carbon black to the plastic, or by using a special absorption layer in the underlying plastic layer. The absorption rate of these wavelengths by the plastic itself is very low.

[0041] In this application, the wavelength of the laser emitted by the welding device is 1940nm. The laser energy is almost entirely used to melt the plastic, rather than being reflected or transmitted. Therefore, the same welding effect can be achieved with lower laser power, which saves energy and reduces equipment cost.

[0042] Laser transmission welding of two transparent plastic workpieces can now be performed directly without any intermediate absorption layer or special treatment. The weld itself is clear, transparent, and virtually invisible, meeting the aesthetic requirements of high-end products. This greatly expands the application of laser welding technology in fields such as optical devices, medical microfluidic chips, and transparent housings.

[0043] Figure 2 This is a schematic diagram of the structure of a laser welding head shown in an embodiment of this application. Figure 3 This is a cross-sectional schematic diagram of a laser welding head shown in an embodiment of this application.

[0044] See Figure 2 and Figure 3 The laser welding head 10 includes a light guide 100 and multiple pressure bar assemblies 200. The light guide 100 is used to connect to the laser generator 20 for laser beam transmission. The pressure bar assemblies 200 are used to press against the surface of the workpiece, effectively ensuring that the workpiece does not move during welding and guaranteeing the quality of the weld. Each pressure bar assembly 200 is configured to elastically extend and retract independently, so that the lower end of each pressure bar assembly 200 can abut against the surface of the workpiece.

[0045] In one embodiment, the laser welding head 10 of this application is mainly used for welding stacked plastic workpieces. The laser welding head 10 is used for laser transmission and pressing the workpieces. Driven by the motion unit, the laser welding head 10 moves downward, causing multiple pressure bar assemblies 200 at the lower part of the laser welding head 10 to contact the upper workpiece. During the continuous downward movement, each pressure bar assembly 200 independently elastically contracts according to the contour of the workpiece surface, thereby automatically adapting to possible flatness errors or macroscopic height differences, and applying a uniform pre-pressure to the entire annular welding area.

[0046] The laser generator 20 is activated, emitting a laser beam of a specific wavelength. The laser beam passes through the light guide 100 and is precisely focused onto the interface between the upper and lower plastic workpieces. The lower plastic layer (or the intermediate layer with an absorbent) absorbs the laser energy and melts rapidly to form a molten pool. Through heat conduction, the contact surface of the upper plastic layer also melts, thus achieving molecular-level fusion.

[0047] During the scanning welding process as the laser welding head 10 moves along a predetermined path, multiple pressure bar assemblies 200 surrounding the laser spot remain in a compressed state. The pressure bar located in front of the welding direction is mainly responsible for the "pre-pressure" function, eliminating air and gaps in the area to be welded; while the pressure bar immediately following the laser spot undertakes the "load holding" function, applying continuous pressure to the still molten plastic fluid, promoting its full fusion, expelling air bubbles, and accelerating solidification and shaping under pressure, ultimately forming a high-strength, high-airtightness weld.

[0048] In another embodiment, the laser welding head 10 can also be used for welding two workpieces arranged horizontally opposite each other. Multiple pressure bar assemblies 200 abut against the opposite ends of the two workpieces to maintain their position relative to each other. Each pressure bar can independently undergo elastic deformation, enabling it to press the two workpieces together when there is a height difference between their surfaces, thereby ensuring the welding quality of the opposite ends of the two workpieces.

[0049] Figure 4 This is a schematic diagram of the structure of the light guide shown in the embodiment of this application. Figure 5 This is a cross-sectional schematic diagram of the light guide component shown in the embodiments of this application.

[0050] See Figures 2 to 5 The light guide 100 is the main structural component and optical channel carrier of the laser welding head 10. A light guide channel 110 is provided inside the light guide 100 for the laser beam to pass through. The light guide channel 110 extends to the light-emitting end 101 of the light guide 100, and the laser beam in the light guide channel 110 exits from the light-emitting end 101 of the light guide 100 to weld the workpiece.

[0051] In one embodiment, the light guide channel 110 is a channel extending in a straight line, passing through both ends of the light guide member 100. The laser generator 20 is fixed to one end of the light guide channel 110 facing away from the light-emitting end 101.

[0052] In one example, a pressure plate 130 is provided at one end of the light guide 100 facing away from the light output end 101, and the laser generator 20 is fixed to the pressure plate 130 by fasteners.

[0053] In another embodiment, the light guide channel 110 is divided into multiple segments with angles between them. Reflectors are provided between the multiple segments to allow the laser beam to propagate within each segment.

[0054] In one example, a series of optical lenses are installed inside the light guide channel 110, including a collimating lens for converting diverging laser light into parallel light and a focusing lens for focusing the parallel light onto the workpiece surface. The laser beam passes through the collimating lens and the focusing lens in sequence, and finally exits from the light-emitting end 101, acting on the workpiece.

[0055] In one embodiment, the light-emitting end 101 of the light guide 100 has a limiting channel 120 for limiting the pressure rod assembly 200. The limiting channel 120 extends in a straight line, and the direction of extension of the limiting channel 120 is parallel to the axial direction of the light guide channel 110. The straight extension of the limiting channel 120 allows the pressure rod assembly 200 to slide relative to the light guide 100 in a straight line, so as to be able to approach and move away from the workpiece, providing a reference for the elastic deformation of the pressure rod assembly 200.

[0056] Figure 6 This is a schematic diagram of the structure of the pressure bar assembly shown in the embodiment of this application. Figure 7 This is a cross-sectional schematic diagram of the pressure bar assembly shown in an embodiment of this application. Figure 8 This is a partial schematic diagram of the pressure bar assembly shown in an embodiment of this application.

[0057] See Figures 6 to 8 The light guide 100 is provided with multiple pressure rod assemblies 200. One end of each pressure rod assembly 200 is limited on the light guide 100, and the other end extends beyond the light-emitting end 101 of the light guide 100, so that the end of the pressure rod assembly 200 extending beyond the light-emitting end 101 of the light guide 100 can abut against the workpiece. Each pressure rod assembly 200 is configured to elastically extend and retract independently, so that the end of each pressure rod assembly 200 extending beyond its light-emitting end 101 can elastically abut against the workpiece to be welded. When the laser welding head 10 presses against the surface of the workpiece, it can automatically adapt to the unevenness or height difference of the workpiece surface, maintain pressure on the workpiece, maintain the position of the workpiece to be welded, thereby improving the welding effect.

[0058] In some embodiments, the pressure bar assembly 200 includes a buffer rod 210 and an elastic member 220. The buffer rod 210 includes a limiting section and a pressing section. The limiting section is slidably disposed in a limiting channel 120 of the light guide 100 along a straight line, and the elastic member 220 extends beyond the light emitting end 101. The elastic member 220 is disposed between the light guide 100 and the limiting section to drive the pressing section to press against the workpiece. The limiting section of the buffer rod 210 slides within the limiting channel 120 to achieve sliding of the buffer rod 210, allowing the buffer rod 210 to adaptively press against the workpiece surface at different heights. The elastic member 220 maintains the pressure of the buffer rod 210 on the workpiece.

[0059] In one embodiment, a limiting hole 211 is provided on the end face of the buffer rod 210 facing away from the abutting section; the elastic member 220 is inserted into the limiting hole 211, and the two ends of the elastic member 220 abut against the light guide member 100 and the buffer rod 210 respectively.

[0060] The elastic element 220 is fitted inside the limiting hole 211 to maintain the elasticity of the elastic element 220 along the extension direction of the buffer rod 210, effectively preventing the elastic element 220 from radially shifting.

[0061] In one example, the limiting channel 120 extends in a straight line and is open at one end toward the light-emitting end 101, so that the buffer rod 210 can pass through the limiting channel 120 and slide in a straight line within the limiting channel 120. The end of the limiting channel 120 opposite to the light-emitting end 101 is closed, and one end of the elastic member 220 abuts against the bottom wall of the limiting hole 211, while the other end abuts against the closed end of the limiting channel 120.

[0062] In another example, the limiting channel 120 extends through both ends, and a pressure plate 130 is provided at one end of the light guide 100 facing away from the light-emitting end 101. One end of the elastic member 220 abuts against the bottom wall of the limiting hole 211, and the other end abuts against the pressure plate 130.

[0063] In another embodiment, the pressure rod assembly 200 includes two support rods that can slide relative to each other, with one end of each support rod sleeved on and capable of sliding relative to each other in a straight line. One support rod is fixed to the light guide 100, and one end of the other support rod extends out of the light-emitting end 101 of the light guide 100 to abut against the workpiece. An elastic element 220 is provided between the two support rods, thereby allowing elastic deformation between the two support rods.

[0064] In one embodiment, multiple limiting channels 120 are provided, and the limiting channels 120 are distributed around the axis of the light guide channel 110, so that multiple pressure rod assemblies 200 within the limiting channels 120 are distributed around the axis of the light guide channel 110.

[0065] The number of pressure bar assemblies 200 can be set to two, three, four, five, or six, etc. In one example, the number of pressure bar assemblies 200 is six. Too few (such as three or four) will result in too large a span between the clamping points, insufficient clamping effect on the middle of the workpiece, and easy gaps; too many will make the structure too complex, and the distance between adjacent pressure bars will be too close, which may interfere with the welding process. Six pressure bars can form a complete and stable pressure ring, which is the most reasonable structure while ensuring uniform clamping.

[0066] In one embodiment, the elastic element 220 can be an elastic structure such as a spring, sheet, or elastic rubber.

[0067] See again Figures 6 to 8 The buffer rod 210 has a rotatable or rollable ball bearing 230 at the end of its abutting section. The ball bearing 230 is located on and protrudes from the abutting section of the buffer rod 210. During welding, the ball bearing 230 abuts against the workpiece. As the laser welding head 10 moves relative to the workpiece, the ball bearing 230 rolls relative to the workpiece, greatly reducing frictional resistance generated during movement on the workpiece surface and effectively preventing scratches or drag marks from being left on the working surface.

[0068] By rolling the ball bearings 230 on the workpiece, the laser welding head 10 moves more smoothly and stably during the welding process, reducing crawling or vibration caused by excessive friction, which helps improve the accuracy of the welding trajectory. When there are small steps or curved surface changes on the workpiece surface, the ball bearing structure 230 can glide over these obstacles more easily, and its self-adaptability is stronger than that of a fixed contact point.

[0069] In one embodiment, a rotating shaft 240 is provided on the ball bearing 230; the rotating shaft 240 passes through the ball bearing 230 and the buffer rod 210, so that the ball bearing 230 can rotate relative to the buffer rod 210. When the ball bearing 230 is pressed against the workpiece and moves relative to the workpiece, the ball bearing 230 can roll relative to the workpiece. The rotating shaft 240 connects the ball bearing 230 to the buffer rod 210, which can effectively prevent the ball bearing 230 from falling off the buffer rod 210.

[0070] In one embodiment, the axes of the multiple rotating shafts 240 on the multiple buffer rods 210 are arranged in parallel, thereby ensuring that the multiple balls 230 can only roll in one direction. This ensures that the laser welding head 10 can move stably along a preset straight trajectory, avoiding trajectory errors caused by mechanical interference. Stable movement means that the laser spot moves at a uniform speed on the workpiece, and the energy input is stable, thus forming a weld with highly consistent width, depth, and appearance, improving the quality of the weld.

[0071] Multiple balls 230 roll in the same direction. When the rolling direction of all balls 230 is strictly consistent with the welding direction, the balls 230 at the front roll purely for "pre-compression." The pure rolling in the forward direction ensures that the area to be welded is compacted smoothly and evenly, effectively eliminating gaps. The balls 230 at the rear roll purely for "load maintenance." The balls 230 at the rear can smoothly roll over the weld that is still in a molten state, uniformly compacting it, effectively removing air bubbles and compensating for shrinkage, without disturbing the molten pool or pulling the weld due to slippage.

[0072] In one embodiment, a bearing 250 is provided between the ball 230 and the shaft 240 so that the ball 230 can only rotate relative to the shaft 240, restricting the movement of the ball 230 along the axial direction of the shaft 240 and limiting the movement trajectory of the ball 230.

[0073] In some embodiments, a limiting groove 212 is formed on the buffer rod 210, and a rotating shaft 240 is disposed within the limiting groove 212. The limiting groove 212 extends along the length direction of the buffer rod 210, and the rotating shaft 240 can be adjusted in position within the limiting groove 212 along its extension direction. Adjusting the position of the rotating shaft 240 in the limiting groove 212 allows for fine-tuning of the exposed length or preload of the ball bearing 230. This provides the laser welding head 10 with greater flexibility and adjustment precision, enabling it to adapt to plastic parts with different hardness and surface conditions. For example, the optimal welding distance between the light-emitting end 101 and the workpiece is fixed. At the optimal welding position, adjusting the position of the rotating shaft 240 adjusts the preload of the ball bearing 230 on the workpiece.

[0074] In one embodiment, the rotating shaft 240 is fixed to the outer side of the buffer rod 210 by fastening bolts. By loosening the special fastening bolts, the position of the rotating shaft 240 can be moved up and down along the extension direction of the limiting groove 212, and then the fastening bolts can be tightened.

[0075] In one embodiment, the radial cross-section of the limiting channel 120 is non-circular, and the outer periphery of the buffer rod 210 is adapted to the inner periphery of the limiting channel 120. This effectively prevents the buffer rod 210 from rotating during sliding, ensuring that the orientation of the ball 230 always conforms to the setting, avoiding jamming of the ball 230 or incorrect clamping direction due to rotation of the buffer rod 210, and improving the reliability of the welding operation.

[0076] In one example, the radial cross-section of the limiting channel 120 is elliptical or polygonal in shape.

[0077] In another example, the radial cross-section of the limiting channel 120 is a shape with a foolproof function, such as a "T", "D" or "L" shape.

[0078] In one embodiment, the radial cross-section of the limiting channel 120 is rectangular, and the rectangular sides of the multiple limiting channels 120 extend in the same direction, thereby ensuring that the axis of the rotating shaft 240 is parallel after the pressure rod assembly 200 is limited within the limiting channel 120.

[0079] In another embodiment, a foolproof groove (not shown in the figure) is formed on the peripheral sidewall of the limiting channel 120, and the opening direction of the foolproof grooves of the multiple limiting channels 120 is consistent; a foolproof protrusion is formed on the outer periphery of the buffer rod 210, and the foolproof protrusion is limited within the foolproof groove. The foolproof protrusion can move along the length direction of the buffer rod 210 within the foolproof groove.

[0080] In one example, the buffer rod 210 passes through the light-emitting end 101 and is installed into the limiting channel 120. The anti-mistake groove extends axially through the limiting channel 120 to the light-emitting end 101, allowing the anti-mistake protrusion to extend into the anti-mistake groove. A protruding step is formed within the anti-mistake groove, and the anti-mistake protrusion is elastically expandable and contractable. When the anti-mistake protrusion extends into the anti-mistake groove, it expands and contracts at the step, allowing it to pass over the step. After the anti-mistake protrusion passes over the step, it returns to its original shape, with its bottom abutting against the step, preventing the buffer rod 210 from dislodging from the limiting channel 120.

[0081] See Figures 1 to 8 The light guide 100 has multiple exhaust ducts 140 on its peripheral sidewall, which are spaced apart along the extension direction of the light guide channel 110. Each exhaust duct 140 extends to both ends of the light guide 100 and the light guide channel 110, respectively. The outer end of the exhaust duct 140 extends to the outer side of the light guide 100, and the inner end extends to the light guide channel 110. The inner end of the exhaust duct 140 and the light outlet of the light guide channel 110 are connected, allowing welding fumes to pass sequentially through the light guide channel 110 and the exhaust duct 140.

[0082] Multiple exhaust ducts 140 are spaced apart along the extension direction of the light guide channel 110, thereby enabling multi-stage exhaust at different heights to ensure the exhaust effect, better solve the problem of smoke and dust blocking light, and improve the stability of weld quality.

[0083] In one embodiment, an air intake is provided at the outer end of the flue 140, and an air intake structure is provided at the air intake, so as to generate negative pressure or airflow near the welding point and directly suck away the welding fumes from the source.

[0084] In one embodiment, the light guide 100 is provided with an air inlet duct 150 and an air inlet 160 corresponding to each exhaust duct 140; the air inlet 160 is located at one end of the air inlet duct 150; the other end of the air inlet duct 150 is opposite to the exhaust duct 140. The addition of the actively supplying air inlet duct 150, working in conjunction with the exhaust duct 140, can form a more powerful and directional "air curtain" or "purge airflow," actively blowing smoke and dust towards the exhaust duct 140 or away from the light path area.

[0085] The embodiments of the present invention have been described in detail above. Specific examples have been used to illustrate the principles and implementation methods of the present invention. The description of the above embodiments is only for the purpose of helping to understand the method and core ideas of the present invention. At the same time, for those skilled in the art, there will be changes in the specific implementation methods and application scope based on the ideas of the present invention. Therefore, the content of this specification should not be construed as a limitation of the present invention.

Claims

1. A laser welding head (10), characterized in that, It includes: A light guide (100) is provided with a light guide channel (110) for the laser beam to pass through; the light guide channel (110) extends to the light-emitting end (101) of the light guide (100). Multiple pressure rod assemblies (200) are distributed around the axis of the light guide channel (110). One end of each pressure rod assembly (200) is limited on the light guide (100), and the other end extends beyond the light-emitting end (101) of the light guide (100). Each pressure rod assembly (200) is configured to elastically extend and retract independently, so that the end of each pressure rod assembly (200) extending beyond the light-emitting end (101) can elastically abut against the welding workpiece.

2. The laser welding head (10) according to claim 1, characterized in that, The light-emitting end (101) of the light guide (100) has a limiting channel (120); the pressure rod assembly (200) includes a buffer rod (210) and an elastic element (220); the buffer rod (210) includes a limiting section and a pressing section; the limiting section is slidably inserted in the limiting channel (120) along a straight line, and the elastic element (220) extends out of the light-emitting end (101); the elastic element (220) is disposed between the light guide (100) and the limiting section so as to drive the pressing section to press against the workpiece.

3. The laser welding head (10) according to claim 2, characterized in that, The buffer rod (210) has a limiting hole (211) on the end face of one end facing away from the abutting section; the elastic member (220) passes through the limiting hole (211), and the two ends of the elastic member (220) abut against the light guide (100) and the buffer rod (210) respectively.

4. The laser welding head (10) according to claim 2, characterized in that, The end of the abutment section is provided with rotatable or rollable ball bearings (230).

5. The laser welding head (10) according to claim 4, characterized in that, A rotating shaft (240) is provided on the ball (230); the rotating shaft (240) passes through the ball (230) and the buffer rod (210) so that the ball (230) can rotate relative to the buffer rod (210).

6. The laser welding head (10) according to claim 5, characterized in that, A limiting groove (212) is provided on the buffer rod (210), and the rotating shaft (240) is disposed in the limiting groove (212); the limiting groove (212) extends along the length direction of the buffer rod (210), and the rotating shaft (240) can be adjusted to a position in the limiting groove (212) along the extension direction of the limiting groove (212).

7. The laser welding head (10) according to claim 4, characterized in that, The axes of multiple rotating shafts (240) on multiple buffer rods (210) are arranged in parallel.

8. The laser welding head (10) according to any one of claims 2 to 7, characterized in that, The limiting channel (120) has a foolproof groove on its peripheral sidewall, and the foolproof grooves of the multiple limiting channels (120) are opened in the same direction; the buffer rod (210) has a foolproof protrusion on its outer periphery, the foolproof protrusion is limited in the foolproof groove, and can move along the length direction of the buffer rod (210) in the foolproof groove.

9. The laser welding head (10) according to claim 2, characterized in that, The radial cross-section of the limiting channel (120) is a non-circular structure, and the outer periphery of the buffer rod (210) is adapted to the inner periphery of the limiting channel (120).

10. The laser welding head (10) according to claim 1, characterized in that, The light guide (100) has a plurality of exhaust ducts (140) on its peripheral sidewall, and the plurality of exhaust ducts (140) are spaced apart along the extension direction of the light guide channel (110); the two ends of each exhaust duct (140) extend to the outer side of the light guide (100) and the light guide channel (110), respectively.

11. The laser welding head (10) according to claim 10, characterized in that, The light guide (100) is provided with an air inlet channel (150) and an air inlet (160) for each of the exhaust ducts (140); the air inlet (160) is located at one end of the air inlet channel (150); the other end of the air inlet channel (150) is opposite to the exhaust duct (140).

12. A laser welding apparatus, characterized in that, Includes a laser generator (20) and a laser welding head (10) according to any one of claims 1 to 11; the laser generator (20) is used to generate and emit a laser beam; the laser generator (20) is fixed on the light guide (100).

13. The laser welding apparatus according to claim 12, characterized in that, The laser generator (20) is a thulium-doped fiber laser capable of emitting a wavelength of 1940 nm.

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