Laser welding head device for inhibiting thermal lens effect and cooling control method thereof

Abstract

The invention provides a laser welding head device for restraining the thermal lens effect and a cooling control method thereof.The laser welding head device comprises a device shell, the device shell is provided with a laser light path channel, and a collimating lens module is arranged on the laser inlet side of the laser light path channel; a laser light path channel is formed in the device shell, a focusing lens module is arranged on the laser emitting side of the laser light path channel, the collimating lens module comprises a collimating lens, the focusing lens module comprises a focusing lens, a water cooling flow channel is formed in the device shell, and cooling liquid in the water cooling flow channel can make contact with the collimating lens and the focusing lens. The restraining effect on the thermal lens effect can be improved, then the light gathering capacity of the laser beam in the welding process is improved, the reliability of the focus position of the laser beam is guaranteed, the welding penetration uniformity is guaranteed, and the laser welding quality is improved.

Description

Technical Field

[0001] The invention belongs to the technical field of laser welding device design, and in particular relates to a laser welding head device capable of suppressing thermal lens effect and a cooling control method thereof. Background Art

[0002] In the nuclear power, energy, chemical and shipbuilding industries, metal thick plates are key structural materials with high demand and quality requirements. The application of metal thick plates involves the core components and equipment manufacturing of these industries. With the improvement of material performance and quality standards in these industries, in addition to higher requirements for the comprehensive performance of the material itself, including strength, toughness, high temperature resistance and corrosion resistance, the welding technology is improved to meet the processing needs of complex structural parts.

[0003] With the continuous development of science and technology, high-power laser welding technology has become a vital welding method in modern industry due to its high efficiency, high speed, high weld quality and strong flexibility. The working principle of a high-power laser welding head is to use a high-energy-density laser beam to locally heat the welding part, so that it quickly melts and forms a welded joint. This welding method has the advantages of fast welding speed, high welding quality and small heat-affected zone, and is particularly suitable for occasions with high-precision welding requirements. Of course, the application of high-power laser welding heads also faces some challenges. For example, high-power welding heads are easily affected by the thermal lens effect during laser processing, which will affect the processing quality and stability. The thermal lens effect is that after the optical element is irradiated by the laser beam for a long time, the temperature rises and produces thermal deformation, which in turn causes the refractive index of the transmissive optical element and the reflection direction of the reflective optical element to change, thereby changing the position of the laser focus, resulting in a decrease in the focusing ability of the laser beam during welding and a change in the focus position. For high-power welding heads, the thermal lens effect is more obvious. The higher the power and the processing of high-reflective materials, the faster the optical element expands due to heat, and the more obvious the thermal lens effect.

[0004] Optical lenses use high-quality quartz and coating technology, and their own factors are constant. As the laser irradiates the optical lens, the temperature of the optical lens will rise. The core issue of reducing the thermal lens effect is to reduce the heat generation of optical lenses such as collimating lenses and focusing lenses. The thermal permeability effect of the 20-60KW welding head is very obvious. Many domestic welding head manufacturers have not yet proposed a reasonable method for high-power welding heads to effectively reduce the temperature of optical lenses for a long time. There are currently two main cooling methods. One is water cooling, which uses cooling water to cool the metal structure around the optical lens and takes away the heat of the lens through circulating cooling water. Usually, a patch type / water-cooled jacket water-cooled structure is used, and the heat transfer effect is limited, which cannot meet the requirements of rapid cooling of optical lenses; the other is air cooling. At present, the welding head only sets a cooling air curtain for the lower protective lens to block the spatter, smoke and other pollutants generated during the welding process and cool the lens.

[0005] For example, the patent with publication number CN210937736U discloses a water-cooling structure for a high-power laser welding head, and provides a method in which channels are set for water flow cooling in each part inside the high-power laser welding head, but the inlet and outlet water cooling channels are only on one side of the optical module of the welding head and the structure is a straight-through water cooling. At the same time, the water cooling seat adopts a single-channel C-type heat transfer water-cooled protective lens module. Without a real-time temperature measurement module, the cooling water flow cannot be automatically adjusted in time, and the cooling effect is limited; the patent with publication number CN211052882U discloses an air path structure for a high-power laser welding head, in which only a single-sided cooling air curtain is set for the protective lens, and the core collimating lens and focusing lens are not cooled. In addition, the cooling air curtain is single-sided cooled, and the upper and lower surface temperatures of the protective lens are uneven. The gas generated by the cooling air curtain is directly discharged into the atmosphere, and it cannot be used in a vacuum environment. Summary of the invention

[0006] Therefore, the present invention provides a laser welding head device for suppressing the thermal lens effect and a cooling control method thereof, which can overcome the technical problems in the prior art that the lens cooling effect in the high-power laser welding head device is poor, the suppression effect of the thermal lens effect is poor, resulting in a decrease in the focusing ability of the laser beam during welding, a change in the focal position, and reduced welding quality.

[0007] In order to solve the above problems, the present invention provides a laser welding head device for suppressing the thermal lens effect, comprising a device housing, the device housing having a laser light path channel, a collimating lens module is provided on the laser entrance side of the laser light path channel, and a focusing lens module is provided on the laser exit side of the laser light path channel, the collimating lens module includes a collimating lens, and the focusing lens module includes a focusing lens, a water-cooling channel is formed in the device housing, and the coolant in the water-cooling channel can contact the collimating lens and the focusing lens.

[0008] In some embodiments, the collimating lens module also includes a collimating lens mounting seat arranged around the outer peripheral edge of the collimating lens, the collimating lens mounting seat is clamped between the collimating lens and the inner wall of the laser light path channel, the collimating lens mounting seat is annular, a first water-cooling ring groove is formed on the inner ring wall of the collimating lens mounting seat, the collimating lens seal is assembled on the notch of the first water-cooling ring groove, and the first water-cooling ring groove is connected to the water-cooling flow channel; and / or, the focusing lens module also includes a focusing lens mounting seat arranged around the outer peripheral edge of the focusing lens, the focusing lens mounting seat is clamped between the focusing lens and the inner wall of the laser light path channel, the focusing lens mounting seat is annular, a second water-cooling ring groove is formed on the inner ring wall of the focusing lens mounting seat, the focusing lens seal is assembled on the notch of the second water-cooling ring groove, and the second water-cooling ring groove is connected to the water-cooling flow channel.

[0009] In some embodiments, the collimating lens module also includes a first protective lens and a second protective lens, which are respectively located on both sides of the laser entrance and exit of the collimating lens; and / or, the focusing lens module also includes a third protective lens and a fourth protective lens, which are respectively located on both sides of the laser entrance and exit of the focusing lens.

[0010] In some embodiments, a first sealed cavity is formed between the first protective lens, the second protective lens and the collimating lens respectively, a second sealed cavity is formed between the third protective lens, the fourth protective lens and the focusing lens respectively, and an air-cooling inlet channel and an air-cooling outlet channel are also formed in the device housing, and the air-cooling inlet channel and the air-cooling outlet channel are connected to the first sealed cavity and the second sealed cavity.

[0011] In some embodiments, the air-cooling inlet flow channel and the air-cooling outlet flow channel are respectively located on two radially opposite sides of the first sealed cavity or the second sealed cavity.

[0012] In some embodiments, the first protective lens and the second protective lens are fixed to the inner wall of the laser light path channel via the first lens seat and the second lens seat, respectively, and the third protective lens and the fourth protective lens are fixed to the inner wall of the laser light path channel via the third lens seat and the fourth lens seat, respectively. The first lens seat, the second lens seat, the third lens seat, the fourth lens seat, the collimating lens mounting seat and the focusing lens mounting seat are all constructed with a first inlet channel and a first outlet channel, the first inlet channel is connected between the air-cooled inlet channel and the first sealed cavity or the second sealed cavity, and the first outlet channel is connected between the air-cooled outlet channel and the first sealed cavity or the second sealed cavity.

[0013] In some embodiments, an optical fiber connector is provided at the end of the device housing corresponding to the laser entrance of the laser optical path channel, an entrance protection lens is provided at the laser entrance, a third sealed cavity is formed between the entrance protection lens and the first protection lens, an exit protection lens is provided at the end corresponding to the laser exit of the laser optical path channel, a fourth sealed cavity is formed between the exit protection lens and the fourth protection lens, a fifth sealed cavity is formed between the second protection lens and the third protection lens, and the air-cooled inlet flow channel and the air-cooled outlet flow channel are all connected to the third sealed cavity, the fourth sealed cavity and the fifth sealed cavity.

[0014] In some embodiments, the air-cooled inlet flow channel and the air-cooled outlet flow channel are connected to the third sealed cavity via the first lens seat, connected to the fourth sealed cavity via the fourth lens seat, and connected to the fifth sealed cavity via the second lens seat and / or the third lens seat.

[0015] In some embodiments, the water-cooling channel is located on a side of the air-cooling inlet channel and the air-cooling outlet channel away from the laser optical path; and / or the cooling gas in the air-cooling inlet channel and the air-cooling outlet channel is an inert gas.

[0016] The present invention also provides a lens cooling control method for the laser welding head device as described above, comprising the following steps:

[0017] Respectively acquiring a first real-time temperature of the collimating lens and a second real-time temperature of the focusing lens;

[0018] When any one of the first real-time temperature and the second real-time temperature is not lower than a set temperature threshold, controlling the water-cooling flow channel, the air-cooling inlet flow channel and the air-cooling outlet flow channel to enter the cooling medium; or,

[0019] When the first real-time temperature and the second real-time temperature are both lower than the set temperature threshold, the cooling medium is controlled to enter the water-cooling flow channel, and the cooling medium is controlled not to enter the air-cooling inlet flow channel and the air-cooling outlet flow channel.

[0020] A laser welding head device for suppressing thermal lens effect and a cooling control method thereof provided by the present invention have the following beneficial effects:

[0021] By directly contacting the water-cooling channel arranged in the device housing with the aforementioned collimating lens and focusing lens, the method of cooling the lens heat through the device housing (also called the laser head outer cylinder) in the prior art is no longer adopted. The lens cooling efficiency is higher and the cooling effect is better, thereby improving the suppression effect of the thermal lens effect, thereby improving the focusing ability of the laser beam during the welding process, and ensuring the reliability of the laser beam focal position, which is conducive to ensuring the uniformity of the welding penetration and improving the quality of laser welding. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] In order to more clearly illustrate the implementation methods of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for the implementation methods or the description of the prior art. The drawings described below are only exemplary, and for ordinary technicians in this field, other implementation drawings can be derived from the provided drawings without creative work.

[0023] Figure 1 It is a schematic diagram of the internal structure of a laser welding head device for suppressing thermal lens effect in one embodiment of the present invention;

[0024] Figure 2 yes Figure 1 A schematic diagram of the three-dimensional structure of a laser welding head device for suppressing thermal lens effect (appearance diagram);

[0025] Figure 3 It is a schematic diagram of the composition of a laser welding head device for suppressing thermal lens effect in another embodiment of the present invention.

[0026] The accompanying drawings are marked as follows:

[0027] 1. Device housing; 11. Water-cooled flow channel; 121. Air-cooled inlet flow channel; 122. Air-cooled outlet flow channel; 21. Collimating lens; 210. First sealed cavity; 22. Collimating lens mounting seat; 231. First protective lens; 232. First lens seat; 241. Second protective lens; 242. Second lens seat; 243. Inlet protective lens; 31. Focusing lens; 310. Second sealed cavity; 32. Focusing lens mounting seat; 331. Third protective lens; 332. Third lens seat; 341. Fourth protective lens; 342. Fourth lens seat; 4. Optical fiber connector; 5. Outlet protective lens; 6. Plane reflector; 71. Control component; 72. Water cooler; 73. Air source; 74. Air pump; 75. Cooling liquid flow regulating valve; 76. Cooling gas flow regulating valve; 77. Temperature detection component. DETAILED DESCRIPTION

[0028] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, rather than all the embodiments. The following description of at least one exemplary embodiment is actually only illustrative and is by no means intended to limit the present invention and its application or use. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0029] In the description of the present invention, it is necessary to understand that the directions or positional relationships indicated by directional words such as "front, back, up, down, left, right", "lateral, vertical, perpendicular, horizontal" and "top, bottom" are usually based on the directions or positional relationships shown in the drawings. They are only for the convenience of describing the present invention and simplifying the description. Unless otherwise specified, these directional words do not indicate or imply that the devices or elements referred to must have a specific direction or be constructed and operated in a specific direction. Therefore, they cannot be understood as limiting the scope of protection of the present invention. The directional words "inside and outside" refer to the inside and outside relative to the contours of each component itself.

[0030] For ease of description, spatially relative terms such as "above", "above", "on the upper surface of", "above", etc. may be used here to describe the spatial positional relationship between a device or feature and other devices or features as shown in the figure. It should be understood that spatially relative terms are intended to include different orientations of the device in use or operation in addition to the orientation described in the figure. For example, if the device in the accompanying drawings is inverted, the device described as "above other devices or structures" or "above other devices or structures" will be positioned as "below other devices or structures" or "below other devices or structures". Thus, the exemplary term "above" can include both "above" and "below". The device can also be positioned in other different ways (rotated 90° or in other orientations), and the spatially relative descriptions used here are interpreted accordingly.

[0031] In addition, it should be noted that the use of terms such as "first" and "second" to limit components is only for the convenience of distinguishing the corresponding components. If not otherwise stated, the above terms have no special meaning and therefore cannot be understood as limiting the scope of protection of the present invention.

[0032] See also Figures 1 to 3As shown, according to an embodiment of the present invention, a laser welding head device for suppressing the thermal lens effect is provided, in particular, a vacuum laser high-power welding head device, including a device housing 1, the device housing 1 having a laser optical path channel (not labeled in the figure), a collimating lens module (not labeled in the figure) is provided on the laser entry side of the laser optical path channel, and a focusing lens module (not labeled in the figure) is provided on the laser emission side of the laser optical path channel, the collimating lens module includes a collimating lens 21, and the focusing lens module includes a focusing lens 31. A water-cooling channel 11 is formed in the device housing 1, and the coolant (such as water) in the water-cooling channel 11 can contact the collimating lens 21 and the focusing lens 31. The main body of the water-cooling channel 11 can be a spiral winding water channel surrounding the laser optical path channel. The water-cooling channel 11 can be directly formed in the device housing 1, and can also be realized in the form of a cooling pipe, and the cooling pipe is preferably a copper pipe. In a preferred embodiment, the coolant inlet of the water-cooling channel 11 is on the laser emission side.

[0033] In this technical solution, by making the water-cooling channel 11 arranged in the device housing 1 directly contact with the aforementioned collimating lens 21 and focusing lens 31, the method of cooling the lens heat through the device housing 1 (also called the laser head outer cylinder) in the prior art is no longer adopted. The lens cooling efficiency is higher and the cooling effect is better, thereby being able to enhance the suppression effect of the thermal lens effect, thereby enhancing the focusing ability of the laser beam during the welding process, and ensuring the reliability of the laser beam focal position, which is beneficial to ensuring the uniformity of the welding penetration and improving the laser welding quality.

[0034] In some embodiments, the collimating lens module further includes a collimating lens mounting seat 22 arranged around the outer peripheral edge of the collimating lens 21, the collimating lens mounting seat 22 is clamped between the collimating lens 21 and the inner wall of the laser light path channel, the collimating lens mounting seat 22 is annular, and a first water-cooling ring groove (not shown in the figure and not labeled) is formed on the inner ring wall of the collimating lens mounting seat 22, the collimating lens 21 is sealed and assembled on the notch of the first water-cooling ring groove, and the first water-cooling ring groove is connected to the water-cooling flow channel 11; and / or, the focusing lens module further includes an outer peripheral edge surrounding the focusing lens 31 The focusing lens mounting seat 32 is arranged on the edge, and the focusing lens mounting seat 32 is clamped between the focusing lens 31 and the inner wall of the laser optical path channel. The focusing lens mounting seat 32 is annular, and a second water-cooling ring groove (not shown in the figure and not labeled) is formed on the inner ring wall of the focusing lens mounting seat 32. The focusing lens 31 is sealed and assembled on the notch of the second water-cooling ring groove, and the second water-cooling ring groove is connected to the water-cooling flow channel 11. In order to ensure the sealing of the first water-cooling ring groove and the second water-cooling ring groove, in a specific embodiment, a corresponding sealing ring (or sealing sheet) is also arranged between the lens and the corresponding lens mounting seat. It can be understood that the outer peripheral edges of the aforementioned collimating lens 21 and focusing lens 31 are both circular, so the corresponding corresponding lens mounting seat can also be designed as a ring structure.

[0035] In this technical solution, by setting a second water-cooling ring groove and a first water-cooling ring groove on the inner ring wall surface of the focusing lens mounting seat 32 and the collimating lens mounting seat 22, the coolant in the water-cooling channel 11 can be set around the focusing lens 31 and the collimating lens 21, thereby achieving uniform cooling of the lens in the circumferential direction and further enhancing the suppression effect of the thermal lens effect.

[0036] In some embodiments, the collimating lens module also includes a first protective lens 231 and a second protective lens 241, which are respectively located on both sides of the laser entrance and exit of the collimating lens 21; and / or, the focusing lens module also includes a third protective lens 331 and a fourth protective lens 341, which are respectively located on both sides of the laser entrance and exit of the focusing lens 31. The first protective lens 231, the second protective lens 241, the third protective lens 331 and the fourth protective lens 341 can all be flat light-transmitting lenses.

[0037] In this technical solution, by respectively arranging the aforementioned protective lenses on both sides of the laser inlet and outlet of the collimating lens 21 and the focusing lens 31, it is possible to prevent the smoke generated by the laser head device during welding from being deposited on the lens surface, thereby protecting the lens from damage.

[0038] In some embodiments, a first sealed cavity 210 is formed between the first protective lens 231 and the second protective lens 241 and the collimating lens 21, and a second sealed cavity 310 is formed between the third protective lens 331 and the fourth protective lens 341 and the focusing lens 31, and an air-cooling inlet channel 121 and an air-cooling outlet channel 122 are also formed in the device housing 1. The air-cooling inlet channel 121 and the air-cooling outlet channel 122 are connected to the first sealed cavity 210 and the second sealed cavity 310, that is, the air-cooling inlet channel 121 and the air-cooling outlet channel 122 are connected via the first sealed cavity 210 and the second sealed cavity 310. It can be understood that the first sealed cavity 210 and the second sealed cavity 310 are respectively located on both sides of the corresponding lens.

[0039] In this technical solution, the cooling gas is introduced into the first sealed cavity 210 and the second sealed cavity 310 through the air-cooling inlet channel 121 and the air-cooling outlet channel 122, and then discharged after heat exchange with the collimating lens 21 and the focusing lens 31, so that the central area of ​​the lens can be cooled more directly and efficiently, and the thermal lens effect can be further improved. It should be emphasized that when the water-cooling channel 11 and the air-cooling channel (including the air-cooling inlet channel 121, the air-cooling outlet channel 122, the first sealed cavity 210 and the second sealed cavity 310) are simultaneously introduced with cooling liquid and cooling gas, the lens can be fully cooled from the periphery to the center area, thereby achieving efficient suppression of the thermal lens effect.

[0040] In some embodiments, the air-cooling inlet channel 121 and the air-cooling outlet channel 122 are respectively located at two opposite radial sides of the first sealed cavity 210 or the second sealed cavity 310, that is, at two ends of the diameter of the collimating lens 21 or the focusing lens 31. This ensures that the cooling gas can fully exchange heat and cool the lens.

[0041] In a specific embodiment, the first protective lens 231 and the second protective lens 241 are fixed on the inner wall of the laser light path channel via the first lens seat 232 and the second lens seat 242 respectively, and the third protective lens 331 and the fourth protective lens 341 are fixed on the inner wall of the laser light path channel via the third lens seat 332 and the fourth lens seat 342 respectively. The first lens seat 232, the second lens seat 242, the third lens seat 332, the fourth lens seat 342, the collimating lens mounting seat 22 and the focusing lens mounting seat 32 are all constructed with a first inlet channel (not shown in the figure, not labeled) and a first outlet channel (not shown in the figure, not labeled), the first inlet channel is connected between the air-cooled inlet channel 121 and the first sealed cavity 210 or the second sealed cavity 310, and the first outlet channel is connected between the air-cooled outlet channel 122 and the first sealed cavity 210 or the second sealed cavity 310.

[0042] In this technical solution, the first inlet channel and the first outlet channel are formed on each mounting seat to simplify the channel design. Specifically, at this time, only the flow channel corresponding to the mounting seat position can be set in the device housing 1, without the need to set corresponding flow channels in the device housing 1 in the corresponding areas on both sides of the lens (i.e., the two first sealed cavities 210 or the two second sealed cavities 310), thereby reducing the difficulty of setting the aforementioned water-cooling channel 11 (there can be a larger setting space). It should be noted that the cooling gas in the first inlet channel and the first outlet channel constructed on the collimating lens mounting seat 22 and the focusing lens mounting seat 32 can form a more efficient heat exchange with the coolant in the first water-cooling ring groove and the second water-cooling ring groove respectively constructed, further ensuring the cooling effect on the lens.

[0043] In some embodiments, an optical fiber connector 4 is provided at the end of the device housing 1 corresponding to the laser entrance of the laser optical path channel, an entrance protection lens 243 is provided at the laser entrance, a third sealed cavity (not labeled in the figure) is formed between the entrance protection lens 243 and the first protection lens 231, an exit protection lens 5 is provided at the end corresponding to the laser emission outlet of the laser optical path channel, a fourth sealed cavity (not labeled in the figure) is formed between the exit protection lens 5 and the fourth protection lens 341, a fifth sealed cavity (not labeled in the figure) is formed between the second protection lens 241 and the third protection lens 331, the air-cooled inlet channel 121 and the air-cooled outlet channel 122 are connected to the third sealed cavity, the fourth sealed cavity and the fifth sealed cavity. In a specific embodiment, a plane reflector 6 is provided in the fifth sealed cavity, and the plane reflector 6 is arranged at 45°, so that the aforementioned laser optical path channel can be an L-shaped structure.

[0044] In this technical solution, cooling gas is introduced into the third sealed cavity, the fourth sealed cavity and the fifth sealed cavity. On the one hand, it can achieve comprehensive cooling of the entire cavity space in the device housing 1, and on the other hand, it can ensure that the atmosphere around the collimating lens 21 and the focusing lens 31 is the same gas, thereby preventing the laser from being refracted under different atmosphere gases.

[0045] In some embodiments, the air-cooled inlet flow channel 121 and the air-cooled outlet flow channel 122 are connected to the third sealed cavity via the first lens seat 232, are connected to the fourth sealed cavity via the fourth lens seat 342, and are connected to the fifth sealed cavity via the second lens seat 242 and / or the third lens seat 332. Specifically, corresponding flow channels are formed on the first lens seat 232, the fourth lens seat 342, the second lens seat 242 and / or the third lens seat 332, respectively, which can further reduce the adverse effects of setting too many channels on the device housing 1 on the structural strength of the device housing 1.

[0046] In some embodiments, the water-cooling channel 11 is located on a side of the air-cooling inlet channel 121 and the air-cooling outlet channel 122 away from the laser optical path channel, wherein only one air-cooling inlet channel 121 and one air-cooling outlet channel 122 are required respectively, thereby reducing the difficulty of setting the contact and connecting channel between the spirally coiled water-cooling channel 11 and each lens.

[0047] In the specific application process, see Figure 3 As shown, the inlet of the aforementioned air-cooling inlet flow channel 121 is connected to the outlet of the air source 73, and the outlet of the air-cooling outlet flow channel 122 is connected to the suction pump 74, so that the cooling gas can be sucked by the suction pump 74, thereby ensuring the rapid flow of the cooling gas and enhancing its cooling effect. The cooling gas in the aforementioned air-cooling inlet flow channel 121 and the air-cooling outlet flow channel 122 can be a clean, dry, safe gas that can be directly discharged into the atmosphere, preferably an inert gas, so as to reduce the absorption of the cooling gas to the laser. In a specific embodiment, the aforementioned cooling gas uses argon (specifically 99.999% high-purity argon); the inlet and outlet of the water-cooling flow channel 11 can be connected to the water inlet and outlet of the water chiller 72 (commercially available parts can be used), and in order to control the flow and on-off of the cooling liquid and the cooling gas, a cooling liquid flow regulating valve 75 and a cooling gas flow regulating valve 76 are set on the corresponding pipelines.

[0048] It can be understood that in order to monitor the real-time temperature of the collimating lens 21 and the focusing lens 31 in real time, a corresponding temperature detection component 77 (specifically, an NTC temperature sensor can be used) is also configured in the device housing 1, and the laser welding head device is also configured with a control component 71. The control component 71 can receive the temperature signal detected in real time by the temperature detection component 77 and issue control instructions based on the built-in control strategy (control method), such as controlling the opening size and on-off of the cooling air flow control valve 76 and the coolant flow control valve 75. Of course, it can also be configured to control the start and stop of the water cooler 72, the air source 73 and the vacuum pump 74.

[0049] In some embodiments, the control component 71 may be, for example, an industrial computer with a display screen, and the real-time temperature monitored by the temperature detection component 77 may be displayed on the display screen. It is understood that the control component 71 is configured with corresponding conventional components such as a host, a signal receiving unit, and a signal transmitting unit.

[0050] In a specific embodiment, the aforementioned lenses and protective lenses are made of quartz glass with high transmittance coating at the working wavelength, and the temperature detection component 77 is set one by one corresponding to each lens; the laser power of the laser welding head device is 20KW-60KW.

[0051] According to an embodiment of the present invention, there is also provided a lens cooling control method of the laser welding head device as described above, comprising the following steps:

[0052] Respectively acquiring a first real-time temperature of the collimating lens 21 and a second real-time temperature of the focusing lens 31;

[0053] When either the first real-time temperature or the second real-time temperature is not lower than the set temperature threshold, the cooling medium is controlled to enter the water-cooling channel 11, the air-cooling inlet channel 121 and the air-cooling outlet channel 122. The set temperature threshold is reasonably selected according to the specific performance of the collimating lens 21 and the focusing lens 31 specifically adopted in the laser welding head device; or, when both the first real-time temperature and the second real-time temperature are lower than the set temperature threshold, the cooling medium is controlled to enter the water-cooling channel 11, and the cooling medium is controlled not to enter the air-cooling inlet channel 121 and the air-cooling outlet channel 122.

[0054] In this technical solution, when the temperature of any one of the collimating lens 21 and the focusing lens 31 is too high, that is, reaches the set temperature threshold, water cooling and air cooling are controlled to be used simultaneously, so that the edge and central area of ​​the lens can be fully cooled and cooled, and the thermal lens effect can be suppressed to the greatest extent, especially under the high-power operation condition of the laser welding head device, so that the uniformity of welding penetration can be guaranteed, thereby ensuring the welding quality during high-power welding. When the real-time temperature of the collimating lens 21 and the focusing lens 31 is lower than the aforementioned set temperature threshold, only water cooling is used to cool the edges of the lens.

[0055] It can be understood that no matter water cooling alone or water cooling and air cooling are used simultaneously, the flow rate of the coolant or cooling gas can be adjusted and controlled in real time according to the real-time detected temperature. A larger flow rate is used when the temperature is high, and a smaller flow rate is used when the temperature is low. The flow rate of the corresponding cooling medium can even be controlled to zero.

[0056] The present invention can quickly and efficiently reduce the surface temperature of the optical lens by designing and manufacturing the spiral water cooling structure of the welding head (that is, the aforementioned water cooling channel 11) and the double-layer double-sided gas cooling structure of the optical lens (that is, the aforementioned air cooling channel connected to the first sealed cavity 210 and the second sealed cavity 310). Combined with the closed-loop control setting of temperature monitoring, the flow of coolant and inert gas, it can not only monitor the temperature of the optical lens, but also effectively adjust the flow of cooling water and inert gas to maintain a stable temperature of the optical lens, thereby suppressing the thermal lens effect caused by the long-term light output of the high-power welding head to increase the internal temperature of the optical lens, so that the focus position of the welding head does not drift, ensuring the accuracy of the laser focus, the stability of the weld size, shape and depth, ensuring the consistency and high quality of the weld, and reducing the downtime of the device, improving production efficiency, and realizing one-pass welding of large thickness and long distance welds. It is worth emphasizing that laser welding of the welding head in a vacuum environment can reduce the influence of airflow and plasma in the atmosphere on the laser beam, and the optical lens avoids oxidation and pollution, and also reduces the thermal lens effect.

[0057] It is easy for those skilled in the art to understand that, without conflict, the advantageous technical features of the above-mentioned methods can be freely combined and superimposed.

[0058] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions and improvements made within the spirit and principle of the present invention shall be included in the protection scope of the present invention. The above description 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 variations can be made without departing from the technical principles of the present invention. These improvements and variations should also be regarded as the protection scope of the present invention.

Claims

1. A laser welding head device for suppressing thermal lens effect, comprising a device housing (1), the device housing (1) having a laser light path channel, a collimating lens module being provided on the laser entrance side of the laser light path channel, and a focusing lens module being provided on the laser exit side of the laser light path channel, the collimating lens module comprising a collimating lens (21), and the focusing lens module comprising a focusing lens (31), characterized in that: A water cooling channel (11) is formed in the device housing (1), and the cooling liquid in the water cooling channel (11) can contact the collimating lens (21) and the focusing lens (31).

2. The laser welding head device according to claim 1, characterized in that: The collimating lens module further comprises a collimating lens mounting seat (22) arranged around the outer peripheral edge of the collimating lens (21), the collimating lens mounting seat (22) being clamped between the collimating lens (21) and the inner wall of the laser light path channel, the collimating lens mounting seat (22) being annular, a first water-cooling annular groove being formed on the inner annular wall of the collimating lens mounting seat (22), the collimating lens (21) being sealed and assembled on the notch of the first water-cooling annular groove, and the first water-cooling annular groove being connected to the water-cooling flow channel (11); and / Alternatively, the focusing lens module further comprises a focusing lens mounting seat (32) arranged around the outer peripheral edge of the focusing lens (31), the focusing lens mounting seat (32) being clamped between the focusing lens (31) and the inner wall of the laser optical path channel, the focusing lens mounting seat (32) being annular, a second water-cooling ring groove being formed on the inner ring wall of the focusing lens mounting seat (32), the focusing lens (31) being sealed and assembled on the notch of the second water-cooling ring groove, and the second water-cooling ring groove being connected to the water-cooling channel (11).

3. The laser welding head device according to claim 2, characterized in that: The collimating lens module further comprises a first protective lens (231) and a second protective lens (241), which are respectively located on both sides of the laser entrance and exit of the collimating lens (21); and / or the focusing lens module further comprises a third protective lens (331) and a fourth protective lens (341), which are respectively located on both sides of the laser entrance and exit of the focusing lens (31).

4. The laser welding head device according to claim 3, characterized in that: A first sealed cavity (210) is formed between the first protective lens (231) and the second protective lens (241) and the collimating lens (21), and a second sealed cavity (310) is formed between the third protective lens (331) and the fourth protective lens (341) and the focusing lens (31). An air-cooling inlet channel (121) and an air-cooling outlet channel (122) are also formed in the device housing (1), and the air-cooling inlet channel (121) and the air-cooling outlet channel (122) are in communication with the first sealed cavity (210) and the second sealed cavity (310).

5. The laser welding head device according to claim 4, characterized in that: The air-cooling inlet flow channel (121) and the air-cooling outlet flow channel (122) are respectively located on two radially opposite sides of the first sealed cavity (210) or the second sealed cavity (310).

6. The laser welding head device according to claim 4, characterized in that: The first protective lens (231) and the second protective lens (241) are fixed to the inner wall of the laser light path channel via a first lens seat (232) and a second lens seat (242), respectively; the third protective lens (331) and the fourth protective lens (341) are fixed to the inner wall of the laser light path channel via a third lens seat (332) and a fourth lens seat (342), respectively; the first lens seat (232), the second lens seat (242), the third lens seat (332), the fourth lens seat (342), the collimating lens mounting seat (22) and the focusing lens mounting seat (32) are all configured with a first inlet channel and a first outlet channel; the first inlet channel is connected between the air-cooling inlet channel (121) and the first sealed cavity (210) or the second sealed cavity (310); the first outlet channel is connected between the air-cooling outlet channel (122) and the first sealed cavity (210) or the second sealed cavity (310).

7. The laser welding head device according to claim 6, characterized in that: An optical fiber connector (4) is provided at the end of the device housing (1) corresponding to the laser entrance of the laser optical path channel, an entrance protection lens (243) is provided at the laser entrance, a third sealed cavity is formed between the entrance protection lens (243) and the first protection lens (231), an exit protection lens (5) is provided at the end corresponding to the laser emission outlet of the laser optical path channel, a fourth sealed cavity is formed between the exit protection lens (5) and the fourth protection lens (341), a fifth sealed cavity is formed between the second protection lens (241) and the third protection lens (331), and the air-cooling inlet flow channel (121) and the air-cooling outlet flow channel (122) are all connected to the third sealed cavity, the fourth sealed cavity and the fifth sealed cavity.

8. The laser welding head device according to claim 7, characterized in that: The air-cooling inlet flow channel (121) and the air-cooling outlet flow channel (122) are connected to the third sealed cavity via the first lens seat (232), are connected to the fourth sealed cavity via the fourth lens seat (342), and are connected to the fifth sealed cavity via the second lens seat (242) and / or the third lens seat (332).

9. The laser welding head device according to claim 4, characterized in that: The water-cooling channel (11) is located on a side of the air-cooling inlet channel (121) and the air-cooling outlet channel (122) away from the laser optical path; and / or the cooling gas in the air-cooling inlet channel (121) and the air-cooling outlet channel (122) is an inert gas.

10. A lens cooling control method for a laser welding head device according to any one of claims 4 to 9, characterized in that: The steps include: Respectively acquiring a first real-time temperature of the collimating lens (21) and a second real-time temperature of the focusing lens (31); When either the first real-time temperature or the second real-time temperature is not lower than a set temperature threshold, controlling the water-cooling flow channel (11), the air-cooling inlet flow channel (121) and the air-cooling outlet flow channel (122) to allow cooling medium to enter; or, When the first real-time temperature and the second real-time temperature are both lower than the set temperature threshold, the water-cooling channel (11) is controlled to allow cooling medium to enter, and the air-cooling inlet channel (121) and the air-cooling outlet channel (122) are controlled not to allow cooling medium to enter.

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