Air knife device for laser machining head and laser machining head

Abstract

The invention discloses an air knife device for a laser processing head and the laser processing head. The air knife device comprises a mounting structure and at least two layers of air knife structures, wherein the mounting structure is used for being mounted and connected with the spraying end of the laser head, and the at least two layers of air knife structures are mounted on the mounting structure; the at least two layers of air knife mechanisms comprise a first air knife structure and a second air knife structure, the laser head, the first air knife structure and the second air knife structure are arranged at intervals in the first direction, and laser beams emitted by the laser head extend in the first direction; a first spraying channel is arranged in the first air knife structure and used for spraying out first airflow in the second direction, and a second spraying channel is arranged in the second air knife structure and used for spraying out second airflow in the second direction; the first air flow is subsonic air flow or supersonic air flow, the second air flow is supersonic air flow, most welding slag can be blown away through the second air flow in the supersonic state, and the slag removal and dust removal capacity of the second air flow is good.

Description

Technical Field

[0001] The invention relates to the technical field of laser processing, and in particular to an air knife device for a laser processing head and a laser processing head. Background Art

[0002] Laser welding uses a high-energy laser beam to locally heat the material, melting it to form a molten pool. During welding, the metal produces high-pressure steam, which drives the liquid metal to splash and reacts with the air to produce smoke. The smoke may contaminate the protective lens in the laser welding head, and in severe cases, the lens may be burned and scrapped, and a new lens must be replaced before it can be used.

[0003] At present, the laser welding system mainly uses 1-2 layers of subsonic air knives to remove welding slag. In low-power scenarios, 1-2 layers of subsonic air knives can provide sufficient welding slag removal effect. However, as the laser power increases, the anti-reverse slag ability of the subsonic air knife gradually becomes insufficient, which can easily lead to lens contamination and burning. Summary of the invention

[0004] The purpose of the present invention is to propose a wind knife device and a laser processing head for a laser processing head, aiming to solve the problem of insufficient anti-slag capability of 1-2 layers of subsonic wind knives in existing laser welding systems under high power conditions.

[0005] In a first aspect, the present invention provides an air knife device for a laser processing head, the air knife device comprising a mounting structure for mounting and connecting with the ejection end of the laser head, and at least two layers of air knife structures mounted on the mounting structure;

[0006] At least two layers of the wind knife mechanism include a first wind knife structure and a second wind knife structure, the laser head, the first wind knife structure and the second wind knife structure are arranged at intervals along a first direction, and the laser beam emitted by the laser head extends along the first direction;

[0007] The first air knife structure is provided with a first injection channel for ejecting a first airflow in a second direction, and the second air knife structure is provided with a second injection channel for ejecting a second airflow in the second direction;

[0008] Wherein, the second airflow is a supersonic airflow, and the first direction and the second direction are arranged at an angle.

[0009] In one embodiment, the second injection channel comprises a contraction section, a throat section and an expansion section which are connected in sequence, the cross-sectional size of the contraction section gradually decreases from the air inlet end to the air outlet end, and the cross-sectional size of the expansion section gradually increases from the air inlet end to the air outlet end;

[0010] The structure of the first injection channel is the same as that of the second injection channel, or the cross-sectional dimension of the first injection channel remains unchanged from the air inlet end to the air outlet end.

[0011] In one embodiment, one second wind knife structure is provided, and a plurality of first wind knife structures are provided, which are sequentially arranged between the mounting structure and the second wind knife structure.

[0012] In one embodiment, the height dimension of the first injection channel is between 0.05 mm and 0.1 mm;

[0013] The second injection channel also includes a holding section located at the air inlet end and connected to the contraction section, the holding section has an extension length of 2mm-4mm, a height dimension of 5.5mm-6.5mm, an extension length of the contraction section of 4mm-6mm, a height dimension of the throat of 2.5mm-3.5mm, an extension length of the expansion section of 3mm-5mm, and a height dimension of 3.5mm-4.5mm at the air outlet end.

[0014] In one embodiment, the first injection channel and the second injection channel both extend along the second direction and are spaced apart along the first direction, and the second direction is set at an angle of -45° to 45° with the horizontal direction; and / or,

[0015] The mounting structure is attached to the bottom or side of the ejection end of the laser head.

[0016] In one embodiment, the mounting structure is a cylindrical structure, which includes a mounting body and a fixing plate arranged on the mounting body, wherein the fixing plate is used for detachable connection with the injection end of the laser head, and a laser channel coaxially arranged with the laser beam emitted by the laser head is arranged in the mounting structure.

[0017] In one embodiment, a magnetic attraction component is disposed in the installation body, and the magnetic attraction component includes a plurality of magnetic attraction parts, each of which is arranged in a ring around the laser channel and is used to magnetically attract metal splashes; and / or,

[0018] The wind knife device also includes multiple mounting gaskets and multiple mounting columns; each mounting gasket is respectively arranged between the mounting body and the first wind knife structure, between two adjacent first wind knife structures, between the first wind knife structure and the second wind knife structure, and on the side of the second wind knife structure away from the mounting structure, and each mounting column is respectively supported and arranged between two adjacent mounting gaskets.

[0019] In one embodiment, each of the mounting gaskets includes a first gasket corresponding to each of the first wind knife structures, and a second gasket corresponding to the second wind knife structure;

[0020] A first through hole coaxially arranged with the laser channel is provided in the first gasket, and a second through hole coaxially arranged with the laser channel is provided in the second gasket, the aperture of the second through hole is smaller than the aperture of the first through hole, and the width of the first injection channel is larger than the aperture of the first through hole, and the width of the second injection channel is larger than the aperture of the second through hole.

[0021] In one embodiment, the spacing between two adjacent first injection channels and between the first injection channel and the second injection channel is between 35 mm and 45 mm.

[0022] In a second aspect, the present invention further provides a laser processing head, the laser processing head comprising a laser head for emitting a laser beam, and a wind knife device mounted on the laser head;

[0023] Wherein, the wind knife device is the wind knife device of any of the above embodiments.

[0024] The embodiments of the present invention have the following beneficial effects:

[0025] The wind knife device and the laser processing head of the present invention are used. The at least two wind knife mechanisms include a first wind knife structure and a second wind knife structure. The laser beam emitted by the laser head extends along a first direction. The first wind knife structure is provided with a first injection channel and is used to eject a first airflow along a second direction. After the first airflow is ejected from the first injection channel, an air curtain is formed, thereby forming a first wind knife. Since the first airflow is a subsonic airflow or a supersonic airflow, the first wind knife is an ordinary wind knife or a supersonic wind knife. The second wind knife structure is provided with a second injection channel and is used to eject a first airflow along a second direction. The second air flow is ejected along the second direction. After the second air flow is ejected from the second injection channel, an air curtain will also be formed, thereby forming a second wind knife. Since the second air flow is a supersonic air flow, the second wind knife is a supersonic wind knife. Most of the welding slag can be blown away by the second wind knife in the supersonic state. The second wind knife has good slag and dust removal capabilities. At the same time, even if part of the welding slag is splashed toward the laser head through the second wind knife, the first wind knife is arranged between the laser head and the second wind knife. The first wind knife can also remove slag and dust from the residual welding slag, thereby ensuring the gas protection effect of the wind knife device. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0027] in:

[0028] Figure 1 Schematic diagram of an air knife device in one embodiment.

[0029] Figure 2 for Figure 1 An enlarged schematic diagram of the first injection channel in the air knife device is shown.

[0030] Figure 3 for Figure 1 An enlarged schematic diagram of the second injection channel in the air knife device is shown.

[0031] Figure 4 Schematic diagram of an air knife device in one embodiment.

[0032] Figure 5 Schematic diagram of an air knife device in one embodiment.

[0033] Figure 6 for Figure 5 The front view of the air knife device is shown.

[0034] Figure 7 for Figure 6 Middle AA section view.

[0035] Figure 8 for Figure 7 Enlarged schematic diagram of point B in the middle.

[0036] Fig. 9 for Figure 7 Enlarged schematic diagram at point C in the middle.

[0037] Fig.10 for Figure 5 Side view of the air knife device shown.

[0038] Fig.11 for Fig.10 Middle DD section view.

[0039] Figure numbers: 100, mounting structure; 110, mounting body; 120, fixing plate; 130, magnetic attraction assembly; 101, laser channel; 200, first wind knife structure; 210, first injection channel; 300, second wind knife structure; 310, second injection channel; 311, contraction section; 312, throat; 313, expansion section; 314, holding section; 410, first gasket; 411, first through hole; 420, second gasket; 421, second through hole; 430, mounting column; 500, quick-tighten connector. DETAILED DESCRIPTION

[0040] 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, not all of the embodiments. 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.

[0041] It should be noted that all directional indications in the embodiments of the present invention (such as up, down, left, right, front, back, etc.) are only used to explain the relative position relationship, movement status, etc. between the components under a certain specific posture (as shown in the accompanying drawings). If the specific posture changes, the directional indication will also change accordingly.

[0042] In addition, the descriptions of "first", "second", etc. in the present invention are only used for descriptive purposes and cannot be understood as indicating or implying their relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" and "second" may explicitly or implicitly include at least one of the features. In addition, the technical solutions between the various embodiments can be combined with each other, but they must be based on the ability of ordinary technicians in the field to implement them. When the combination of technical solutions is contradictory or cannot be implemented, it should be deemed that such a combination of technical solutions does not exist and is not within the scope of protection required by the present invention.

[0043] Laser welding is a welding method that uses a high-energy laser beam to locally heat the material in a small area, and the energy of the laser radiation melts the material to form a specific molten pool. Due to the instantaneous high temperature during welding, the metal will produce a large amount of high-pressure steam, which will drive the molten liquid metal to splash out. In addition, the liquid metal will react with the surrounding air, etc., and produce a large amount of smoke and dust. When the smoke enters the interior of the laser welding head, it may adhere to the internal protective lens. When the pollution is serious, the protective lens will be burned and scrapped when it hinders the laser transmission. A new protective lens must be replaced for normal use.

[0044] Based on this, an embodiment of the present invention discloses a laser processing head to solve the above problems. The laser processing head is mainly used for laser processing such as laser welding on workpieces. The laser processing head of one embodiment includes a laser head for emitting a laser beam, and a wind knife device installed on the laser head. The wind knife device forms an air curtain by spraying an air flow to a preset position of the laser head, effectively isolating external dust, grease and other impurities, keeping the processing environment clean, and especially preventing welding slag from splashing toward the laser head, reducing the risk of lens contamination, thereby extending the service life of the equipment.

[0045] In one embodiment, see Figures 1 to 11 The wind knife device includes a mounting structure 100 for being mounted and connected to the injection end of the laser head, and at least two layers of wind knife structures mounted on the mounting structure 100; the at least two layers of wind knife structures include a first wind knife structure 200 and a second wind knife structure 300, the laser head, the first wind knife structure 200 and the second wind knife structure 300 are arranged at intervals along a first direction, and the laser beam emitted by the laser head extends along the first direction; a first injection channel 210 is arranged in the first wind knife structure 200, and is used to eject a first airflow along a second direction, and a second injection channel 310 is arranged in the second wind knife structure 300, and is used to eject a second airflow along the second direction; wherein the first airflow is a subsonic airflow or a supersonic airflow, the second airflow is a supersonic airflow, and the first direction is arranged at an angle to the second direction.

[0046] In this embodiment, after the first airflow is ejected from the first injection channel 210, an air curtain will be formed, thereby forming a first air knife. Since the first airflow is a subsonic airflow or a supersonic airflow, the first air knife is an ordinary air knife or a supersonic air knife. At the same time, after the second airflow is ejected from the second injection channel 310, an air curtain will also be formed, thereby forming a second air knife. Since the second airflow is a supersonic airflow, the second air knife is a supersonic air knife. Most of the welding slag can be blown away by the second air knife in a supersonic state. The second air knife has better slag and dust removal capabilities. At the same time, even if part of the welding slag is splashed toward the laser head through the second air knife, the first air knife is arranged between the laser head and the second air knife. The first air knife can also remove slag and dust from the residual welding slag, thereby ensuring the gas protection effect of the air knife device.

[0047] It can be understood that, due to the Coanda effect, the airflow ejected from the first injection channel 210 or the second injection channel 310 will drive the surrounding air to form an air curtain. The first injection channel 210 and the second injection channel 310 are both passed through high-speed airflow, which can be provided by an air source such as a high-pressure blower. These airflows are blown out in the form of thin sheets after passing through the first injection channel 210 and the second injection channel 310. This high-speed airflow has a strong impact and cutting force, and can effectively blow away the air, dust, welding slag and other impurities around the welding area. Moreover, the wind knife can also form an isolation wind curtain to block external air and impurities from entering the welding area, protecting the weld from oxidation and pollution.

[0048] In one embodiment, the second injection channel 310 includes a contraction section 311, a throat 312 and an expansion section 313 connected in sequence. The cross-sectional size of the contraction section 311 gradually decreases from the air inlet end to the air outlet end. Therefore, the second airflow can be accelerated in the process of passing through the contraction section 311 and reach the speed of sound in the throat 312. The cross-sectional size of the expansion section 313 gradually increases from the air inlet end to the air outlet end. Subsequently, the second airflow can expand and reach a supersonic state in the process of passing through the expansion section 313. After the second airflow is ejected from the second injection channel 310, a second wind knife is formed. Most of the welding slag can be blown away by the second wind knife in the supersonic state. The second wind knife has good slag and dust removal capabilities.

[0049] In this embodiment, the cross-sectional size of the first injection channel 210 remains unchanged from the air inlet end to the air outlet end, or the structure of the first injection channel 210 is the same as the structure of the second injection channel 310 .

[0050] It can be understood that when the cross-sectional size of the first jet channel 210 remains unchanged from the air inlet end to the air outlet end, a subsonic airflow will be formed after the first airflow is ejected from the first jet channel 210. Therefore, the first wind knife is an ordinary wind knife. The formation of the ordinary wind knife mainly utilizes the slit compression of the first jet channel 210 to achieve airflow acceleration to realize the wind knife function.

[0051] When the structure of the first injection channel 210 is the same as that of the second injection channel 310 , a supersonic airflow will be formed after the first airflow is ejected from the first injection channel 210 . Therefore, the first air knife may also be a supersonic air knife.

[0052] In summary, even if part of the welding slag is splashed toward the laser head through the first air knife, a first air knife is arranged between the laser head and the second air knife. The first air knife can be selected as an ordinary air knife or a supersonic air knife. The first air knife can also remove slag and dust from the residual welding slag, thereby increasing the gas protection effect of the air knife device under high power conditions.

[0053] In one embodiment, see Figures 5 to 11The first wind knife structure 200 is provided with a plurality of first wind knife structures, and is sequentially arranged between the mounting structure 100 and the second wind knife structure 300. By setting a plurality of first wind knife mechanisms, a plurality of first wind knives can be arranged between the second wind knife and the laser head to form a plurality of first wind knives, thereby increasing the gas protection effect of the wind knife device.

[0054] Furthermore, in this embodiment, three first wind knife structures 200 are provided, and one second wind knife structure 300 is provided. The first wind knife generated by the first wind knife structure 200 is a subsonic wind knife, and the second wind knife generated by the second wind knife structure 300 is a supersonic wind knife. Compared with the subsonic wind knife, the supersonic wind knife has a stronger air curtain shielding ability, and thus the slag removal and dust removal are also stronger. Therefore, one supersonic wind knife can be equivalent to the dust removal and slag removal capabilities of multiple subsonic wind knives. By setting a four-layer wind knife structure, the gas protection effect of the wind knife device can be better guaranteed.

[0055] Specifically, one supersonic wind knife can be equivalent to three subsonic wind knives. The first wind knife structure 200 can also be provided with two, four or more. Of course, in other embodiments, in order to further enhance the dust removal and slag removal capabilities of the wind knife device, the second wind knife structure 300 can also be provided with two or other numbers. The specific arrangement selection and arrangement number of the wind knife structures can be adaptively adjusted according to the power of the laser head and the installation space of the wind knife device on the laser head.

[0056] In order to ensure that the second wind knife generated by the second wind knife structure 300 is a supersonic wind knife, the air source can be supplied by an air compressor, and the total pressure needs to reach more than 1.89 times the static pressure so that the second wind knife can reach a supersonic wind knife. For the first wind knife structure 200, pressurization can increase the wind speed of the first wind knife generated by the first wind knife structure 200, but the first wind knife can only reach subsonic speed and will not reach supersonic speed. For the supersonic wind knife, the unique structure of the second wind knife structure 300 and the air source volume must be combined to promote it, and during the processing, the pressure of the air source needs to be kept constant as much as possible.

[0057] In one embodiment, see Figure 1 The laser beam emitted by the laser head extends along the first direction, the first injection channel 210 and the second injection channel 310 both extend along the second direction and are spaced apart along the first direction, and the first direction is set at an angle to the second direction, so that the first wind knife and the second wind knife are arranged in sequence in the laser beam emission direction of the laser head. Figure 1 The direction pointed by the arrow X is the second direction, and the direction pointed by the arrow Y is the first direction.

[0058] In this embodiment, the second direction is set at an angle of -45° to 45° with the horizontal direction, so that the first air knife and the second air knife can be flexibly set. Specifically, the second direction can be set at an angle of -45°, -30°, 15°, -5°, 0, 5°, 15°, 30° or 45° with the horizontal direction. When the second direction can be set at an angle of 0° with the horizontal direction, the second direction is parallel to the horizontal direction, that is, the first injection channel 210 and the second injection channel 310 both extend in the horizontal direction.

[0059] In one embodiment, see Figures 1 to 4 The height dimension H1 of the first injection channel 210 is between 0.05 mm and 0.1 mm. The first airflow is ejected through the flat and narrow gap so that the first airflow can reach a subsonic state, thereby removing slag and dust.

[0060] In this embodiment, the second injection channel 310 further includes a holding section 314 located at the air inlet end and connected to the contraction section 311, the extension length L1 of the holding section 314 is 2mm-4mm, the height dimension H2 is 5.5mm-6.5mm, the extension length L2 of the contraction section 311 is 4mm-6mm, the height dimension H3 of the throat 312 is 2.5mm-3.5mm, the extension length L3 of the expansion section 313 is 3mm-5mm, and the height dimension H4 of the air outlet end is 3.5mm-4.5mm. By such an arrangement, the second injection channel 310 can be formed into an airflow acceleration structure of the Laval nozzle.

[0061] Specifically, the width dimension W1 of the first injection channel 210 is 25 mm-35 mm, and further, the width dimension W1 of the first injection channel 210 can be selected as 25 mm, 28 mm, 30 mm, 32 mm or 35 mm. The width dimension W2 of the second injection channel 310 is 22 mm-26 mm, and further, the width dimension W2 of the first injection channel 210 can be selected as 22 mm, 23 mm, 24 mm, 25 mm or 26 mm.

[0062] In one embodiment, the mounting structure 100 is attached to the bottom or side of the ejection end of the laser head, so that the air knife device can be flexibly arranged according to the volume size and working environment of the laser processing head.

[0063] In this example, see Figure 5 The mounting structure 100 is a cylindrical structure, and includes a mounting body 110 and a fixing plate 120 disposed on the mounting body 110. The fixing plate 120 is used to be detachably connected to the ejection end of the laser head. A laser channel 101 is disposed in the mounting structure 100 and is coaxial with the laser beam emitted by the laser head. This arrangement facilitates the installation of the air knife device on the laser head.

[0064] In one embodiment, see Figures 1 to 11 The mounting body 110 is provided with a magnetic attraction assembly 130, which includes a plurality of magnetic attraction members, each of which is arranged around the laser channel 101 and is used to magnetically attract metal splashes. By such an arrangement, the adsorption capacity of the air knife device for metal splashes can be increased, thereby further increasing the slag removal and dust removal effects of the air knife device.

[0065] It can be understood that the second wind knife is a supersonic wind knife, and one layer of the second wind knife can remove more than 90% of the spatter. The first wind knife is a subsonic wind knife. Multi-layer subsonic wind knives can further clean and blow out the remaining residual and rebounded spatter, and can blow away the low-speed welding slag to protect the lens and processing area, and prevent the welding slag from contaminating and damaging the workpiece and optical components. The wind knife can stabilize the metal vapor generated during the welding process, reduce the impact of metal vapor on the laser, and improve the stability and accuracy of the processing; the uppermost magnetic suction component 130 can also absorb metal spatter, thereby achieving the purpose of protecting the lens to the greatest extent under high power conditions.

[0066] Specifically, the magnetic attraction member is provided with two half-ring magnet rings, and a groove for installing the magnet ring is opened on the mounting body 110. The groove is arranged as far away from the protective lens as possible to form an annular magnetic field to absorb metal splashes, thereby achieving the purpose of protecting the lens under high power conditions.

[0067] Furthermore, in this embodiment, the wind knife device further includes a plurality of mounting pads and a plurality of mounting columns 430; each mounting pad is respectively arranged between the mounting body 110 and the first wind knife structure 200, between two adjacent first wind knife structures 200, between the first wind knife structure 200 and the second wind knife structure 300, and on the side of the second wind knife structure 300 away from the mounting structure 100, and each mounting column 430 is respectively supported and arranged between two adjacent mounting pads. Specifically, the mounting column 430 can be selected as a stud. By such an arrangement, the installation stability and reliability of several wind knife structures can be ensured.

[0068] In one embodiment, see Figures 5 to 11 Each mounting gasket includes a first gasket 410 corresponding to each first air knife structure 200, and a second gasket 420 corresponding to the second air knife structure 300; a first through hole 411 coaxially arranged with the laser channel 101 is arranged in the first gasket 410, and a second through hole 421 coaxially arranged with the laser channel 101 is arranged in the second gasket 420, the aperture of the second through hole 421 is smaller than the aperture of the first through hole 411, and the width dimension of the first injection channel 210 is larger than the aperture of the first through hole 411, and the width dimension of the second injection channel 310 is larger than the aperture of the second through hole 421.

[0069] Through such a configuration, since the aperture of the second through hole 421 is smaller than the aperture of the first through hole 411, the second gasket 420 can directly physically block more welding slag, and in order to ensure the dust removal and slag removal effects of the first air knife and the second air knife, the width of the first injection channel 210 is larger than the aperture of the first through hole 411, and the width of the second injection channel 310 is larger than the aperture of the second through hole 421, thereby ensuring that the first air knife can cover the first through hole 411 and the second air knife can cover the second through hole 421, so as to avoid welding slag from the first through hole 411 and the second through hole 421 splashing toward the laser head.

[0070] In this embodiment, the velocity of the supersonic air flow at the outlet of the second wind knife can be selected to be Mach 2, and the wind speed at the first through hole 411 is twice that of the subsonic first wind knife.

[0071] In one embodiment, see Figure 4 , the spacing dimension H5 between two adjacent first injection channels 210, and between the first injection channel 210 and the second injection channel 310 is between 35mm-45mm. By setting in this way, not only can the interference between two adjacent first airflows, or between the first airflow and the second airflow be avoided, but also the structure of the wind knife device can be compact and miniaturized. It is understandable that because the distance between the two airflows is too close, the airflow will form a vortex when it is blown out, and the distance is too close will cause the two airflows to collide, affecting its slag removal and dust removal capabilities.

[0072] Specifically, the spacing dimension H5 between the first injection channel 210 and the second injection channel 310 may be 35 mm, 38 mm, 40 mm, 42 mm or 45 mm.

[0073] In one embodiment, the air knife device further includes a quick-screw connector 500 , and the external air pipe is installed on the air knife structure through the quick-screw connector 500 and is connected to the first injection channel 210 or the second injection channel 310 .

[0074] The above disclosure is only the preferred embodiment of the present invention, which certainly cannot be used to limit the scope of the present invention. Therefore, equivalent changes made according to the claims of the present invention are still within the scope of the present invention.

Claims

1. A wind knife device for a laser processing head, characterized in that: The wind knife device comprises a mounting structure for mounting and connecting with the ejection end of the laser head, and at least two layers of wind knife structures mounted on the mounting structure; At least two layers of the wind knife mechanism include a first wind knife structure and a second wind knife structure, the laser head, the first wind knife structure and the second wind knife structure are arranged at intervals along a first direction, and the laser beam emitted by the laser head extends along the first direction; The first air knife structure is provided with a first injection channel for ejecting a first airflow in a second direction, and the second air knife structure is provided with a second injection channel for ejecting a second airflow in the second direction; The first airflow is a subsonic airflow or a supersonic airflow, the second airflow is a supersonic airflow, and the first direction and the second direction are arranged at an angle.

2. The air knife device for a laser processing head according to claim 1, characterized in that: The second injection channel comprises a contraction section, a throat section and an expansion section which are connected in sequence, the cross-sectional size of the contraction section gradually decreases from the air inlet end to the air outlet end, and the cross-sectional size of the expansion section gradually increases from the air inlet end to the air outlet end; The cross-sectional size of the first injection channel remains unchanged from the air inlet end to the air outlet end, or the structure of the first injection channel is the same as that of the second injection channel.

3. The air knife device for a laser processing head according to claim 2, characterized in that: One second wind knife structure is provided, and a plurality of first wind knife structures are provided, which are sequentially arranged between the mounting structure and the second wind knife structure.

4. The air knife device for a laser processing head according to claim 2, characterized in that: The height dimension of the first injection channel is between 0.05mm and 0.1mm; The second injection channel also includes a holding section located at the air inlet end and connected to the contraction section, the holding section has an extension length of 2mm-4mm, a height dimension of 5.5mm-6.5mm, an extension length of the contraction section of 4mm-6mm, a height dimension of the throat of 2.5mm-3.5mm, an extension length of the expansion section of 3mm-5mm, and a height dimension of 3.5mm-4.5mm at the air outlet end.

5. The air knife device for a laser processing head according to claim 1, characterized in that: The first injection channel and the second injection channel both extend along the second direction and are spaced apart along the first direction, and the second direction is set at an angle of -45° to 45° with the horizontal direction; and / or, The mounting structure is attached to the bottom or side of the ejection end of the laser head.

6. The air knife device for a laser processing head according to claim 1, characterized in that: The mounting structure is a cylindrical structure, comprising a mounting body and a fixing plate arranged on the mounting body, wherein the fixing plate is used for detachable connection with the ejection end of the laser head, and a laser channel coaxially arranged with the laser beam emitted by the laser head is arranged in the mounting structure.

7. The air knife device for a laser processing head according to claim 6, characterized in that: A magnetic attraction component is arranged in the installation body, and the magnetic attraction component includes a plurality of magnetic attraction parts, each of which is arranged in a ring around the laser channel and is used to magnetically attract metal splashes; and / or, The wind knife device also includes multiple mounting gaskets and multiple mounting columns; each mounting gasket is respectively arranged between the mounting body and the first wind knife structure, between two adjacent first wind knife structures, between the first wind knife structure and the second wind knife structure, and on the side of the second wind knife structure away from the mounting structure, and each mounting column is respectively supported and arranged between two adjacent mounting gaskets.

8. The air knife device for a laser processing head according to claim 7, characterized in that: Each of the mounting gaskets includes a first gasket corresponding to each of the first wind knife structures, and a second gasket corresponding to the second wind knife structure; A first through hole coaxially arranged with the laser channel is provided in the first gasket, and a second through hole coaxially arranged with the laser channel is provided in the second gasket, the aperture of the second through hole is smaller than the aperture of the first through hole, and the width of the first injection channel is larger than the aperture of the first through hole, and the width of the second injection channel is larger than the aperture of the second through hole.

9. The air knife device for a laser processing head according to claim 1, characterized in that: The spacing between two adjacent first injection channels and between the first injection channel and the second injection channel is between 35 mm and 45 mm.

10. A laser processing head, characterized in that: The laser processing head comprises a laser head for emitting a laser beam, and a wind knife device installed on the laser head; Wherein, the wind knife device is the wind knife device for a laser processing head as described in any one of claims 1 to 9.

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