Totally-closed high-reliability laser welding reflector path device and using method

Abstract

The invention discloses a totally-closed high-reliability laser welding reflector path device and a using method, and the totally-closed high-reliability laser welding reflector path device comprises a totally-closed reflector path structure assembly which is of a closed structure and is used for transmitting and focusing a laser beam; the first end of the protective gas circulation control assembly is communicated with the first end of the totally-closed external light path structure assembly; one end of a laser output unit is communicated with the second end of the totally-closed external light path structure assembly, and the laser output unit is communicated with the second end of the protective gas circulation control assembly; and the anti-splashing purging assembly is arranged at the output end of the laser output unit and used for preventing splashing welding slag in the laser welding process and avoiding damage to the lens. According to the laser welding device, a totally-closed structure is adopted, the laser beams are effectively prevented from making contact with outside air in the transmission process, attenuation and scattering of the laser beams are reduced, and the stability and reliability of laser welding are improved.

Description

Technical Field

[0001] This invention relates to the field of laser welding, and in particular to a fully enclosed, high-reliability external optical path device for laser welding and its usage method. Background Technology

[0002] The cold-rolled acid-continuous laser welding machine is mainly used for welding hot-rolled strip steel with a thickness of 2mm-4mm and a hardness of HR30Te of 42-65. The output mirror of the welding machine's laser source body outputs a laser beam with a spot diameter of 22mm and a power of 8KW. The laser welding of the steel plate is achieved through multiple reflections and final focusing in the external optical path. The existing welding machine's laser beam external optical path system is based on a stainless steel pipeline, which consists of a pipeline, a reflector, a focusing lens, and a laser processing head. Compressed gas is passed through the laser beam external optical path pipeline for protection, which can block the influence of general external dust and ensure the cleanliness of the internal part of the external optical path and the stability of laser transmission.

[0003] In the prior art, patent application number CN202111200266.7 discloses an intelligent laser welding machine for a cold rolling production line, including a base, a conveying mechanism, a centering mechanism, a pressing and pushing mechanism, a shearing mechanism, a welding torch traveling mechanism, a copper liner welding mechanism, a storage mechanism, and an electrical control operating system. The conveying mechanism is mounted on the base, with two centering mechanisms at the front and rear ends. A pressing and pushing mechanism and a storage mechanism are located between the two centering mechanisms at the head and the two at the tail. A shearing mechanism, a welding torch traveling mechanism, and a copper liner welding mechanism are located between the two centering mechanisms in the middle. The electrical control operating system is also located on the base. This invention features a reasonable structural design, eliminates the need for manual intervention when replacing the steel strip, employs a servo-controlled positioning mechanism for increased positioning accuracy, and utilizes laser welding to improve welding quality.

[0004] like Figure 6 As shown, the existing laser welding machine 1 includes a welding machine exit frame 2, a welding machine inlet frame 3, a welding machine carriage C-shaped frame 4, a laser source resonant cavity 5, a laser welding external optical path 10, a welding machine exit strip 100, and a welding machine inlet strip 101. When the ambient temperature is relatively high, especially in the hot summer, the position of the laser beam is prone to deflection, and the actual welding penetration rate of the laser transmission will decrease, that is, the laser transmission efficiency will decrease. The higher the ambient temperature, the more obvious it will be. In this case, the only way to compensate for the beam deflection and the decrease in welding penetration rate is to reduce the welding speed. In addition, the optical reflectors and focusing mirrors inside the external optical path are particularly prone to getting dirty, and the mirror surfaces are also prone to burning, which has a great impact on normal welding production.

[0005] Therefore, it is necessary to improve such a structure to overcome the above-mentioned defects. Summary of the Invention

[0006] The purpose of this invention is to provide a fully enclosed, high-reliability laser welding external optical path device and its usage method.

[0007] The above-mentioned technical objective of this invention has been achieved by the following technical solutions:

[0008] A fully enclosed, high-reliability laser welding external optical path device and its usage method, including,

[0009] The fully enclosed external optical path structure component is a closed structure used to transmit and focus the laser beam, transmitting the laser beam to the laser processing head;

[0010] A protective gas circulation control component, the first end of which is connected to the first end of the fully enclosed external optical path structure component, is used to introduce protective gas into the fully enclosed external optical path structure component.

[0011] The laser output and automatic lens replacement assembly includes a laser output unit and an automatic lens replacement unit. One end of the laser output unit is connected to the second end of the fully enclosed external optical path structure assembly, and the laser output unit is also connected to the second end of the protective gas circulation control assembly. After processing, the protective gas can flow back into the protective gas circulation control assembly for easy reuse. The output end of the laser output unit faces the strip steel, and the laser beam in the optical path irradiates the strip steel through the laser output unit. The automatic lens replacement unit is used to replace lenses whose performance has deteriorated.

[0012] The anti-splatter blow-off assembly is located at the output end of the laser output unit. It is used to prevent welding slag from splashing during laser welding and avoid damage to the lens.

[0013] A further feature of the present invention is that the fully enclosed external optical path structure component includes,

[0014] The horizontal main pipe is a hollow pipe made of stainless steel. An insulation sleeve is installed on the outside of the horizontal main pipe. The first end of the horizontal main pipe is connected to the output end of the protective gas circulation control component, so that the protective gas can be input into the horizontal main pipe.

[0015] The longitudinal main pipe is a hollow pipe made of stainless steel. An insulation sleeve is installed on the outside of the longitudinal main pipe. The first end of the longitudinal main pipe is connected to the second end of the transverse main pipe through a mirror mount. Protective gas can be introduced into the longitudinal main pipe from the transverse main pipe. An optical reflector is installed inside the mirror mount. The laser beam in the transverse main pipe can enter the longitudinal main pipe through the optical reflector. A mirror mount is installed at the second end of the longitudinal main pipe. An optical reflector is installed inside the mirror mount. An external optical path focusing mirror is also installed. The laser beam in the longitudinal main pipe enters the external optical path focusing mirror through the optical reflector and is focused by the external optical path focusing mirror before being emitted outward.

[0016] A further provision of the present invention is that the protective gas circulation control component includes,

[0017] The protective gas source is filled with nitrogen.

[0018] The gas source connector has a first end connected to the protective gas source and a second end connected to the horizontal main pipeline. Protective nitrogen can be introduced into the fully enclosed external optical path structure component through the gas source connector.

[0019] The pressure control valve is installed on the gas source connector and is used to control the opening and closing of the gas source connector, thereby regulating the input of protective nitrogen.

[0020] The recycling cabinet contains a receiving chamber and an air pump. The recycling cabinet integrates a flow control unit and a temperature and humidity control unit. The flow control unit is used to precisely control the flow rate of the protective gas, and the temperature and humidity control unit is used to regulate the temperature and humidity of the protective gas.

[0021] The intake pipe has one end connected to the air pump and the other end connected to the horizontal main pipe. A flow detection unit is installed on the intake pipe to detect the flow rate of the protective gas flowing through the intake pipe.

[0022] The return gas pipeline has one end connected to the mirror base and the other end connected to the air pump. It can enter the recovery cabinet through the return gas pipeline. A filter unit is installed on the return gas pipeline to filter the recovered nitrogen.

[0023] A further configuration of the present invention is as follows: the laser output and automatic lens replacement assembly includes a laser output mechanism, the laser output mechanism includes a laser processing head, one end of the laser processing head is disposed on the lens mount two, and the output end of the laser processing head is oriented toward the strip steel.

[0024] A further feature of the present invention is that the laser output and lens automatic replacement assembly includes an automatic replacement mechanism, the automatic replacement mechanism comprising,

[0025] The mounting frame is set inside the lens mount and located on the laser processing head. The mounting frame has a lens in use. A new lens storage box is set at the first end of the mounting frame, and an old lens storage box is set at the second end of the mounting frame.

[0026] The lens ejection mechanism is located on one side of the new lens storage box, with the ejection end of the mechanism facing the new lens storage box. The new lens is pushed into the input end of the laser processing head through the lens ejection mechanism, and the old lens that has reached the end of its service life is ejected into the old lens storage box.

[0027] A further provision of the present invention is that the anti-splash blowing assembly includes,

[0028] The nozzle unit is equipped with a nozzle flow control valve. The nozzle unit is used to emit airflow to blow away the welding slag that splashes during the welding process.

[0029] The flow guide is positioned so that its input end faces the output end of the nozzle unit. The airflow ejected from the nozzle unit is output through the flow guide to clean the surface of the strip steel before welding, removing foreign matter such as iron oxide powder that may affect the welding quality, thereby improving the welding quality.

[0030] A method for using a fully enclosed, high-reliability laser welding external optical path device includes the following steps:

[0031] S1: Protective gas injection, open the pressure control valve to allow nitrogen to enter the fully enclosed external optical path structure component from the protective gas source through the gas source connector and the horizontal main pipe;

[0032] S2: Protect gas circulation, start the gas pump in the recovery cabinet to start nitrogen circulation, and adjust the nitrogen pressure, flow rate and temperature and humidity according to actual needs;

[0033] S3: Optical path guidance, start the laser welding machine, the laser beam enters the horizontal main pipe, and enters the vertical main pipe through the reflection of the first optical reflector. The laser beam continues to transmit in the vertical main pipe and enters the external optical path focusing lens through the reflection of the second optical reflector.

[0034] S4: Optical path focusing. The laser beam is efficiently focused by the external optical path focusing mirror. The focused laser beam is emitted outward from the external optical path focusing mirror for welding.

[0035] S5: Anti-spatter blow-off. During the welding process, the nozzle unit of the anti-spatter blow-off component emits airflow to blow away the spattered weld slag, while the guide port blows the surface of the strip steel before welding.

[0036] S6: Lens replacement. When the performance of the lens deteriorates, the lens ejection mechanism of the automatic lens replacement component pushes the new lens into the input end of the laser processing head and ejects the old lens that has reached the end of its service life into the old lens storage box.

[0037] S7: After completing the welding task, recover the nitrogen, close the pressure control valve and the gas pump, and disconnect the nitrogen supply.

[0038] In summary, the present invention has the following beneficial effects:

[0039] 1. High reliability: The device adopts a fully enclosed structure, which effectively prevents the laser beam from coming into contact with the outside air during transmission, reduces the attenuation and scattering of the laser beam, and improves the stability and reliability of laser welding.

[0040] 2. Protective gas recycling: The protective gas recycling control component can recycle protective gases such as nitrogen, reducing resource waste and ensuring a clean and stable supply of protective gases.

[0041] 3. Automatic lens replacement: The laser output and automatic lens replacement component can automatically replace lenses with degraded performance, ensuring the continuity and stability of laser welding and improving work efficiency.

[0042] 4. Anti-splatter function: The anti-splatter blowing component can prevent the welding slag from splashing during the welding process from damaging the lens, and at the same time blow the surface of the strip steel to improve the welding quality. Attached Figure Description

[0043] Figure 1 This is a schematic diagram of the structure of the present invention.

[0044] Figure 2 This is a schematic diagram of the fully enclosed external optical path structure component of the present invention.

[0045] Figure 3 This is a schematic diagram of the structure of the protective gas circulation control component of the present invention.

[0046] Figure 4 This is a schematic diagram of the structure of the laser output and automatic lens replacement component of the present invention.

[0047] Figure 5 This is a schematic diagram of the anti-splash blowing assembly of the present invention.

[0048] Figure 6 This is a structural schematic diagram of an existing laser welding machine. Detailed Implementation

[0049] To make the technical means, creative features, objectives and effects of this invention easier to understand, the invention will be further described below with reference to the figures and specific embodiments.

[0050] like Figures 1 to 6 As shown, the present invention proposes a fully enclosed, high-reliability laser welding external optical path device and its usage method, comprising,

[0051] The fully enclosed external optical path structure component 20 is a closed structure used to transmit and focus the laser beam, and transmit the laser beam to the laser processing head 26.

[0052] A protective gas circulation control component 30 is provided, with its first end connected to the first end of the fully enclosed external optical path structure component 20, and is used to introduce protective gas into the fully enclosed external optical path structure component 20.

[0053] The laser output and automatic lens replacement assembly 40 includes a laser output unit and an automatic lens replacement unit. One end of the laser output unit is connected to the second end of the fully enclosed external optical path structure assembly 20, and the laser output unit is also connected to the second end of the protective gas circulation control assembly 30. After processing, the protective gas can flow back into the protective gas circulation control assembly 30 for easy reuse. The output end of the laser output unit faces the strip steel, and the laser beam in the optical path irradiates the strip steel through the laser output unit. The automatic lens replacement unit is used to replace lenses whose performance has deteriorated.

[0054] Anti-splatter blowing assembly 50 is installed on the output end of the laser output unit. It is used to prevent welding slag from splashing during laser welding and to avoid damage to the lens caused by the welding slag.

[0055] In this embodiment, the fully enclosed external optical path structure component 20 includes,

[0056] The horizontal main pipe 21 is a hollow pipe made of stainless steel. An insulation sleeve 22 is fitted on the outside of the horizontal main pipe 21. The first end of the horizontal main pipe 21 is connected to the output end of the protective gas circulation control component 30, and the protective gas can be input into the horizontal main pipe 21.

[0057] The longitudinal main pipe 24 is a hollow pipe made of stainless steel. The outer side of the longitudinal main pipe 24 is fitted with a second insulation sleeve 25. The first end of the longitudinal main pipe 24 is connected to the second end of the transverse main pipe 21 through a first mirror mount 23. Protective gas can be introduced into the longitudinal main pipe 24 from the transverse main pipe 21. An optical reflecting mirror is installed in the first mirror mount 23. The laser beam in the transverse main pipe 21 can enter the longitudinal main pipe 24 through the first optical reflecting mirror. A second mirror mount 27 is installed on the second end of the longitudinal main pipe 24. An optical reflecting mirror is installed in the second mirror mount 27. An external optical path focusing mirror 28 is also installed. The laser beam in the longitudinal main pipe 24 enters the external optical path focusing mirror 28 through the second optical reflecting mirror, and is focused by the external optical path focusing mirror 28 and then emitted outward.

[0058] By using the protective gas circulation control component 30, protective gas is introduced into the transverse main pipe 21 and the longitudinal main pipe 24, effectively preventing attenuation or scattering of the laser beam due to contact with air during transmission, thus improving the transmission quality of the laser beam. Through the design of optical reflector one and optical reflector two, the laser beam can be transmitted efficiently and accurately from the transverse main pipe 21 to the longitudinal main pipe 24, and then focused by the external optical path focusing lens 28 before being emitted outward, ensuring the transmission efficiency and focusing effect of the laser beam. The fully enclosed structure reduces the interference of the external environment on the transmission of the laser beam.

[0059] The operation of the fully enclosed external optical path structure component 20 is as follows: First, protective gas is input into the transverse main pipe 21 through the protective gas circulation control component 30 to ensure that the laser beam is adequately protected during transmission. The laser beam enters the transverse main pipe 21 from the output end of the protective gas circulation control component 30, and enters the longitudinal main pipe 24 through the reflection of the first optical reflector. In the longitudinal main pipe 24, the laser beam continues to transmit and enters the external optical path focusing lens 28 through the reflection of the second optical reflector. Under the action of the external optical path focusing lens 28, the laser beam is efficiently focused. The focused laser beam is emitted outward from the external optical path focusing lens 28 for welding. Throughout the operation, the protective gas continuously circulates within the transverse main pipe 21 and the longitudinal main pipe 24, effectively preventing attenuation or scattering caused by the laser beam contacting air, thus ensuring the transmission quality and stability of the laser beam.

[0060] In this embodiment, the protective gas circulation control component 30 includes a protective gas source 31 filled with nitrogen, a gas source connector 32, the first end of which is connected to the protective gas source 31, and the second end of which is connected to the transverse main pipe 21, allowing protective nitrogen to enter the fully enclosed external optical path structure component 20 through the gas source connector 32; a pressure control valve 33, which is installed on the gas source connector 32 and is used to control the opening and closing of the gas source connector 32, thereby regulating the input of protective nitrogen; and a recovery cabinet, which has a receiving cavity and a gas pump, and integrates a flow control unit 34 and a temperature and humidity control unit 37. The flow control unit 34 is used for... The flow rate of the protective gas is precisely controlled, and the temperature and humidity control unit 37 is used to adjust the temperature and humidity of the protective gas. An inlet pipe 38 is connected at one end to an air pump and at the other end to a transverse main pipe 21. A flow detection unit 35 is installed on the inlet pipe 38 to detect the flow rate of the protective gas flowing through it. A return gas pipe 39 is connected at one end to a mirror mount 27 and at the other end to an air pump, allowing gas to enter the recovery cabinet. A filter unit 36 ​​is installed on the return gas pipe 39 to filter the recovered nitrogen, ensuring its cleanliness.

[0061] The operation of the protective gas circulation control component 30 is as follows: First, open the pressure control valve 33 to allow nitrogen to enter the fully enclosed external optical path structure component 20 from the protective gas source 31 through the gas source connector 32 and the horizontal main pipe 21. Then, start the air pump in the recovery cabinet to start the nitrogen circulation. According to actual needs, the pressure, flow rate, temperature and humidity of the nitrogen are adjusted through the pressure control valve 33, the flow control unit 34 and the temperature and humidity control unit 37. After completing the protective function, the nitrogen enters the recovery cabinet through the return gas pipeline 39. After being filtered by the filter unit 36, it is sucked in by the air pump again and recycled. The flow detection unit 35 monitors the flow rate of nitrogen through the inlet pipeline 38 in real time to ensure the accuracy and stability of the flow rate.

[0062] In this embodiment, the laser output and automatic lens replacement assembly 40 includes a laser processing head 26, one end of which is mounted on a lens mount 27; a mounting frame 41, which is located inside the lens mount and on the laser processing head 26, and has a used lens 42 mounted on it; a new lens storage box 43 is located at the first end of the mounting frame 41, and an old lens storage box 45 is located at the second end of the mounting frame 41; and a lens ejection mechanism 44, which is located on one side of the new lens storage box 43, with its ejection end facing the new lens storage box 43. The lens ejection mechanism 44 pushes new lenses into the input end of the laser processing head 26 and ejects old lenses that have reached the end of their service life into the old lens storage box 45, ensuring the performance of the lenses.

[0063] In this embodiment, the anti-splatter blowing assembly 50 includes a nozzle unit 51, on which a nozzle flow control valve 53 is provided. The nozzle unit 51 is used to emit airflow to blow away the spattered welding slag during the welding process. A guide port 52 is provided with its input end facing the output end of the nozzle unit 51. The airflow emitted by the nozzle unit 51 is output through the guide port 52 to blow away the surface of the strip steel before welding, removing foreign matter such as iron oxide powder that may affect the welding quality and improving the welding quality.

[0064] In summary, the fully enclosed external optical path structure component is responsible for the transmission and focusing of the laser beam, accurately transmitting the laser beam to the laser processing head to achieve laser welding; the protective gas circulation control component provides stable and clean protective gas to prevent the laser beam from being contaminated and attenuated during transmission, thus improving welding quality; the laser output and automatic lens replacement component ensures that the lens is always in optimal working condition, avoiding the impact of lens aging or damage on the welding effect; and the anti-spatter blowing component prevents weld slag from damaging the lens and strip steel, while simultaneously blowing away the surface of the strip steel to ensure welding quality.

[0065] The usage process of this invention is as follows: Open the pressure control valve to allow nitrogen gas from the protective gas source to enter the fully enclosed external optical path structure assembly through the gas source connector and the horizontal main pipe; start the gas pump in the recovery cabinet to begin nitrogen circulation, and adjust the nitrogen pressure, flow rate, temperature, and humidity according to actual needs; check the new lens storage box and old lens storage box in the automatic lens replacement assembly to ensure there are lenses available for replacement; the laser beam enters the horizontal main pipe from the output end of the protective gas circulation control assembly, and enters the vertical main pipe through the reflection of the first optical reflector; the laser beam continues to propagate within the vertical main pipe and passes through the optical reflector... The laser beam is reflected by the second element and enters the external optical path focusing lens. Under the action of the external optical path focusing lens, the laser beam is efficiently focused and emitted outwards for welding. During welding, the nozzle unit of the anti-spatter blowing assembly emits airflow to blow away the spatter, while the guide port cleans the surface of the strip steel before welding. When the lens performance deteriorates, the lens ejection mechanism of the automatic lens replacement assembly pushes a new lens into the input end of the laser processing head and ejects the old lens that has reached the end of its service life into the old lens storage box. The quantity and quality of lenses in the lens storage box are checked regularly, and timely replenishment and replacement are carried out. After the welding task is completed, nitrogen is recovered, the pressure control valve and air pump are closed, and the nitrogen supply is disconnected.

[0066] In the description of this invention, it should be noted that the terms "upper," "lower," "inner," "outer," "left," and "right," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, or the orientation or positional relationship commonly used when the product of this invention is in use, or the orientation or positional relationship commonly understood by those skilled in the art. These terms are used only for the convenience of describing this invention and for simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this invention. Furthermore, the terms "first," "second," etc., are used only to distinguish descriptions and should not be construed as indicating or implying relative importance. In the description of this invention, it should also be noted that, unless otherwise explicitly specified and limited, terms such as "set" and "connect" should be interpreted broadly. For example, "connection" can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium; it can be a connection within two components. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances. In this document, the terms “comprising,” “including,” or any other variations thereof are intended to cover non-exclusive inclusion, which includes not only the elements listed but also other elements not expressly listed.

[0067] The foregoing has shown and described the basic principles, main features, and advantages of the present invention. Those skilled in the art should understand that the present invention is not limited to the above embodiments. The embodiments and descriptions in the specification are merely illustrative of the principles of the invention. Various changes and modifications can be made to the invention without departing from its spirit and scope, and all such changes and modifications fall within the scope of the present invention as claimed. The scope of protection of this invention is defined by the appended claims and their equivalents.

Claims

1. A fully enclosed, high-reliability laser welding external optical path device, characterized in that, include, The fully enclosed external optical path structure component is a closed structure used to transmit and focus the laser beam, transmitting the laser beam to the laser processing head; A protective gas circulation control component, the first end of which is connected to the first end of the fully enclosed external optical path structure component, is used to introduce protective gas into the fully enclosed external optical path structure component. The laser output and automatic lens replacement assembly includes a laser output unit and an automatic lens replacement unit. One end of the laser output unit is connected to the second end of the fully enclosed external optical path structure assembly, and the laser output unit is also connected to the second end of the protective gas circulation control assembly. After processing, the protective gas can flow back into the protective gas circulation control assembly for easy reuse. The output end of the laser output unit faces the strip steel, and the laser beam in the optical path irradiates the strip steel through the laser output unit. The automatic lens replacement unit is used to replace lenses whose performance has deteriorated. The anti-splatter blow-off assembly is located at the output end of the laser output unit. It is used to prevent welding slag from splashing during laser welding and avoid damage to the lens.

2. The fully enclosed, high-reliability laser welding external optical path device according to claim 1, characterized in that, The fully enclosed external optical path structure components include, The horizontal main pipe is a hollow pipe made of stainless steel. An insulation sleeve is installed on the outside of the horizontal main pipe. The first end of the horizontal main pipe is connected to the output end of the protective gas circulation control component, so that the protective gas can be input into the horizontal main pipe. The longitudinal main pipe is a hollow pipe made of stainless steel. An insulation sleeve is installed on the outside of the longitudinal main pipe. The first end of the longitudinal main pipe is connected to the second end of the transverse main pipe through a mirror mount. Protective gas can be introduced into the longitudinal main pipe from the transverse main pipe. An optical reflector is installed inside the mirror mount. The laser beam in the transverse main pipe can enter the longitudinal main pipe through the optical reflector. A mirror mount is installed at the second end of the longitudinal main pipe. An optical reflector is installed inside the mirror mount. An external optical path focusing mirror is also installed. The laser beam in the longitudinal main pipe enters the external optical path focusing mirror through the optical reflector and is focused by the external optical path focusing mirror before being emitted outward.

3. The fully enclosed, high-reliability laser welding external optical path device according to claim 1, characterized in that, The protective gas circulation control component includes, The protective gas source is filled with nitrogen. The gas source connector has a first end connected to the protective gas source and a second end connected to the horizontal main pipeline. Protective nitrogen can be introduced into the fully enclosed external optical path structure component through the gas source connector. The pressure control valve is installed on the gas source connector and is used to control the opening and closing of the gas source connector, thereby regulating the input of protective nitrogen. The recycling cabinet contains a receiving chamber and an air pump. The recycling cabinet integrates a flow control unit and a temperature and humidity control unit. The flow control unit is used to precisely control the flow rate of the protective gas, and the temperature and humidity control unit is used to regulate the temperature and humidity of the protective gas. The intake pipe has one end connected to the air pump and the other end connected to the horizontal main pipe. A flow detection unit is installed on the intake pipe to detect the flow rate of the protective gas flowing through the intake pipe. The return gas pipeline has one end connected to the mirror base and the other end connected to the air pump. It can enter the recovery cabinet through the return gas pipeline. A filter unit is installed on the return gas pipeline to filter the recovered nitrogen.

4. The fully enclosed, high-reliability laser welding external optical path device according to claim 1, characterized in that, The laser output and automatic lens replacement assembly includes a laser output mechanism, which includes a laser processing head. One end of the laser processing head is mounted on the lens mount 2, and the output end of the laser processing head is oriented towards the strip steel.

5. The fully enclosed, high-reliability laser welding external optical path device according to claim 4, characterized in that, The laser output and lens automatic replacement assembly includes an automatic replacement mechanism, which includes... The mounting frame is set inside the lens mount and located on the laser processing head. The mounting frame has a lens in use. A new lens storage box is set at the first end of the mounting frame, and an old lens storage box is set at the second end of the mounting frame. The lens ejection mechanism is located on one side of the new lens storage box, with the ejection end of the mechanism facing the new lens storage box. The new lens is pushed into the input end of the laser processing head through the lens ejection mechanism, and the old lens that has reached the end of its service life is ejected into the old lens storage box.

6. The fully enclosed, high-reliability laser welding external optical path device according to claim 1, characterized in that, The anti-splash purging assembly includes, The nozzle unit is equipped with a nozzle flow control valve. The nozzle unit is used to emit airflow to blow away the welding slag that splashes during the welding process. The flow guide is positioned so that its input end faces the output end of the nozzle unit. The airflow ejected from the nozzle unit is output through the flow guide to clean the surface of the strip steel before welding, removing foreign matter such as iron oxide powder that may affect the welding quality, thereby improving the welding quality.

7. The method of using the fully enclosed high-reliability laser welding external optical path device according to any one of claims 1-6, characterized in that, Includes the following steps: S1: Protective gas injection, open the pressure control valve to allow nitrogen to enter the fully enclosed external optical path structure component from the protective gas source through the gas source connector and the horizontal main pipe; S2: Protect gas circulation, start the gas pump in the recovery cabinet to start nitrogen circulation, and adjust the nitrogen pressure, flow rate and temperature and humidity according to actual needs; S3: Optical path guidance, start the laser welding machine, the laser beam enters the horizontal main pipe, and enters the vertical main pipe through the reflection of the first optical reflector. The laser beam continues to transmit in the vertical main pipe and enters the external optical path focusing lens through the reflection of the second optical reflector. S4: Optical path focusing. The laser beam is efficiently focused by the external optical path focusing mirror. The focused laser beam is emitted outward from the external optical path focusing mirror for welding. S5: Anti-spatter blow-off. During the welding process, the nozzle unit of the anti-spatter blow-off component emits airflow to blow away the spattered weld slag, while the guide port blows the surface of the strip steel before welding. S6: Lens replacement. When the performance of the lens deteriorates, the lens ejection mechanism of the automatic lens replacement component pushes the new lens into the input end of the laser processing head and ejects the old lens that has reached the end of its service life into the old lens storage box. S7: After completing the welding task, recover the nitrogen, close the pressure control valve and the gas pump, and disconnect the nitrogen supply.

Images