Water-conducting laser processing device and processing method under multiple water-air composite modes

Abstract

The present invention discloses a water-guided laser processing device under a multiple water-gas composite mode and a processing method thereof. An auxiliary atmosphere input gas path (9) is provided in the interlayer between a light-water coupling device (2) and an annular water jet device (3), and the auxiliary atmosphere input gas path (9) ejects the auxiliary atmosphere through an annular gas nozzle (6) to form an auxiliary airflow layer (8). A nozzle (4) is provided at the lower end of the light-water coupling device (2), and an annular liquid nozzle (5) is provided at the bottom of the annular water jet device (3). The light-water coupling device (2) is used to couple a laser beam (1) with an internal liquid and then eject a single water jet (10) from the nozzle (4). The annular water jet device (3) is used to eject the internal liquid from the annular liquid nozzle (5) to form an annular water curtain (7) surrounding the light-guided water jet (10), and the annular water curtain (7) envelops the auxiliary airflow layer (8). The present invention is used to effectively extend the stable jet length.

Description

Technical Field

[0001] The present invention belongs to the technical field of laser processing, and in particular relates to a water-conducting laser processing device and a processing method thereof in a multiple water-air composite mode. Background Art

[0002] In high-end manufacturing companies such as aerospace equipment, medical equipment, and semiconductor micro-machining, many key precision parts have extremely high technical requirements for machining accuracy, efficiency, thermal damage, and fracture quality during manufacturing. Conventional processing methods are difficult to effectively take into account the above requirements. Water-guided laser technology is a green, efficient and precision processing technology. Its principle is to couple a high-energy laser beam into a micro-water jet, and the water jet guides the laser to the surface of the workpiece to achieve precision thermal processing such as cutting, drilling, and grooving of the workpiece. At the same time, the water jet can take away excess heat and residue. Therefore, water-guided laser technology can achieve precise control of high-density energy in the "cold and hot source" mode, and then obtain ultra-precise, efficient, and high-quality incisions. It is very suitable for fine processing of materials such as high-temperature alloys, wafers, and carbon fibers, and processing of parts of biomedical devices. However, there are two most critical factors that determine the precision processing capability of water-guided lasers, namely the water jet diameter and the stable water jet length. Because the water jet diameter of the water-guided laser has a great influence on the processing accuracy. The smaller the nozzle diameter, the smaller the diameter of the sprayed water jet, and the higher the processing accuracy. In addition, the processing depth and processing distance of water-guided lasers depend on the stable length of the light-guiding water jet, that is, the length of the jet section with the best light-guiding effect in the light-guiding water jet, which has the characteristics of smooth surface, smoothness, and tight cylindrical shape of liquid flow. Therefore, the industry pays great attention to these two technical indicators. However, it is difficult to achieve consistency enhancement for these two indicators. Because the high-pressure water jet will have violent friction with the surrounding air after it is ejected from the nozzle, causing the internal stable laminar state to gradually become disordered, so the water jet will leave the stable state after a certain distance, resulting in rupture and formation of water droplets, which will cause the light-water coupling channel to be destroyed. Studies have shown that the smaller the diameter of the water jet, the greater the impact, and the shorter the stable water jet length. Even if some researchers apply auxiliary atmosphere at the water jet nozzle to isolate the air and extend the length of the stable liquid flow to a certain extent, the auxiliary atmosphere will also have violent friction with the surrounding air after it is ejected, so the distance that the auxiliary atmosphere can maintain a tight state is also extremely limited, and the protective effect disappears immediately after diffusing for a certain distance. Therefore, the current water-guided laser technology is still a contradiction in terms of processing accuracy and processing thickness, and it is difficult to ensure both at the same time.

[0003] During water-guided laser processing, the fine light-guiding water jet is easily affected by the violent friction of the surrounding air during the spraying process and gradually deviates from the stable state, resulting in the destruction of the stable light-guiding channel. Therefore, how to effectively extend the stable jet length is a key issue. Summary of the invention

[0004] The object of the present invention is to provide a water-guided laser processing device and a processing method thereof in a multiple water-air composite mode, which can effectively extend the stable water jet length and enhance the processing stability while keeping the water jet diameter unchanged.

[0005] The present invention is achieved through the following technical solutions:

[0006] A water-conducting laser processing device in a multiple water-gas composite mode, the water-conducting laser processing device comprises a light-water coupling device 2, an annular water jet device 3, a nozzle 4 and an annular liquid nozzle 5, an auxiliary atmosphere input gas path 9,

[0007] An auxiliary atmosphere input gas path 9 is provided in the interlayer between the light-water coupling device 2 and the annular water jet device 3. The auxiliary atmosphere input gas path 9 ejects the auxiliary atmosphere through the annular gas nozzle 6 to form an auxiliary airflow layer 8. A nozzle 4 is provided at the lower end of the light-water coupling device 2. An annular liquid nozzle 5 is provided at the bottom of the annular water jet device 3. The light-water coupling device 2 is used to couple the laser beam 1 with the internal liquid and then eject a single water jet 10 from the nozzle 4. The annular water jet device 3 is used to eject the internal liquid from the annular liquid nozzle 5 to form an annular water curtain 7 surrounding the light-guiding water jet 10. The annular water curtain 7 covers the auxiliary airflow layer 8.

[0008] Furthermore, the single-channel water jet 10, the auxiliary airflow layer 8 and the annular water curtain 7 are a coaxial composite structure from inside to outside, that is, an inside-outside coaxial composite structure under multiple water-air-water modes.

[0009] Furthermore, the annular water jet device 3 is connected to the lower end of the optical-water coupling device 2 .

[0010] Furthermore, a laser emitting device is arranged above the optical-water coupling device 2 for emitting the laser beam 1 into the optical-water coupling device 2 .

[0011] Furthermore, the laser beam 1 is a single energy beam or a composite energy beam.

[0012] Furthermore, the optical-water coupling device 2 and the annular water jet device 3 are both provided with high-pressure water inlets.

[0013] A water-conducting laser processing method in a multiple water-air composite mode, the water-conducting laser processing method comprising the following steps:

[0014] Step 1: spraying water in the water-conducting laser processing device at high speed under pressure to form a single-channel water jet;

[0015] Step 2: Coaxially compound an auxiliary atmosphere to enclose the single water jet formed in step 1, and coaxially compound another annular water curtain outside the auxiliary atmosphere to form an internal and external coaxial composite structure under multiple water-air-water modes;

[0016] Step 3: Couple the high-energy laser beam into the single-channel water jet formed in step 1 to form a light-guiding water jet, and spray it onto the surface of the workpiece to be processed together with the auxiliary atmosphere and the annular water curtain.

[0017] Furthermore, the single-channel water jet in step 1 has a diameter of 10-600 μm and a water pressure range of 0-100 MPa.

[0018] Furthermore, the auxiliary atmosphere gas pressure in step 2 is 0.1-10 MPa.

[0019] Furthermore, the water in the light-water coupling device and the annular water jet device includes pure water or distilled water or other liquids that meet the light guiding requirements.

[0020] The beneficial effects of the present invention are:

[0021] The present invention effectively prolongs the stable water jet length and enhances processing stability under the condition that the water jet diameter remains unchanged.

[0022] The invention is used to improve the stable jet length, processing stability and anti-interference ability in water-conducting laser cutting, drilling, grooving and other processing.

[0023] The effect of extending the length of the stable water jet of the present invention is significantly better than that of the conventional auxiliary atmosphere protection method. The conventional auxiliary atmosphere protection method is to apply a coaxial auxiliary atmosphere outside the light-guiding water jet. Although it can play a role in isolating the air and extending the stable length of the light-guiding water jet to a certain extent, the auxiliary atmosphere is directly in contact with the air and will also be subject to severe friction from environmental resistance. Therefore, the distance that the auxiliary atmosphere can maintain a tight state is also extremely limited. After spraying a certain distance, the air flow movement will deviate from the axis direction and diffuse outward, and the density and uniformity of the air flow will also decrease at the same time. At this time, the external gas will enter the interior in the form of turbulence, interfere with the light-guiding water jet, and the protective effect of the auxiliary atmosphere will disappear immediately. The multiple water-gas composite design of the present invention, that is, an annular water curtain is added outside the original auxiliary atmosphere. The purpose is that since the density of water is much greater than the density of gas, the annular water curtain has a larger impulse after being sprayed out, and is less likely to be affected by the surrounding atmosphere and cause the spraying shape to be destroyed. Therefore, the annular water curtain has better stability and density than spraying the auxiliary atmosphere alone, has a longer stable spraying distance, and has a better isolation effect on external gas. At the same time, since the annular water curtain does not participate in the thermal processing process, the width of its liquid flow will not affect the processing accuracy, so the effective air isolation protection distance can be greatly extended by appropriately increasing the width of the annular liquid flow.

[0024] The annular water curtain design of the present invention can limit the external diffusion of the internal auxiliary atmosphere and generate the same direction movement as the auxiliary atmosphere, so it can effectively restrain and maintain the stable flow state of the auxiliary atmosphere, extend the length of the auxiliary atmosphere maintained in a tight state, and thereby simultaneously extend the stable length of the light-guiding water jet in the auxiliary atmosphere.

[0025] The multiple water-air composite water-conducting laser processing method under the annular water curtain composite of the present invention can more effectively remove excess processing heat and cutting residues, so the obtained incision heat-affected zone will be smaller and the incision quality will be better.

[0026] The multiple water-air composite water-conducting laser processing device of the present invention is simple in design and easy to implement, but has more composite beneficial effects, obvious effects and good practicality. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Figure 1 It is a structural schematic diagram of the present invention.

[0028] Figure 2 It is a flow chart of the method of the present invention. DETAILED DESCRIPTION

[0029] In the following description, specific details such as specific system structures, technologies, etc. are provided for the purpose of illustration rather than limitation, so as to provide a thorough understanding of the embodiments of the present application. However, it should be clear to those skilled in the art that the present application may also be implemented in other embodiments without these specific details. In other cases, detailed descriptions of well-known systems, devices, circuits, and methods are omitted to prevent unnecessary details from obstructing the description of the present application.

[0030] It should be understood that when used in this specification and the appended claims, the term "comprising" indicates the presence of described features, integers, steps, operations, elements and / or components, but does not exclude the presence or addition of one or more other features, integers, steps, operations, elements, components and / or groups thereof.

[0031] It should also be understood that the terms used in this application specification are only for the purpose of describing specific embodiments and are not intended to limit the application. As used in this application specification and the appended claims, the singular forms "a", "an" and "the" are intended to include plural forms unless the context clearly indicates otherwise.

[0032] The following is a clear and complete description of the technical solutions in the embodiments of the present application in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of this application.

[0033] In the following description, many specific details are set forth to facilitate a full understanding of the present application, but the present application may also be implemented in other ways different from those described herein, and those skilled in the art may make similar generalizations without violating the connotation of the present application. Therefore, the present application is not limited to the specific embodiments disclosed below.

[0034] The present invention is a composite water-guided laser processing method that sequentially coaxially compounds an auxiliary atmosphere and an annular water curtain outside a light-guided water jet to form a three-layer structure with the light-guided water jet as the center, the auxiliary atmosphere, and the inner and outer annular water curtain.

[0035] A water-conducting laser processing device in a multiple water-gas composite mode, the water-conducting laser processing device comprises a light-water coupling device 2, an annular water jet device 3, a nozzle 4 and an annular liquid nozzle 5, an auxiliary atmosphere input gas path 9,

[0036] An auxiliary atmosphere input gas path 9 is provided in the interlayer between the light-water coupling device 2 and the annular water jet device 3. The auxiliary atmosphere input gas path 9 ejects the auxiliary atmosphere through the annular gas nozzle 6 to form an auxiliary airflow layer 8. A nozzle 4 is provided at the lower end of the light-water coupling device 2. An annular liquid nozzle 5 is provided at the bottom of the annular water jet device 3. The light-water coupling device 2 is used to couple the laser beam 1 with the internal liquid and then eject a single water jet 10 from the nozzle 4. The annular water jet device 3 is used to eject the internal liquid from the annular liquid nozzle 5 to form an annular water curtain 7 surrounding the light-guiding water jet 10. The annular water curtain 7 covers the auxiliary airflow layer 8.

[0037] Furthermore, the single-channel water jet 10, the auxiliary airflow layer 8 and the annular water curtain 7 are a coaxial composite structure from inside to outside, that is, an inside-outside coaxial composite structure under multiple water-air-water modes.

[0038] When the laser beam 1 enters the light-water coupling device 2, the laser beam will converge at the inlet of the nozzle 4 and couple into the single-channel water jet 10 to form a light-guiding water jet. The light-guiding water jet, the auxiliary air flow 8 and the annular water curtain 7 will be sprayed onto the surface of the workpiece to be processed.

[0039] Furthermore, the annular water jet device 3 is connected to the lower end of the optical-water coupling device 2; by integrating the annular water jet device 3 and the optical-water coupling device 2, space can be saved, and it is more conducive to setting the nozzle 4 and the annular liquid nozzle 5 in a coaxial form. A flange can be set at the lower end of the nozzle 4, and a stable annular water curtain 7 can be formed through the cooperation of the flange and the annular liquid nozzle 5.

[0040] Furthermore, a laser emitting device is arranged above the optical-water coupling device 2 for emitting the laser beam 1 into the optical-water coupling device 2 .

[0041] Furthermore, the laser beam 1 is a single energy beam or a composite energy beam. The device can adapt to different types of laser beams and has strong versatility. This can be achieved by adding different types of laser emitting devices.

[0042] Furthermore, both the light-water coupling device 2 and the annular water jet device 3 are provided with high-pressure water inlets; this arrangement can control the hydraulic pressure in the light-water coupling device 2 and the annular water jet device 3 separately, thereby realizing independent regulation of the light-guiding water jet and the annular water curtain jet. The high-pressure water inlets of the light-water coupling device 2 and the annular water jet device 3 can be arranged on the same side, which is convenient for installation and the arrangement of the high-pressure water pipeline is more reasonable.

[0043] A water-conducting laser processing method in a multiple water-air composite mode, the water-conducting laser processing method comprising the following steps:

[0044] Step 1: spraying water in the water-conducting laser processing device at high speed under pressure to form a single-channel water jet;

[0045] Step 2: Coaxially compound an auxiliary atmosphere to enclose the single water jet formed in step 1, and coaxially compound another annular water curtain outside the auxiliary atmosphere to form an internal and external coaxial composite structure under multiple water-air-water modes;

[0046] The auxiliary atmosphere is ejected coaxially and in the same direction as the single-channel water jet inside it, so that the single-channel water jet maintains laminar flow characteristics, prolongs the stable length of the jet, and isolates the single-channel water jet from contact with the annular water curtain, so that the single-channel water jet maintains a complete liquid-gas boundary film, thereby allowing the laser beam to maintain total reflection propagation in the single-channel water jet.

[0047] Step 3: Couple the high-energy laser beam into the single-channel water jet formed in step 1 to form a light-guiding water jet, and spray it onto the surface of the workpiece to be processed together with the auxiliary atmosphere and the annular water curtain.

[0048] The annular water curtain wraps the auxiliary atmosphere. The annular water curtain does not participate in the heat treatment process. Its main function is to isolate the influence of the external gas flow field on the auxiliary atmosphere, limit the internal auxiliary atmosphere from diffusing outward, and move in the same direction as the auxiliary atmosphere, thereby reducing the environmental friction resistance of the auxiliary atmosphere during injection. Therefore, it can effectively restrain and maintain the stable flow state of the auxiliary atmosphere, enhance the protective effect of the auxiliary atmosphere on the single-channel water jet, and further extend the stable length of the jet.

[0049] Furthermore, the single-channel water jet in step 1 has a diameter of 10-600 μm and a water pressure range of 0-100 MPa.

[0050] Furthermore, the auxiliary atmosphere gas pressure in step 2 is 0.1-10 MPa.

[0051] The auxiliary atmosphere provided in this manner can envelop the single-channel water jet 10 , and even when the annular water curtain 7 is slightly offset toward the single-channel water jet 10 , a good and normal cutting effect can still be ensured.

[0052] Furthermore, the water in the light-water coupling device and the annular water jet device includes pure water or distilled water or other liquids that meet the light guiding requirements.

Claims

1. A water-conducting laser processing device in multiple water-air composite modes, characterized in that: The water-conducting laser processing device comprises a light-water coupling device (2), an annular water jet device (3), a nozzle (4), an annular liquid nozzle (5) and an auxiliary atmosphere input gas path (9). An auxiliary atmosphere input gas path (9) is provided in the interlayer between the light-water coupling device (2) and the annular water jet device (3), and the auxiliary atmosphere input gas path (9) ejects the auxiliary atmosphere through the annular gas nozzle (6) to form an auxiliary airflow layer (8). A nozzle (4) is provided at the lower end of the light-water coupling device (2), and an annular liquid nozzle (5) is provided at the bottom of the annular water jet device (3). The light-water coupling device (2) is used to couple the laser beam (1) with the internal liquid and then eject a single water jet (10) from the nozzle (4). The annular water jet device (3) is used to eject the internal liquid from the annular liquid nozzle (5) to form an annular water curtain (7) surrounding the single water jet (10), and the annular water curtain (7) envelops the auxiliary airflow layer (8); The single-channel water jet (10), the auxiliary airflow layer (8) and the annular water curtain (7) are a coaxial composite structure from inside to outside, that is, an inside-outside coaxial composite structure under multiple water-air-water modes; The annular water jet device (3) is connected to the lower end of the light-water coupling device (2); A laser emitting device is arranged at the upper end of the light-water coupling device (2) for emitting a laser beam (1) into the light-water coupling device (2); The laser beam (1) is a single energy beam or a composite energy beam; The light-water coupling device (2) and the annular water jet device (3) are both provided with a high-pressure water inlet.

2. A water-conducting laser processing method in multiple water-air composite modes, characterized in that: The water-conducting laser processing method comprises the following steps: Step 1: spraying water in the water-conducting laser processing device as claimed in claim 1 at high speed under pressure to form a single water jet; Step 2: Coaxially compound an auxiliary atmosphere to enclose the single water jet formed in step 1, and coaxially compound another annular water curtain outside the auxiliary atmosphere to form an internal and external coaxial composite structure under multiple water-air-water modes; Step 3: Couple the high-energy laser beam into the single-channel water jet formed in step 1 to form a light-guiding water jet, and spray it onto the surface of the workpiece to be processed together with the auxiliary atmosphere and the annular water curtain.

3. The water-conducting laser processing method according to claim 2, characterized in that: The single-channel water jet in step 1 has a diameter of 10-600 µm and a water pressure range of 0-100 MPa.

4. The water-conducting laser processing method according to claim 2, characterized in that: The auxiliary atmosphere gas pressure in step 2 is 0.1-10 MPa.

5. The water-conducting laser processing method according to claim 2, characterized in that: The water in the light-water coupling device and the annular water jet device includes pure water or distilled water.

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