High-fluidity water-guided laser coupling cavity structure and installation method

Abstract

The invention discloses a high-flowability water-guided laser coupling cavity structure and an installation method. The structure comprises an incident laser beam, an optical protection lens, a nozzle support, an auxiliary nozzle, a main nozzle, a high-pressure water inlet and a coupling water cavity. The optical protective glass, the coupling water cavity and the auxiliary nozzle are fixedly connected in sequence from top to bottom; the high-pressure water inlet is arranged along the peripheral tangent line of the coupling water cavity and is communicated with the coupling water cavity; the auxiliary nozzles and the main nozzles are vertically arranged on the nozzle bracket, are communicated with the coupling water cavity, have the same pipe diameter and are equally distributed by taking the center of the nozzle bracket as a circle center; incident laser beams sequentially penetrate through the optical protection glass and the coupling water cavity, are focused on the main nozzle, are conducted along main water jet sprayed out of the main nozzle based on the total reflection effect of light and are finally transmitted to a material to be machined, and water-guided laser machining is achieved. According to the coupling cavity structure, the auxiliary nozzle can accelerate drainage of water flow in the cavity, an active drainage effect is formed, and the situation that heated water and ionized water flow damage the stability of main water jet is fundamentally avoided.

Description

Technical Field

[0001] This invention belongs to the technical field of water-guided laser equipment, and more specifically, relates to a highly mobile water-guided laser coupling cavity structure and its installation method. Background Technology

[0002] Water-guided laser processing couples a high-energy laser beam into a high-pressure water jet, which then conducts it to the material being processed. Due to the light-guiding and cooling effects of the high-pressure water jet, water-guided laser processing offers advantages such as no need for focusing, high processing precision, high surface quality, and no heat-affected zone, providing efficient and precise processing for difficult-to-machine materials.

[0003] In water-guided laser processing, a high-energy laser beam needs to be focused at a nozzle by an optical protective lens, and then guided to the material being processed by a water jet. Traditional coupling cavities use a single central nozzle for water output, which causes rapid heating and ionization of the water flow near the nozzle when the high-energy laser beam is focused. This heating or ionization can easily disrupt the stability of the ejected water jet, reducing its ability to carry the laser beam. In severe cases, it can cause the water jet to lose its function of guiding laser transmission, thus limiting the application of higher-power, shorter-pulse lasers in water-guided laser processing.

[0004] Therefore, there is an urgent need for a high-flow-rate water-guided laser coupling cavity structure. By optimizing the water flow design inside the coupling cavity and using auxiliary nozzles to accelerate the flow and discharge of water inside the cavity, heat and ionized particles near the coupling nozzle can be quickly removed, thereby improving the water jet's ability to carry high-power, short-pulse lasers. Summary of the Invention

[0005] To address the problems of unstable water jets and limited laser power caused by the design of existing water-guided laser gate nozzles, this invention provides a high-fluidity water-guided laser coupling cavity structure and installation method to solve these problems.

[0006] To achieve the above objectives, this invention provides a high-flow-rate water-guided laser coupling cavity structure, comprising, from top to bottom, a protective optical mirror, a coupling water cavity, and an auxiliary nozzle fixedly connected. The coupling water cavity and the auxiliary nozzle are disc-shaped structures with their vertical central axes coinciding. A high-pressure water inlet is arranged along the tangent of the outer periphery of the coupling water cavity and communicates with it. An auxiliary nozzle and a main nozzle are vertically mounted on a nozzle support and communicate with the coupling water cavity, respectively. Both nozzles have the same diameter and are evenly distributed with the center of the nozzle support as the center. An incident laser beam passes sequentially through the protective optical mirror and the coupling water cavity and is focused onto the main nozzle, and is ejected along the main nozzle based on the total internal reflection effect. The main water jet is conducted and ultimately transmitted to the material to be processed, realizing water-guided laser processing. After high-pressure water is injected tangentially from the coupling water cavity, it forms a radial flow along the cavity wall. According to the requirements of water-guided laser processing, the number, diameter and spacing of the nozzles are adjusted. The radially flowing high-pressure water is accelerated out from the auxiliary nozzles, forming a stable symmetrical flow field and generating an active flow-guiding effect. This quickly removes the heat generated by laser focusing near the main nozzle, and at the same time, removes the particles generated after water ionization in a timely manner, and reduces the generation of turbulence. This ensures the stability of the main water jet and the ability to bear high-power, short-pulse lasers, realizing efficient and precise water-guided laser processing.

[0007] Furthermore, the number of nozzles is adjusted through the following steps: clarifying the corresponding basic parameters, calculating the minimum total flow rate according to the heat balance equation, obtaining the single nozzle flow rate by combining the orifice outflow formula, deriving the minimum number, and then correcting it according to symmetrical arrangement, verifying the structural and flow constraints, and determining the total number of nozzles; the nozzle diameter is adjusted through the following steps: based on the determined number of nozzles and corresponding parameters, calculating the minimum single nozzle flow rate, deriving the minimum diameter, and verifying it by combining the sapphire processing limit, light guiding requirements, and Reynolds number, to determine the final nozzle diameter; the nozzle spacing is adjusted through the following steps: calculating the water cavity radius from the coupled water cavity volume, determining the nozzle circumference radius, calculating the geometric spacing according to the circumference chord length formula, taking the maximum value of it and 3 times the nozzle diameter as the initial spacing, and determining the nozzle layout spacing after flow field verification and optimization.

[0008] Furthermore, the optical protective mirror, coupling water cavity, and auxiliary nozzle are all installed and fixed on the coupling body base, which is made of high-strength alloy material and has a stepped chamber inside; the stepped chamber is adapted to the optical protective mirror, coupling water cavity, and auxiliary nozzle, and limits and fixes the three of them.

[0009] Furthermore, the optical protective mirror is made of a light-transmitting material and is located in the stepped cavity of the coupling body seat, fixed to the top of the coupling water cavity; the incident laser beam enters vertically from the top of the optical protective mirror, passes through the coupling water cavity, and is focused on the main nozzle.

[0010] Furthermore, the coupling water cavity is made of a light-transmitting material and has a disc-shaped structure. A high-pressure water inlet is provided in the tangential direction of the outer periphery, and a corresponding number of water outlet holes are provided at the bottom. The water holes are evenly distributed with the bottom center as the center and are used to seal and connect with the top of the corresponding auxiliary nozzle and the main nozzle. The inner wall surface of the water cavity is polished and the smoothness Ra≤0.8μm.

[0011] Furthermore, the main nozzle and the auxiliary nozzle have the same orifice diameter, both ranging from 30μm to 200μm, and their outlet ends are flush; the main nozzle is a sapphire nozzle.

[0012] According to another aspect of the present invention, a method for installing a high-fluidity water-conducting laser coupling cavity structure is also provided, comprising the following steps: S100: Design the number of nozzles, clarify the corresponding basic parameters, calculate the minimum total flow rate according to the heat balance equation, obtain the flow rate of a single nozzle by combining the orifice outflow formula, derive the minimum number and then correct it according to the symmetrical arrangement, verify the structural and flow constraints, and determine the total number of nozzles. S200: Design the nozzle diameter. Based on the determined number of nozzles and corresponding parameters, calculate the minimum flow rate of a single nozzle, derive the minimum diameter, and combine the sapphire processing limits, light guiding requirements, and Reynolds number verification to determine the final nozzle diameter. S300: Design layout spacing: Calculate the water cavity radius from the coupled water cavity volume, determine the nozzle circumference radius, calculate the geometric spacing according to the circumference chord length formula, take the maximum value of the chord length and 3 times the nozzle diameter as the initial spacing, and determine the nozzle layout spacing after flow field verification and optimization. S400: Process the corresponding components of the water-guided laser coupling cavity structure according to the design parameters, and check the accuracy and cleanliness of each component; S500: Disassemble the coupling main body (1), and then insert the optical protective lens (3), coupling water cavity (9), and auxiliary nozzle (5) in sequence to ensure coaxiality and connectivity; S600: Install the main nozzle (7) and auxiliary nozzle (5) into the nozzle bracket (1) at intervals, mate and couple the main body seat (1) and seal and fix it; S700: Align the two halves of the seat and tighten them evenly with bolts to ensure reliable positioning; S800: Connect to the high-pressure water pipeline and test the sealing performance and water flow uniformity by introducing high-pressure water. S900: Adjust the stability of laser coupling and main water jet, and finally fix it after it meets the standard.

[0013] Further, in step S100, the number of designed nozzles includes the following steps: S101: Clearly define the known basic parameters: laser power Nozzle pressure difference The density of water Specific heat capacity of water Maximum allowable temperature rise Flow coefficient Preliminary value of preset nozzle diameter (Tentatively set within the 30μm-200μm range); S202: Calculate the minimum total flow rate: according to the heat balance equation. To obtain the minimum total flow rate that can remove all the heat from the laser. S303: Based on the orifice outflow formula This yields the flow rate of a single nozzle; S104: Derive the minimum number of nozzles using the following formula Calculate the theoretical minimum value, round it up, and then correct it to a symmetrical integer according to the principle of "equal division". S105: Verify constraints: Confirm that the corrected number of nozzles meets the spacing requirements between adjacent nozzles. and total flow rate of high-pressure water ≥ If not satisfied, adjust. After recalculation, the total number of nozzles was finally determined. ; in, The rated output power of the incident laser. To allow the maximum water temperature rise, The density of water, The specific heat capacity of water, This represents the total flow rate of the high-pressure water. For a single nozzle flow rate, For nozzle pressure differential, Nozzle diameter, This is the flow coefficient.

[0014] Further, in step S200, designing the nozzle diameter includes the following steps: S201: Specify known parameters, total number of nozzles Laser power Nozzle pressure difference Flow coefficient The density of water Specific heat capacity of water Maximum allowable temperature rise ; S202: Calculate the minimum flow rate of a single nozzle. Ensure that the flow rate of a single nozzle meets the heat dissipation requirements; S203: Minimum nozzle diameter at the derivation point , S204: Adjusted for actual diameter, taking into account light guiding requirements and the limitations of sapphire processing. And not exceeding 200 μm; verify Reynolds number If the value is ≤2300, the diameter should be increased appropriately to determine the final nozzle diameter. .

[0015] In step S300, the design of the nozzle spacing includes the following steps: S301: Specify known parameters, total number of nozzles Nozzle diameter Coupled water cavity volume Coupling water cavity height ; S302: Calculate the radius of the coupled water cavity To ensure the nozzle is located within the chamber, take ; S303: Geometric spacing is obtained using the formula for the length of a chord. ; S304: Correct the lower limit of the spacing, take... To avoid mutual impact and interference between adjacent nozzle jets, the initial spacing... ; S305: Verification Optimization: Calculate the radial velocity of the water flow , Verify Reynolds number If the condition is not met, then increase n or The layout spacing L was recalculated and finally determined.

[0016] In summary, compared with the prior art, the above-described technical solutions conceived by this invention can achieve the following beneficial effects: 1. In the water-guided laser coupling cavity structure of the present invention, the nozzle and auxiliary nozzle are equally distributed with the center of the nozzle support as the center, and the two are on the same circumference with the central angles of adjacent nozzles being equal. This arrangement allows water to flow into each nozzle along a symmetrical path, resulting in balanced forces, forming a stable and symmetrical flow field, effectively suppressing turbulence generation, avoiding local water flow stagnation, and providing a basis for the stable formation of the main water jet.

[0017] 2. The water-guided laser coupling cavity structure of this invention breaks away from the traditional design thinking of single and fixed nozzles, and deeply integrates the adjustability of the number of nozzles, the precision of the diameter, and the symmetry of the spacing through parametric logic: the number is adjusted to adapt to the needs of the scenario, the formulaic diameter is matched with the multi-dimensional functions of optics, fluid and high pressure, and the uniform spacing is used to stabilize the flow field environment. The three form a closed-loop design of scenario-parameter-structure. This design completely solves the technical bottlenecks of traditional single-nozzle structures, such as easy heating and ionization of water flow, poor stability of water jet, and inability to carry high-power short-pulse lasers, and achieves a dual breakthrough in water-guided laser processing efficiency and precision.

[0018] 3. The water-guided laser coupling cavity structure of the present invention, through the adjustable central symmetry design of 1 main nozzle and N auxiliary nozzles, breaks through the functional limitations of the traditional single nozzle. The multiple auxiliary nozzles form an all-round active flow-guiding effect. Combined with the radial flow field formed by the tangential high-pressure water inlet of the coupling water cavity, the heated / ionized water flow near the main nozzle is quickly and without dead angles, avoiding local stagnation. The adjustable number of nozzles allows the structure to be adapted to various processing scenarios from low power to high power and from short pulse to ultra-short pulse, greatly improving the versatility and adaptability of the structure.

[0019] 4. The water-guided laser coupling cavity structure of this invention abandons the traditional design logic of fixed nozzle diameter and empirical approach. It creatively correlates the nozzle diameter with multiple dimensions such as laser transmission, water flow dynamics, and high-pressure environment. Through formulaic calculation, it achieves triple adaptation of optical requirements (stable light guiding), fluid requirements (rapid drainage), and structural requirements (adaptation to high pressure), avoiding the contradiction of insufficient light guiding flow of the main nozzle or insufficient drainage capacity of the auxiliary nozzle. The equal diameter design of the main and auxiliary nozzles ensures uniform water flow distribution between the main and auxiliary nozzles, avoiding flow field disturbance caused by diameter differences. The diameter range of 30μm-200μm accurately adapts to the requirements of high-pressure water jet formation and total internal reflection transmission of laser. Combined with formulaic and accurate calculation, the structure can maintain the stability of the main water jet under different processing scenarios, significantly improving the load-bearing capacity of high-power, short-pulse lasers.

[0020] 5. The water-guided laser coupling cavity structure of this invention overcomes the drawbacks of traditional nozzles with no clear spacing design or asymmetrical arrangement. It creatively binds the spacing design with the number, diameter and depth of nozzles. Through the structural design of the same circumference and uniform division, it eliminates turbulence caused by uneven water flow force from the root and constructs a stable and symmetrical flow field environment. The uniform spacing allows water to flow into each nozzle along a symmetrical path, with balanced force, effectively suppressing the generation of turbulence. Combined with the main and auxiliary equal diameter design, it ensures that the guiding effect of the nozzles is symmetrically distributed, avoiding fluctuations in the main water jet caused by turbulence. In conjunction with the polishing treatment of the inner wall of the coupling water cavity, it further reduces water flow resistance, increases the water flow replacement rate in the cavity by several times, and ensures the stability of laser transmission and processing accuracy. Attached Figure Description

[0021] Figure 1 This is a schematic diagram of a high-fluidity water-guided laser coupling cavity structure according to an embodiment of the present invention; Figure 2 This is a diagram showing different arrangements of the main nozzle and auxiliary nozzles in an embodiment of the present invention; Figure 3 This is a schematic diagram of the radial flow of high-pressure water in the coupling water cavity in an embodiment of the present invention; Figure 4This is a flowchart illustrating the installation steps of a high-fluidity water-guided laser coupling cavity structure according to an embodiment of the present invention.

[0022] In all the accompanying drawings, the same reference numerals denote the same technical features, specifically: 1-Coupled main body seat, 2-Incident laser beam, 3-Optical protective mirror, 4-Nozzle support, 5-Auxiliary nozzle, 6-Main water jet, 7-Main nozzle, 8-High-pressure water inlet, 9-Coupled water cavity. Detailed Implementation

[0023] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the invention. Furthermore, the technical features involved in the various embodiments of this invention described below can be combined with each other as long as they do not conflict with each other.

[0024] like Figure 1-3 As shown, this invention provides a high-flow-rate water-guided laser coupling cavity structure, including an incident laser beam 2, an optical protective mirror 3, a nozzle support 4, an auxiliary nozzle 5, a main nozzle 7, a high-pressure water inlet 8, and a coupling water cavity 9. The optical protective mirror 3, the coupling water cavity 9, and the auxiliary nozzle 5 are fixedly connected sequentially from top to bottom. The coupling water cavity 9 and the auxiliary nozzle 5 are disc-shaped structures with their vertical central axes coinciding. The high-pressure water inlet 8 is arranged along the tangent of the outer periphery of the coupling water cavity 9 and communicates with it. The auxiliary nozzle 5 and the main nozzle 7 are both vertically arranged on the nozzle support 4 and communicate with the coupling water cavity 9. They have the same diameter and are evenly distributed with the center of the nozzle support 4 as the center. The incident laser beam 2 passes through the optical protective mirror 3 and the coupling water cavity 9 sequentially and is focused on the main nozzle 7. Based on the total internal reflection effect of light, it is conducted along the main water jet 6 ejected from the main nozzle 7 and finally transmitted to the material to be processed, realizing water-guided laser processing. The coupling cavity structure of this invention, after high-pressure water is injected tangentially from the coupling water cavity 9, forms a radial flow along the cavity wall. When the radially flowing high-pressure water flows through the auxiliary nozzle 5, it is further accelerated and discharged by the auxiliary nozzle, forming an active drainage effect. This quickly removes the heat generated by laser focusing near the main nozzle 7, and at the same time, promptly removes particles generated after water ionization, and reduces the generation of turbulence. This ensures the stability of the main water jet and the ability to withstand high-power, short-pulse lasers, ultimately achieving efficient and precise water-guided laser processing.

[0025] In this embodiment of the invention, the optical protective lens 3, the coupling water cavity 9, and the auxiliary nozzle 5 are all mounted and fixed on the coupling main body 1, which is made of high-strength alloy material and has a stepped chamber inside. This stepped chamber is adapted to the optical protective lens 3, the coupling water cavity 9, and the auxiliary nozzle 5, limiting and fixing the three components. During installation, the coupling main body 1 is split into two halves along the vertical direction. The optical protective lens 3, the coupling water cavity 9, and the auxiliary nozzle 5 are then inserted into the chambers of each half of the body. The other half of the body is then joined together and secured with bolts, thereby limiting and fixing the optical protective lens 3, the coupling water cavity 9, and the auxiliary nozzle 5.

[0026] In this embodiment of the invention, the optical protective mirror 3 is made of a light-transmitting material and is located in the stepped cavity of the coupling body seat 1, fixed to the top of the coupling water cavity 9; the incident laser beam 2 is vertically injected from the top of the optical protective mirror 3, passes through the coupling water cavity 9 and is focused on the main nozzle 7.

[0027] The coupling water cavity 9 is made of a light-transmitting material and has a disc-shaped structure. A high-pressure water inlet 8 is located tangentially on its outer periphery, and a corresponding number of water outlets are located at the bottom. These outlets are evenly distributed around the bottom center and are used for sealing connections with the tops of the corresponding auxiliary nozzles 5 and main nozzles 7. The inner wall of the water cavity is polished to a smoothness Ra≤0.8μm, reducing water flow resistance. This coupling water cavity 9 is a closed chamber, which maintains a high-pressure environment within the cavity and provides an interference-free focusing space for the laser beam. This ensures that after passing through the optical protective lens, the laser propagates in a straight line in the water and is precisely focused on the main nozzle 7, providing the necessary conditions for the total internal reflection effect to guide the laser along the main water jet. Furthermore, as a transition chamber for high-pressure water, the coupling water cavity 9 can buffer the impact force when high-pressure water is injected, allowing the water flow to diffuse evenly within the cavity before being diverted to the main nozzle and auxiliary nozzle. This avoids fluctuations in the main water jet caused by water flow impact and ensures the stability of laser transmission. At the same time, when the high-energy laser beam is focused on the main nozzle 7, it will cause the surrounding water flow to heat up and ionize. The radial flow field within the coupling water cavity can quickly drive these problematic water flows toward the auxiliary nozzle and discharge them out of the cavity through the auxiliary nozzle, thus preventing the heated water and ionized water flow from damaging the stability of the main water jet at the source.

[0028] like Figure 1-2As shown in the embodiment of the present invention, the nozzle support 4 is a unified mounting carrier for the main nozzle 7 and the auxiliary nozzle 5, connecting and coupling the water cavity 9 and the nozzle assembly. The nozzle support 4 is a disc-shaped structure, and its vertical central axis coincides with the central axis of the coupling water cavity 9. Further, the nozzle support 4 is provided with a corresponding number of mounting holes, which are equally distributed with the center of the nozzle support 4 as the center, and are used to install the main nozzle 7 and the auxiliary nozzle 5 respectively, so that the main nozzle 7 and all auxiliary nozzles 5 are located on the same circumference, and the central angle between adjacent nozzles is equal. For example, if there are 2 nozzles, they are arranged symmetrically; if there are 3 nozzles (1 main + 2 auxiliary), they are distributed in an equilateral triangle; if there are 4 nozzles (1 main + 3 auxiliary), they are distributed in a regular quadrilateral, ensuring that the water flow is evenly stressed and the flow field is symmetrical when it is discharged from each nozzle. The nozzles are evenly distributed by the nozzle bracket 4, and the water flow can flow into the main nozzle 7 and each auxiliary nozzle 5 along a symmetrical path. The main nozzle 7 outputs a stable main water jet 6 for guiding light. Each auxiliary nozzle 5 synchronously and evenly drives the heated water and ionized water near the main nozzle 7 to be discharged, forming a symmetrical flow field, avoiding local water flow stagnation, and greatly improving the water flow replacement rate in the cavity.

[0029] In this embodiment of the invention, the main nozzle 7 and the auxiliary nozzle 5 have the same aperture, both ranging from 30μm to 200μm, and their outlet ends are flush. The main nozzle 7 is a sapphire nozzle, which has the advantages of high hardness, high light transmittance, high temperature resistance, and corrosion resistance, making it suitable for the high-precision and high-stability processing requirements of water-guided laser coupling cavities.

[0030] In this embodiment of the invention, by setting the appropriate number of nozzles, the heated / ionized water flow generated by laser focusing near the main nozzle 7 is ensured to be quickly discharged, avoiding damage to the stability of the main water jet, while meeting the requirements of flow field symmetry and flow matching, ultimately supporting the stable processing of high-power, short-pulse lasers.

[0031] The number of nozzles is determined through the following steps: Step 1: Establish the relationship between total flow rate and laser power based on thermal balance; The laser input power should not exceed the maximum heat absorption power of the water flow to ensure that the water flow can carry away the laser energy in time and avoid overheating and ionization. The minimum total flow rate is: ; Step 2: Establish the relationship between the flow rate and diameter of a single nozzle based on the orifice outflow; Determine the flow rate of a single nozzle using a small-orifice outflow model; The nozzle outlet velocity is obtained using Bernoulli's equation: ; Combined with nozzle cross-sectional area: Considering the flow coefficient , This yields the flow rate of a single nozzle: ; Step 3: Establish the relationship between total flow rate and number of nozzles based on flow rate allocation; The total flow rate is the sum of the flow rates of all nozzles. Based on the minimum total flow rate, the constraint relationship regarding the number of nozzles can be derived: ; By substituting these values ​​into the formula for the flow rate of a single nozzle, we can obtain the formula relating the total flow rate to the number of nozzles: ; Step 4: Derive the minimum number of nozzles based on the minimum total flow rate. To meet the heat balance requirement, the total flow rate must be ≥ ,Right now: ; Rearranging the terms in the above equation, we obtain the minimum total number of nozzles: (1) The minimum number of nozzles in the above steps If the calculation result is a decimal, it needs to be rounded up; where, The rated output power of the incident laser. To allow the maximum water temperature rise, The density of water, The specific heat capacity of water, This represents the total flow rate of the high-pressure water. For a single nozzle flow rate, For nozzle pressure differential, Nozzle diameter, For flow coefficient, The nozzle outlet velocity is [value].

[0032] In this embodiment of the invention, the main nozzle 7 and the auxiliary nozzle 5 have the same diameter. By setting corresponding diameters for both, the optical-fluid requirements for stable light guiding of the main water jet are met, and the flow rate requirements for rapid heat dissipation and ionization particle removal of the auxiliary nozzle are matched. At the same time, it adapts to the high-pressure environment and structural size constraints of the coupling cavity, and finally realizes stable transmission and efficient processing of high-power laser.

[0033] Combining formula (1), by rearranging terms to treat the nozzle diameter as the sole dependent variable, and other parameters (total flow rate, number of nozzles, pressure difference, etc.) as known or calculable quantities, a diameter formula is formed: (2) In practical applications, the nozzle diameter needs to be greater than [a certain value]. And the values ​​must meet the processing accuracy requirements, with a range of 30μm-200μm.

[0034] To avoid turbulence in the main water jet, the flow rate of a single nozzle needs to be controlled within the laminar flow range, corresponding to a Reynolds number. ≤2300, where the Reynolds number formula is: , This represents the theoretical flow velocity of water through the nozzle. This is the kinematic viscosity of water at room temperature.

[0035] In this embodiment of the invention, by adjusting the nozzle spacing, high-pressure water is ensured to be uniformly distributed radially within the coupling water cavity, forming a symmetrical radial flow field. This avoids turbulence caused by local differences in water flow velocity. Furthermore, the symmetrical flow field allows the active drainage effect of the auxiliary nozzles to uniformly cover the area surrounding the main nozzle, preventing local water flow stagnation and ensuring rapid and comprehensive discharge of heat and ionized particles. Therefore, a reasonable spacing directly determines the uniformity of drainage efficiency: if the spacing is too large, a "drainage blind zone" will form between the main and auxiliary nozzles, where heated water and ionized particles cannot be discharged in time, accumulating and disrupting the stability of the main water jet; if the spacing is too small, the drainage ranges of adjacent auxiliary nozzles overlap, leading to excessively high local water flow velocities, which also causes flow field turbulence and reduces overall heat removal efficiency.

[0036] The nozzle spacing is determined by the following steps: Step 1: All nozzles (main nozzle + auxiliary nozzle) are located on a circle with radius r centered at the center of the coupling water cavity. According to the formula for the chord length of a circle, the spacing between adjacent nozzles is: Step 2: Radius constraint based on the coupled water cavity volume; The coupling water cavity is disc-shaped with a volume of ,therefore To ensure the nozzle is located within the chamber, take (Reserving space for the flow field buffer), substituting, we get: In the above steps, the nozzle spacing must ensure that there is no water flow interference at the nozzle outlet and avoid mutual impact between adjacent nozzle jets. ;in, The radius of the coupling water cavity; This refers to the volume of the coupling water cavity; Specify the nozzle spacing; Nozzle diameter, This refers to the number of nozzles. The height of the coupling water cavity.

[0037] In the water-guided laser coupling cavity structure of this invention, the nozzle and auxiliary nozzle are equally distributed around the center of the nozzle support, with both located on the same circumference and adjacent nozzles having equal central angles. This arrangement allows water to flow into each nozzle along a symmetrical path, resulting in balanced forces, a stable and symmetrical flow field, effectively suppressing turbulence, avoiding local water flow stagnation, and providing a foundation for the stable formation of the main water jet.

[0038] The water-guided laser coupling cavity structure of this invention has a unified aperture of 30μm-200μm for both the main nozzle and the auxiliary nozzle, and the water outlet ends are flush. The aperture matching ensures that the flow rate of the main water jet formation and the auxiliary water discharge are adapted, which does not weaken the light-guiding capacity of the main water jet, and allows the auxiliary nozzle to drive the surrounding water flow synchronously and evenly. The flush water outlet ends avoid directional interference when the water is discharged, further improving the smoothness of the water flow and accelerating the replacement of water flow in the cavity.

[0039] The water-guided laser coupling cavity structure of this invention breaks away from the traditional design thinking of single and fixed nozzles. It deeply integrates the adjustability of the number of nozzles, the precision of the diameter, and the symmetry of the spacing through parametric logic: the number of nozzles is adjusted to adapt to the needs of the scenario, the formulaic diameter is matched with the multi-dimensional functions of optics, fluid and high pressure, and the uniform spacing is used to stabilize the flow field environment. The three form a closed-loop design of scenario-parameter-structure. This design completely solves the technical bottlenecks of traditional single-nozzle structures, such as easy heating and ionization of water flow, poor stability of water jet, and inability to carry high-power short-pulse lasers. It achieves a dual breakthrough in water-guided laser processing efficiency and precision.

[0040] The water-guided laser coupling cavity structure of this invention, through the adjustable central symmetry design of 1 main nozzle and N auxiliary nozzles, breaks through the functional limitations of traditional single nozzles. Multiple auxiliary nozzles form an all-round active flow-guiding effect, which, together with the radial flow field formed by the tangential high-pressure water inlet of the coupling water cavity, enables the heated / ionized water flow near the main nozzle to be discharged quickly and without dead angles, avoiding local stagnation. The adjustable number of nozzles allows the structure to be adapted to diverse processing scenarios from low power to high power and from short pulses to ultra-short pulses, greatly improving the versatility and adaptability of the structure.

[0041] The water-guided laser coupling cavity structure of this invention abandons the traditional design logic of fixed nozzle diameter and empirical approach. Instead, it creatively correlates the nozzle diameter with multiple dimensions such as laser transmission, hydrodynamics, and high-pressure environment. Through formulaic calculations, it achieves a triple adaptation of optical requirements (stable light guiding), fluid requirements (rapid drainage), and structural requirements (adaptation to high pressure), avoiding the contradiction of insufficient light guiding flow of the main nozzle or insufficient drainage capacity of the auxiliary nozzle. The equal diameter design of the main and auxiliary nozzles ensures uniform water flow distribution between them, avoiding flow field disturbance caused by diameter differences. The diameter range of 30μm-200μm precisely adapts to the requirements of high-pressure water jet formation and total internal reflection laser transmission. Combined with formulaic and precise calculations, the structure can maintain the stability of the main water jet under different processing scenarios, significantly improving the load-bearing capacity for high-power, short-pulse lasers.

[0042] The water-guided laser coupling cavity structure of this invention overcomes the drawbacks of traditional nozzles with no clear spacing design or asymmetrical arrangement. It creatively binds the spacing design with the number, diameter and depth of nozzles. Through the structural design of the same circumference and uniform division, it eliminates turbulence caused by uneven water flow force at the source and builds a stable and symmetrical flow field environment. The uniform spacing allows water to flow into each nozzle along a symmetrical path, with balanced force and effectively suppressing turbulence. Combined with the main and auxiliary equal diameter design, it ensures that the guiding effect of the nozzles is symmetrically distributed, avoiding fluctuations in the main water jet caused by turbulence. In conjunction with the polishing treatment of the inner wall of the coupling water cavity (Ra≤0.8μm), it further reduces water flow resistance, increases the water flow replacement rate in the cavity by several times, and ensures the stability of laser transmission and processing accuracy.

[0043] like Figure 4 As shown, the present invention also provides a method for installing a high-fluidity water-conducting laser coupling cavity structure, comprising the following steps: S100: Design the number of nozzles, clarify the corresponding basic parameters, calculate the minimum total flow rate according to the heat balance equation, obtain the flow rate of a single nozzle by combining the orifice outflow formula, derive the minimum number and then correct it according to the symmetrical arrangement, verify the structural and flow constraints, and determine the total number of nozzles. S200: Design the nozzle diameter. Based on the determined number of nozzles and corresponding parameters, calculate the minimum flow rate of a single nozzle, derive the minimum diameter, and combine the sapphire processing limits, light guiding requirements, and Reynolds number verification to determine the final nozzle diameter. S300: Design layout spacing: Calculate the water cavity radius from the coupled water cavity volume, determine the nozzle circumference radius, calculate the geometric spacing according to the circumference chord length formula, take the maximum value of the chord length and 3 times the nozzle diameter as the initial spacing, and determine the nozzle layout spacing after flow field verification and optimization. S400: Process the corresponding components of the water-guided laser coupling cavity structure according to the design parameters, and check the accuracy and cleanliness of each component; S500: The coupling main body is disassembled, and the optical protective lens, coupling water cavity, and auxiliary nozzle are embedded in sequence to ensure coaxiality and connectivity; S600: Install the main nozzle and auxiliary nozzle into the nozzle bracket at the specified intervals, mate and couple them to the main body seat, and seal and fix them. S700: Align the two halves of the seat and tighten them evenly with bolts to ensure reliable positioning; S800: Connect to the high-pressure water pipeline and test the sealing performance and water flow uniformity by introducing high-pressure water. S900: Adjust the stability of laser coupling and main water jet, and finally fix it after it meets the standard.

[0044] In step S100, the number of nozzles to be designed includes the following steps: S101: Clearly define the known basic parameters: laser power Nozzle pressure difference The density of water Specific heat capacity of water Maximum allowable temperature rise Flow coefficient Preliminary value of preset nozzle diameter (Tentatively set within the 30μm-200μm range); S202: Calculate the minimum total flow rate: according to the heat balance equation. To obtain the minimum total flow rate that can remove all the heat from the laser. S303: Based on the orifice outflow formula This yields the flow rate of a single nozzle; S104: Derive the minimum number of nozzles using the following formula Calculate the theoretical minimum value, round it up, and then correct it to a symmetrical integer according to the principle of "equal division". S105: Verify constraints: Confirm that the corrected number of nozzles meets the spacing requirements between adjacent nozzles. and total flow rate of high-pressure water ≥ If not satisfied, adjust. After recalculation, the total number of nozzles was finally determined. .

[0045] In step S200, designing the nozzle diameter includes the following steps: S201: Specify known parameters, total number of nozzles Laser power Nozzle pressure difference Flow coefficient The density of water Specific heat capacity of water Maximum allowable temperature rise ; S202: Calculate the minimum flow rate of a single nozzle. Ensure that the flow rate of a single nozzle meets the heat dissipation requirements; S203: Minimum nozzle diameter at the derivation point , S204: Corrects the actual diameter, taking into account light guiding requirements ( , (referring to the laser wavelength) and the processing limits of sapphire (30μm-200μm), taking And not exceeding 200 μm; verify Reynolds number If the value is ≤2300, the diameter should be increased appropriately to determine the final nozzle diameter. .

[0046] In step S300, the design of the nozzle spacing includes the following steps: S301: Specify known parameters, total number of nozzles Nozzle diameter Coupled water cavity volume Coupling water cavity height ; S302: Calculate the radius of the coupled water cavity To ensure the nozzle is located within the chamber, take ; S303: Geometric spacing is obtained using the formula for the length of a chord. ; S304: Correct the lower limit of the spacing, take... To avoid mutual impact and interference between adjacent nozzle jets, the initial spacing... ; S305: Verification Optimization: Calculate the radial velocity of the water flow , Verify Reynolds number If the condition is not met, then increase n or The layout spacing L was recalculated and finally determined.

[0047] Those skilled in the art will readily understand that the above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A high-fluidity water-conducting laser coupling cavity structure, characterized in that, include: An optical protective mirror (3), a coupling water cavity (9), and an auxiliary nozzle (5) are fixedly connected from top to bottom. The coupling water cavity (9) and the auxiliary nozzle (5) are disc-shaped structures and their vertical central axes coincide. A high-pressure water inlet (8) is provided and connected to the outer circumference tangent of the coupling water cavity (9); The auxiliary nozzle (5) and the main nozzle (7) are vertically mounted on the nozzle support (4) and connected to the coupling water chamber (9) respectively. The two nozzles have the same pipe diameter and are arranged in equal parts with the center of the nozzle support (4) as the center. The incident laser beam (2) passes through the optical protective mirror (3) and the coupling water cavity (9) in sequence and is focused on the main nozzle (7). Based on the total internal reflection effect of light, it is transmitted along the main water jet (6) ejected from the main nozzle (7) and finally transmitted to the material to be processed, realizing water-guided laser processing. After high-pressure water is injected tangentially into the coupling water cavity (9), it will form a radial flow along the cavity wall. According to the requirements of water-guided laser processing, the number, diameter and spacing of the nozzles are adjusted. The radially flowing high-pressure water is accelerated out from the auxiliary nozzle (5) to form a stable symmetrical flow field and generate an active flow effect. It quickly removes the heat generated by laser focusing near the main nozzle (7), and at the same time removes the particles generated after the water flow is ionized in time, and reduces the generation of turbulence. It ensures the stability of the main water jet and the ability to carry high-power, short-pulse lasers, and realizes efficient and precise water-guided laser processing.

2. The high-fluidity water-guided laser coupling cavity structure according to claim 1, characterized in that, The number of nozzles is adjusted through the following steps: clarify the corresponding basic parameters, calculate the minimum total flow rate according to the heat balance equation, obtain the flow rate of a single nozzle by combining the orifice outflow formula, derive the minimum number and then correct it according to the symmetrical arrangement, verify the structural and flow constraints, and determine the total number of nozzles. The nozzle diameter is adjusted through the following steps: based on the determined number of nozzles and corresponding parameters, the minimum flow rate of a single nozzle is calculated, the minimum diameter is derived, and the final nozzle diameter is determined by combining the sapphire processing limit, light guiding requirements and Reynolds number verification. The nozzle spacing is adjusted through the following steps: the water cavity radius is calculated from the coupling water cavity volume, the nozzle circumference radius is determined, the geometric spacing is calculated according to the circumference chord length formula, and the maximum value of the chord length and three times the nozzle diameter is taken as the initial spacing. After flow field verification and optimization, the nozzle layout spacing is determined.

3. A high-fluidity water-guided laser coupling cavity structure according to any one of claims 1-2, characterized in that, The optical protective mirror (3), coupling water cavity (9) and auxiliary nozzle (5) are all installed and fixed on the coupling body seat (1). They are made of high-strength alloy material and have a stepped chamber inside. The stepped chamber is compatible with the optical protective mirror (3), coupling water cavity (9) and auxiliary nozzle (5) to limit and fix the three.

4. The high-fluidity water-guided laser coupling cavity structure according to claim 3, characterized in that, The optical protective mirror (3) is made of a light-transmitting material and is located in the stepped cavity of the coupling body seat (1) and fixed to the top of the coupling water cavity (9). The incident laser beam (2) is injected vertically from the top of the optical protective mirror (3) and focuses on the main nozzle (7) after passing through the coupling water cavity (9).

5. A high-fluidity water-guided laser coupling cavity structure according to any one of claims 1-2, characterized in that, The coupling water cavity (9) is made of light-transmitting material and has a disc-shaped structure. A high-pressure water inlet (8) is provided in the tangential direction of the outer periphery, and a corresponding number of water outlet holes are provided at the bottom. The water outlet holes are arranged in equal parts with the bottom center as the center, and are used to seal and connect with the top of the corresponding auxiliary nozzle (5) and main nozzle (7). The inner wall of the water cavity is polished and the smoothness Ra≤0.8μm.

6. A high-fluidity water-guided laser coupling cavity structure according to any one of claims 1-2, characterized in that, The main nozzle (7) and the auxiliary nozzle (5) have the same orifice diameter, both being 30μm-200μm, and their outlet ends are flush; the main nozzle (7) is a sapphire nozzle.

7. A method for installing a high-fluidity water-conducting laser coupling cavity structure, characterized in that, Includes the following steps: S100: Design the number of nozzles, clarify the corresponding basic parameters, calculate the minimum total flow rate according to the heat balance equation, obtain the flow rate of a single nozzle by combining the orifice outflow formula, derive the minimum number and then correct it according to the symmetrical arrangement, verify the structural and flow constraints, and determine the total number of nozzles. S200: Design the nozzle diameter. Based on the determined number of nozzles and corresponding parameters, calculate the minimum flow rate of a single nozzle, derive the minimum diameter, and combine the sapphire processing limits, light guiding requirements, and Reynolds number verification to determine the final nozzle diameter. S300: Designed installation spacing: The radius of the water cavity is calculated from the volume of the coupled water cavity, the circumferential radius of the nozzle is determined, the geometric spacing is calculated according to the formula of circumferential chord length, and the maximum value of the chord length and three times the nozzle diameter is taken as the initial spacing. After flow field verification and optimization, the nozzle layout spacing is determined. S400: Process the corresponding components of the water-guided laser coupling cavity structure according to the design parameters, and check the accuracy and cleanliness of each component; S500: Disassemble the coupling main body (1), and then insert the optical protective lens (3), coupling water cavity (9), and auxiliary nozzle (5) in sequence to ensure coaxiality and connectivity; S600: Install the main nozzle (7) and auxiliary nozzle (5) into the nozzle bracket (1) at intervals, mate and couple the main body seat (1) and seal and fix it; S700: Align the two halves of the seat and tighten them evenly with bolts to ensure reliable positioning; S800: Connect to the high-pressure water pipeline and test the sealing performance and water flow uniformity by introducing high-pressure water. S900: Adjust the stability of laser coupling and main water jet, and finally fix it after it meets the standard.

8. The installation method of a high-fluidity water-guided laser coupling cavity structure according to claim 7, characterized in that, In step S100, the number of nozzles to be designed includes the following steps: S101: Clearly define the known basic parameters: laser power Nozzle pressure difference The density of water Specific heat capacity of water Maximum allowable temperature rise Flow coefficient Preliminary value of preset nozzle diameter (Tentatively set within the 30μm-200μm range); S102: Calculate the minimum total flow rate: according to the heat balance equation. To obtain the minimum total flow rate that can remove all the heat from the laser. S103: Based on the orifice outflow formula This yields the flow rate of a single nozzle; S104: Derive the minimum number of nozzles using the following formula Calculate the theoretical minimum value, round it up, and then correct it to a symmetrical integer according to the principle of "equal division". S105: Verify constraints: Confirm that the corrected number of nozzles meets the spacing requirements between adjacent nozzles. and total flow rate of high-pressure water ≥ If not satisfied, adjust. After recalculation, the total number of nozzles was finally determined. ; in, The rated output power of the incident laser. To allow the maximum water temperature rise, The density of water, The specific heat capacity of water, This represents the total flow rate of the high-pressure water. For a single nozzle flow rate, For nozzle pressure differential, Nozzle diameter, This is the flow coefficient.

9. The installation method of a high-fluidity water-guided laser coupling cavity structure according to claim 8, characterized in that, In step S200, designing the nozzle diameter includes the following steps: S201: Specify known parameters, total number of nozzles Laser power Nozzle pressure difference Flow coefficient The density of water Specific heat capacity of water Maximum allowable temperature rise ; S202: Calculate the minimum flow rate of a single nozzle. Ensure that the flow rate of a single nozzle meets the heat dissipation requirements; S203: Minimum nozzle diameter at the derivation point , S204: Adjusted for actual diameter, taking into account light guiding requirements and the limitations of sapphire processing. And not exceeding 200 μm; verify Reynolds number If the value is ≤2300, the diameter should be increased appropriately to determine the final nozzle diameter. .

10. The installation method of a high-fluidity water-guided laser coupling cavity structure according to claim 9, characterized in that, In step S300, the design of the nozzle spacing includes the following steps: S301: Specify known parameters, total number of nozzles Nozzle diameter Coupled water cavity volume Coupling water cavity height ; S302: Calculate the radius of the coupled water cavity To ensure the nozzle is located within the chamber, take ; S303: Geometric spacing is obtained using the formula for the length of a chord. ; S304: Correct the lower limit of spacing, take... To avoid mutual impact and interference between jets from adjacent nozzles, the initial spacing... ; S305: Verification Optimization: Calculate the radial velocity of the water flow , Verify Reynolds number If the condition is not met, then increase n or The layout spacing L was recalculated and finally determined.

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