A high power water guided laser generation device and method

Abstract

The application discloses a high-power water-guided laser generating device and method, and belongs to the water-guided laser field.The technical scheme of the application is as follows: a high-power water-guided laser generating device comprises a light source module and a coupling module, the bottom of the coupling module is provided with a jet nozzle, the jet nozzle is inverted conical, the center of the jet nozzle is communicated with a water inlet cavity through a straight hole, an aperture adjusting ring is arranged in the straight hole, and the upper end inner edge of the aperture adjusting ring is a right angle; a guide module is further arranged, the guide module is provided with a gas nozzle, the gas nozzle is coaxially arranged below the jet nozzle, and the guide module can emit high-speed airflow through the gas nozzle.The application has the beneficial effects that: cavitation is generated by arranging the aperture adjusting ring, so that the water jet is separated from the nozzle, the energy deposition of the water-guided laser on the material surface is avoided, the thermal damage of the nozzle is avoided, and the energy utilization rate is improved; the guide module forms an air curtain, the water-guided laser is isolated from the static air outside, and the holding degree of the water-guided laser in the inclined state is improved.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of water guided laser, in particular to a high-power water guided laser generating device and a high-power water guided laser generating method. BACKGROUND

[0002] Water guided laser processing is a processing method that uses liquid jet as medium and projects laser onto workpiece to realize cutting by using light guiding principle similar to optical fiber. Compared with dry laser, water guided laser has the advantages of large working distance, no need for high-precision alignment, elongated laser focusing mirror, increased depth-diameter ratio, no phenomenon of star chasing cut and edge burr, ability to take away slag and cool down by water flow, small cutting gap and high precision.

[0003] At present, the method for obtaining water guided laser is to obtain fine water jet by liquid nozzle and then to couple laser into water jet to obtain water guided laser.

[0004] However, the existing water guided laser has the following disadvantages: firstly, when water guided laser passes through the nozzle, because the refractive index of water is less than that of the nozzle material, the total reflection condition is not met on the contact surface between water and nozzle inner wall, which causes laser energy to deposit on the nozzle surface, on one hand causing thermal damage to the nozzle material, and on the other hand causing energy loss, especially when high-power light source is used, which will greatly exacerbate nozzle loss; water guided laser uses high-speed water jet as carrier, and the water jet and the surrounding static air rub each other violently to exchange momentum and mass, and turbulent diffusion occurs, with the increase of jet distance, turbulent diffusion is enhanced, the air entrained by the jet beam is continuously increased, which produces resistance to the jet, causing the jet speed to continuously decrease, and the jet boundary gradually expands to both sides, and finally disperses into droplets; at the same time, because the water jet will be affected by gravity, the water jet will bend when it is inclined, which causes the laser to be unable to continue to propagate in a straight line, which is not conducive to the processing of inclined bevels. SUMMARY

[0005] The present application provides a high-power water guided laser generating device to solve the problems of nozzle thermal damage and energy loss caused by energy deposition at the nozzle of the current water guided laser, and the reduction of water jet turbulent diffusion speed.

[0006] To solve the above problems, the technical scheme adopted by the present application is as follows: a high-power water guide laser generation device, comprising a light source module and a coupling module, the coupling module is internally provided with a water inlet cavity, the top of the coupling module is provided with an optical window, the bottom of the coupling module is provided with a jet nozzle, the light source module, the optical window and the jet nozzle are coaxially arranged, the jet nozzle is in an inverted conical shape, the center of the jet nozzle is communicated with the water inlet cavity through a straight hole, an aperture adjusting ring is installed in the straight hole, the upper end inner edge of the aperture adjusting ring is in a right angle; further comprising a guide module, the guide module is internally provided with an air inlet cavity, the guide module is provided with a gas nozzle, the diameter of the gas nozzle is not less than the inner diameter of the aperture adjusting ring, the gas nozzle is communicated with the air inlet cavity, the gas nozzle is coaxially arranged below the jet nozzle, the guide module can emit high-speed airflow through the gas nozzle.

[0007] By arranging the aperture adjusting ring, the right angle edge thereof is used to make the high-speed water flow produce cavitation phenomenon and shrink, so that the water jet is separated from the inner wall of the aperture adjusting ring and the jet nozzle, thereby avoiding energy deposition of the water guide laser after coupling laser on the material surface, avoiding thermal damage of the nozzle and improving energy utilization rate; meanwhile, by arranging the guide module, the airflow is used to form an air curtain to isolate the water guide laser from the external static air, thereby avoiding diffusion and speed reduction of the water guide laser due to external interference, and the retention of the water guide laser in the inclined state can be improved.

[0008] Preferably, an annular groove is arranged at the connection between the jet nozzle and the coupling module, the groove bottom is provided with a threaded hole arranged along the radial direction of the jet nozzle, the threaded hole penetrates into the straight hole, a fixing bolt is installed in the threaded hole, the outer peripheral surface of the aperture adjusting ring is provided with an annular positioning groove, and the screw rod end of the fixing bolt abuts against the annular positioning groove. Different aperture adjusting rings with different inner diameters can be replaced according to different Reynolds numbers of the liquid.

[0009] Preferably, the gas nozzle comprises coaxially arranged first and second conical walls, the first conical wall is located at the top of the guide module and is recessed towards the inside of the air inlet cavity, the second conical wall is located at the bottom of the guide module and is recessed downwards relative to the bottom surface of the guide module, a conical gap is formed between the first and second conical walls, and the conical gap is communicated with the air inlet cavity; the center of the first conical wall is provided with a jet hole, the diameter of the jet hole is not less than the inner diameter of the aperture adjusting ring, the middle part of the second conical wall is provided with an airflow hole, and the diameter of the airflow hole is greater than the diameter of the jet hole. The jet nozzle and the gas nozzle jointly form a jet channel with an approximately rhombic axial section, so that the nozzle material is separated from the water guide laser, energy deposition is avoided, the gas nozzle is coaxially arranged below the jet nozzle, an annular air curtain is formed around the water guide laser, the water-air friction loss is reduced, the stable water guide laser is protected from being damaged by any upward water mist, liquid droplets and particles, the length and retention of the water guide laser are improved, the processing distance is increased and inclined bevel cutting can be performed; by adjusting the gas pressure and flow rate, the water flow speed of the surface layer of the water guide laser is greater than the internal water flow speed, and the processing taper effect can be improved.

[0010] Preferably, the lower end of the second conical wall is provided with a cylindrical extension, and the gas flow hole is arranged through the extension. The extension makes the annular gas curtain formed by the gas flow more stable.

[0011] Preferably, an annular baffle is arranged inside the gas inlet cavity, the baffle is located above the second conical wall, the inner diameter of the annular baffle is the same as the top diameter of the second conical wall, a plurality of gas guide pipes are arranged on the baffle in the circumferential direction, one end of the gas guide pipe is deep into the conical gap, and the axis of the one end is at an angle of 45° with the horizontal plane. Through the arrangement of the baffle and the gas guide pipe, the gas enters the conical gap more uniformly, the conical gap and the gas guide pipe are arranged at an angle, so that the annular gas flow sprayed by the gas nozzle is more attached to the water-guided laser, does not affect the direction of the water flow, and a more stable water-guided laser is obtained.

[0012] Preferably, the coupling module and the guide module are detachably linked, the bottom surface of the coupling module is provided with a first connecting ring, the top surface of the guide module is provided with a second connecting ring, one of the first connecting ring and the second connecting ring is provided with an external thread, and the other is provided with an internal thread, and the internal thread and the external thread are matched with each other. The coupling module and the guide module are arranged in a split manner, which facilitates the installation and replacement of the internal caliber adjusting ring, and facilitates overall manufacturing and assembly, and the threaded connection of the connecting rings ensures the coaxiality of the two modules.

[0013] Preferably, the length l and the diameter d of the inner hole of the caliber adjusting ring satisfy 0.625≤l / d≤0.681. In this interval, the best flow contraction effect can be obtained, the laser and the water are coupled without contacting the nozzle wall, there is no energy loss caused by heat transfer, the coupling power is 100%, the nozzle is prevented from being deformed and damaged due to high temperature, and the service life is greatly improved.

[0014] On the other hand, the application provides another high-power water-guided laser generation method, which uses the high-power water-guided laser generation device described above, and the method comprises the following steps:

[0015] S1. connecting the water inlet cavity with the liquid supply system and connecting the gas inlet cavity with the gas source;

[0016] S2. starting the liquid supply system, and filling the water inlet cavity with liquid;

[0017] S3. forming a stable flow contraction in the caliber adjusting ring, and spraying from the water jet nozzle through the gas nozzle;

[0018] S4. starting the light source module, and coupling the laser in the water jet to form a water-guided laser;

[0019] S5. starting the gas source, and spraying the water-guided laser wrapped by the gas guided by the gas nozzle to form a coaxial annular gas curtain outside the water-guided laser.

[0020] Preferably, in step S3, the high-speed flowing liquid generates cavitation phenomenon through the inner right-angle edge of the upper end of the caliber adjusting ring, the inner diameter of the caliber adjusting ring is separated from the water jet, and the water jet satisfies total reflection.

[0021] Preferably, the caliber adjusting ring with a proper inner diameter is selected according to the liquid Reynolds number of the liquid supply system.

[0022] The method can separate the water guide laser from the inner surface of the nozzle by forming a convergent flow at the entrance of the jet nozzle, avoid energy deposition, avoid nozzle thermal damage, improve laser power, and improve coupling power and energy utilization rate; the generated water guide laser is isolated from the external air by the annular air curtain, reduces external interference, and is guided to make the water guide laser have stronger holding force, and can perform inclined bevel cutting.

[0023] As can be seen from the above technical solutions, the advantages of the present application are that: the diameter of the water guide laser is smaller than the nozzle aperture by the size of the caliber adjusting ring and its inner hole, so that a stable "convergent flow" state is achieved, energy deposition on the wall surface is avoided, and the nozzle material is thermally damaged, and the coupled energy beam no longer contacts the nozzle after formation; a coaxial annular air curtain is generated by using a guide module, which isolates upward water mist, droplets and particles, forms a liquid flow film on the machining surface, has no cutting pollution, and protects the cutting surface; at the same time, the annular air curtain can offset the influence of gravity on the water flow, so that the water guide laser has stronger straightness when it is inclined, prolongs the straight machining section during inclined cutting, improves the machining range of the water guide laser, improves the thickness of the cuttable material, simplifies the cutting program, and improves the machining robustness and reliability; the high-pressure airflow of the annular air curtain makes the liquid flow rate on the surface of the water guide laser greater than the internal flow rate, which can improve the machining taper effect; the overall structure of the device is convenient to manufacture and use, and the laser coupling and output precision are high; at the same time, the water guide laser generation method of the device avoids energy loss in the coupling process and thermal damage of the nozzle, improves energy utilization, can be applied to a larger power light source module, and improves output power. BRIEF DESCRIPTION OF DRAWINGS

[0024] In order to more clearly illustrate the technical solutions of the present application, the drawings required in the description will be briefly introduced below. Obviously, the drawings in the following description are only some embodiments of the present application, and other drawings can be obtained by those skilled in the art without creative labor.

[0025] Figure 1 The figure is a structural schematic diagram of a high-power water guide laser generation device in the specific embodiment of the present application.

[0026] Figure 2 The figure is a sectional view schematic diagram of a coupling module in the specific embodiment of the present application.

[0027] Figure 3 Fig. 6 is a magnified view of the area A in Fig. 5. Figure 2 Fig. 6 is a magnified view of the area A in Fig. 5.

[0028] Figure 4 Fig. 7 is a structural schematic diagram of the guide module in the embodiment of the present application.

[0029] Figure 5 Fig. 7 is a structural schematic diagram of the guide module in the embodiment of the present application. Figure 1 .

[0030] Figure 6 Fig. 7 is a structural schematic diagram of the guide module in the embodiment of the present application. Figure 2 .

[0031] Figure 7 Fig. 8 is a structural schematic diagram of the air guide tube in the embodiment of the present application.

[0032] Figure 8 Fig. 9 is a diagram of the normalized reconnection length of the caliber adjusting ring versus the Reynolds number.

[0033] Fig. 1 is a schematic diagram of the laser water guide. Fig. 2 is a schematic diagram of the coupling module. Fig. 3 is a schematic diagram of the jet nozzle. Fig. 4 is a schematic diagram of the caliber adjusting ring. Fig. 5 is a schematic diagram of the guide module. Fig. 6 is a schematic diagram of the water inlet pipe. Fig. 7 is a schematic diagram of the water guide laser. Fig. 8 is a schematic diagram of the air curtain. Fig. 9 is a schematic diagram of the first connecting ring. Fig. 10 is a schematic diagram of the inner hole. Fig. 11 is a schematic diagram of the water inlet cavity. Fig. 12 is a schematic diagram of the air inlet cavity. Fig. 13 is a schematic diagram of the air inlet pipe. Fig. 14 is a schematic diagram of the second connecting ring. Fig. 15 is a schematic diagram of the gas nozzle. Fig. 16 is a schematic diagram of the jet hole. Fig. 17 is a schematic diagram of the extension. Fig. 18 is a schematic diagram of the groove. Fig. 19 is a schematic diagram of the fixing bolt. Fig. 20 is a schematic diagram of the air guide tube. Fig. 21 is a schematic diagram of the partition. Fig. 22 is a schematic diagram of the driving motor. Fig. 23 is a schematic diagram of the driving gear. Fig. 24 is a schematic diagram of the driven gear ring. DETAILED DESCRIPTION

[0034] In order to make the objectives, characteristics and advantages of the present application more obvious and easy to understand, the technical solutions in the present application will be described clearly and completely below in combination with the drawings in the embodiments. Obviously, the embodiments described below are only some of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present patent, all the other embodiments obtained by those skilled in the art without creative labor fall within the scope of protection of the present patent.

[0035] As Figures 1-3As shown, a high-power water-guided laser generating device includes a light source module, a coupling module 4, and a guiding module 7. The coupling module 4 has a cylindrical structure with a water inlet cavity 13 inside. An optical window 3 is located at the center of the top of the coupling module, and a circular plane lens is embedded in the optical window 3. A water inlet pipe 8 is located on the outer peripheral wall of the coupling module 4, which is connected to the water inlet cavity 13 and is used to connect to an external liquid supply system. A jet nozzle 5 is located at the center of the bottom of the coupling module 4. The jet nozzle 5 is an inverted conical nozzle, and the top of the jet nozzle 5 is connected to a straight hole. The water inlet chamber is connected, and the lower part of the straight hole is tapered and enlarged. A diameter adjustment ring 6 is installed in the straight hole. The upper inner edge of the diameter adjustment ring 6 is right-angled. Specifically, an annular groove 20 is provided at the connection between the jet nozzle 5 and the coupling module. The bottom of the groove 20 is provided with a threaded hole arranged radially along the jet nozzle 5. The threaded hole extends into the straight hole, and a fixing bolt 21 is installed in the threaded hole. An annular positioning groove is provided on the outer circumferential surface of the diameter adjustment ring 6. The screw end of the fixing bolt 21 abuts in the annular positioning groove, which facilitates the disassembly and replacement of the diameter adjustment ring 6.

[0036] like Figure 4 , 5 As shown, the guide module 7 has a cylindrical structure with an internal air intake chamber 14. An air intake pipe 15 is located on the outer peripheral wall of the guide module 7, connecting to the internal air intake chamber 14 and used to connect to an external air source. The guide module also includes a gas nozzle 17, specifically as shown... Figure 5 As shown, the gas nozzle 17 includes a first conical wall 17-1 and a second conical wall 17-2 coaxially arranged. The first conical wall 17-1 is located at the top of the guide module and recessed into the air intake chamber 14. The second conical wall 17-2 is located at the bottom of the guide module and recessed relative to the bottom surface of the guide module. The generatrices of the first conical wall 17-1 and the second conical wall 17-2 form an angle of 45° with the horizontal plane. A conical gap is formed between the first conical wall 17-1 and the second conical wall 17-2, which communicates with the air intake chamber 14. A jet hole 18 is provided at the center of the first conical wall 17-1. The diameter of the jet hole 18 is not less than the inner diameter of the orifice adjustment ring 6. The second conical wall 17-1... -2 has an airflow hole in the middle, the diameter of which is larger than that of the jet hole. The lower end of the second conical wall 17-2 has a cylindrical extension 19 through which the airflow hole passes. The air inlet chamber 14 has an annular baffle 23 inside, which is located above the second conical wall 17-2. The annular inner diameter of the baffle 23 is the same as the top diameter of the second conical wall 17-2. Multiple air guides 22 are provided on the baffle 23 along the circumferential direction. Each air guide includes a connecting part and a bending part. The connecting part is fixedly connected to the baffle (23). The bending part extends into the conical gap. The axes of the multiple bending parts are spirally inclined relative to the axis of the guide module. An angle-adjustable structure is used between the connecting part and the bending part, for example... Figure 7 At least one transition portion 22-3 is provided between the connecting portion 22-1 and the bending portion 22-2. Figure 7The two end faces of the transition portion 22-3 are arranged at an angle, and the transition portion 22-3 is provided with a driving motor 24 at the connection with the connecting portion 22-1, the connection between adjacent transition portions, and the connection between the transition portion and the curved portion 22-2, respectively. The driving motor is installed on the side wall of the transition portion 22-3 or the connecting portion 22-1 or the curved portion 22-2. A driving gear 25 is arranged on the output shaft of the driving motor 24. A driven gear ring 26 is arranged on the outer periphery of the transition portion 22-3 or the connecting portion 22-1 or the curved portion 22-2. The driving gear 25 is engaged with the driven gear ring 26. The driving motor 24 drives the driving gear to rotate, thereby driving the corresponding driven gear ring to drive the transition portion or the curved portion to rotate, so as to change the angle between the curved portion and the connecting portion.

[0037] The gas enters the gas inlet cavity 7, passes through the gas guide pipe 22 into the tapered gap, and the curved portion of the plurality of gas guide pipes 22 is spirally inclined, so that the gas entering the tapered gap rotates spirally. When the gas encounters the water jet, it closely adheres to the periphery of the water jet and spirally descends, thereby better protecting the direction of the water jet from changing.

[0038] Further, when the groove is cut, the water guide laser is in an inclined state, in order to prolong the available working section, that is, to keep the bending degree of the water jet less than the limit condition of light-water coupling, and the linear error between the cutting point and the nozzle is less than the maximum error allowed in processing. According to Bernoulli's principle, the faster the air flow speed, the smaller the pressure. The cutting maximum angle is 45 degrees. When the groove is cut, the air pressure in the plane composed of the gas outlet of the gas guide pipe does not change from the 9 o'clock direction to the 3 o'clock direction, and the air pressure gradually decreases from the lower direction. The air pressure of each point direction decreases, and the air pressure of the 6 o'clock direction is the lowest. When the groove angle decreases by one degree, the pressure difference of the decreasing air pressure also decreases. And through calculation to control the angle of the gas guide pipe, keep the integrity of the air curtain, through the airflow to assist the correction of the jet, compared with the traditional water guide laser structure, when cutting at an angle, corresponding to the groove angle to be cut, through the structure design of the gas guide pipe, the pressure difference can be accurately manufactured, the influence of gravity on the jet is resisted, the processing range and cutting precision during groove cutting are prolonged.

[0039] The coupling module and the guide module are detachably linked. Specifically, the bottom surface of the coupling module is provided with a first connecting ring 11, the outer wall of the first connecting ring 11 is provided with external threads, the top surface of the guide module is provided with a second connecting ring 16, the inner wall of the second connecting ring 16 is provided with internal threads, and the first connecting ring 11 and the second connecting ring 16 are connected through the cooperation of the internal threads and the external threads.

[0040] The light source module is arranged above the coupling module, a focusing mirror 2 is arranged between the light source module and the coupling module, the light source module, the focusing mirror 2, the optical window 3, the jet nozzle 5 and the gas nozzle 17 are coaxially arranged, laser generated by the light source module is focused by the focusing mirror and then enters the water jet generated by the jet nozzle, water-guided laser 9 is obtained by coupling, the gas nozzle sprays the annular gas curtain 10 closely wrapped in the water-guided laser through angle setting, the momentum loss caused by water and gas friction is reduced, thereby the laminar flow characteristics of the water jet are optimized, and the purpose of prolonging the stable length of the jet is achieved; when the gas pressure reaches or exceeds 0.3MPa, the high-speed gas effectively divides the flow field around the water jet, separates the stable jet from the downstream area of the air inlet, and thus protects the stable jet from being damaged by any upward water mist, liquid droplets and particles.

[0041] When the water-guided laser is coupled through the nozzle, because the refractive index of water is less than the refractive index of the nozzle material, the laser no longer satisfies the total reflection condition on the contact surface between water and the inner wall of the nozzle, and therefore part of the laser energy is deposited on the nozzle surface.

[0042] The present application is aimed at the phenomenon of energy deposition of the existing water-guided laser at the nozzle, and the 90-degree edge of the inner hole 12 of the caliber adjusting ring is used to make the water layer with high transverse momentum on the bottom surface of the water inlet cavity generate a “shrink flow” phenomenon after entering the caliber adjusting ring, that is, the water flow cannot suddenly deflect along the 90-degree edge, but passes through a distance of transition, and a water jet with a diameter smaller than the inner diameter of the caliber adjusting ring is formed below the caliber adjusting ring (at the lower end of the jet nozzle), so that the water jet is separated from the inner wall of the caliber adjusting ring and the jet nozzle, and then the water jet satisfies the total reflection condition to avoid energy deposition on the nozzle surface. In order to obtain stable shrink flow effect, by analyzing:

[0043] The length of the inner hole 12 of the caliber adjusting ring 6 is l, the diameter is d, the flow simulation is carried out by using a 128-micron water jet hole, and the relationship diagram of the normalized reconnection length (l / d) and the Reynolds number (a similar criterion number representing the influence of viscosity in fluid mechanics, denoted as Re, when the Reynolds number is small, the influence of viscous force on the flow field is greater than the influence of inertia, the disturbance of flow velocity in the flow field will decay due to viscous force, and the fluid flow is stable, which is laminar flow; on the contrary, when the Reynolds number is large, the influence of inertia on the flow field is greater than the influence of viscous force, the fluid flow is relatively unstable, and a small change in flow velocity is easy to develop and strengthen, forming a turbulent and irregular turbulent flow field) of AR=1 is drawn, that is, Figure 6 .

[0044] As Figure 6As shown, the test results show that, to obtain the non-cavitation contraction water jet formation process, the length of the inner hole 12 (i.e. the capillary length) should be less than 70% of its diameter, if the nozzle occurs hydraulic overturning, a contracted water jet can also be formed, however, in this case, the jet is first atomized, and then becomes a laminar long complete length flow, i.e. when the length l is less than the critical value 0.7d, due to the existence of system vibration or flow pulsation, the water jet is still not easy to reconnect.

[0045] The simulation flow coefficient is measured through simulation experiment:

[0046] According to the calculation formula of Reynolds number Re = ρvd / μ (in the formula, v, ρ and μ are respectively the flow rate, density and viscosity coefficient of the fluid, and d is the characteristic length, which is the inner diameter of the circular pipe), it can be known that the inner diameter d of the pipe is positively correlated with the Reynolds number. For example, Figure 6 As shown, the re-attachment length increases with the increase of the Reynolds number, and reaches a plateau at about 10000 Reynolds number, i.e. to realize that the jet is no longer in contact with the inner wall, the Reynolds number should be greater than 10000, and then through the formula:

[0047]

[0048] The range of the simulated l / d is obtained, and the intersection of the experimental results is obtained, 0.625≤l / d≤0.681, and the best contraction effect is obtained in this interval, for example, when the inner hole diameter d is 0.5mm, according to 0.625≤l / d≤0.681, the length l should be selected as 0.3125mm≤l≤0.3405mm, and the optimal length is 0.34mm.

[0049] Based on the above device and principle, the application further provides a high-power water guide laser generation method, which comprises the following steps:

[0050] S1. According to the Reynolds number of the used liquid, the Reynolds number should be greater than 10000, a suitable caliber adjusting ring 6 is installed in the straight hole of the jet nozzle, and the water inlet cavity is connected with the liquid supply system, and the air inlet cavity is connected with the gas source;

[0051] S2. Start the liquid supply system, fill the water inlet cavity 13 with liquid, and set the liquid pressure to 20MPa;

[0052] S3. Through the right angle setting of the upper end inner edge of the caliber adjusting ring 6, the high-speed flow of the water flow when entering the caliber adjusting ring 6 causes cavitation phenomenon, the liquid forms a stable contraction flow in the caliber adjusting ring 6, so that the inner wall of the caliber adjusting ring 6 in the lower conical nozzle does not contact the water flow, and the water flow is ejected from the jet nozzle 5 through the gas nozzle 17;

[0053] S4. Start the light source module, and the laser satisfies total reflection to be coupled in the water jet to form a water guide laser 9;

[0054] S5. Start the gas source, the inlet pipe 15 enters the high-density gas, the gas pressure is 0.3Mpa, the gas is guided by the gas nozzle 17, is attached to the water guide laser and is parallel to the water guide laser, is sprayed, forms a coaxial annular gas curtain 10 outside the water guide laser 9, the gas curtain 10 effectively splits the flow field around the water jet, separates the stable jet from the downstream area of the air inlet, so as to protect the stable jet from being damaged by any upward water mist, liquid droplets and particles.

[0055] Through the above implementation, the beneficial effects of the present application are that, by adjusting the size of the caliber adjusting ring and the inner hole thereof, the diameter of the water guide laser is smaller than the nozzle caliber, so that a stable "shrink flow" state is achieved, the loss caused by wall energy deposition and the thermal damage of the nozzle material are avoided, and the coupled energy beam is no longer in contact with the nozzle after being formed; the coaxial annular gas curtain is generated by the guide module, which isolates the upward water mist, liquid droplets and particles, forms a liquid flow film on the machining surface, avoids cutting pollution, and protects the cutting surface; at the same time, the annular gas curtain can offset a part of the influence of gravity on the water flow, so that the straight line of the water guide laser is more straight when it is inclined, the machining distance and the straight line machining section when cutting obliquely are prolonged, the water guide laser machining range is improved, the thickness of the cuttable material is improved, the cutting program is simplified, and the machining robustness and reliability are improved; the high-pressure gas flow of the annular gas curtain makes the liquid flow speed on the surface of the water guide laser greater than the internal flow speed, so that the machining taper effect can be improved; the overall structure of the device is convenient to manufacture and use, the laser coupling and output precision are high; at the same time, the water guide laser generation method of the device avoids energy loss in the coupling process and thermal damage of the nozzle, improves energy utilization, can be applied to a larger power light source module and improves the output power.

[0056] The above description of disclosed embodiments enables one of ordinary skill in the art to make or use the application. Various modifications to these embodiments will be readily apparent to those of ordinary skill in the art, and the generic principles defined herein can be applied to other embodiments without departing from the spirit or scope of the application. Thus, the present application is not intended to be limited to the embodiments shown herein but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A high-power water-guided laser generation device, comprising a light source module and a coupling module (4), wherein an inlet water cavity (13) is arranged inside the coupling module (4), an optical window (3) is arranged on the top of the coupling module, and a jet nozzle (5) is arranged at the bottom of the coupling module (4), and the light source module, the optical window (3) and the jet nozzle (5) are coaxially arranged, characterized in that, The jet nozzle (5) is inverted conical, the center of the jet nozzle (5) is communicated with the water inlet cavity (13) through a straight hole, a caliber adjusting ring (6) is installed in the straight hole, the caliber adjusting ring with a proper inner diameter is selected according to the liquid Reynolds number of the liquid supply system, the upper end inner edge of the caliber adjusting ring (6) is a right angle, the inner hole length l of the caliber adjusting ring (6) and the diameter d satisfy 0.625≤l / d≤0.681, the high-speed flow of the water flow when entering the caliber adjusting ring causes cavitation phenomenon, the liquid forms stable contraction flow in the caliber adjusting ring, so that the caliber adjusting ring inner wall in the lower conical nozzle is not contacted with the water flow, and the water flow is shot out from the jet nozzle through the gas nozzle; Further comprising a guide module (7), the guide module (7) is internally provided with an air inlet cavity (14), the guide module is provided with a gas nozzle (17), the diameter of the gas nozzle is not less than the inner diameter of the caliber adjusting ring (6), the gas nozzle (17) is communicated with the air inlet cavity (14), the gas nozzle (17) is coaxially arranged below the jet nozzle (5), the guide module can shoot high-speed airflow through the gas nozzle (17); The air inlet cavity (14) is internally provided with an annular partition plate (23), a plurality of air guide pipes (22) are circumferentially arranged on the partition plate (23), when the bevel is cut, the water guide laser is in an inclined state, in the plane composed of the air outlet of the air guide pipe, when the maximum angle of the cut bevel is 45 degrees, the air pressure from the upper 9 o'clock direction to the 3 o'clock direction is unchanged, the lower air pressure gradually decreases, the air pressure of each direction decreases, and the air pressure of the 6 o'clock direction is the lowest.

2. The high power water guided laser generation apparatus according to claim 1, wherein, The connecting part of the jet nozzle (5) and the coupling module is provided with an annular groove (20), the groove bottom of the groove (20) is provided with a threaded hole arranged along the radial direction of the jet nozzle (5), the threaded hole penetrates into the straight hole, a fixing bolt (21) is installed in the threaded hole, the outer circumferential surface of the caliber adjusting ring (6) is provided with an annular positioning groove, and the screw rod end of the fixing bolt (21) abuts against the annular positioning groove.

3. The high power water guided laser generation apparatus of claim 1, wherein, The gas nozzle (17) comprises coaxially arranged first and second conical walls (17-1) and (17-2), the first conical wall (17-1) is located at the top of the guide module and is recessed into the air inlet cavity (14), the second conical wall (17-2) is located at the bottom of the guide module and is recessed downward relative to the bottom surface of the guide module, a conical gap is formed between the first and second conical walls (17-1) and (17-2), and the conical gap is communicated with the air inlet cavity (14); the center of the first conical wall (17-1) is provided with a jet hole (18), the diameter of the jet hole (18) is not less than the inner diameter of the caliber adjusting ring (6), and the middle part of the second conical wall (17-2) is provided with an airflow hole, the diameter of the airflow hole is greater than that of the jet hole.

4. The high power water guided laser generation apparatus of claim 3, wherein, The lower end of the second conical wall (17-2) is provided with a cylindrical extension (19), and the airflow hole penetrates through the extension.

5. The high power water guided laser generation apparatus of claim 3, wherein, The partition plate (23) is located above the second conical wall (17-2), the annular inner diameter of the partition plate (23) is the same as the top diameter of the second conical wall (17-2), and one end of the air guide pipe (22) is deeply inserted into the conical gap.

6. The high power water guided laser generation apparatus of claim 5, wherein, The gas guide pipe comprises a connecting part and a curved part, the connecting part is fixedly connected with the partition plate (23), the curved part extends into the tapered gap, the axes of the plurality of curved parts are inclined spirally around the axis of the gas nozzle (17), and the included angle between the connecting part and the axis of the curved part is adjustable.

7. The high power water guided laser generation apparatus according to any one of claims 1 to 6, characterized by, The coupling module and the guide module are detachably linked, the bottom surface of the coupling module is provided with a first connecting ring (11), the top surface of the guide module is provided with a second connecting ring (16), one of the first connecting ring (11) and the second connecting ring (16) is provided with an external thread, and the other is provided with an internal thread, and the internal thread and the external thread are matched with each other.

8. A method of high power water-guided laser generation, characterized by, The method comprises the following steps: S1. connecting the water inlet cavity with the liquid supply system and connecting the air inlet cavity with the air source; S2. starting the liquid supply system to fill the water inlet cavity (13) with liquid; S3. forming a stable convergent flow of liquid in the caliber adjusting ring (6) and ejecting the liquid from the jet nozzle (5) through the gas nozzle (17); S4. starting the light source module to couple laser in the water jet to form a water guide laser (9); S5. starting the air source to wrap the water guide laser with air ejected through the gas nozzle (17) to form a coaxial annular air curtain (10) outside the water guide laser (9).

9. The high power water guided laser generation method of claim 8, wherein, In step S3, the high-speed flowing liquid generates cavitation phenomenon through the inner right-angle edge of the upper end of the caliber adjusting ring (6), the inner diameter of the caliber adjusting ring (6) is separated from the water jet, and the water jet satisfies total reflection.

10. The high power water guided laser generation method of claim 8, wherein, The caliber adjusting ring (6) with a proper inner diameter is selected according to the liquid Reynolds number of the liquid supply system, and the liquid Reynolds number is not less than 10,000.

11. The high power water guided laser generation method of claim 8, wherein, The focal point of the light source module is located above the inner hole of the caliber adjusting ring.

12. The high power water guided laser generation method of claim 8, wherein, In step S2, the liquid pressure is 20 MPa; in step S5, the air pressure is not less than 0.3 MPa.

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