Water guide laser coupling device with quick replacement of nozzle core

Abstract

The application discloses a water guide laser coupling device with a nozzle core capable of being quickly replaced, which comprises an upper rotating sleeve, a middle cavity, a nozzle sleeve and a lower rotating sealing cover. A laser incidence cavity is formed in the upper rotating sleeve; a containing cavity is formed in the middle of the middle cavity, water inlets and high-pressure water inlets are formed on the two sides of the middle cavity; the upper rotating sleeve and the nozzle sleeve are both axially installed in the containing cavity; an optical window is installed between the upper rotating sleeve and the middle cavity; the optical window and the top of the nozzle sleeve form a thin water layer; a nozzle core is installed on the top of the nozzle sleeve; the bottom of the nozzle sleeve is threadedly and rotatably combined with the middle cavity to achieve fastening and sealing; a through hole and an annular air outlet are arranged on the bottom of the lower rotating sealing cover, and the annular air outlet is in communication with the air inlet through an air inlet cavity. The device is fastened by thread rotation of each component, the nozzle core and the optical window are easy to disassemble and replace, the whole device is fast and convenient to install, and the sealing performance is high; the internal flow field is simple, the water inlets and the air inlets adopt a symmetrical double-inlet mode, and the stability length of the water jet and the stability of the machining process are improved.

Description

Technical Field

[0001] This invention relates to the field of water-guided laser processing equipment technology, specifically a water-guided laser coupling device for quick nozzle core replacement. Background Technology

[0002] Water-guided laser processing technology addresses the urgent need for precision parts manufacturing in high-end fields, providing an innovative and efficient solution. Traditional laser processing suffers from large heat-affected zones and high surface roughness, while water-guided laser processing effectively overcomes these limitations by introducing water as a guiding medium. Water-guided laser processing is an advanced processing method based on the principle of total internal reflection. In this process, the laser beam is completely encased in a water jet, and through total internal reflection at the air-water interface, the laser beam propagates to the workpiece surface via the water jet. The unique aspect of this technology lies in its full utilization of the cooling properties of water, which can be used simultaneously to cool the cutting area and promptly flush away debris generated by laser ablation. Compared to traditional laser processing, water-guided laser processing significantly reduces the heat-affected zone, greatly minimizing problems such as thermally induced microcracks, thermal deformation, and residual slag on the cross-section. Simultaneously, it results in less heat accumulation and fewer burrs, leading to a smoother surface in the processed area.

[0003] The basic principle of water-guided laser processing is that the laser beam enters the water jet beam through total internal reflection, and a stable water jet beam is fundamental to improving processing depth and accuracy. Current research focuses on how to further improve the coupling device to enhance the stable flow state of the water jet. To realize water-guided laser processing technology, several key scientific and technological problems need to be addressed, one of which is ensuring a stable flow field and generating and controlling the water jet fiber. In the process of effectively coupling the laser beam and water jet to form the water jet fiber, the stable collimation of the water jet is a crucial prerequisite. If the water jet experiences fluctuations, divergence, or breakage, even if the incident angle of the laser beam meets the requirements, laser energy will dissipate, total internal reflection will not be achieved, and the water jet fiber cannot be formed. Therefore, only by ensuring the stability of the water jet can the technical requirements for efficient coupling of water and laser be met. The main coupling point between the laser and water jet is inside the nozzle core with a very small aperture (30μm-200μm). If there is a certain deviation in the coupling, it will damage the inner surface of the nozzle core, thus affecting the quality of water-guided laser processing. Therefore, it is necessary to provide a device structure that is easy to disassemble and install to improve processing efficiency.

[0004] To further improve water-laser coupling efficiency, it is necessary to optimize the coupling water cavity and nozzle structure to enhance the stability of the water-guided laser beam. On the other hand, introducing an air jet can enhance the length and flow stability of the water-guided laser beam, thereby increasing the processing distance. Continuous optimization and innovation of this technology are expected to drive the development of the precision laser processing industry.

[0005] To address the aforementioned issues, a water-guided laser coupling device with a rapidly replaceable nozzle core is proposed. This device can provide stable high-pressure water and uses auxiliary gas to extend the stable length of the jet beam. The internal nozzle core and optical window are easy to disassemble and replace, and it has strong sealing capabilities. Summary of the Invention

[0006] To overcome the shortcomings of existing technologies, this invention provides a water-guided laser coupling device. Both the water inlet and the air inlet adopt a symmetrical dual-inlet design, which can stabilize the liquid pressure in the water cavity, thereby effectively improving the stable length of the water jet and the stability of the processing process. The overall structure is simple, and all parts are sealed by spiral fastening through their own threads, which has strong sealing performance. Disassembly and installation are simple, and different sizes of nozzle cores and optical windows can be quickly replaced according to processing requirements, thereby improving processing efficiency.

[0007] The objective of this invention can be achieved through the following technical solutions:

[0008] A water-guided laser coupling device for quick nozzle core replacement includes an upper rotating sleeve, an intermediate cavity, a nozzle sleeve, and a lower rotating sealing cover. The upper rotating sleeve has a laser incident cavity; the intermediate cavity has a central receiving cavity and two side water inlets and high-pressure water inlets; both the upper rotating sleeve and the nozzle sleeve are axially installed within the receiving cavity, and an optical window is installed between the upper rotating sleeve and the intermediate cavity, forming a thin water layer with the top of the nozzle sleeve; a nozzle core is installed on the top of the nozzle sleeve, and the bottom of the nozzle sleeve and the lower rotating sealing cover are tightly sealed to the intermediate cavity via threaded rotation; the bottom of the lower rotating sealing cover has a through hole and an annular vent hole, which communicates with the vent hole through the vent cavity.

[0009] The upper rotating sleeve has a countersunk through-hole laser incident cavity at its center, which provides an entrance for the laser to enter the coupling device.

[0010] The central cavity of the intermediate cavity has a receiving cavity, and water inlets and high-pressure water inlets are opened on both sides. The high-pressure water inlets are connected to the receiving cavity.

[0011] The top of the nozzle sleeve is equipped with a rotating fastening cap and a nozzle core, and the center of the nozzle sleeve has a layered, slender through hole.

[0012] The lower rotating sealing cover is installed at the bottom of the intermediate cavity, and the nozzle sleeve is fastened and sealed to the intermediate cavity by rotating its own thread. A through hole is opened at the bottom of the lower rotating sealing cover; an air inlet chamber is opened inside the lower rotating sealing cover.

[0013] Furthermore, the upper rotating sleeve is fastened to the intermediate cavity via a threaded connection; the top of the upper rotating sleeve has four wrench locking grooves; the bottom of the upper rotating sleeve has an O-ring sealing groove.

[0014] Furthermore, the intermediate cavity contains a receiving cavity and a high-pressure water inlet cavity; the receiving cavity and the high-pressure water inlet cavity are arranged in a cross shape; the upper part of the receiving cavity is a countersunk through-hole structure, and an O-ring sealing groove is formed on the upper surface of the countersunk inner step; the upper part of the receiving cavity of the countersunk inner step is used to install the upper rotating sleeve and the optical window; the lower part of the receiving cavity of the countersunk inner step is used to install the nozzle sleeve; the water inlet is threaded for installing an external high-pressure water pipe; an O-ring sealing groove is formed at the bottom of the intermediate cavity; and external threads are formed in the lower part of the intermediate cavity.

[0015] Furthermore, the upper surface of the optical window is attached to the first O-ring seal at the bottom of the upper rotating sleeve and is fastened by threaded rotation through the upper rotating sleeve; the lower surface of the optical window is attached to the inner step of the countersunk head through the second O-ring seal; a "U"-shaped liquid layer cavity is formed between the optical window, the top of the nozzle sleeve, and the inner step of the countersunk head, which can form a thin water layer after water is injected; the high-pressure water inlet cavity is connected to the liquid layer cavity;

[0016] Furthermore, the top of the nozzle sleeve is provided with a countersunk hole; the countersunk hole is used to install the nozzle core; the top of the nozzle sleeve is provided with a thread, and the rotating fastening cap rotates and fastens the nozzle core into the countersunk hole by rotating its own thread; the upper surface of the rotating fastening cap is provided with a tapered through hole with a tapered angle of 45°; the upper surface of the nozzle sleeve base is provided with an O-ring sealing groove.

[0017] Furthermore, the top surface of the nozzle core has a straight hole, and the bottom surface has a lower conical opening; the straight hole corresponds to the center position of the laser incident cavity; the lower conical opening corresponds to the position of the layered slender through hole of the nozzle sleeve, and the angle of the lower conical opening is 60°.

[0018] Furthermore, a countersunk hole is formed on the upper inner surface of the lower rotary sealing cover, which fits against the lower surface of the nozzle sleeve base; an internal thread is formed on the inner side of the lower rotary sealing cover, which is tightened to the intermediate cavity by the thread, and the upper surface of the nozzle sleeve base and the lower surface of the intermediate cavity are fitted and sealed by a third O-ring; an annular vent is formed at the bottom of the lower rotary sealing cover, which is connected to two air inlets through the air inlet chamber; and wrench locking grooves are formed on the four sides of the bottom outer side of the lower rotary sealing cover.

[0019] Furthermore, the optical cavity, water cavity, and air cavity are all cylindrical cavity structures;

[0020] Furthermore, the optical window is made of quartz glass material with high light transmittance and strong pressure resistance, and is in the shape of a disc.

[0021] Further, the nozzle core is made of industrial-grade ruby material with high hardness and high wear resistance;

[0022] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0023] (1) Simple installation and disassembly: The overall structure is an axial installation structure. The upper rotating sleeve, the middle cavity and the lower rotating seal cover are all installed and connected by their own threads, and there is no need to use external thread fasteners for fastening;

[0024] (2) Convenient replacement of components: The optical window, the nozzle sleeve and the nozzle core are all separable structures. In order to meet different processing requirements, the coupling device can be quickly and simply disassembled to replace the optical window and the nozzle core;

[0025] (3) High jet stability: High-pressure water enters the inside of the coupling device from the side, forms a "Ji"-shaped thin overflow layer before reaching the straight hole of the nozzle core, and then forms a high-speed and stable micro-water jet beam through the straight hole of the nozzle core; The lower rotating seal cover conveys high-pressure gas from the side to the annular air outlet hole, and the high-pressure gas sprays out from the annular air outlet hole to form an annular protective cover around the micro-water jet beam, reducing the divergence phenomenon of the jet beam caused by the entrainment effect with air, and at the same time reducing the water jet sputtering when the jet beam impacts the workpiece surface, improving the stability of the jet beam and extending the stable length. Among them, the high-pressure water inlet cavity and the air inlet cavity both adopt a symmetric double-channel distribution, which can effectively reduce the instability of a single channel.

[0026] (4) Good sealing performance: The overall structure is fastened and sealed by the self-threads of each component, and multiple O-ring seals are arranged inside to improve the overall sealing performance of the coupling device. Description of the Drawings

[0027] The drawings are used to provide a further understanding of the embodiments of the present invention, and constitute a part of the specification. Together with the following specific embodiments, they are used to explain the embodiments of the present invention, but do not constitute a limitation to the embodiments of the present invention. In the drawings:

[0028] Figure 1 It is the main sectional view of the water-guided laser coupling device of the present invention;

[0029] Figure 2 It is the top view of the water-guided laser coupling device of the present invention;

[0030] Figure 3 It is the bottom view of the lower rotating seal cover of the water-guided laser coupling device of the present invention;

[0031] Figure 4 It is the sectional view of the nozzle core of the water-guided laser coupling device of the present invention;

[0032] Wherein, 1 is the upper rotating sleeve, 2 is the middle cavity, 3 is the nozzle sleeve, 4 is the lower rotating sealing cap, 5 is the air inlet, 6 is the air inlet chamber, 7 is the annular air outlet, 8 is the laser incident cavity, 9 is the first O-ring seal, 10 is the optical window, 11 is the second O-ring seal, 12 is the high-pressure water inlet chamber, 13 is the water inlet, 14 is the overflow liquid layer chamber, 15 is the rotating fastening cap, 16 is the nozzle core, 17 is the layered slender through hole, 18 is the third O-ring seal, 19 is the nozzle sleeve base, 20 is the jet outlet, 21 is the upper rotating sleeve wrench locking groove, 22 is the middle cavity wrench locking groove, 23 is the lower rotating sealing cap wrench groove, 24 is the nozzle core straight hole, and 25 is the nozzle core lower conical opening. Detailed Implementation

[0033] The specific embodiments of the present invention will be described in detail below with reference to the accompanying drawings, providing a clear and complete description of the technical solutions in the embodiments of the present invention. The described embodiments are merely some embodiments of the present invention, and not all embodiments. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without creative effort are within the scope of protection of the present invention.

[0034] This invention relates to a water-guided laser coupling device for quick nozzle core replacement; please refer to [link to relevant documentation]. Figures 1-4 As shown, its main structure includes an upper rotating sleeve 1, an intermediate cavity 2, a nozzle sleeve 3, a lower rotating sealing cover 4, an optical window 10, and a nozzle core 16.

[0035] Please see Figure 1 and Figure 2 The upper rotating sleeve 1 has a countersunk through-hole laser entrance cavity 8 at its center, providing an entrance for the laser to enter the coupling device; the upper part of the outer side of the upper rotating sleeve 1 has a wrench locking groove 22, and the lower part has an internal thread; the middle cavity 2 has a receiving cavity and a high-pressure water inlet cavity 12 inside; the water inlet 13 of the high-pressure water inlet cavity 12 has an internal thread for installing an external high-pressure water pipe; the receiving cavity and the high-pressure water inlet cavity 12 are arranged in a "+" shape; the upper half of the receiving cavity is a countersunk through-hole structure, with an internal thread and a groove inside; the upper rotating sleeve 1 and the middle cavity 2 are fastened to the optical window 10 in the groove by rotating the threads, and the upper and lower surfaces of the optical window 10 are respectively attached to the first O-ring seal 9 and the second O-ring seal 11, realizing the sealing of the upper rotating sleeve 1 and the optical window 10 inside the middle cavity 2;

[0036] Furthermore, the optical window is made of quartz glass material with high light transmittance and strong pressure resistance, and is in the shape of a disc.

[0037] Please see Figure 1 and Figure 3, a counterbore is provided at the top of the nozzle sleeve, and an external thread is provided on the outer side of the top; an internal thread is provided inside the rotary fastening cap, and a tapered through hole is provided on the upper surface, with a taper angle of 45°; the nozzle core 16 is installed in the counterbore provided at the top of the nozzle sleeve, and is tightly fitted and sealed by the rotary fastening cap through threaded rotation; a layered slender through hole 17 is provided at the center inside the nozzle sleeve; a straight hole 24 is provided on the top surface of the nozzle core, and a lower tapered opening 25 is provided on the bottom surface, with a taper angle of 60 degrees; the straight hole 24 of the nozzle core corresponds to the central position of the laser incident cavity 8, and the lower tapered opening 25 corresponds to the central position of the layered slender through hole 17 of the nozzle sleeve;

[0038] Further, a "C" - shaped overflow liquid layer cavity 14 is formed between the optical window 10, the top of the nozzle sleeve 3, and the counterbored inner step on the upper half of the accommodating cavity of the intermediate cavity 2. A thin water layer can be formed after water injection; the high - pressure water inlet cavity 12 is connected to the overflow liquid layer cavity 14;

[0039] Further, the nozzle core is made of industrial - grade ruby material with high hardness and high wear resistance;

[0040] Please refer to Figure 1 and Figure 4 , a counterbored through hole is provided on the upper surface inside the lower rotary sealing cap 4, and the upper surface of the counterbore is fitted with the lower surface of the base 19 of the nozzle sleeve; an internal thread is provided inside the lower rotary sealing cap 4, which is rotationally fastened to the intermediate cavity 2 through threads, and the upper surface of the base 19 of the nozzle sleeve and the lower surface of the intermediate cavity 2 are tightly fitted and sealed through the third O - ring 18; an annular air hole 7 is provided at the bottom of the lower rotary sealing cap 4, and the annular air hole 7 is correspondingly connected to the two air inlets 5 through the air inlet cavity 6; the through hole at the bottom of the lower rotary sealing cap corresponds to the center of the layered slender through hole of the nozzle sleeve; the annular air hole and the through hole at the bottom of the lower rotary sealing cap are concentric;

[0041] The present invention provides a method for fastening each component through its own thread, without using external threaded fasteners for fastening, and the overall structure is an axial installation structure, which can conveniently and quickly replace vulnerable parts while ensuring the stability of the coupling device;

[0042] The present invention adopts a symmetrical double - channel side water inlet cavity structure, which can effectively reduce the disturbance formed by a single channel inside the coupling device; high - pressure water enters the inside of the coupling device from the two water inlets 13, forms a "C" - shaped overflow thin water layer before reaching the straight hole 24 of the nozzle core, and then forms a high - speed and stable micro - water jet beam through the straight hole 24 of the nozzle core, reducing the direct impact of the internal high - pressure water flow on the nozzle core 16;

[0043] The present invention has an air inlet cavity structure inside the lower rotating sealing cover 4, and the air inlet cavity structure is also a symmetrical double channel structure. High pressure gas is input from the air inlets 5 on both sides, and after passing through the air inlet cavity 6, it is ejected in the annular air hole to form an annular protective cover surrounding the micro water jet beam. This reduces the divergence phenomenon of the jet beam due to the entrainment effect with air and reduces water jet splashing when the jet beam hits the workpiece surface, thereby improving the stability of the jet beam and extending the stable length.

[0044] The working principle of this invention is as follows:

[0045] During operation, high-pressure water enters the coupling device from the two inlets 13 and flows upward through the outer wall of the nozzle sleeve 3. An overflow thin water layer is generated in the gap between the top surface of the nozzle sleeve 3 and the optical window 10, improving the flow stability near the nozzle core and solving the problem of unstable light-guiding water jets caused by inconsistent flow around the nozzle core 16. The overflow thin water layer of high-pressure water generates a stable, slender water jet downward through the nozzle core 16. The laser beam enters the coupling device from the laser incident cavity 8 of the upper rotating sleeve 1 after passing through the lens, and then focuses inside the straight hole 24 of the nozzle core after passing through the optical window 10 and the overflow thin water layer. When the laser beam in the water jet satisfies an incident angle greater than the critical angle for total internal reflection, the laser beam will undergo total internal reflection in the stable water jet. Reflection, the water jet is equivalent to a water fiber "enveloping" the laser beam inside for zigzag propagation, thus forming a water-guided laser beam that can be used for processing. After the water-guided laser beam is generated, high-pressure gas is introduced into the two air inlets 5 at the lower rotating sealing cover 4. The high-pressure gas is ejected from the annular air holes 7. The annular air holes 7 are aligned with the water jet direction in the outlet direction and are distributed in a ring along the bottom through hole of the lower rotating sealing cover 4. The high-pressure gas ejected from the annular air holes 7 can prevent ambient air from entering the water jet, reduce the divergence of the high-pressure water jet, and the high-pressure air can quickly remove processing residue from the processing area, preventing residue accumulation from reducing processing efficiency, improving the stability of the light-guided water jet during processing, and thus greatly improving the processing distance and accuracy of the water-guided laser.

[0046] In the description of this invention, it should be understood that the terms "upper surface," "lower surface," "side surface," "internal center," "top," "bottom," "inner," and "outer," etc., used to describe orientations or positional relationships are based on the orientations or positional relationships shown in the accompanying drawings. Their main purpose is to facilitate the explanation of this invention, rather than requiring the device or element to have a specific orientation, structure, or mode of operation. Therefore, these descriptions should not be regarded as specific limitations on this invention.

[0047] The embodiments described above are merely preferred embodiments of the present invention and are not intended to limit the scope of the present invention. Various modifications and improvements made by those skilled in the art to the technical solutions of the present invention without departing from the spirit of the present invention should fall within the protection scope defined by the claims of the present invention.

Claims

1. A water-guided laser coupling device for quick nozzle core replacement, characterized in that, include: The upper rotating sleeve (1) has a laser incident cavity (8) at its center, which provides an entrance for the laser to enter the coupling device. The intermediate cavity (2) has a receiving cavity in the center and water inlets (13) and high-pressure water inlets (12) on both sides. The high-pressure water inlets (12) are connected to the receiving cavity. The upper rotating sleeve (1) is fastened to the intermediate cavity (2) by its own thread. The upper rotating sleeve (1) has a wrench locking groove (21) on the outer side of the top. The upper rotating sleeve (1) has an O-ring sealing groove at the bottom. The nozzle sleeve (3) is equipped with a rotating fastening cap (15) and a nozzle core (16) on its top; a layered elongated through hole (17) is opened in the center of the nozzle sleeve (3); a nozzle sleeve base (19) is provided at the bottom of the nozzle sleeve (3); an O-ring groove is opened on the upper surface of the nozzle sleeve base (19), and a third O-ring (18) is provided in the O-ring groove. The lower rotating sealing cover (4) is installed at the bottom of the intermediate cavity (2). The nozzle sleeve (3) is fastened and sealed to the intermediate cavity (2) by rotating the thread. The bottom of the lower rotating sealing cover (4) has a countersunk through hole. The lower rotating sealing cover has two air inlet chambers (6) inside. The upper inner surface of the lower rotating sealing cover (4) has a countersunk hole that fits with the lower surface of the nozzle sleeve base (19). The inner side of the lower rotating sealing cover (4) has an internal thread that is fastened to the intermediate cavity (2) by rotating the thread. The upper surface of the nozzle sleeve base (19) and the lower surface of the intermediate cavity (2) are fitted and sealed by the third O-ring (18). The bottom of the lower rotating sealing cover (4) has an annular air outlet (7). The annular air outlet (7) is connected to the two air inlets (5) through the air inlet chamber (6). The outer side of the bottom of the lower rotating sealing cover has a wrench locking groove (23).

2. The water-guided laser coupling device for quick nozzle core replacement according to claim 1, characterized in that: The intermediate cavity (2) has an internal receiving cavity and a high-pressure water inlet cavity (12); the receiving cavity and the high-pressure water inlet cavity (12) are arranged in a "+" shape; the upper part of the receiving cavity is a countersunk through hole structure, and an O-ring sealing groove is provided on the upper surface of the countersunk inner step; the upper part of the receiving cavity of the countersunk inner step is used to install the upper rotating sleeve (1) and the optical window (10); the lower part of the receiving cavity of the countersunk inner step is used to install the nozzle sleeve (3); the water inlet (13) is provided with an internal thread for installing an external high-pressure water pipe; the bottom of the intermediate cavity (2) is provided with an O-ring sealing groove; the lower part of the intermediate cavity (2) is provided with an external thread; a wrench locking groove (22) is provided on the outside of the intermediate cavity.

3. A water-guided laser coupling device for quickly replacing a nozzle core according to claim 2, further comprising an optical window (10); the upper surface of the optical window (10) is fitted to the first O-ring (9) at the bottom of the upper rotating sleeve (1) and is rotationally fastened by screwing the upper rotating sleeve (1); the lower surface of the optical window (10) is fitted to the counterbore inner step through the second O-ring (11); a "ji" - shaped overflow liquid layer cavity (14) is formed between the optical window (10), the top of the nozzle sleeve (3), and the counterbore inner step, and a thin water layer can be formed after water injection; the high-pressure water inlet cavity (12) is connected to the overflow liquid layer cavity (14).

4. The water-guided laser coupling device for quick nozzle core replacement according to claim 3, characterized in that: A counterbore is provided at the top of the nozzle sleeve (3); the counterbore is used for installing the nozzle core (16); threads are provided at the top of the nozzle sleeve (3), and the rotating fastening cap (15) rotates and fastens the nozzle core (16) inside the counterbore by its own threads; a tapered hole with a taper angle of 45° is provided on the upper surface of the rotating fastening cap (15).

5. A water-guided laser coupling device for quick nozzle core replacement according to claim 4, characterized in that: A straight hole (24) is provided on the top surface of the nozzle core (16), and a lower tapered opening (25) with a taper angle of 60 degrees is provided on the bottom surface; the straight hole (24) corresponds to the central position of the laser incident cavity (8); the lower tapered opening (25) corresponds to the central position of the layered slender through - hole (17) of the nozzle sleeve.

6. A water-guided laser coupling device for quick nozzle core replacement according to claim 3, characterized in that: The optical window (10) is made of quartz glass material.

7. A water-guided laser coupling device for quick nozzle core replacement according to claim 5, characterized in that: The nozzle core (16) is made of ruby material.

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