Water-guided laser cutting device and method for deep sea environment

Abstract

The invention discloses a deep sea environment water-guided laser cutting device and method. The deep sea environment water-guided laser cutting device comprises a spray head device, a drainage cover device, a self-circulation pressurizing device, a laser generating device and a mobile positioning system. The nozzle device is provided with an annular water channel to stabilize water jet; the drainage cover coaxially sleeves the outer side of the spray head, and a local dry cavity is formed through gas injection; the self-circulation pressurizing device is used for extracting seawater and pressurizing and conveying the seawater; the laser generating device calibrates a laser focus through the calibration lens cone and the optical lens, and coaxial coupling of the water jet and the laser beam is achieved. The deep sea cutting precision and efficiency are improved, environmental interference is reduced, and the method is suitable for underwater high-precision machining.

Description

Technical Field

[0001] The present invention relates to the technical field of underwater cutting and processing, in particular to a water-guided laser cutting device and method for deep-sea environment. Background Art

[0002] With the increasing development of marine resources and underwater engineering activities, the need for safe dismantling of decommissioned marine equipment (such as oil platforms, subsea pipelines, abandoned ships, etc.) is imminent. In recent years, water-guided laser technology has emerged in the onshore industrial field. By using high-pressure water jets to confine the laser transmission, it has both high energy utilization efficiency and low thermal damage characteristics, and has been successfully used for precision cutting of steel materials and the like. Traditional underwater cutting technologies mainly include mechanical cutting, flame cutting, laser cutting and other methods, but they have significant defects in the deep-sea high-pressure, low-temperature, and turbid environment. The mechanical cutting method relies too much on physical contact, with low cutting efficiency, poor precision, serious tool wear, and it is difficult to handle the cutting of high-hardness metals. Thermal cutting technologies rely on high temperatures to melt materials, have a large heat-affected zone, and produce harmful gases and slag, polluting the marine environment. Although underwater laser cutting has a large energy density, the scattering and absorption effects of the water environment on the laser beam result in energy density attenuation, and it relies on high-power lasers. At the same time, the interference of water vapor and bubbles generated during laser cutting easily causes the cutting surface to be rough and it is difficult to achieve precision machining.

[0003] The invention patent with the Chinese patent publication number CN112831629A provides a surface hardening system based on water-guided laser. The invention includes a laser, an optical path system, a laser coupling device, a workbench, and a high-pressure water supply system. During operation, the water inlet end of the high-pressure water supply system is connected to a water tank, and the water outlet end is connected to a coupling cavity. This device can form a stable reverse-flow type constricted laser beam and can reduce the working distance of the water jet. However, the generation of high-pressure water jets relies on a closed water circulation device, which requires a large water tank, has a complex structure, a cumbersome process, and cannot be directly transplanted to the deep-sea environment.

[0004] The invention patent with the Chinese patent publication number CN112192051A discloses an underwater laser cutting device, which relates to the field of underwater laser cutting. The device includes a water-based control host and a gas control device. The underwater cutting end device is connected to the underwater laser cutting nozzle device through fixing screws and flexible sealing strips. The water-based control device and the underwater cutting device communicate through a connecting wire harness. Gas is input into the laser cutting head to drain water, so that the light beam coming out of the lens is not affected by water. The modular design includes a detachable handle and end devices (such as top wheels, laser cutting heads, alignment fixing brackets, etc.), which is convenient for maintenance and adapting to different operation requirements. This cutting device solves the problems of slow cutting speed, poor cutting ability, poor surface finish of the cut, high energy consumption, high equipment cost and many other adverse factors caused by the influence of water. However, due to the interference of factors such as water vapor and water scattering in the water environment, problems such as inaccurate cutting and rough cutting parts occur. Summary of the Invention

[0005] Object of the Invention: The object of the present invention is to provide a water-guided laser cutting device and method for deep-sea environments in view of the limitations of existing underwater cutting technologies, so as to solve the disadvantages of complex operation and low cutting accuracy of traditional underwater cutting methods.

[0006] Technical Solution: To achieve the above object, the present invention adopts the following technical solutions:

[0007] In the first aspect of the present invention, a water-guided laser cutting device for deep-sea environments is provided, which includes a nozzle device, a drainage hood device, a self-circulating pressurization device, a transportation device, a clamping device and a laser generating device; the nozzle device includes an upper nozzle and a lower nozzle connected coaxially, and an annular water storage cavity and a water inlet channel are formed inside; the drainage hood device is coaxially sleeved outside the nozzle device, and is provided with an air inlet channel and an exhaust channel; the self-circulating pressurization device includes a vortex separator, a high-pressure submersible pump and a ball valve, and is used for pumping and pressurizing seawater.

[0008] Further, the nozzle device further includes an upper end convex cover, a high-pressure water inlet and a water outlet. One end of the upper end convex cover is connected to the clamping device, and the other end is welded and fixed to the upper nozzle. The upper nozzle and the lower nozzle are tightly fixed together through circular through holes and bolts arranged along the circumference. An optical lens is provided inside the upper nozzle. The annular water storage cavity is surrounded by the semi-circular cavities inside the upper nozzle and the lower nozzle. Each of the upper nozzle and the lower nozzle has a semi-circular water inlet channel, and a complete water inlet channel is formed by mutual enclosure.

[0009] Further, the air inlet channel is six through holes arranged annularly along the central axis of the drainage hood device. The air inlet channel communicates with the exhaust channel. The upper part of the drainage hood device is fixed to the upper end convex cover by welding. The lower part of the drainage hood device is tightly fixed to the upper part of the drainage hood device through through holes.

[0010] Further, it includes a flange-to-thread adapter. The ball valve is a stainless steel ball valve. The vortex separator, the high-pressure submersible pump, the ball valve, and the flange-to-thread adapter are connected in sequence. Among them, the vortex separator and the high-pressure submersible pump are hermetically connected to filter the pumped seawater. The other end of the high-pressure submersible pump is provided with an outlet, which is connected to the stainless steel ball valve. The other end of the ball valve is connected to the flange-to-thread adapter, and the flange-to-thread adapter cooperates with the water inlet channel.

[0011] Further, the transportation device includes an upper hydraulic-driven propeller, a lower hydraulic-driven propeller, and a real-time monitoring component. The real-time monitoring component includes a high-definition camera and a laser rangefinder arranged at the front end.

[0012] Further, the clamping device includes a base fixed to the front end of the transportation device, and its end is connected to the upper end cover of the nozzle device through an adaptive fixture.

[0013] Further, the laser generating device includes a calibration lens barrel sealed in the upper end cover, an optical lens arranged on the upper nozzle, and a low-expansion alloy pressing ring. The optical lens is fixed in the inner cavity of the upper nozzle through the low-expansion alloy pressing ring. The calibration lens barrel is installed in the inner cavity of the upper end cover through auxiliary positioning. The surface of the optical lens is coated with a hydrophobic coating to reduce the formation of water mist.

[0014] The second aspect of the present invention provides a deep-sea environmental water-guided laser cutting method based on the above device. The method includes the following steps:

[0015] S1: Install the water-guided laser cutting nozzle at the end of the clamping device, carry it to the vicinity of the deep-sea target by a cable-operated remotely operated vehicle (ROV). Use the high-definition camera and laser rangefinder of the ROV to determine the cutting path and adjust the nozzle to the initial working position to ensure that the opening of the drainage hood device faces the target directly.

[0016] S2: Start the drainage hood device, inject gas into the air inlet channel, and discharge the seawater in the hood to form a local dry space.

[0017] S3: Open the vortex separator at the water inlet channel of the nozzle, extract external seawater and filter it; the seawater is pressurized by the high-pressure submersible pump and then transported to the annular water storage cavity.

[0018] S4: Start the laser, and the laser beam is vertically incident on the center of the high-pressure water jet; use the calibration lens barrel and the optical lens in the cavity to make the laser beam and the water jet accurately coaxially coupled to form a stable water-guided laser beam stream.

[0019] S5: The clamping device moves along a preset trajectory, and the water-guided laser beam stream acts on the metal surface to achieve continuous cutting.

[0020] S6: After the cutting work is completed, raise the clamping device, turn off the self-circulating pressurization device, turn off the high-pressure gas after turning off the laser, and then turn off the recovery device.

[0021] Advantages: Compared with the prior art, the present invention has the following advantages:

[0022] (1) The present invention adds a self-circulating pressurization system, which cleverly utilizes the surrounding seawater to achieve self-circulation, effectively reducing the overall size of the device, reducing the weight of the device, and also significantly reducing the operating cost of the device. Cancel large water tanks, high-pressure water recovery units and other devices used in the onshore water-guided laser system.

[0023] (2) The present invention uses the water-guided laser technology combined with the drainage hood device to cut underwater workpieces. Through the high-energy density water-guided laser jet, the size of the heat-affected zone caused by cutting can be reduced, the incision width can be reduced, and at the same time the roughness of the cutting surface can be reduced, realizing precision machining that cannot be achieved by traditional underwater cutting, greatly improving the quality and efficiency of underwater cutting, and facilitating the realization of automatic control.

[0024] (3) The present invention greatly reduces the adverse effects on the marine environment and marine organisms during the traditional underwater cutting process. The use of the self-circulating system can achieve zero pollution to the marine environment, greatly improving the accuracy and efficiency of underwater cutting in the marine environment, and greatly improving the operability and flexibility of the equipment. It can be widely used in the field of underwater cutting in the marine environment. Description of the Drawings

[0025] Figure 1 It is a schematic diagram of the overall structure of the device provided by the embodiment of the present invention;

[0026] Figure 2 It is a schematic diagram of the structure of the water-guided laser cutting head provided by the embodiment of the present invention;

[0027] Figure 3 It is a schematic cross-sectional view of the water-guided laser cutting head provided by the embodiment of the present invention;

[0028] Figure 4 It is a schematic diagram of the structure of the nozzle device provided by the embodiment of the present invention;

[0029] Figure 5 It is a schematic diagram of the structure of the drainage hood device provided by the embodiment of the present invention;

[0030] Figure 6 It is a schematic diagram of the structure of the self-circulating pressurization device provided by the embodiment of the present invention;

[0031] Figure 7 It is a schematic diagram of the structure of the laser generating device provided by the embodiment of the present invention. Detailed Embodiments

[0032] The present invention will be further illustrated below in conjunction with the accompanying drawings and specific embodiments. These embodiments are implemented on the premise of the technical solution of the present invention. It should be understood that these embodiments are only used to illustrate the present invention and not to limit the scope of the present invention.

[0033] A deep-sea environment water-guided laser cutting device according to this embodiment, in combination with Figure 1 , includes a nozzle device 1, a drainage hood device 2, a self-circulating pressurization device 3, a transportation device 4, a clamping device 5, and a laser generating device 6.

[0034] In combination with Figure 2 , the nozzle device 1 includes an upper convex cover 101, an upper nozzle 102, a lower nozzle 103, an annular water storage cavity 104, a water inlet channel 105, a high-pressure water inlet 106, and a water outlet 107. The drainage hood device 2 is coaxially arranged outside the nozzle device and includes an upper part 201 of the drainage hood device, a lower part 202 of the drainage hood device, an air inlet channel 203, and an exhaust channel 204. The vortex separator 301 and the high-pressure submersible pump 302 are hermetically connected and used to filter the extracted seawater. The other end of the high-pressure submersible pump 302 is provided with an outlet, which is connected to a stainless steel ball valve 303. The other end of the stainless steel ball valve is connected to a flange-to-thread adapter 304. The flange-to-thread adapter cooperates with the water inlet channel.

[0035] In combination with Figure 3 , the nozzle device 1 and the drainage hood device 2 are coaxially arranged. The self-circulating pressurization device 3 is fixed above the drainage hood device by bolts. The laser generating device 6 is arranged in the placement cavity inside the nozzle device.

[0036] In combination with Figure 4 , the nozzle device 1 is provided with a plurality of high-pressure water inlets 106, and a water outlet 107 is arranged below. One end of the upper convex cover 101 is connected to the clamping device 5, and the other end is welded and fixed to the upper nozzle 102. The upper nozzle 102 and the lower nozzle 103 are tightly fixed together by circular through holes and bolts arranged along the circumference. An optical lens 602 is provided inside the upper nozzle. The annular water storage cavity 104 is formed by enclosing the semi-circular cavities inside the upper nozzle 102 and the lower nozzle 103. Each of the upper nozzle 102 and the lower nozzle 103 has a semi-circular water inlet channel, and the complete water inlet channel 105 is formed by mutual enclosure.

[0037] In combination with Figure 5, a plurality of air inlets are arranged circumferentially on the drainage hood device 2, and an inclined annular exhaust passage 204 is arranged below the drainage hood device 2. The air inlet passage 203 is six through holes arranged annularly along the central axis of the drainage hood device, and the air inlet passage 203 communicates with the exhaust passage 204. The upper part 201 of the drainage hood device is fixedly connected to the upper end convex cover 101 by welding. The lower part 202 of the drainage hood device is tightly fixed to the upper part of the drainage hood device through through holes.

[0038] Combined with Figure 6 , the self-circulation pressurization device 3 includes a vortex separator 301, a high-pressure submersible pump 302, a stainless steel ball valve 303, and a flange-to-thread adapter 304 connected in sequence for pumping and pressurizing seawater. The vortex separator 301 and the high-pressure submersible pump 302 are hermetically connected for filtering the pumped seawater. The other end of the high-pressure submersible pump 302 is provided with an outlet connected to the stainless steel ball valve 303. The other end of the stainless steel ball valve is connected to the flange-to-thread adapter 304. The flange-to-thread adapter cooperates with the water inlet passage.

[0039] Combined with Figure 7 , the laser generating device 6 includes a calibration lens 601 sealed in the upper end convex cover 101, an optical lens 602 arranged on the upper spray head 102, and a low-expansion alloy pressure ring 603. The optical lens 602 is fixed in the cavity inside the upper spray head through the low-expansion alloy pressure ring 603.

[0040] A deep-sea environment water-guided laser cutting method based on the above embodiments includes the following steps:

[0041] Step 1: Install the water-guided laser cutting nozzle at the end of the clamping device 5 and carry it to the vicinity of the deep-sea target by a cable-controlled remotely operated vehicle. Use the high-definition camera 403 and the laser rangefinder 404 of the cable-controlled remotely operated vehicle to determine the cutting path and adjust the nozzle to the initial working position to ensure that the opening of the drainage hood device 2 faces the target.

[0042] Step 2: Start the drainage hood device, inject gas into the air inlet passage 203, and discharge the seawater in the hood to form a local dry space.

[0043] Step 3: Open the vortex separator 301 at the water inlet passage 105 of the nozzle, pump external seawater and filter it; the seawater is pressurized by the high-pressure submersible pump 302 and then transported to the annular water storage cavity 104.

[0044] Step 4: Start the laser, and the laser beam is vertically incident on the center of the high-pressure water jet; use the calibration lens barrel 601 and the optical lens 603 in the cavity to make the laser beam and the water jet accurately coaxially coupled to form a stable water-guided laser beam flow.

[0045] Step Five: The clamping device 5 moves along a preset trajectory, and the water-guided laser beam acts on the metal surface to achieve continuous cutting.

[0046] Step Six: After the cutting work is completed, raise the clamping device 5, turn off the self-circulating pressurizing device 3, turn off the laser and then the high-pressure gas recovery device.

[0047] The above embodiments are merely examples for clearly illustrating the present invention, rather than limitations on the implementation manners. For those of ordinary skill in the art, other different forms of changes or modifications can be made based on the above description. It is not necessary and impossible to list all implementation manners here. And the obvious changes derived therefrom still fall within the protection scope of the present invention.

Claims

1. A deep sea environment water-guided laser cutting device, characterized in that: The invention comprises a nozzle device (1), a drainage cover device (2), a self-circulating pressurizing device (3), a conveying device (4), a clamping device (5) and a laser generating device (6); the nozzle device (1) comprises an upper nozzle (102) and a lower nozzle (103) which are coaxially connected, and an annular water storage chamber (104) and a water inlet channel (105) are formed inside; the drainage cover device (2) is coaxially sleeved on the outside of the nozzle device (1), and is provided with an air inlet channel (203) and an air exhaust channel (204); the self-circulating pressurizing device (3) comprises a vortex separator (301), a high-pressure submersible pump (302) and a ball valve (303), and is used for extracting and pressurizing seawater.

2. The deep sea environment water-conducting laser cutting device according to claim 1, characterized in that: The nozzle device (1) further comprises an upper convex cover (101), a high-pressure water inlet (106) and a water outlet (107); one end of the upper convex cover (101) is connected to the clamping device (5), and the other end is welded and fixed to the upper nozzle (102); the upper nozzle (102) and the lower nozzle (103) are tightly fixed together via circular through holes and bolts arranged along the circumference; an optical lens (602) is arranged inside the upper nozzle; the annular water storage chamber (104) is formed by the semicircular cavities inside the upper nozzle (102) and the lower nozzle (103); the upper nozzle (102) and the lower nozzle (103) each have a semicircular water inlet channel inside, and a complete water inlet channel (105) is formed by mutually enclosing each other.

3. The deep sea environment water-conducting laser cutting device according to claim 1, characterized in that: The air inlet channel (203) is six through holes arranged in a ring shape along the central axis of the drain cover device. The air inlet channel (203) is connected to the exhaust channel (204). The upper part (201) of the drain cover device is fixed to the upper end convex cover (101) by welding, and the lower part (202) of the drain cover device is tightly fixed to the upper part (201) of the drain cover device through the through holes.

4. The deep sea environment water-conducting laser cutting device according to claim 1, characterized in that: The self-circulating pressurizing device (3) further comprises a flange-to-thread adapter (304), the ball valve (303) is a stainless steel ball valve (303), the vortex separator (301), the high-pressure submersible pump (302), the ball valve (303) and the flange-to-thread adapter (304) are connected in sequence, wherein the vortex separator (301) and the high-pressure submersible pump (302) are sealedly connected to filter the extracted seawater, the other end of the high-pressure submersible pump (302) is provided with an outlet connected to the stainless steel ball valve (303), the other end of the ball valve (303) is connected to the flange-to-thread adapter (304), and the flange-to-thread adapter (304) cooperates with the water inlet channel.

5. The deep sea environment water-conducting laser cutting device according to claim 1, characterized in that: The transport device (4) comprises an upper hydraulically driven propeller (401), a lower hydraulically driven propeller (402) and a real-time monitoring component, wherein the real-time monitoring component comprises a high-definition camera (403) and a laser rangefinder (404) arranged at the front end.

6. The deep sea environment water-conducting laser cutting device according to claim 2, characterized in that: The clamping device (5) comprises a base (501) fixed to the front end of the conveying device (4), and the end thereof is connected to the upper end convex cover (101) of the nozzle device (1) through an adaptive clamp (502).

7. The deep sea environment water-conducting laser cutting device according to claim 2, characterized in that: The laser generating device (6) comprises a calibration lens barrel (601) sealed in an upper convex cover (101), an optical lens (602) and a low expansion alloy pressure ring (603) arranged on an upper nozzle (102), wherein the optical lens (602) is fixed in a cavity inside the upper nozzle via the low expansion alloy pressure ring (603), and the calibration lens barrel (601) is installed in the cavity inside the upper convex cover (101) via auxiliary positioning, and a hydrophobic coating is coated on the surface of the optical lens to reduce the formation of water mist.

8. A water-guided laser cutting method in a deep sea environment, characterized in that: Using the deep sea environment water-conducting laser cutting device as described in any one of claims 1 to 7 comprises the following steps: S1: Install the water-guided laser cutting nozzle at the end of the clamping device, and carry it to the vicinity of the deep-sea target through a cable remote-controlled submersible. Use the high-definition camera and laser rangefinder of the cable remote-controlled submersible to determine the cutting path and adjust the nozzle to the initial operating position, ensuring that the opening of the drainage cover device faces the target; S2: Start the drainage hood device, inject gas into the air inlet channel, and discharge the seawater in the hood to form a local dry space; S3: Open the vortex separator at the water inlet channel of the nozzle to extract external seawater and filter it; the seawater is pressurized by a high-pressure submersible pump and transported to the annular water storage chamber; S4: Start the laser, and the laser beam is incident vertically to the center of the high-pressure water jet; use the calibration lens barrel and the optical lens in the cavity to make the laser beam and the water jet precisely coaxially coupled to form a stable water-guided laser beam; S5: The clamping device moves along the preset trajectory, and the water-guided laser beam acts on the metal surface to achieve continuous cutting; S6: After the cutting work is completed, raise the clamping device, turn off the self-circulating pressurizing device, turn off the laser, and then turn off the high-pressure gas and recovery device.

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