Underwater jet trenching and cable laying operation system and method

Abstract

The present invention relates to the technical field of underwater operation, and in particular to an underwater jet trenching and cable laying operation system and method. An underwater traveling device is provided at the lower end of a main unit body; two jetting arms are located at the front end of the main unit body; a jetting and suction device is provided at the rear end of the main unit body and comprises suction pipes and second jetting pipes; the suction pipes are used for suctioning silt in an ocean trench through suction ports before a cable settles to the bottom of the ocean trench, and discharging the silt to the outside of the ocean trench through discharge ports; and the second jetting pipes spray horizontal jet flow to scour the inner side wall and the bottom of the ocean trench in the length direction of the ocean trench, so as to maintain the trench profile of the ocean trench during settling of the cable to the bottom of the ocean trench. The present invention is suitable for hyper-soft seabed conditions, and in the case where a cable can only settle naturally due to its large bending radius, it can be ensured that the cable is laid to a target depth to satisfy the operation requirements.

Description

An underwater jet trenching and cable laying operation system and operation method Technical Field

[0001] The present invention belongs to the technical field of underwater operations, and in particular relates to an underwater jet trenching and cable laying operation system and an operation method. Background Art

[0002] The current installation of underwater cables requires burying the cables under the seabed. The operation process is relatively complicated and requires the use of an underwater operating system to move along the direction of the cables pre-laid on the seabed, and to use the trenching device on board to open a trench on the seabed so that the cables sink to the bottom of the trench and ensure that the burial depth meets the requirements. For seabeds with sparse and soft soil, the trenching device is generally a jet trenching device, which uses a jet arm to spray a jet toward the seabed to create a trench. For cables with a large bending radius, such as cables with a large diameter and high surface hardness, the degree of bending is greatly limited. When laying them, they generally cannot use other auxiliary cable pressing devices, but need to rely on the natural sinking of the cables to the bottom of the trench to ensure that the cables are not crushed during laying. However, if the cables are laid naturally, since they are usually laid in the deep sea, they are subject to large underwater buoyancy and their natural settling speed is relatively slow. This is especially true for cables with large bending radius or deep trenches. The distance between the cables falling from the seabed and completely settling to the trench bottom is large. For seabeds with soft and sparse soil, the sediment on the seabed is easily backfilled by ocean currents, and the sides of the trench are prone to collapse and slide backfilling the trench bottom, resulting in the trench becoming shallower before the cables are completely settled to the trench bottom, causing the final buried depth of the cables to fail to meet the standards.

[0003] Summary of the Invention

[0004] The technical problem to be solved by the present invention is to provide an underwater jet trenching and cable laying operation system and operation method that can be applied to the soft seabed with sparse soil and where the cable has a large bending radius and can only settle naturally, ensuring that the cable is laid to the target depth.

[0005] The present invention provides an underwater jet trenching and cable laying system, comprising:

[0006] fuselage body;

[0007] An underwater walking device, the underwater walking device being arranged at the lower end of the fuselage body;

[0008] a jet-blasting earth-breaking device, the jet-blasting earth-breaking device comprising two jet-blasting arms, the two jet-blasting arms being located at the front end of the fuselage main body and each being provided with a front nozzle for ejecting a jet to open a trench on the seabed; a jet-blasting suction device, the jet-blasting suction device being provided at the rear end of the fuselage main body, the jet-blasting suction device comprising a suction pipeline and a jet-blasting pipe 2, the suction pipeline being provided with a discharge port and a suction port, the suction port being used to face the bottom of the trench, the discharge port being located higher than the suction port and being arranged transversely relative to the suction port, the suction pipeline being used to suck sediment in the trench through the suction port before the cable is sunk to the bottom of the trench, and to discharge the sediment to the outside of the trench through the discharge port;

[0009] The second jet flushing pipe is located at the rear side of the suction pipeline, and a jet flushing port is provided on the second jet flushing pipe. The jet flushing port is horizontally arranged in a direction away from the suction pipeline. The second jet flushing pipe is used to spray a horizontal jet through the jet flushing port to flush the inner wall and bottom of the trench along the length direction of the trench after the suction pipeline sucks the sediment in the trench, so as to maintain the trench shape when the cable sinks to the bottom of the trench.

[0010] Furthermore, the spraying and earth-breaking device also includes a deployment mechanism 1, which includes a fixed pipeline, a rotating pipeline, a drive mechanism 1 and a drive mechanism 2. The fixed pipeline is fixed to the fuselage body, the rotating pipeline is rotatably set on the fixed pipeline and is connected to the fixed pipeline, the drive mechanism 1 is used to drive the rotating pipeline to rotate around the fixed pipeline, the two spray arms are both rotatably set on the rotating pipeline and are connected to the rotating pipeline, and the drive mechanism 2 is used to drive the two spray arms to rotate around the rotating pipeline.

[0011] Furthermore, the spraying and earth-breaking device also includes a driving mechanism three, which can drive the two spraying arms to move along the axial direction of the rotating pipeline to adjust the distance between the two spraying arms.

[0012] Furthermore, there are two suction pipes, which are spaced apart along the width direction of the fuselage body, and the distance between the two suction pipes is adjustable. There are two spray pipes, which are spaced apart along the width direction of the fuselage body, and the distance between the two spray pipes is adjustable.

[0013] Furthermore, the jet-suction device further includes a second deployment mechanism, a support seat, and a first drive assembly. The second deployment mechanism is arranged at the rear end of the fuselage main body, the support seat is arranged at one end of the second deployment mechanism away from the fuselage main body, a single jet-suction pipe is fixedly connected to a single suction pipeline, and the single jet-suction pipe and the suction pipeline to which it is fixedly connected constitute a jet-suction assembly. The two jet-suction assemblies are both arranged on the support seat, and the two jet-suction assemblies are spaced apart. The cable can fall into the trench along the space between the two jet-suction assemblies.

[0014] Among the two spray-suction assemblies, at least one spray-suction assembly is slidably arranged on the support seat, and the driving assembly drives the sliding spray-suction assembly to move to adjust the distance between the two spray-suction assemblies.

[0015] Furthermore, a tail nozzle is provided at the bottom of each of the two spray arms, and the spraying direction of the tail nozzle is arranged away from the spraying direction of the front nozzle.

[0016] Furthermore, the deployment heights of the two spray arms and the two spray suction assemblies are adjustable.

[0017] Furthermore, the suction pipeline is provided with a water inlet 1 at one end and a horizontal arrangement at the other end, and the discharge port is located at one end of the horizontal arrangement. A pipe diameter contraction section is provided on the suction pipeline between the water inlet 1 and the discharge port, and an extension pipe is provided on the side of the pipe diameter contraction section extending longitudinally, and the suction port is located on the extension pipe. An end cover is provided on the suction pipeline at the position of the discharge port, and the degree of opening and closing between the end cover and the discharge port is adjustable.

[0018] Furthermore, it also includes a front spray mechanism, which is arranged at the front end of the fuselage body and in front of the two spray arms. The front spray mechanism is provided with a front nozzle to blow and / or pre-ditch the seabed before the two spray arms operate.

[0019] The present invention further provides an underwater jet trenching and cable laying method, using the underwater jet trenching and cable laying system described above. The method comprises the following steps:

[0020] S1. Lower the underwater jet trenching and cable burying operation system to the seabed where the trenching and cable burying are to be carried out, and make the projections of the two jet arms on the seabed be located on both sides of the cable;

[0021] S2. The underwater jet trenching and cable burying system uses an underwater walking device to move along the length of the cable on the seabed, and sprays jets through the front nozzles on the two spray arms to spray and break the seabed along the length of the cable to create a trench;

[0022] S3. When the cable falls into the trench, the suction port of the suction pipeline sucks the sediment in the trench, and discharges the sediment to the outside of the trench through the discharge port. The horizontal jet is ejected from the flushing port along the length of the trench to flush the inner wall and bottom of the trench, continuously liquefying the soil in the trench and maintaining the trench shape. The cable naturally sinks to the bottom of the trench.

[0023] The present invention has the beneficial effect of accommodating the natural settlement of cables with large bending radii, where the distance from the seabed to their complete ditch bottom is long, by positioning the jet-and-suction device on the rear exterior of the main body, with a large distance between it and the two jet-and-suction arms. This adapts to the natural settlement of the cable. The underwater walking device drives the entire operating system along the length of the cable on the seabed, while the two jet-and-suction arms spray water to break the seabed and create a trench. Due to the high softness of the soil, the trench is prone to collapse in a short period of time after the ground is broken and the trench is opened. By installing a jet suction device at the rear end of the fuselage, after the trench is opened and before the cable is lowered to the bottom of the trench, the natural return flow and the sediment deposited at the bottom of the trench due to the collapse of the two sides of the trench are extracted through the suction pipeline, and the extracted sediment is discharged to the outside of the trench to ensure the depth of the trench. After the suction pipeline, the cable is continuously connected, and the jet pipe is used to continuously generate a horizontal jet in the trench along the length of the trench, flushing the inner wall and bottom of the trench, continuously liquefying the soil, and maintaining the trench shape when the cable sinks to the bottom of the trench, ensuring the depth of the trench and ensuring that the laying depth meets the operation requirements, improving the safety and stability of the cable after it is buried on the seabed.

[0024] On the one hand, the present invention can discharge the sediment deposited on the bottom of the trench to the outside of the trench on both sides after the jet blasting device digs the trench and before the cable completely falls to the bottom of the trench, and use two jet ports to continuously maintain the trench shape, ensuring that the naturally settled cable can fall to the bottom of the trench. On the other hand, since the suctioned and discharged sediment is discharged to the outside of the trench and is subsequently backfilled into the trench for a second time under the action of ocean currents, for large-diameter cables and deep trenches, it is beneficial to use the natural ocean currents to bury the cables after they sink to the bottom of the trench, ensuring that the cables will not be exposed, thereby improving the reliability of underwater cable burying operations. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] FIG1 is a schematic structural diagram of the underwater jet trenching and cable burying system of the present invention in a first operating posture.

[0026] FIG2 is a schematic structural diagram of the underwater jet trenching and cable burying system of the present invention in a second operating posture.

[0027] FIG3 is a schematic structural diagram of the underwater walking device of the present invention.

[0028] FIG4 is a schematic structural diagram of a rotatable propeller in the underwater walking device of the present invention.

[0029] FIG5 is a schematic structural diagram of a first arrangement of the crawler mechanism in the underwater walking device of the present invention.

[0030] FIG6 is a schematic structural diagram of a second arrangement of the crawler mechanism in the underwater walking device of the present invention.

[0031] FIG7 is a schematic diagram of the downward tilting posture of the crawler module in the underwater walking device of the present invention.

[0032] FIG8 is a schematic structural diagram of the soil-breaking device of the present invention.

[0033] FIG9 is a schematic diagram of the first lowering posture of the soil-breaking device of the present invention.

[0034] FIG10 is a left side view of the spray pattern 9 of the present invention.

[0035] FIG11 is a schematic diagram showing the embodiment of the present invention in which the distance between the two spray arms in spray diagram 9 is increased.

[0036] FIG12 is a schematic diagram of the second lowering posture of the soil-breaking device of the present invention.

[0037] FIG13 is a schematic diagram of the recovery posture of the soil-breaking device of the present invention.

[0038] FIG14 is a schematic structural diagram of the front jet mechanism of the present invention.

[0039] FIG15 is a schematic structural diagram of the spray-sucking device of the present invention from a first perspective.

[0040] FIG16 is a schematic structural diagram of the spray-suction device of the present invention from a second viewing angle.

[0041] FIG17 is a schematic diagram of the recovery posture of the spray-suction device of the present invention.

[0042] FIG18 is a schematic diagram of the lowering posture of the spray-sucking and suction device of the present invention.

[0043] FIG19 is a schematic diagram of the left-swing posture of the spray-suction device of the present invention.

[0044] In the figure: 1. fuselage body; 2. underwater walking device; 21. skid shoe; 22. crawler mechanism; 221. crawler module; 23. drive module 1; 24. connecting rod; 25. vertical thruster; 26. horizontal thruster; 27. rotatable thruster; 271. connecting rod; 272. thruster body; 28. drive module 2; 3. jetting device; 31. fixed pipeline; 32. rotating pipeline; 321. elbow; 322. mounting rod; 33. drive mechanism 1; 34. jet arm; 341. jet pipe 1; 3411. front nozzle; 3412. inner nozzle; 3413. tail nozzle; 35. guide piece; 351. guide plug; 3 52. Connecting sleeve; 36. Driving mechanism 2; 37. Driving mechanism 3; 38. Water pump mechanism; 4. Spraying and suction device; 41. Support seat; 42. Suction pipeline; 421. Water inlet 1; 422. Discharge port; 423. Suction port; 424. End cover; 43. Spray pipe 2; 431. Water inlet 2; 432. Spray port; 44. Driving component 1; 45. Driving component 2; 46. Fixed frame; 461. Hinge part; 47. Moving frame; 48. Driving component 3; 49. Driving component 4; 5. Front spray mechanism; 51. Support pipe; 52. Front nozzle; 51. Front nozzle; 53. Driving mechanism 5; 100. Cable. DETAILED DESCRIPTION

[0045] As shown in Figures 1-19, the present invention provides an underwater jet trenching and cable laying system, which includes a main body 1, an underwater traveling device 2, a jetting and earth-breaking device 3, and a jetting and suctioning device and a cable-breaking device 4. The underwater traveling device 2 is disposed at the lower end of the main body 1 and is used to drive the underwater jet trenching and cable-laying system to move on the seabed. The jetting and earth-breaking device 3 includes a deployment mechanism 1 and two jetting arms 34. The deployment mechanism 1 is disposed on the main body 1. The two jetting arms 34 are disposed on the deployment mechanism 1 and are located at the front end of the main body 1. Each of the two jetting arms 34 is provided with a front nozzle 3411 for spraying a jet to create a trench on the seabed.

[0046] The jet suction device 4 is arranged at the rear end of the fuselage body 1, and the jet suction device 4 includes a suction pipeline 42 and a jet pipe 43. The suction pipeline 42 is provided with a discharge port 422 and a suction port 423. The suction port 423 is used to face the bottom of the trench. The position of the discharge port 422 is higher than the suction port 423 and is arranged horizontally relative to the suction port 423. During the trenching and cable laying operation, the suction pipeline 42 operates after the jet arm and is used to suck the mud and sand in the trench through the suction port 423 before the cable sinks to the bottom of the trench, and discharge the mud and sand to the outside of the trench through the discharge port 422 to ensure that the depth of the trench meets the laying requirements. Specifically, the height difference between the discharge port 422 and the suction port 423 is greater than the required trench depth, so that after the end of the suction pipe provided with the suction port 423 is extended into the trench, the discharge port 422 is on the upper side of the trench. When the suction port 423 sucks the mud at the bottom of the trench, the mud is discharged on the upper side of the trench to ensure that the mud in the trench is effectively pumped out.

[0047] The second jet pipe 43 is located at the rear side of the suction pipeline 42, and a jet port 432 is provided on the second jet pipe 43. The jet direction of the jet port 432 is horizontally arranged in the direction away from the suction pipeline 42. When in use, the second jet pipe 43 with one end of the jet port 432 extends into the trench. As the fuselage body 1 moves during trenching, the jet port 432 can spray a horizontal jet toward the rear side of the fuselage body 1 along the length direction of the trench, so that after the second jet pipe 43 is used to suck the mud and sand in the trench through the suction pipeline 42, the horizontal jet is sprayed along the length direction of the trench to flush the inner wall and bottom of the trench, continuously liquefy the soil, maintain the trench shape when the cable sinks to the bottom of the trench, and ensure that the settlement depth of the cable meets the operation requirements when the cable falls to the bottom of the trench. As shown in Figures 1 and 2, for cables 100 with large bend radii, the distance from the seabed to their complete sinking to the trench bottom is long. By positioning the two jet-and-suction assemblies on the rear and exterior sides of the main body 1, with a greater distance between them and the two jet-and-suction arms 34, the natural sinking amplitude of the cable 100 is accommodated. The underwater traveling device 2 drives the entire operating system along the length of the cable 100 on the seabed. The two jet-and-suction arms 34 spray water to break the soil and create a trench. This makes it more suitable for seabeds with softer soil than mechanical cutting devices. Due to the high softness of the soil, the trench is prone to collapse in a short time after the ground is broken and the trench is opened. By arranging a jet suction device 4 at the rear end of the fuselage body 1, after the trench is opened and before the cable sinks to the bottom of the trench, the natural backflow and the sediment deposited at the bottom of the trench due to the collapse of the two sides of the trench are extracted through the suction pipe 42, and the extracted sediment is discharged to the outside of the trench to ensure the depth of the trench. After the suction pipe 42, the cable is continuous, and the jet pipe 43 is used to continuously generate horizontal jets in the trench along the length of the trench to flush the inner wall and bottom of the trench, continuously liquefy the soil, maintain the trench shape when the cable sinks to the bottom of the trench, ensure the depth of the trench, ensure that the laying depth meets the operation requirements, and improve the safety and stability of the cable after it is buried on the seabed. On the one hand, the present invention can discharge the sediment deposited on the bottom of the trench to the outside of the trench on both sides after the jetting device 3 opens the trench and before the cable completely falls to the bottom of the trench, and use the two jet ports 432 to continuously maintain the trench shape, ensuring that the naturally settled cable 100 can fall to the bottom of the trench. On the other hand, since the suction-discharged sediment is discharged to the outside of the trench on both sides and is subsequently backfilled into the trench for a second time under the action of ocean currents, for large-diameter cables 100 and deep trenches, the cable 100 can be buried by the flushing of natural ocean currents after it sinks to the bottom of the trench, ensuring that the cable 100 will not be exposed, thereby improving the reliability of underwater cable burial operations.

[0048] The underwater walking device includes a walking mechanism and a propulsion mechanism. The propulsion mechanism is mounted on the main body 1 and is used to generate thrust to assist in the movement and posture adjustment of the underwater walking device. Two walking mechanisms are provided, one on each side of the main body 1, and the other on the other side. The walking mechanisms are connected to the main body 1. In one embodiment of the present invention, as shown in Figure 3, the walking mechanism is a sliding shoe 21, which is fixedly connected to the main body 1. The thrust generated by the propulsion mechanism enables the operating system to glide on the seabed. Compared to a track mechanism, the sliding shoe 21 has a simpler structure and is lighter in weight, reducing the overall underwater weight of the operating system and making it suitable for operation on soft soil prone to collapse.

[0049] In another embodiment of the present invention, as shown in Figures 5-7, the traveling mechanism is a crawler mechanism 22, which is hingedly connected to the fuselage body 1. Both crawler mechanisms 22 have a travel range that allows them to tilt relative to the fuselage body 1, that is, the posture of the two crawler mechanisms 22 on the fuselage body 1 is adjustable. Drive mechanisms are provided on both sides of the fuselage body 1, respectively, for driving the crawler mechanisms 22 located on both sides of the fuselage body 1 to move, thereby adjusting the posture of the crawler mechanisms 22, thereby adjusting the inclination of the crawler mechanisms 22 relative to the fuselage body 1 and adjusting the angle between the bottoms of the two crawler mechanisms 22.

[0050] The underwater walking device provided by the present invention, in an embodiment based on the track mechanism 22, can adjust the inclination of the track mechanism 22 relative to the fuselage main body 1 and the angle between the bottoms of the two track mechanisms 22 by adjusting the posture of the track mechanism 22, so that the bottom surfaces of the two track mechanisms 22 are on the same horizontal plane, which is suitable for walking on a flat seabed, or the bottom surfaces of the two track mechanisms 22 form an upward or downward angle, which is suitable for a seabed with a ridge-like protrusion or a seabed with a groove-like downward depression, thereby improving the gripping ability of the track mechanism 22 under such seabed terrain and improving the underwater walking performance. The propulsion mechanism can adjust the posture of the device and provide auxiliary thrust for the device. Combined with the thrust of the track mechanism 22 itself when working, the thrust requirement for walking on a seabed with soft mud is met, slipping is avoided, and the underwater walking performance is further improved, the walking requirements and reliability of different underwater terrains are met, the flexibility of underwater operations is improved, and the range of operable scenarios is broadened. As shown in FIG7 , the two crawler mechanisms 22 are in a state where the postures of the two crawler mechanisms 22 are adjusted to adapt to a groove-shaped, downwardly concave seabed. When used to adapt to a ridge-shaped, convex seabed, the two crawler mechanisms 22 are tilted downward.

[0051] In one configuration of the present invention, as shown in FIG5 , a single crawler mechanism 22 is a crawler traveling mechanism, that is, only one crawler traveling mechanism is provided on one side of the fuselage body 1 .

[0052] In a preferred embodiment of the present invention, as shown in Figures 6 and 7 , a single crawler mechanism 22 comprises two crawler modules 221, both of which are hingedly connected to the main body 1 and have a travel range that tilts relative to the main body 21. A single crawler module 221 constitutes a crawler travel mechanism, meaning that two crawler travel mechanisms are provided on one side of the main body 21. The specific structural principles of the crawler travel mechanisms are the same as those in the prior art and are not further described here. A single drive mechanism comprises two drive modules 1 23, each of which is used to drive the two crawler modules 221 to rotate about their hinges with the main body 1. In this embodiment, a total of four crawler modules 221 are provided on both sides of the main body 1, each driven and adjusted in position by a corresponding drive module 1 23. Therefore, the four crawler modules 221 can have different tilt angles on a rugged seabed, improving grip and facilitating navigation on a seabed with coarse rock.

[0053] The track module 221 is connected to the fuselage main body 1 via a connecting rod 24. It cooperates with the drive module 1 23 to adjust the track module 221's posture. Compared to a rotational drive module that directly drives the track module 221 for rotation, the use of a connecting rod structure improves load-bearing capacity and reduces the strength requirements of the drive module 1 23. Specifically, a single track module 221 is connected to the fuselage main body 1 via two connecting rods 24. One end of each connecting rod 24 is hinged to the fuselage main body 1, and the other end is hinged to the track module 221, forming a quadrilateral structure. The presence of two connecting rods 24 in a single track module 221 improves structural strength and distributes load. Given the same load-bearing capacity, a single connecting rod 24 experiences less load, requiring less strength and size. The drive module 1 23 is a linear drive module, such as a cylinder or other linear output drive module. The cylinder's cylinder end is hinged to the fuselage main body 21, and its piston end is hinged to one of the connecting rods.

[0054] The propulsion mechanism includes vertical thrusters 25 and horizontal thrusters 26, both of which are mounted on the main fuselage 1. As shown in Figure 3, the vertical thrusters 25 are arranged vertically along the main fuselage 1 and are used to generate vertical thrust to assist the ascent and descent of the operating system. The horizontal thrusters 26 are arranged horizontally along the main fuselage 1 and are used to generate horizontal thrust in the fore-aft and lateral directions of the operating system, providing auxiliary thrust for forward and backward and lateral movement of the operating system and improving the flexibility of underwater operations.

[0055] The propulsion mechanism also includes a rotatable propeller 27, which is arranged on the main body 1 and has a movable stroke that can be tilted relative to the main body 1 to adjust the inclination of the rotatable propeller 27, thereby adjusting the thrust direction. For example, when the original thrust of the operating system is insufficient to meet the walking action in a seabed with fine mud or complex terrain, additional horizontal or vertical thrust can be generated on top of the thrust of the original vertical propeller 25 or horizontal propeller 26 to increase the horizontal or vertical thrust, thereby achieving the walking action of the operating system. This arrangement, because the thrust direction of the rotatable propeller 27 is adjustable, a single rotatable propeller 27 can be used to increase the vertical thrust of the operating system or to increase the horizontal thrust of the device, which provides high flexibility in use. When the thruster power is the same and the vertical maximum thrust and horizontal maximum thrust of the operating system are the same, the total number of propellers can be reduced. The present invention also includes a second drive module 28. The rotatable propeller 27 includes a connecting rod 271 and a propeller body 272 fixed to the connecting rod 271. The propeller body 272 moves and rotates with the connecting rod 271. The connecting rod 271 is hingedly mounted on the fuselage body 1 and has a rotational travel on the fuselage body 1. The second drive module 28 is used to drive the connecting rod 271 to rotate to adjust the inclination of the rotatable propeller 27 relative to the fuselage body 1, thereby adjusting the inclination of the rotatable propeller 28. Specifically, the second drive module 28 is a cylinder or other linear output drive module. The cylinder end of the cylinder is hinged to the fuselage body 21, and the piston end is hinged to the side of the connecting rod 271. When the piston end of the cylinder is extended, it pushes the connecting rod 271 to rotate. The structural principles of the above-mentioned vertical propeller, horizontal propeller, and propeller body are the same as those of conventional propellers and will not be repeated here.

[0056] The present invention is also provided with a cable-finding module, which is arranged on the fuselage body 1 and is located at the front end of the operating system, and has two sets of installation interfaces at different heights. There are two-stage oil cylinders on the frame of the cable-finding module. The first-stage oil cylinder drives the frame of the cable-finding module to rotate, and the second-stage oil cylinder changes the height of the cable-finding module, and finally realizes four laying heights of the cable-finding module to adapt to different geological conditions and the detection of cables of different diameters. The cable-finding module is specifically a sensor that utilizes electromagnetic induction cables. It is electrically connected to the control system of the operating system, and is used to sense the position of the cable and transmit the position information to the control system of the operating system. After judgment and calculation, the control system automatically controls the propulsion mechanism and the walking mechanism, and adjusts the overall direction and speed of the operating system, so that the operating system can automatically follow the length direction of the cable to dig trenches and lay cables, reducing the operator's active intervention and making the trenching and laying process more intelligent. Among them, the laying described in this article is to lower the target mechanism to a working posture.

[0057] The first deployment mechanism includes a fixed pipeline 31, a rotating pipeline 32, a first drive mechanism 33, and a second spray drive mechanism 36. The fixed pipeline 31 is mounted on the main body of the fuselage. The rotating pipeline 32 is rotatably mounted on the fixed pipeline 31 and is in communication with the fixed pipeline 31. Specifically, the rotating pipeline 32 has a radial rotational travel on the fixed pipeline 31, and after rotation, the rotating pipeline 32 maintains communication with the fixed pipeline 31. The first drive mechanism 33 is used to drive the rotating pipeline 32 to rotate about the fixed pipeline 31. The driving mechanism 33 is a cylinder with a piston end hinged to the rotating pipeline 32 and a cylinder end hinged to the main body of the fuselage, forming a similar connecting rod structure. This allows the rotating pipeline 32 to rotate while improving its load-bearing capacity. A guide member 35 is fixedly provided on the water inlet end of each of the two spray arms 34, and each spray arm 34 is connected to its corresponding guide member 35. The two guide members 35 are both rotatably mounted on the rotating pipe 32 and are connected to the rotating pipe 32. That is, the two guide members 35 have a radial rotation stroke on the rotating pipe 32. After rotation, the two guide members 35 remain connected to the rotating pipe 32, thereby maintaining the two spray arms 34 in communication with the rotating pipe 32. The second driving mechanism 36 is used to drive the two spray arms 34 and the two guide members 35 to rotate around the rotating pipe 32. The number of the second driving mechanisms 36 corresponds to the number of the guide members 35, that is, there are two. The second driving mechanism 36 is an oil cylinder, the piston end of the oil cylinder is hinged to the guide member 35, and the cylinder end is hinged to the main body of the machine body, forming a similar connecting rod structure, which enables the two guide members 35 and the two spray arms 34 to rotate while having better load-bearing capacity.

[0058] The present invention provides a spraying and earth-breaking device in which the fixed pipeline 31 and the rotating pipeline 32 serve as both the water supply pipelines for the two spraying arms 34 and the mounting and supporting structure for the two spraying arms 34. This allows for the installation of the two spraying arms 34 without the need for additional pipelines that meet the required lowering depth to connect the two spraying arms 34 with the water pump mechanism. This ensures that the spraying arms 34 remain connected to the water pump mechanism even when they are lowered to different depths, simplifying the overall structure, reducing the overall volume, and minimizing space occupancy. Compared to conventional pipelines, the fixed pipeline 31 and the rotating pipeline 32 serve as the mounting and supporting structure for the two spraying arms 34, resulting in greater strength and hardness. When used as water supply pipelines, they are less susceptible to leakage due to impact with underwater organisms or rocks, resulting in higher reliability. The two-stage drive structure is formed by driving mechanism 1 33 and driving mechanism 2 36, which can not only realize the lowering and recovery of the two spray arms 34, but also when driving mechanism 1 33 drives the rotating pipeline 32 to flip to realize the lowering of the two spray arms 34, driving mechanism 2 36 can synchronously drive the two spray arms 34 to rotate to adjust the posture. When the two spray arms 34 are lowered deeper or shallower, the angle of the front nozzle relative to the vertical can be maintained in the optimal spray angle range, ensuring that the injection angle of the water jet is the optimal angle for spraying and breaking the soil, so that the present invention can be applied to trenching operations at different depths, while ensuring the quality and efficiency of trenching, and has high flexibility in underwater operations.

[0059] As shown in Figure 9, this is the posture of the two spray arms 34 after being fully lowered, that is, the posture when lowered to the lowest position, which can be used for trenching operations in deeper trenches; as shown in Figure 10, this is the posture of the two spray arms 34 when lowered to a shallower depth, which can be used for trenching operations in shallower trenches; in these two postures, the direction of the front nozzle and the angle relative to the vertical are consistent.

[0060] In one embodiment of the present invention, the fixed conduit 31 and the rotating conduit 32 can be connected via a flexible conduit, ensuring connectivity while ensuring the rotational travel of the rotating conduit 32. The rotating conduit 32 is connected to the two flow guides 35 via a flexible conduit, ensuring connectivity while ensuring the movement travel of the two flow guides 35.

[0061] In a preferred embodiment of the present invention, a radial dynamic seal is provided at the rotational engagement between the rotating conduit 32 and the fixed conduit 31, enabling direct communication between the rotating conduit 32 and the fixed conduit 31 while ensuring the required rotational travel. The two flow guides 35 are also provided with radial dynamic seals at their rotational engagement with the rotating conduit 32, enabling direct communication between the two flow guides 35 and the rotating conduit 32 while ensuring the required rotational travel. This embodiment eliminates the need for additional flexible piping, reducing piping complexity and the risk of damage and leakage at the connection points.

[0062] Two sets of fixed pipelines 31 are provided, each connected to a water pump mechanism 38. In other words, the two sets of fixed pipelines 31 are supplied with water through their corresponding water pump mechanisms 38. The rotating pipeline 32 is U-shaped, as shown in FIG8 . Each end of the rotating pipeline 32 is provided with an elbow 321. Both sets of fixed pipelines 31 are transversely bent. The elbows 321 at both ends of the rotating pipeline 32 are rotatably connected to the transverse portions of the two sets of fixed pipelines 31 and radially dynamically sealed to provide direct communication. While ensuring connectivity, the rotating pipeline 32 as a whole can rotate around the two sets of fixed pipelines 31 under the action of the first drive mechanism 33. Furthermore, the two sets of fixed pipelines 31 are connected via a branch pipe, and / or the ends of the rotating pipeline 32 are connected via a branch pipe. If one set of water pump mechanisms 38 malfunctions or fails, the remaining set of water pump mechanisms 38 can maintain water supply to the two spray arms 34, maintaining operation and avoiding interruption. Among them, a connecting sleeve 352 is fixedly provided on the upper end of the guide member 35. As shown in Figure 8, the connecting sleeves 352 of the two guide members 35 are both sleeved on the rotating pipeline 32, that is, the guide member 35 is connected to the rotating pipeline 32 through the connecting sleeve 352. In the embodiment where the guide member 35 and the rotating pipeline 32 are dynamically sealed, the guide member 35 is communicated with the guide sleeve 352. Specifically, the guide sleeve 352 and the rotating pipeline 32 are dynamically sealed on the guide member 35, and a water hole is provided on the side wall of the rotating pipeline 32 at the overlap with the connecting sleeve 352. The water flow in the rotating pipeline 32 enters the guide member 35 along the connecting sleeve 352 through the water hole, and flows into the spray arm 34 from the guide member 35 along the water inlet end of the spray arm 34.

[0063] There are several front nozzles 3411 on a single spray arm 34, and the several front nozzles 3411 are arranged along the height direction of the spray arm 34. Specifically, the single spray arm 34 includes an array of spray pipes 341, and the lengths of the arrays of spray pipes 341 are different. The arrays of spray pipes 341 are arranged in parallel in order of length, that is, they are arranged in parallel from short to long, and the arrays of spray pipes 341 are all connected to the guide member 35, and the arrays of spray pipes 341 are all provided with front nozzles 341. As shown in Figures 12 and 13, among the array of spray tubes 341, the front nozzle 341 of the shortest spray tube 341 is arranged on the side of the spray tube 341 away from the remaining spray tubes 341, and the front nozzles 3411 of the remaining spray tubes 341 are arranged in an area longer than the adjacent spray tubes 341, and the front nozzles 3411 on all the spray tubes 341 are arranged in the same direction. As shown in Figures 10 and 11, when the spray arm 34 is viewed from above, the front nozzles 341 on the array of spray tubes 341 are arranged along the height direction of the spray arm 34.

[0064] The flow guide 35 is provided with a flow guide plug 351, which is used to block or open a portion of the spray pipes 341 on the shorter side of the plurality of spray pipes 341. Since the plurality of spray pipes 341 are arranged in parallel in length, the shorter side is specifically the side where the shortest spray pipe 341 in the spray arm 34 is located. The number of spray pipes 341 in a single spray arm 34 that can be blocked or opened by the flow guide plug 351 is less than the total number of spray pipes 341 in the spray arm 34. When there are at least two groups of spray pipes 341 that can be blocked or opened by the flow guide plug 351, the at least two groups are counted sequentially along the length direction starting from the shortest spray pipe 341. When the trench to be opened is deep, the depth of the jet arm 34 submerged in the seabed is deep. As shown in Figure 1, all jet pipes 341 are submerged in the seabed, and all front nozzles 3411 are basically not higher than the seabed, that is, all front nozzles 3411 participate in the seabed breaking and trenching operation. When the trench to be opened is shallow, as shown in Figure 2, the depth of the jet arm 34 submerged in the seabed is shallow. At this time, some front nozzles 3411 will be significantly higher than the seabed and will not participate in the seabed breaking and trenching operation. The jet pipe 341 where the front nozzle 3411 is located is blocked by the diversion plug 351, so that the jet pipe 341 located above the seabed has no water jet spraying, and all water flow is directed to the jet pipe 341 located inside the seabed, thereby improving the efficiency of water jet utilization and trenching efficiency. Among them, the position of the guide plug 351 on the guide member 35 is above the spray pipe 341. The guide plug 351 specifically includes a driving mechanism four and a plug body. The driving mechanism four is preferably an oil cylinder, and its cylinder end is fixedly set on the guide member 35. The plug body is set on the piston end of the oil cylinder, and the plug body is passed through the inside of the guide member 35 and is dynamically sealed with the guide member 35. The plug body is driven by the oil cylinder to move toward the spray pipe 341 and inserted into the spray pipe 341 to achieve sealing, and the plug body is driven by the oil cylinder to move away from the spray pipe 341 to achieve opening.

[0065] The present invention also includes a third drive mechanism 37, which drives the flow guide 35 to move axially along the rotating pipeline 32 to adjust the spacing between the two spray arms 34 to accommodate trenches of varying widths. The axial travel of the flow guide 35 within the rotating pipeline 32 corresponds to the axial travel of the connecting sleeve 352 within the rotating pipeline 32. In embodiments of the present invention based on dynamic sealing, the dynamic seal between the connecting sleeve 352 and the rotating pipeline 32 on the flow guide 35 also includes an axial dynamic seal, meaning that the flow guide 35 also has an axial travel within the rotating pipeline 32. When the connecting sleeve 352 moves axially within the rotating pipeline 32, the water passage remains within the overlap between the connecting sleeve 352 and the rotating pipeline 32. In embodiments of the present invention based on flexible pipe connections, the length of the flexible pipe only needs to meet the travel of the flow guide 35. This ensures that after the spacing between the two spray arms 34 is adjusted, the two spray arms 34 remain connected to the rotating pipeline 32 via the flow guide 35. The third drive mechanism 37 is a hydraulic cylinder connected between the two guide members 35 to drive the synchronous movement of the two guide members 35. Alternatively, two hydraulic cylinders may be provided. A mounting rod 322 is fixedly mounted on the rotating pipeline 32. The cylinder ends of the two hydraulic cylinders are fixed to the mounting rod 322, and the piston ends are connected to the two guide members 35 respectively.

[0066] Each of the spray pipes 1 (341) in the array of two spray arms 34 is provided with an inner nozzle 3412. The inner nozzle 3412 of the shortest spray pipe 1 (341) in the array is located on the inner side of that spray pipe 1 (341). The front nozzles 3411 on the remaining spray pipes 1 (341) are located on the inner side of an area longer than the adjacent spray pipe 1 (341). Furthermore, the inner nozzles 3412 in the two spray arms 34 are positioned opposite each other. When the desired trench width is wide, the spacing between the two spray arms 34 is large, and the soil in the middle of the trench may not be liquefied. The inner nozzles 3412 can form opposing water jets within the trench along the trench width, liquefying the soil between the two spray arms 34. This facilitates the creation of a wide trench for a large-diameter cable 100 and ensures the proper trench shape, further enhancing operational flexibility.

[0067] The bottom of each spray arm 34 is provided with a tail nozzle 3413. The spray direction of the tail nozzle 3413 is set to be opposite to the spray direction of the front nozzle 3411. That is, the water jet from the tail nozzle 3413 is in the opposite direction from the water jet from the front nozzle 3411, and the water jet from the tail nozzle 3413 is parallel to the bottom of the trench. The installation of the tail nozzle 3413 can use the high-pressure water flow within the spray arm 34 to generate a horizontal jet in the trench in the opposite direction of the front nozzle 3411 after the trench is opened by the front nozzle 3411. This continuously liquefies the soil in the rear trench, maintains the trench shape, reduces the backfill of sediment before the two spray and suction assemblies operate, and reduces the suction workload and water pressure requirements of the two spray and suction assemblies. Especially when the seabed is soft and the cable has a large bending radius, resulting in a large distance between the two jet and suction assemblies and the two jet arms 34, the tail nozzle 3413 can cooperate with the two jet and suction assemblies to better ensure the trench shape and depth before the cables are completely settled. Tail nozzle 3413 is preferably placed at the bottom of jet pipe 341, the longest of the jet arms 34. This allows tail nozzle 3413 to remain at the bottom of the trench regardless of the trench depth.

[0068] As shown in Figure 14, the present invention also includes a pre-spray mechanism 5, which is mounted on the main body 1 and located between the two spray arms 4. The pre-spray mechanism 5 serves as a pre-spray mechanism before the spray arms 34 break through the soil. On the one hand, it can be used to clear mud, debris, and marine organisms from the seabed and cables. On the other hand, it can create a shallow trench on the seabed surface before the spray arms 34, forming a pre-ditch. This reduces the difficulty of the spray arms 34 breaking through the soil and ditching during turns, facilitating trenching and cable burial operations. The pre-spray mechanism 5 includes a support tube 51, a pre-spray nozzle 52, and a drive mechanism 53. The support tube 51 is connected to an external water supply unit. The pre-spray nozzle 52 is rotatably mounted at the lower end of the support tube 51 and is dynamically sealed. A pre-spray nozzle 521 is provided at the lower end of the pre-spray nozzle 52 for spraying a water jet. The drive mechanism 53 is specifically a cylinder, which is hingedly mounted between the support tube 51 and the pre-spray nozzle 52. Specifically, as shown in Figure 14, two front nozzles 52 are provided. Both front nozzles 52 are bent and one end facing away from the front nozzle 521 is rotatably connected to the lower end of the support tube 51 and dynamically sealed. The two front nozzles 52 together form a U-shaped nozzle structure, and the two front nozzles 52 are fixedly connected by a rod body. The oil cylinder is specifically hinged between the support tube 51 and the rod body.

[0069] As shown in Figures 15-19, the jet-sucking and suction device 4 also includes a second deployment mechanism, a support base 41, and a first drive assembly 44. The second deployment mechanism is arranged at the rear end of the fuselage body 1, and the support base 41 is arranged at the end of the second deployment mechanism facing away from the fuselage body 1. A single second jet pipe 43 is fixedly connected to a single suction pipe 42. Two jet-sucking and suction assemblies are arranged at the end of the second deployment mechanism facing away from the fuselage body 1 through the support base 41. The two jet-sucking and suction assemblies are spaced apart to allow cables to pass through. In the working state, the cables can fall into the trench along the space between the two jet-sucking and suction assemblies. This arrangement can pump out sediment and continuously liquefy the soil inside the trench without affecting the normal settlement of the cables. The lower end of the second jet pipe 43 is arranged in parallel with the lower end of the suction pipe 42, and a jet port 432 is provided on the side of the second jet pipe 43. The jet port 432 is specifically located on the side of the second jet pipe 43 away from the two jet arms. The jet direction of the jet port 432 is perpendicular to the suction direction of the suction port 423. When the jet suction device 4 is in operation, the two jet suction components are used simultaneously. The suction port 423 and the jet port 432 are both located in the trench. The suction port 423 is arranged toward the bottom surface of the trench, and the jet direction of the jet port 432 is arranged along the length direction of the trench, that is, the jet direction is toward the right side of Figures 1 and 2. When the jet port 432 is located in the trench, the jet port 432 ejects a horizontal jet along the length direction of the trench in a direction away from the two jet arms.

[0070] When the cable bend radius is large or the trench is deep, deployment mechanism 2 is preferably extended away from the main body 1 to increase the distance between the two jet-suction assemblies and the two jet arms, thereby slowing the cable's movement from the seabed to the trench bottom. At least one of the two jet-suction assemblies is slidably mounted on support base 41, and drive assembly 1 44 drives the sliding jet-suction assembly to adjust the distance between the two assemblies to accommodate trenches of varying widths.

[0071] A pipe diameter contraction section is provided on the suction pipeline 42 between the water inlet 421 and the suction port 423, and the suction port 423 is connected to the side of the pipe diameter contraction section. Specifically, the suction pipeline 42 is provided with a contraction setting in the middle position between the water inlet 421 and the suction port 423 to form the above-mentioned pipe diameter contraction section, and an extension pipe is longitudinally connected to the side of the pipe diameter contraction section to form the lower end of the suction pipeline 42, and the end of the extension pipe is the suction port 423. Based on the Venturi effect, when the water flows rapidly along the water inlet 21 to the discharge port 22, low pressure is generated at the suction port 23, thereby generating an adsorption effect. Water pumps are respectively provided on the suction pipe 42 and the spray pipe 43, which are used to drive the water flow along the direction of water inlet 1 421 to the discharge port 422 and to drive the water flow along the direction of water inlet 2 431 to the spray port 432, respectively. Among them, the position of the water pump on the suction pipe 42 is set at the water inlet 1 421 to ensure that the water flows along the direction of water inlet 1 421 to the discharge port 422, and the position of the water pump on the spray pipe 43 is set at the water inlet 2 431, and it can also be set at other positions of the spray pipe 43 to ensure that the water flows along the direction of water inlet 2 431 to the spray port 432.

[0072] The jet-suction device also includes a support seat 41 and a drive assembly 44. The two jet-suction assemblies are arranged at the end of the deployment mechanism 2 away from the fuselage body 1 through the support seat 41. Among the two jet-suction assemblies, at least one jet-suction assembly is slidably arranged on the support seat 41. The drive assembly 44 drives the sliding jet-suction assembly to move to adjust the distance between the two jet-suction assemblies to adapt to trenches of different widths.

[0073] Preferably, both of the two spray-suction assemblies are slidably arranged on the support seat 1, and the drive assembly 44 is located between the two spray-suction assemblies. The fixed end of the drive assembly 44 is connected to one of the spray-suction assemblies, and the movable end is connected to the other spray-suction assembly, so as to ensure the symmetry of the two spray-suction assemblies on the support seat 1, and under the same spacing adjustment, the moving stroke of a single spray-suction assembly is smaller. Specifically, the suction lines 42 in the two spray-suction assemblies are slidably connected to the support seat 41 through a slider, and the drive assembly 44 is an oil cylinder, the cylinder end of the oil cylinder is fixed to the suction line 42 in one of the spray-suction assemblies, and the piston end is fixed to the suction line 42 in the other spray-suction assembly. As shown in Figure 16, the number of drive assemblies 44 can also be set to two.

[0074] A water inlet is provided at one end of the suction pipeline 42, and the other end is arranged horizontally. The discharge port 422 is located at one end of the horizontal arrangement. A pipe diameter contraction section is provided on the suction pipeline 42 between the water inlet 421 and the discharge port 422. An extension pipe is provided on the side of the pipe diameter contraction section to extend longitudinally. The suction port 423 is located on the extension pipe. Based on the Venturi effect, when the water flows rapidly along the water inlet 421 to the discharge port 422, low pressure is generated at the suction port 423, thereby generating an adsorption effect. Water pumps are respectively provided on the suction pipe 42 and the spray pipe 43, which are used to drive the water flow along the direction of water inlet 1 421 to the discharge port 422 and to drive the water flow along the direction of water inlet 2 431 to the spray port 432, respectively. Among them, the position of the water pump on the suction pipe 42 is set at the water inlet 1 421 to ensure that the water flows along the direction of water inlet 1 421 to the discharge port 422, and the position of the water pump on the spray pipe 43 is set at the water inlet 2 431, and it can also be set at other positions of the spray pipe 43 to ensure that the water flows along the direction of water inlet 2 431 to the spray port 432.

[0075] An end cap 424 is provided on the suction pipe 42 at the discharge port 422. The degree of opening and closing between the end cap 424 and the discharge port 422 is adjustable to adjust the water flow rate of the discharge port 422 according to the operating conditions. If silt clogs the suction port 423, the end cap 424 closes the discharge port 422, and the water flows in the direction from the water inlet 421 to the suction port 423, allowing the suction port 423 to be flushed back to clear the blockage.

[0076] The present invention further includes a second drive assembly 45, which drives the end cap 424 to move or rotate, thereby adjusting the degree of opening and closing between the end cap 424 and the discharge port 422. The end cap 424 is hingedly mounted at the end of the discharge port 422 of the suction line 42. The second drive assembly 45 is specifically a cylinder, whose cylinder end is hingedly connected to the suction line 42 and whose piston end is hingedly connected to one side of the end cap 424. The cylinder piston retracts and retracts to drive the opening and closing of the end cap 424.

[0077] The present invention also includes a drive assembly 3 48, which drives the support seat 41 to rise and fall, thereby realizing the recovery and lowering of the two jet suction assemblies and adjusting the lower height to adapt to trenches of different depths.

[0078] The present invention also includes a fixed frame 46 and a mobile frame 47. The fixed frame 46 is connected to the main body 1. One end of the mobile frame 47 is hinged to the fixed frame 46, and the other end is hinged to the support base 41. The drive assembly 3 48 is hingedly arranged between the fixed frame 46 and the support base 41 to form a connecting rod mechanism. This arrangement can realize the deployment, recovery and adjustment of the lowering height of the two spray and suction assemblies, and cooperate with the two spray arms 34 with adjustable lowering height to realize the opening of trenches of different depths and the burial of cables 100. As shown in Figure 1, the two spray arms 34 and the two spray and suction assemblies are lowered deeper, and the depth of the trench opened is deeper. As shown in Figure 2, the two spray arms 34 and the two spray and suction assemblies are lowered shallower, and the depth of the trench opened is shallower, ensuring the effective and reliable burial of cables 100 in both deep and shallow trenches. On the other hand, compared with directly setting up a vertical linear drive mechanism, using a connecting rod mechanism to drive the two spray-suction components to recover and lower them will not take up too much height space when the recovery and lowering strokes are the same, making it convenient to carry other tools on the fuselage body 1 and reduce interference between tools.

[0079] Among them, the driving component three 48 is specifically a cylinder, the cylinder end of which is hinged to the fixed frame 46, and the piston end is hinged to the support seat 41. The number of driving components three 48 can be two, and the layout is shown in Figures 15, 17, and 19.

[0080] The present invention also includes a drive assembly 49. The fixed frame 46 is provided with a hinge 461, which is hinged to the main body 1 via the hinge 461. The hinge axis is arranged along the lifting direction of the support base 41, i.e., vertically. The drive assembly 49 is used to drive the fixed frame 46 to rotate about the hinge on the main body 1, thereby achieving left and right swinging of the entire device, as shown in Figures 5 and 6, to accommodate turning areas or curved trenches. The drive assembly 49 is specifically a cylinder, with its cylinder end hinged to the fixed frame 6 and its piston end hinged to the main body 1. The piston end's extension and retraction drives the entire device's left and right swing, coordinating with the turning motion of the operating system.

[0081] The present invention also provides an underwater jet trenching and cable laying method, which uses the underwater jet trenching and cable laying system as described above and includes the following steps:

[0082] S1. Lower the underwater jet trenching and cable burying system to the seabed where trenching and cable burying are to be carried out, and ensure that the projections of the two jet arms 34 on the seabed are located on both sides of the cable 100, that is, in the height direction, the two jet arms 34 do not overlap with the cable 100 to avoid crushing the cable 100 during the lowering of the jet arms 34 and trenching operations;

[0083] S2. Deploy two spray arms 34 downward, and use the front nozzles 3411 on the two spray arms to spray jets. The underwater jet trenching and cable burying operation system moves on the seabed along the length of the cable 100 via the underwater walking device 2 to spray and break the seabed along the length of the cable 100 to open a trench. At the same time, the tail nozzle 3413 sprays jets away from the direction of the front nozzle 3411 to continuously liquefy the soil in the trench, maintain the trench shape and depth, and reduce sediment backfill deposition and trench collapse.

[0084] S3. Deploy the jet-sucking and suction device 4 downward so that the two jet-sucking and suction components extend into the trench. When the cable falls into the trench, the sediment in the trench is sucked out through the suction port 423 of the suction pipe 42, and the sediment is discharged to the outside of the trench through the discharge port 422 to ensure that the trench depth meets the operation requirements. A horizontal jet is sprayed in the trench away from the two jet arms 34 through the jet port 432 to continuously liquefy the soil in the trench. The cable 100 naturally sinks to the bottom of the trench along the line between the two jet-sucking and suction components.

[0085] Among them, since the jet ejected from the jet outlet 432 only needs to maintain the groove shape and does not need to play an additional role in breaking the soil, the required water pressure is less than the jet water pressure ejected from the front nozzle 3411, that is, in S3, the jet water pressure ejected from the jet outlet 432 is less than the jet water pressure ejected from the front nozzle 3411.

[0086] Those skilled in the art should understand that the discussion of any of the above embodiments is merely illustrative and is not intended to imply that the scope of protection of the present application is limited to these examples. In line with the present application, the technical features in the above embodiments or different embodiments may be combined, the steps may be implemented in any order, and there are many other variations of different aspects of one or more embodiments of the present application as described above, which are not provided in detail for the sake of simplicity.

[0087] The one or more embodiments of this application are intended to encompass all such substitutions, modifications, and variations that fall within the broad scope of this application. Therefore, any omissions, modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of one or more embodiments of this application should be included in the scope of protection of this application.

Claims

1. An underwater jet trenching and cable laying system, characterized in that: include: The main body of the fuselage (1); An underwater walking device (2), wherein the underwater walking device (2) is arranged at the lower end of the fuselage body (1); A spraying and earth-breaking device (3), the spraying and earth-breaking device (3) comprising two spraying arms (34), the two spraying arms (34) being located at the front end of the fuselage body (1), and both being provided with a front nozzle (3411) for spraying a jet to open a trench on the seabed; A jet suction device (4), the jet suction device (4) being arranged at the rear end of the fuselage body (1), the jet suction device (4) comprising a suction pipeline (42) and a jet pipe (43), the suction pipeline (42) being provided with a discharge port (422) and a suction port (423), the suction port (423) being used to face the bottom of the trench, the discharge port (422) being located higher than the suction port (423) and being arranged transversely relative to the suction port (423), the suction pipeline (42) being used to suck mud and sand in the trench through the suction port (423) before the cable sinks to the bottom of the trench, and to discharge the mud and sand to the outside of the trench through the discharge port (423); The second jet pipe (43) is located at the rear side of the suction pipeline (42). The second jet pipe (43) is provided with a jet port (432). The jet port (432) is arranged horizontally in a direction away from the suction pipeline (42). The second jet pipe (43) is used to spray a horizontal jet through the jet port (432) to flush the inner wall and bottom of the trench along the length direction of the trench after the suction pipeline (42) sucks the sediment in the trench, so as to maintain the trench shape when the cable sinks to the bottom of the trench.

2. The underwater jet trenching and cable laying system according to claim 1, characterized in that: The spraying and earth-breaking device (3) further comprises a first deployment mechanism, wherein the first deployment mechanism comprises a fixed pipeline (31), a rotating pipeline (32), a first drive mechanism (33) and a second drive mechanism (36), wherein the fixed pipeline (31) is fixed to the main body (1), the rotating pipeline (32) is rotatably arranged on the fixed pipeline (31) and is in communication with the fixed pipeline (31), the first drive mechanism (33) is used to drive the rotating pipeline (32) to rotate around the fixed pipeline (31), the two spraying arms (34) are both rotatably arranged on the rotating pipeline (32) and are in communication with the rotating pipeline (32), and the second drive mechanism (36) is used to drive the two spraying arms (34) to rotate around the rotating pipeline (32).

3. The underwater jet trenching and cable laying system according to claim 2, characterized in that: The spraying and earth-breaking device (3) further comprises a driving mechanism three (37), which can drive the two spraying arms (34) to move along the axial direction of the rotating pipeline (32) to adjust the distance between the two spraying arms (34).

4. The underwater jet trenching and cable laying system according to claim 2 or 3, characterized in that: Two suction pipes (42) are provided, the two suction pipes (42) are spaced apart along the width direction of the fuselage body (1), and the spacing between the two suction pipes (42) is adjustable; two spray pipes (43) are provided, the two spray pipes (43) are spaced apart along the width direction of the fuselage body (1), and the spacing between the two spray pipes (43) is adjustable.

5. The underwater jet trenching and cable laying system according to claim 4, characterized in that: The spray-sucking suction device (4) further comprises a second deployment mechanism, a support seat (41) and a first drive assembly (44), wherein the second deployment mechanism is arranged at the rear end of the fuselage body (1), the support seat (41) is arranged at one end of the second deployment mechanism away from the fuselage body (1), a single second spray-sucking pipe (43) is fixedly connected to a single suction pipeline (42), and the single second spray-sucking pipe (43) and the suction pipeline (42) to which it is fixedly connected form a spray-sucking suction assembly, and the two spray-sucking suction assemblies are both arranged on the support seat (41), and the two spray-sucking suction assemblies are arranged at an interval, and the cable can fall into the trench along the space between the two spray-sucking suction assemblies; At least one of the two spray-sucking and suction components is slidably arranged on a support seat (41), and the driving component (44) drives the slidably arranged spray-sucking and suction component to move so as to adjust the distance between the two spray-sucking and suction components.

6. The underwater jet trenching and cable laying system according to claim 5, characterized in that: The bottoms of the two spray arms (34) are each provided with a tail nozzle (3413), and the spray direction of the tail nozzle (3413) is arranged away from the spray direction of the front nozzle (3411).

7. The underwater jet trenching and cable laying system according to claim 5 or 6, characterized in that: The deployment heights of the two spray arms (34) and the two spray suction assemblies are adjustable.

8. The underwater jet trenching and cable laying system according to any one of claims 1 to 3, 5 and 6, characterized in that: The suction pipeline (42) is provided with a water inlet (421) at one end and is transversely arranged at the other end. The discharge port (422) is located at the transversely arranged end. A pipe diameter contraction section is provided on the suction pipeline (42) between the water inlet (421) and the discharge port (422). An extension pipe is longitudinally extended on the side of the pipe diameter contraction section. The suction port (423) is located on the extension pipe. An end cover (424) is provided on the suction pipeline (42) at the position of the discharge port (422). The degree of opening and closing between the end cover (424) and the discharge port (422) is adjustable.

9. The underwater jet trenching and cable laying system according to any one of claims 1 to 3, 5 and 6, characterized in that: The invention also comprises a front spray mechanism (5), which is arranged at the front end of the fuselage body (1) and is located in front of the two spray arms (34). The front spray mechanism (5) is provided with a front nozzle (51) for sweeping and / or pre-ditching the seabed before the two spray arms (34) operate.

10. An underwater jet trenching and cable laying method, characterized in that: The underwater jet trenching and cable laying operation system according to any one of claims 1 to 9 is used, and the operation method comprises the following steps: S1, dropping the underwater jet trenching and cable burying operation system onto the seabed where trenching and cable burying are to be carried out, and making the projections of the two jetting arms (34) on the seabed correspondingly located on both sides of the cable (100); S2, the underwater jet trenching and cable burying operation system moves on the seabed along the length direction of the cable (100) through the underwater walking device (2), and sprays jets through the front nozzles (3411) on the two spray arms (34) to spray and break the seabed along the length direction of the cable (100) to open a trench; S3. When the cable falls into the trench, the silt in the trench is sucked out through the suction port (423) of the suction pipeline (42), and the silt is discharged to the outside of the trench through the discharge port (423). A horizontal jet is ejected through the flushing port (432) along the length of the trench to flush the inner wall and bottom of the trench, continuously liquefying the soil in the trench and maintaining the trench shape. The cable (100) naturally sinks to the bottom of the trench.

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