Hydrodynamic heavy hammers at two ends of antarctic krill trawl foot line and use method of hydrodynamic heavy hammers

Abstract

The invention discloses a hydrodynamic heavy hammer at the two ends of a foot line of an euphausia superba trawl and a using method of the hydrodynamic heavy hammer, and belongs to the technical field of trawl fishing equipment.The hydrodynamic heavy hammer comprises a hammer body with sinking force, the hammer body is provided with a first surface and a second surface which are oppositely arranged up and down, and the first surface and the second surface are each of a cambered surface structure; the width of one end of the section of the hammer body is reduced towards the other end; the first surface is provided with a short line hanging ring, and a short line is connected to the short line hanging ring. The radius of curvature of the first surface is greater than the radius of curvature of the second surface. Continuous opening and stable shape of the net opening in the fishing process can be ensured, and the problems that the height of the net opening is reduced and the sea sweeping area is reduced when the superficial layer krill is fished at a high dragging speed are solved.

Description

Technical Field

[0001] This invention relates to the field of trawl fishing equipment technology, specifically to a hydrodynamic weight at both ends of the lower net of an Antarctic krill trawl and its usage method. Background Technology

[0002] Antarctic krill (Euphausia superba, hereinafter referred to as krill) resources are abundant and rich in various bioactive substances, making them an important polar marine biological resource. In the 21st century, new continuous fishing technologies have significantly improved fishing efficiency compared to traditional trawls, promoting the large-scale and modern development of the krill industry. The new continuous fishing technology uses beam trawls, which use rigid beams to maintain the stability of the net's horizontal expansion, unaffected by operating parameters (trawl speed, towing line length) and factors such as wind, waves, and currents. Continuous fishing for several days to several weeks requires no net hauling, with an effective operating time of over 95%. Live krill are pumped to the catch storage tank using a suction pump and a delivery hose at the end of the net, offering advantages such as high efficiency, time-saving, and high-quality catch.

[0003] Because krill exhibit irregular clustering and diurnal vertical movement, their vertical movement is greatest in summer and least in winter. The key to continuous fishing with beam trawls for several days to weeks lies in: ① the proper allocation of weights at both ends of the lower line; ② timely adjustment of towing speed or line length based on fish finder images, controlling the net to reach the high-density krill population layer while maintaining the net opening height (vertical expansion) to achieve targeted and efficient harvesting. During fishing operations, the captain must determine the weights of the weights at both ends of the lower line based on the recent krill population distribution layer and diurnal vertical movement amplitude. During continuous fishing, the weights at both ends of the lower line cannot be adjusted. This significantly reduces the net opening height at higher towing speeds (maintaining a distance between the net and the ship to reduce the impact of the ship's wake on krill entry) when catching shallow-water krill, resulting in a significant reduction in the area swept by the net.

[0004] Currently, there are some improved technologies for addressing the stability issue of net openings during fishing. For example, existing patent technology KR1020240177882A discloses a fishing technology that can make the net opening form a horizontal line during fishing, maximizing the capture of Jali dome nets and improving fishing efficiency. It also allows for easy and economical installation and modification of existing fishing gear, as well as the functionality of counterweights, lift lines, and bubble louvers. Another example is existing patent technology NO20210685A1, which discloses a trawl system including airfoil members that provide lift to the trawl opening. This invention further provides a trawl pushing system, which includes one or more airfoil bodies. The airfoil bodies can change their angle of attack with respect to the flow vector, thereby changing the upward thrust. However, the aforementioned existing patent technologies still have room for improvement in ensuring the continuous opening and shape control of the net opening during fishing. Summary of the Invention

[0005] The purpose of this invention is to provide a hydrodynamic weight at both ends of the lower line of an Antarctic krill trawl and its method of use, which can ensure the continuous opening of the net opening and its stable shape during the fishing process, and solve the problems of reduced net opening height and reduced sea sweep area when fishing for shallow krill at high trawl speed.

[0006] To solve the above-mentioned technical problems, the present invention specifically provides the following technical solution: a hydrodynamic weight at both ends of the lower line of an Antarctic krill trawl, comprising a hammer body with sinking force, the hammer body having a first surface and a second surface arranged opposite to each other, both the first surface and the second surface being arc-shaped structures, and the width of one end of the hammer body cross-section decreasing towards the other end; The first surface has a short-wire loop, to which a short wire is attached. The radius of curvature of the first surface is greater than that of the second surface.

[0007] This invention enhances the hydrodynamic efficiency of water flowing through the hammer by setting the upper and lower surfaces of the hammer body as a double-arc structure and reducing its cross-sectional width towards one end. Specifically, the water flowing through the hammer body is directed to change its flow trajectory after flowing along the first and second surfaces, causing it to flow downwards. This creates a stable downward additional force. Combined with the connection structure between the short rope hanging ring on the first surface and the short rope, and the weight of the hammer body, this further ensures that the trawl net opening is open and that the opening remains open. This solves the problems of reduced net opening height, reduced sweeping area, and uneven force on the hammer causing it to tilt during continuous high-speed trawl fishing of Antarctic krill.

[0008] According to one embodiment of the present invention, the hammer body has at least three short rope attachment rings on the same surface, and adjacent short ropes are connected by rods, which are interconnected to form a polygonal structure. By setting at least three short rope attachment rings on the same surface of the hammer body, and connecting adjacent short ropes by rods to form a polygonal structure, a multi-point balanced force connection system is formed, which disperses the local stress generated by dragging and water flow impact, effectively avoiding or reducing excessive hammer body offset, further ensuring that the trawl net opening continuously maintains the preset vertical expansion shape, and improving the net opening height stability and the accuracy of the swept area.

[0009] According to one embodiment of the present invention, the hammer body has a traction lug on its side. By providing the traction lug on the side of the hammer body, a traction force point is provided.

[0010] According to one embodiment of the present invention, a monitor is provided on the side of the hammer. The monitor is a position monitor used to monitor its position and status in the water in real time. It is connected to a receiver processor on the hull via a data transmission line. The data transmission line is generally connected together with the towing line to reduce the risk of breakage when the data transmission line is used alone.

[0011] According to one embodiment of the present invention, a trawl net with hydrodynamic weights at both ends of the lower line of an Antarctic krill trawl net is used. The trawl net has a net cover with an opening, and a side line with a frame structure is provided at the opening of the net cover. The bottom ends of the side line are connected to the short line by rods through the lower line cable. The present invention strengthens the rigidity of the net opening by setting the side line with a frame structure at the net opening, and uses the sinking force of the weights and their structural shape to guide the flow of water below, thereby avoiding or reducing the twisting and deformation of the side line, ensuring the pre-set vertical expansion shape of the net opening, and stabilizing the net opening height and the swept area at high trawl speeds.

[0012] According to one embodiment of the present invention, the mesh opening of the net is provided with at least two side ribs with frame structures. The bottom part of the side ribs is provided with a guide plate assembly that can move relative to them. The guide plate assembly includes two parallel steel pipes that pass through the bottom part of the side ribs and are connected by a first plate. By providing at least two side ribs with frame structures at the mesh opening and assembling a guide plate assembly that can move relative to them at the bottom part of the side ribs, the two parallel steel pipes passing through the side ribs and connected by the first plate can support the mesh opening and strengthen its overall shape to prevent deformation. Furthermore, by moving the guide plate assembly, the net can adapt to changes in water flow, disperse impact stress, and prevent the mesh opening from shrinking or shifting. Combined with the hydrodynamic sinking action of the hammer and the balanced force transmission of the short ribs, the net opening can be further ensured to maintain a preset vertical expansion shape, thereby improving the accuracy of the swept area.

[0013] According to one embodiment of the present invention, the guide plate assembly further includes a second plate disposed on one side of the steel pipe. The second plate forms an angle with the first plate and is disposed outside the opening of the net. The present invention, by setting a second plate at an angle to the first plate on one side of the steel pipe of the guide plate assembly and placing it outside the opening of the net, utilizes the angled structure to divert the outer water flow and change the water flow trajectory to weaken the impact force, preventing the water flow from directly acting on the net opening. Combined with the support of the steel pipe and the first plate, the hydrodynamic sinking effect of the hammer, and the balanced force transmission of the short line, the pre-set vertical expansion shape of the net opening is further stabilized, improving the stability and accuracy of the sweeping area, and adapting to the harvesting needs of irregular krill colonies and diurnal vertical movement.

[0014] According to one embodiment of the present invention, the guide plate assembly further includes a base disposed on both sides of the first plate and connected to a steel pipe. The base is a plate structure, and the two sides of the base have swingable side plates, with a float connected between the side plates. The float is disposed above the second plate. The base enhances the overall support rigidity of the guide plate assembly and the connection effect with the side rails of the net opening. Furthermore, the swingable side plates and floats adaptively adjust the angle with the water flow to dynamically balance the forces on the upper and lower parts of the net opening, preventing the net opening from sinking or tilting excessively, ensuring stable and controllable vertical expansion height, and dispersing some of the impact force of the water on the first and second plates. In conjunction with the second plate, it diverts water flow and guides the captured fish to enter the trawl at different angles, preventing the fish from being excessively crushed and dying or their tissues from being damaged due to concentrated entry.

[0015] A method for using hydrodynamic weights at both ends of the lower line of an Antarctic krill trawl includes the following steps: Step 1: Based on the water flow velocity and krill colony distribution in the target fishing area, select a hammer of suitable specifications. Connect at least three short lines to the corresponding hanging rings on the first surface of the hammer. Adjacent short lines are fixedly connected by a rod to form a polygonal structure. Adjust the length of the short lines to a preset value (adapting to the target net opening height). Then, fix the polygonal rod to the lower line of the trawl net. Install a monitor on the side of the hammer. Connect one end of the data transmission line to the monitor, and the other end is bound along the side line and tow line to the receiver processor on the hull, ensuring stable signal transmission.

[0016] Step 2: Release the trawl net into the sea using the ship's winch, activate the receiver processor, and confirm that the monitor can transmit real-time data on the position of the counterweight and the status of the net opening. Adjust the length of the towing line and the ship's towing speed according to the target water depth for the krill, and stabilize the towing direction of the towing line with the help of the towing support rod.

[0017] Step 3: During the operation, the processor receives real-time monitoring data on the hammer position and water flow transmitted by the monitor, and combines this with the krill cluster movement trajectory fed back by the fish finder to dynamically adjust the towing speed of the vessel or the length of the towing line.

[0018] Step 4: After the fishing operation is completed, slowly retrieve the trawl net 20 using a winch, and finally dry and store all parts for use in the next operation.

[0019] Compared with existing technologies, the beneficial effects of this invention are as follows: By setting the upper and lower surfaces of the hammer body to a double-arc structure and reducing its cross-sectional width towards one end, this invention enhances the hydrodynamic utilization efficiency when water passes through the hammer body. Simultaneously, the frame structure strengthens the rigidity of the net opening, and the downward force of the hammer and its structural shape guide the flow of water below, avoiding or reducing the twisting deformation of the side rails. This ensures the pre-set vertical expansion shape of the net opening, stabilizing the net opening height and sweeping area under high towing speeds. Furthermore, this invention diverts the outer water flow and changes the water flow trajectory through the angled structure of the guide plate assembly to weaken the impact force, preventing the water flow from directly acting on the net opening and further stabilizing the pre-set vertical expansion shape of the net opening. Attached Figure Description

[0020] To more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are merely exemplary, and those skilled in the art can derive other embodiments based on the provided drawings without creative effort.

[0021] Figure 1 This is a schematic diagram showing the application of the hydrodynamic weights at both ends of the lower net of an Antarctic krill trawl according to the present invention. Figure 2 This is a schematic diagram of the connection scheme between the trawl net and the guide plate assembly of the present invention; Figure 3 This is a schematic diagram of the counterweight structure of the present invention; Figure 4 This is a schematic diagram of the connection scheme between the counterweight and the short frame of the present invention; Figure 5 This is a schematic diagram of the second surface of the hammer of the present invention; Figure 6 This is a schematic diagram of the guide plate assembly scheme of the present invention; Figure 7 This is a schematic diagram of the connection scheme between the trawl net, guide plate assembly, and auxiliary components of the present invention; Figure 8 This is a schematic diagram of the auxiliary component solution of the present invention.

[0022] Explanation of reference numerals in the attached drawings: 10. Hull; 11. Receiver / processor; 12. Towing support rod; 13. Towing line; 14. Suction pipe; 15. Data transmission line; 20. Trawl; 21. Side line; 30. Counterweight; 31. Lower line cable; 32. Hammer body; 321. First surface; 322. Second surface; 33. Traction lug; 34. Short line tethering ring; 35. Monitor; 36. Short line; 37. Recessed hole; 40. Guide plate assembly; 41. Base; 42. Steel pipe; 43. First plate; 44. Side plate; 45. Float; 46. Second plate; 50. Auxiliary component; 51. Sliding sleeve; 52. Sliding plate; 53. Bend plate; 54. Annular plate. Detailed Implementation

[0023] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0024] The concepts involved in this application will first be described with reference to the accompanying drawings. It should be noted that the following descriptions of various concepts are only for the purpose of making the content of this application easier to understand and do not constitute a limitation on the scope of protection of this application; furthermore, the embodiments and features in the embodiments of this application can be combined with each other unless otherwise specified. This application will now be described in detail with reference to the accompanying drawings and embodiments.

[0025] Example 1: As shown in the attached figure Figure 1 - Appendix Figure 6 As shown, a hydrodynamic weight at both ends of the lower line of an Antarctic krill trawl includes a hammer body 32 with a sinking force. The hammer body 32 has a first surface 321 and a second surface 322 arranged opposite to each other. Both the first surface 321 and the second surface 322 are arc-shaped structures. The width of the cross-section of the hammer body 32 decreases from one end to the other end. The first surface 321 has a short-wire loop 34, on which a short wire 36 is connected. The radius of curvature of the first surface 321 is greater than that of the second surface 322.

[0026] This invention enhances the hydrodynamic efficiency of water flowing through the hammer 32 by setting the upper and lower surfaces of the hammer body 32 to a double-arc structure and reducing its cross-sectional width towards one end. Specifically, the water flowing through the hammer body 32 changes its flow trajectory after flowing along the first surface 321 and the second surface 322, causing it to flow downwards, thus forming a stable downward additional force. Combined with the connection structure between the short rope hanging ring 34 and the short rope 36 on the first surface 321 and the gravity of the hammer body 32, this further ensures that the trawl net opening is open and that the opening is maintained. This solves the problems of reduced net opening height, reduced sweeping area, and uneven force on the hammer causing easy tilting during high-speed continuous fishing of Antarctic krill.

[0027] The hammer body 32 has at least three short rope attachment rings 34 on the same surface. Adjacent short ropes 36 are connected by rods, which are interconnected to form a polygonal structure. By setting at least three short rope attachment rings 34 on the same surface of the hammer body 32, and connecting adjacent short ropes 36 through rods to form a polygonal structure, a multi-point balanced force connection system is formed. This disperses the local stress generated by dragging and water flow impact, effectively avoiding or reducing excessive displacement of the hammer body 32. This further ensures that the trawl net 20 continuously maintains the preset vertical expansion shape, improving the stability of the net opening height and the accuracy of the swept area.

[0028] The hammer body 32 has a traction lug 33 on its side. By providing the traction lug 33 on the side of the hammer body 32, a traction force point is provided.

[0029] The hammer body 32 has a monitor 35 on its side. The monitor 35 is a position monitor used to monitor its position and status in the water in real time. It is connected to the receiver processor 11 on the hull 10 via a data transmission line 15. The data transmission line 15 is generally connected together with the towing cable 13 to reduce the risk of breakage when the data transmission line 15 is used alone.

[0030] This invention relates to a trawl net employing hydrodynamic weights at both ends of the lower line of an Antarctic krill trawl. The trawl net 20 has a net cover with an opening, and a side line 21 with a frame structure is provided at the opening of the net cover. The bottom ends of the side line 21 are connected to the short line 36 by rods between the lower line cable 31 and the short line 36. By setting the side line 21 with a frame structure at the opening of the trawl net 20, and connecting the bottom ends of the side line 21 to the short line 36 by rods between the lower line cable 31 and the short line 36, the rigidity of the net opening is strengthened through the frame structure. The sinking force of the weights 32 and their structural shape guide the flow of water below, thereby avoiding or reducing the twisting and deformation of the side line 21. This ensures the pre-set vertical expansion shape of the net opening, stabilizing the net opening height and the swept area at high trawl speeds.

[0031] The netting opening is equipped with at least two side ribs 21 with frame structures. The bottom portion of each side rib 21 has a guide plate assembly 40 that can move relative to it. The guide plate assembly 40 includes two parallel steel pipes 42 that pass through the bottom portion of the side ribs 21, connected by a first plate 43. By using two parallel steel pipes 42 to pass through the side ribs 21 and connect them via the first plate 43, the netting opening is supported and its overall shape is strengthened to prevent deformation. Furthermore, the guide plate assembly 40 moves to adapt to changes in water flow, dispersing impact stress and preventing the netting opening from shrinking or shifting. Combined with the hydrodynamic sinking action of the hammer 32 and the balanced force transmission of the short ribs 36, this further ensures that the netting opening maintains its preset vertical expansion shape, improving the accuracy of the swept area.

[0032] The guide plate assembly 40 also includes a second plate 46 disposed on one side of the steel pipe 42. The second plate 46 forms an angle with the first plate 43 and is disposed outside the opening of the net. This invention, by setting a second plate 46 at an angle to the first plate 43 on one side of the steel pipe 42 of the guide plate assembly 40 and placing it outside the opening of the net, utilizes the angled structure to divert the outer water flow and change the water flow trajectory to weaken the impact force, preventing the water flow from directly acting on the net opening. Combined with the support of the steel pipe 42 and the first plate 43, the hydrodynamic sinking effect of the hammer 32, and the balanced force transmission of the short wire 36, it further stabilizes the pre-set vertical expansion shape of the net opening, improves the stability and accuracy of the sweeping area, and adapts to the harvesting needs of irregular krill colonies and diurnal vertical movement.

[0033] The guide plate assembly 40 also includes bases 41 disposed on both sides of the first plate 43 and connected to the steel pipes 42. The bases 41 are plate structures, and the sides of the two bases 41 have swingable side plates 44, with floats 45 connected between the side plates 44. The floats 45 are located above the second plate 46. The bases 41 enhance the overall support rigidity of the guide plate assembly 40 and the connection effect with the side rails 21 of the net opening. Furthermore, the swingable side plates 44 and floats 45 adaptively adjust the angle with the water flow to dynamically balance the forces on the upper and lower parts of the net opening, preventing the net opening from sinking or tilting excessively, ensuring a stable and controllable vertical expansion height, and dispersing some of the impact force of the water on the first plate 43 and the second plate 46. In conjunction with the second plate 46, the second plate 46 diverts the water flow and guides the captured fish to enter the trawl net 20 at different angles, preventing the fish from being squeezed and killed or their tissues damaged due to concentrated entry.

[0034] A method for using hydrodynamic weights at both ends of the lower line of an Antarctic krill trawl includes the following steps: Step 1: Based on the water flow velocity and krill cluster distribution in the target fishing area, select a hammer body 32 of suitable specifications. Connect at least three short lines 36 to the short line hanging rings 34 on the first surface 321 of the hammer body 32. Adjacent short lines 36 are fixedly connected by a rod to form a polygonal structure. Adjust the length of the short lines 36 to a preset value (adapting to the target net opening height). Then, fix the polygonal rod to the lower line cable 31 of the trawl net 20. Install a monitor 35 on the side of the hammer body 32. Connect one end of the data transmission line 15 to the monitor 35, and the other end is bound along the side line 21 to the towing line 13 and connected to the receiver processor 11 of the hull 10 to ensure stable signal transmission.

[0035] Step 2: Release the trawl net 20 into the sea via the winch of the hull 10, activate the receiver processor 11, and confirm that the monitor 35 can transmit the position of the counterweight and the status data of the net opening in real time. Adjust the length of the towing line 13 and the towing speed of the hull according to the target water depth of the krill, and stabilize the traction direction of the towing line 13 with the help of the towing support rod 12.

[0036] Step 3: During the operation, the processor 11 receives real-time data on the position of the hammer 32 and the water flow transmitted by the monitor 35. Combined with the krill cluster movement trajectory fed back by the fish finder, the towing speed of the boat or the length of the towing line 13 is dynamically adjusted.

[0037] Step 4: After the fishing operation is completed, slowly retrieve the trawl net 20 using a winch, and finally dry and store all parts for use in the next operation.

[0038] Example 2: In this embodiment, see Appendix Figure 5 As shown, the second surface 322 is arrayed with concave holes 37. In Antarctic krill harvesting, the second surface 322 of the hammer 32 is prone to turbulence due to water flow, which increases navigation resistance and weakens hydrodynamic conversion efficiency, affecting the stability of sinking force. By arraying concave holes 37 on the second surface 322, the water flow adhesion layer is destroyed to reduce turbulence interference, reduce water flow resistance, and optimize the hydrodynamic transmission path. Combined with the double-arc surface design of the first surface 321 and the second surface 322 and the reduced cross-section structure of the hammer 32, the stability of downward additional force is further enhanced.

[0039] Example 3: In this embodiment, see Appendix Figure 7 Appendix Figure 8As shown, an auxiliary component 50 is provided on the bottom part of the side beam 21, which can slide relative to it. The auxiliary component 50 is provided on both sides of the guide plate assembly 40. The auxiliary component 50 includes a sliding sleeve 51 that is slidably connected to the bottom part of the side beam 21. A circular sliding plate 52 is coaxially connected to the outside of the sliding sleeve 51. Annular plates 54 are provided on both sides of the sliding plate 52. The annular plates 54 have an opening in the center, and the diameter of the opening is larger than the outer diameter of the sliding sleeve 51. A bent plate 53 is arranged around the annular plate 54 and the sliding plate 52. The sliding sleeve 51, which can slide on the bottom part of the side strip 21, along with the annular plate 54 and the curved plate 53, restricts the relative movement of the guide plate assembly 40. This prevents the bottom part of the side strip 21 of the guide plate assembly 40 from moving too fast, thus creating a buffer and reducing the probability of the guide plate assembly 40 shaking or deviating. In addition, by setting the auxiliary component 50, the movement limit range of the guide plate assembly 40 can be limited to prevent it from staying at the edge of the mesh opening and affecting the horizontal dragging effect of the mesh opening.

[0040] Example 4: In this embodiment, see Appendix Figure 1 As shown, the side rope at the opening of the trawl net 20 is connected to the towing support rod 12 via the towing rope 13. The towing support rod 12 is mounted on the hull 10. The tail of the trawl net 20 is connected to the hull 10 via the suction pipe 14, which is used to transport the material at the tail of the trawl net 20 to the hull 10 to prevent it from bursting and to maintain the shape of the trawl net 20 in the water to prevent its tail from being too heavy to be towed.

[0041] It should also be noted that the terms "center," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation on this application. Unless otherwise expressly specified and limited, the terms "installed," "connected," "linked," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication between two elements. For those skilled in the art, the specific meaning of the above terms in this application can be understood according to the specific circumstances.

[0042] The embodiments and / or implementation methods described above are merely preferred embodiments and / or implementation methods for implementing the technology of the present invention, and are not intended to limit the implementation methods of the technology of the present invention in any way. Any person skilled in the art can make some modifications or alterations to other equivalent embodiments without departing from the scope of the technical means disclosed in the content of the present invention, but they should still be regarded as the technology or embodiments that are substantially the same as the present invention.

[0043] This document uses specific examples to illustrate the principles and implementation methods of this application. The descriptions of the above embodiments are only for the purpose of helping to understand the methods and core ideas of this application. The above descriptions are only preferred embodiments of this application. It should be noted that due to the limitations of written expression, while there are objectively infinite specific structures, those skilled in the art can make several improvements, modifications, or changes without departing from the principles of this application, and can also combine the above technical features in an appropriate manner. These improvements, modifications, changes, or combinations, or the direct application of the inventive concept and technical solution to other situations without modification, should all be considered within the scope of protection of this application.

Claims

1. A hydrodynamic weight at both ends of the lower line of an Antarctic krill trawl, comprising a hammer body (32) with a sinking force, characterized in that, The hammer body (32) has a first surface (321) and a second surface (322) arranged opposite to each other. Both the first surface (321) and the second surface (322) are arc-shaped structures. The width of one end of the cross-section of the hammer body (32) decreases towards the other end. The first surface (321) has a short-line hanging ring (34) on which a short line (36) is connected.

2. The hydrodynamic weights at both ends of the lower line of an Antarctic krill trawl according to claim 1, characterized in that, The hammer (32) has at least three short rope hanging rings (34) on the same surface, and adjacent short ropes (36) are connected by rods, which are connected to each other to form a polygonal structure.

3. The hydrodynamic weights at both ends of the lower line of an Antarctic krill trawl according to claim 1, characterized in that, The hammer (32) has a traction earring (33) on its side.

4. The hydrodynamic weights at both ends of the lower line of an Antarctic krill trawl according to claim 1, characterized in that, The hammer (32) has a monitor (35) on its side.

5. A trawl net employing the hydrodynamic weights at both ends of the lower line of an Antarctic krill trawl net as described in any one of claims 1-4, characterized in that, The trawl net (20) has a net with a mesh opening, and the mesh opening of the net is provided with a side rope (21) with a frame structure. The bottom ends of the side rope (21) are connected to the rod between the lower rope (31) and the short rope (36).

6. The trawl net according to claim 5, which utilizes hydrodynamic weights at both ends of the lower line of an Antarctic krill trawl net, is characterized in that... The mesh opening is provided with at least two side rails (21) with frame structure. The bottom part of the side rail (21) is provided with a guide plate group (40) that can move relative to it. The guide plate group (40) includes two parallel steel pipes (42) that pass through the bottom part of the side rail (21). The two steel pipes (42) are connected by a first plate (43).

7. The trawl net according to claim 6, which utilizes hydrodynamic weights at both ends of the lower line of an Antarctic krill trawl net, is characterized in that... The guide plate assembly (40) further includes a second plate (46) disposed on one side of the steel pipe (42), the second plate (46) having an angle with the first plate (43), and the second plate (46) being disposed outside the mesh opening of the mesh.

8. The trawl net according to claim 6, which utilizes hydrodynamic weights at both ends of the lower line of an Antarctic krill trawl net, is characterized in that... The guide plate assembly (40) also includes a base (41) disposed on both sides of the first plate (43) and connected to the steel pipe (42). The base (41) is a plate structure. The two bases (41) have side plates (44) that can swing. A floating plate (45) is connected between the side plates (44).

9. A method for using the hydrodynamic weights at both ends of the lower line of an Antarctic krill trawl as described in any one of claims 1-4, characterized in that, Based on the water flow velocity and krill cluster distribution in the target fishing area, select a hammer body (32) of appropriate specifications, and connect at least three short lines (36) to the short line hanging ring (34) of the hammer body (32).

10. The hydrodynamic weights at both ends of the lower line of an Antarctic krill trawl according to claim 9 and their method of use, characterized in that, The length of the short section (36) needs to be adjusted to the preset value.

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