Turtle escape trawl device

Abstract

The application discloses a turtle escape trawl device, aiming to provide a turtle escape trawl device which can make turtles in the trawl escape and effectively improve the problem that fish in the trawl escape through an escape port. The device comprises a net bag and a turtle escape device arranged in the net bag. The turtle escape device comprises a frame arranged on the net bag and provided with a limiting piece, a fence which divides the inner cavity of the net bag into two cavities and is rotatably arranged on the frame through a main shaft rod, an escape port arranged on the side wall of the net bag of the rear cavity and close to the limiting piece, a shielding net piece with the front side connected to the other end of the fence and the rear side connected to the net bag behind the escape port, and a first elastic element, wherein the other end of the fence is rotated to the front cavity direction under the action of the first elastic element and abuts against the limiting piece, and at this time, the shielding net piece shields the escape port.

Description

Technical Field

[0001] This invention relates to a trawl net, and more specifically to a trawl net device for escaping sea turtles. Background Technology

[0002] Currently, both the International Union for Conservation of Nature (IUCN) and the Convention on International Trade in Endangered Species of Wild Fauna and Flora (CITES) have identified all sea turtles as endangered species, strictly prohibiting international trade and protecting them. my country also listed sea turtles as national protected animals in the 1980s, and upgraded them to first-class protected animals in 2021. The five main factors threatening sea turtle survival are fishing, direct predation, coastal beach development, environmental pollution and disease, and global warming. Trawling often results in sea turtles being caught along with the fish. Since sea turtles breathe with lungs, they are unable to return to the surface to breathe and eventually drown. Furthermore, when sea turtles are accidentally caught, their struggles while trapped in fishing nets can damage the nets, causing losses for fishermen.

[0003] To address the problem of accidentally catching sea turtles during trawl fishing, some inventors have installed turtle escape devices on trawl nets. Specifically, a slanted fence panel is installed inside the trawl net's sac, with an escape opening below the fence panel. During trawl fishing, fish can pass through the fence panel into the end of the sac, while sea turtles, once inside, are blocked by the fence panel and can escape through the escape opening. While this current turtle escape device can help sea turtles escape, it has several drawbacks. Fish inside the trawl net can also escape through the escape opening; especially when a large number of fish enter the sac simultaneously, the fish may not be able to pass through the fence panel smoothly. Those fish that cannot pass through the fence panel in time may escape through the escape opening, resulting in losses for fishermen. Summary of the Invention

[0004] The purpose of this invention is to provide a turtle escape trawl net device that can both enable sea turtles to escape from the trawl net and effectively improve the problem of fish escaping through the escape port in the trawl net.

[0005] The technical solution of this invention is:

[0006] A sea turtle escape trawl device includes a net bag and a sea turtle escape device disposed within the net bag. The sea turtle escape device includes:

[0007] A frame is set on the net bag, and a limiting component is provided thereon;

[0008] The fence divides the inner cavity of the mesh bag into two cavities, front and back. One end of the fence is mounted on the frame via a main shaft.

[0009] The escape port is located on the side wall of the mesh bag in the rear cavity and near the limiting element;

[0010] The shielding mesh is connected to the other end of the fence on its front side and to the mesh bag behind the escape opening on its rear side.

[0011] The first elastic element, under its action, causes the other end of the fence to rotate towards the front cavity and abut against the limiting member. At this time, the blocking net covers the escape opening. In this turtle escape device, the escape opening is located on the side wall of the net bag in the rear cavity, and the blocking net covers the escape opening when the other end of the fence abuts against the limiting member. Therefore, during trawl fishing, fish entering the net bag can pass through the fence into the rear cavity. When a large number of fish enter the net bag simultaneously, and the fish cannot pass through the fence smoothly, those fish that cannot pass through the fence in time cannot escape through the escape opening. When a turtle enters the trawl net, it will be blocked by the fence. Subsequently, under the impact of the water flow, the fence will overcome the force of the first elastic element, causing the other end of the fence to rotate backward, and gradually opening the escape opening with the blocking net, allowing the turtle to escape through the escape opening. Therefore, the turtle escape device in this solution can not only enable turtles that have entered the trawl net to escape, but also effectively improve the problem of fish escaping through the escape port in the trawl net.

[0012] As a preferred option, the turtle escape device also includes:

[0013] The secondary shaft and the main shaft are hollow structures. The secondary shaft is rotatably installed inside the main shaft. The side wall of the main shaft is provided with a fence passage. The fence includes a main fence and a secondary fence. One end of the main fence is fixed to the main shaft, and the other end of the main fence abuts against the limiting member. One end of the secondary fence passes through the fence passage and is fixedly connected to the secondary shaft.

[0014] The second elastic element causes the other end of the sub-grid to rotate toward the rear cavity under the action of the second elastic element.

[0015] A fixed magnetic attractor and a moving magnetic attractor that can attract each other, wherein the fixed magnetic attractor is fixed on the frame and the moving magnetic attractor is fixed on the secondary shaft or secondary fence;

[0016] When the other end of the main fence abuts against the limiting member, the fixed magnetic suction member and the moving magnetic suction member attract and overcome the force of the second elastic element acting on the secondary fence, causing the other end of the secondary fence to rotate towards the front cavity and overlap with the main fence. When a large number of fish enter the net bag at the same time, and the fish cannot pass through the fence smoothly, although the fish that cannot pass through the fence in time generally cannot escape through the escape opening, when a large number of fish are stuck in front of the fence, the fish may be squeezed against the fence under the impact of the water flow. The impact of the water flow overcomes the force of the first elastic element, causing the other end of the fence to rotate backward, and driving the blocking net to gradually open the escape opening, resulting in some fish that could not pass through the fence escaping through the opened escape opening. To solve this problem, this solution has further improved the turtle escape device, specifically...

[0017] When the fish are pressed against the fence by the impact of the water flow, the force of the water flow overcomes the force of the first elastic element and the attraction force between the fixed and moving magnetic components. As the other end of the fence rotates backward, the separation distance between the fixed and moving magnetic components increases, and the attraction force between them gradually decreases. When the main fence rotates backward by a set angle (e.g., 5-10 degrees), the second elastic element will overcome the attraction force between the fixed and moving magnetic components, driving the other end of the secondary fence to rotate towards the rear cavity. This effectively increases the gap between the fences and eliminates the obstruction of the secondary fences to the fish, allowing the fish pressed against the fence to pass through quickly. At the same time, fish stuck in front of the fence can pass through smoothly. At this time, the escape hatch is not yet open or has only partially opened, thus effectively solving the above problems.

[0018] Preferably, when the main fence rotates backward by a set angle T from the state of being pressed against the limiting member, the second elastic element will overcome the attraction force between the fixed magnetic suction member and the moving magnetic suction member, and drive the other end of the secondary fence to rotate towards the rear cavity.

[0019] Preferably, one end of the secondary shaft is provided with a mounting plate, and the moving magnetic suction component is fixed on the mounting plate. This facilitates the installation of the moving magnetic suction component.

[0020] Preferably, the mounting plate is located on the outside of the mesh bag, and the moving magnetic suction component is fixed to the mounting plate with bolts. This facilitates the installation, removal, and replacement of the moving magnetic suction component.

[0021] Preferably, both the fixed and moving magnetic components are covered with a waterproof insulating layer on their outer surfaces. This helps protect the fixed and moving magnetic components and extends their service life.

[0022] Preferably, the main fence includes a number of main fence posts arranged sequentially along the axial direction of the main shaft, and the secondary fence includes a number of secondary fence posts arranged sequentially along the axial direction of the secondary shaft, with the main fence posts and secondary fence posts alternating in sequence.

[0023] Preferably, when the other end of the main fence abuts against the limiting member, the other end of the main fence tilts forward, and the tilt angle of the main fence is less than or equal to 10 degrees. When the other end of the main fence abuts against the limiting member, the other end of the main fence tilts forward, which does not affect the fish passing through the fence. When the fish are squeezed against the fence under the impact of the water flow, the impact force of the water flow overcomes the force of the first elastic element and the attraction force between the fixed magnetic suction and the moving magnetic suction. During the process of the other end of the fence rotating backward, before the other end of the main fence tilts backward or at a small angle, the second elastic element can overcome the attraction force between the fixed magnetic suction and the moving magnetic suction, driving the other end of the secondary fence to rotate towards the rear cavity. This effectively increases the gap of the fence and eliminates the obstruction of the secondary fence to the fish. At the same time, since the other end of the main fence has not tilted backward or at a small angle, the fish squeezed against the fence can quickly pass through the fence without sliding down the main fence and passing through the escape opening. This is more conducive to the fish squeezed against the fence passing through the fence quickly. On the other hand, when the other end of the main fence is against the limiting member, the other end of the main fence tilts forward, and the tilt angle of the main fence is less than or equal to 10 degrees. This tilt angle cannot be too large, otherwise when the sea turtle enters the trawl net, it will be blocked by the fence, which will affect the other end of the fence to rotate backward, thus affecting the sea turtle's escape.

[0024] Preferably, the main fence has several protrusions on the side facing the front cavity. When fish are pressed against the fence by the water flow, the protrusions can prevent them from sliding along the main fence. Thus, when fish are pressed against the fence by the water flow, the force of the water flow overcomes the force of the first elastic element and the attraction force between the fixed and moving magnetic elements, causing the other end of the main fence to rotate backward by a set angle (e.g., 10 degrees). The second elastic element overcomes the attraction force between the fixed and moving magnetic elements, driving the other end of the secondary fence to rotate towards the rear cavity, thereby effectively increasing the gap between the fences and eliminating the obstruction of the secondary fences to the fish. At this time, the protrusions can prevent the fish from sliding along the main fence, making it easier for the fish pressed against the fence to pass through quickly.

[0025] Preferably, the other end of the main fence is provided with a rearward-extending mesh support rod, and the blocking mesh is located above the mesh support rod. During the rearward rotation of the other end of the main fence, the mesh support rod blocks the mesh from falling outside the mesh bag. Thus, when the fence resets and the other end rotates forward towards the cavity under the action of the first elastic element and abuts against the limiting member, it facilitates the smooth reset of the blocking mesh and the blocking of the escape opening.

[0026] The beneficial effects of this invention are: it can enable sea turtles that have entered the trawl net to escape, and it can also effectively improve the problem of fish escaping through the escape opening in the trawl net; in particular, it can effectively improve the problem of fish escaping through the escape opening when a large number of fish enter the net bag at the same time and the fish cannot pass through the fence smoothly. Attached Figure Description

[0027] Figure 1 This is a partial structural diagram of a sea turtle escape trawling device of the present invention in a certain state during use (in this diagram, the other end of the main fence abuts against the limiting member, and the fixed magnetic suction member and the moving magnetic suction member are attracted together, and the secondary fence overlaps with the main fence).

[0028] Figure 2 This is a partial structural diagram of the fence according to the present invention.

[0029] Figure 3 yes Figure 1 A partial structural diagram of the fence in the image.

[0030] Figure 4 This is a partial structural diagram of a sea turtle escape trawling device of the present invention in another state during use (in this diagram, the main fence rotates backward from the state of being pressed against the limiting member, and the second elastic element will overcome the attraction force between the fixed magnetic suction member and the moving magnetic suction member, driving the other end of the auxiliary fence to rotate relative to the main fence in the direction of the rear cavity by a set angle T1).

[0031] Figure 5 yes Figure 4 A partial structural diagram of the fence in the image.

[0032] Figure 6 This is a partial structural diagram of a sea turtle escape trawl net device of the present invention in the third state during use.

[0033] In the picture:

[0034] Reticulus 1, anterior cavity 1.1, posterior cavity 1.2;

[0035] Frame 2, limiting component 2.1;

[0036] Fence 3, main fence 3.1, main fence post 3.11, main shaft 3.12, fence opening 3.13, protrusion 3.14, mesh support 3.15, secondary fence 3.2, secondary fence post 3.21, secondary shaft 3.22, mounting plate 3.23;

[0037] Escape port 4;

[0038] 5. Covering mesh panels;

[0039] 6.1 Moving magnetic chuck, 6.2 Fixed magnetic chuck. Detailed Implementation

[0040] The present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments:

[0041] Specific Implementation Example 1, such as Figure 1 , Figure 2 , Figure 3 As shown, a sea turtle escape trawl device includes a net bag 1 and a sea turtle escape device disposed within the net bag 1. The sea turtle escape device includes a frame 2, a fence 3, an escape opening 4, a shielding net 5, and a first elastic element. The frame 2 is disposed within the net bag 1. A limiting member 2.1 is provided on the frame 2. In this embodiment, the frame 2 includes a front frame, a rear frame, and a plurality of connecting rods connecting the front frame and the rear frame. The front frame and the rear frame are circular, rectangular, or other polygonal.

[0042] The fence 3 divides the inner cavity of the net bag 1 into two chambers (i.e., the front chamber 1.1 and the rear chamber 1.2). One end of the fence 3 is rotatably mounted on the frame 2 via the main shaft 3.12. The escape port 4 is located on the side wall of the net bag 1 in the rear chamber 1.2, that is, the escape port 4 is located on the outer shell of the net bag 1 in the rear chamber 1. The escape port 4 and the main shaft 3.12 are located on opposite sides of the net bag 1. The blocking mesh 5 is used to block the escape port 4. The front side of the blocking mesh 5 is connected to the other end of the fence 3, and the rear side of the net bag 1 is connected to the net bag 1 behind the escape port 4.

[0043] The first elastic element is a torsion spring, which is sleeved on the main shaft 3.12. One end of the torsion spring abuts against the frame 2, and the other end abuts against the fence 3. Under the action of the first elastic element, the other end of the fence 3 rotates towards the front cavity 1.1 and abuts against the limiting member 2.1. At this time, the shielding mesh 5 blocks the escape port 4. Of course, it should be noted that the purpose is that the first elastic element can also be a tension spring or rubber band connecting the frame 2 and the fence 3, so that the other end of the fence 3 rotates towards the front cavity 1.1 and abuts against the limiting member 2.1 under the action of the first elastic element.

[0044] In this embodiment of the turtle escape device, since the escape opening 4 is located on the side wall of the net bag 1 in the rear cavity 1.2, the other end of the fence 3 rotates towards the front cavity 1.1 under the action of the first elastic element and abuts against the limiting member 2.1. When the other end of the fence 3 abuts against the limiting member 2.1, the blocking net 5 blocks the escape opening 4. Based on this, during the trawl fishing process, fish entering the net bag 1 can enter the rear cavity 1.2 through the fence 3. When a large number of fish enter the net bag 1 at the same time, the fish cannot pass through the fence 3 smoothly, and the fish that cannot pass through the fence 3 in time cannot escape through the escape opening 4. When the turtle enters the trawl, it will be blocked by the fence 3. Subsequently, under the impact of the water flow, the fence 3 will overcome the force of the first elastic element, causing the other end of the fence 3 to rotate backward, and driving the blocking net 5 to gradually open the escape opening 4, allowing the turtle to escape through the escape opening 4. Therefore, the turtle escape device in this scheme can not only enable turtles that have entered the trawl net to escape, but also effectively improve the problem of fish in the trawl net escaping through the escape port 4.

[0045] Specific embodiment two, such as Figure 1 , Figure 2 , Figure 3 As shown, a sea turtle escape trawl device includes a net bag 1 and a sea turtle escape device disposed within the net bag 1. The sea turtle escape device includes a frame 2, a fence 3, an escape opening 4, a shielding mesh 5, a first elastic element, a secondary shaft 3.22, a second elastic element, and a fixed magnetic attractor 6.2 and a movable magnetic attractor 6.1 that can attract each other. The frame 2 is disposed within the net bag 1. A limiting member 2.1 is provided on the frame 2. In this embodiment, the frame 2 includes a front frame, a rear frame, and a plurality of connecting rods connecting the front frame and the rear frame. The front frame and the rear frame are circular, rectangular, or other polygonal.

[0046] The fence 3 divides the inner cavity of the net bag 1 into two chambers (i.e., the front chamber 1.1 and the rear chamber 1.2). One end of the fence 3 is rotatably mounted on the frame 2 via the main shaft 3.12. The escape port 4 is located on the side wall of the net bag 1 in the rear chamber 1.2, that is, the escape port 4 is located on the outer shell of the net bag 1 in the rear chamber 1. The escape port 4 and the main shaft 3.12 are located on opposite sides of the net bag 1. The blocking mesh 5 is used to block the escape port 4. The front side of the blocking mesh 5 is connected to the other end of the fence 3, and the rear side of the net bag 1 is connected to the net bag 1 behind the escape port 4.

[0047] The first elastic element is a torsion spring, which is sleeved on the main shaft 3.12. One end of the torsion spring abuts against the frame 2, and the other end abuts against the fence 3. Under the action of the first elastic element, the other end of the fence 3 rotates towards the front cavity 1.1 and abuts against the limiting member 2.1. At this time, the shielding mesh 5 blocks the escape port 4. Of course, it should be noted that the purpose is that the first elastic element can also be a tension spring or rubber band connecting the frame 2 and the fence 3, so that the other end of the fence 3 rotates towards the front cavity 1.1 and abuts against the limiting member 2.1 under the action of the first elastic element.

[0048] In this embodiment, the main shaft 3.12 is a hollow structure, and its inner hole forms a shaft hole with openings at both ends. The auxiliary shaft 3.22 is rotatably mounted within the shaft hole of the main shaft 3.12. The auxiliary shaft 3.22 is coaxially distributed with the main shaft 3.12. A fence opening 3.13 is provided on the side wall of the main shaft 3.12.

[0049] The fence 3 includes a main fence 3.1 and a secondary fence 3.2. One end of the main fence 3.1 is fixed to the main shaft 3.12. The other end of the main fence 3.1 abuts against the limiting member 2.1. Specifically, the other end of the main fence 3.1 rotates towards the front cavity 1.1 under the action of the first elastic element and abuts against the limiting member 2.1, while the other end of the torsion spring constituting the first elastic element abuts against the main fence 3.1.

[0050] One end of the secondary fence 3.2 passes through the fence opening 3.13 and is fixedly connected to the secondary shaft 3.22. The other end of the secondary fence 3.2 rotates relative to the main fence 3.1 in the rear cavity 1.2 under the action of the second elastic element. In this embodiment, the second elastic element is a torsion spring, which is sleeved on the secondary shaft 3.22. One end of the torsion spring abuts against the main fence 3.1 or the main shaft 3.12, and the other end abuts against the secondary fence 3.2, so that the other end of the secondary fence 3.2 rotates in the rear cavity 1.2 under the action of the second elastic element.

[0051] The fixed magnetic chuck 6.2 is fixed to the frame 2. The movable magnetic chuck 6.1 is fixed to the secondary shaft 3.22 or the secondary fence 3.2. In this embodiment, both the fixed magnetic chuck 6.2 and the movable magnetic chuck 6.1 are magnets; alternatively, one of the fixed magnetic chuck 6.2 and the movable magnetic chuck 6.1 can be a magnet, and the other can be an iron part.

[0052] When the other end of the main fence 3.1 abuts against the limiting member 2.1, the fixed magnetic attractor 6.2 and the moving magnetic attractor 6.1 are attracted together. The attraction force of the fixed magnetic attractor 6.2 and the moving magnetic attractor 6.1 overcomes the force of the second elastic element acting on the secondary fence 3.2, causing the other end of the secondary fence 3.2 to rotate towards the front cavity 1.1 and overlap with the main fence 3.1. In this embodiment, the overlap of the secondary fence 3.2 and the main fence 3.1 means that the included angle between the secondary fence 3.2 and the main fence 3.1 is zero degrees.

[0053] like Figure 4 , Figure 5 As shown, when the main fence 3.1 rotates backward by a set angle T from its position against the limiting member 2.1, the second elastic element will overcome the attraction force between the fixed magnetic attractor 6.2 and the moving magnetic attractor 6.1, driving the other end of the secondary fence 3.2 to rotate relative to the main fence 3.1 in the direction of the rear cavity 1.2 until the angle between the main fence 3.1 and the secondary fence 3.2 is the set angle T1. The set angle T is 5-15 degrees; in this embodiment, the set angle T is 12 degrees and the set angle T1 is 10 degrees.

[0054] In this embodiment of the turtle escape device, since the escape opening 4 is located on the side wall of the net bag 1 in the rear cavity 1.2, the other end of the fence 3 rotates towards the front cavity 1.1 under the action of the first elastic element and abuts against the limiting member 2.1. When the other end of the fence 3 abuts against the limiting member 2.1, the blocking net 5 blocks the escape opening 4. Based on this, during the trawling process, if... Figure 6 As shown, when the sea turtle enters the trawl net, it will be blocked by the fence 3. Then, under the impact of the water flow, the fence 3 will overcome the force of the first elastic element, causing the other end of the fence 3 to rotate backward, and driving the shielding net 5 to gradually open the escape opening 4, allowing the sea turtle to escape through the escape opening 4.

[0055] Fish that have entered the net bag 1 can enter the rear cavity 1.2 through the fence 3.

[0056] When a large number of fish enter the net bag 1 at the same time, and the fish cannot pass through the fence 3 smoothly, the other end of the fence 3 rotates towards the front cavity 1.1 under the action of the first elastic element and abuts against the limiting member 2.1, and the blocking net 5 blocks the escape opening 4. Therefore, the fish that cannot pass through the fence 3 in time cannot escape through the escape opening 4.

[0057] Furthermore, such as Figure 4 , Figure 5As shown, when a large number of fish simultaneously enter the net bag 1 and cannot pass through the fence 3 smoothly, these fish, which cannot pass through the fence 3 in time, generally cannot escape through the escape opening 4. However, when a large number of fish remain in front of the fence 3, the fish may be squeezed against the fence 3 under the impact of the water flow. This water flow force acts on the fence 3, causing it to overcome the force of the first elastic element, causing the other end of the fence 3 to rotate backward. This rotates the shielding net 5, gradually opening the escape opening 4, allowing some of the fish that could not pass through the fence 3 to escape through the opened escape opening 4. The turtle escape device of this embodiment can effectively solve this problem. Specifically,

[0058] When the fish are pressed against the fence 3 by the impact of the water flow, the impact force of the water flow acts on the fence 3. This impact force overcomes the force of the first elastic element and the attraction force between the fixed magnetic attractor 6.2 and the moving magnetic attractor 6.1. As the other end of the fence 3 rotates backward, the separation distance between the fixed magnetic attractor 6.2 and the moving magnetic attractor 6.1 increases, and the attraction force between them gradually decreases. When the other end of the main fence 3.1 rotates backward by 10 degrees, the second elastic element... The mechanism overcomes the attraction force between the fixed magnetic attractor 6.2 and the moving magnetic attractor 6.1, driving the other end of the secondary fence rod 3.21 to rotate in the direction of the rear cavity 1.2. This effectively increases the gap between the fences 3 and eliminates the obstruction of the secondary fence 3.2 on the fish, allowing the fish squeezed on the fence 3 to pass through the fence 3 quickly. At the same time, the fish stuck in front of the fence 3 can pass through the fence 3 smoothly. Meanwhile, the escape port 4 is not yet open or is only partially open, effectively preventing the fish stuck in front of the fence 3 from escaping through the escape port 4.

[0059] In this embodiment, the frame 2 is located inside the net bag 1 and is connected to the net bag 1 by a connecting rope.

[0060] like Figure 2 As shown, the main fence 3.1 includes several main fence posts 3.11 arranged side by side, with each main fence post 3.11 distributed sequentially along the axial direction of the main shaft 3.12. The length direction of the main fence posts 3.11 extends radially along the main shaft 3.12.

[0061] The secondary fence 3.2 includes several secondary fence bars 3.21 arranged side by side, with each secondary fence bar 3.21 distributed sequentially along the axial direction of the main shaft 3.12. The length direction of the secondary fence bars 3.21 extends radially along the secondary shaft 3.22. The main fence bars 3.11 of the main fence 3.1 and the secondary fence bars 3.21 of the secondary fence 3.2 are distributed alternately in sequence. The fence openings 3.13 correspond one-to-one with the secondary fence bars 3.21, with one end of the secondary fence bar 3.21 passing through the corresponding fence opening 3.13 and connecting to the secondary shaft 3.22. When the other end of the secondary fence 3.2 (i.e., the other end of the secondary fence bar 3.21) rotates relative to the main fence 3.1 in the rear cavity 1.2 direction under the action of the second elastic element until the secondary fence bar 3.21 abuts against the inner wall of the fence opening 3.13, the included angle between the main fence 3.1 and the secondary fence 3.2 is a set angle T1.

[0062] In one embodiment of this invention, one end of the secondary shaft 3.22 extends to the outside of the main shaft 3.12. A mounting plate 3.23 is provided at one end of the secondary shaft 3.22, and the mounting plate 3.23 is fixed to the secondary shaft 3.22. The movable magnetic chuck 6.1 is fixed to the mounting plate 3.23. This facilitates the installation of the movable magnetic chuck 6.1. The movable magnetic chuck 6.1 is located near the edge of the mounting plate 3.23.

[0063] In another embodiment of this invention, both ends of the secondary shaft 3.22 extend to the outside of the main shaft 3.12. Each end of the secondary shaft 3.22 is provided with a mounting plate 3.23. The mounting plate 3.23 is fixed to the secondary shaft 3.22. The mutually engaging fixed magnetic attractors 6.2 and movable magnetic attractors 6.1 are in two sets. In one set, the movable magnetic attractor 6.1 is fixed to one mounting plate 3.23; in the other set, the movable magnetic attractor 6.1 is fixed to another mounting plate 3.23. This facilitates the installation of the movable magnetic attractor 6.1. The movable magnetic attractor 6.1 is located near the edge of the mounting plate 3.23.

[0064] In the third embodiment of this example, the moving magnetic suction component 6.1 is fixed on the sub-fence 3.2.

[0065] Furthermore, the mounting plate 3.23 is located on the outside of the mesh bag 1, and the moving magnetic suction component 6.1 is fixed to the mounting plate 3.23 by bolts. This facilitates the installation, removal, and replacement of the moving magnetic suction component 6.1. It should be noted that the moving magnetic suction component 6.1 is also fixed to the mounting plate 3.23 by adhesive or snap-fit ​​methods.

[0066] Furthermore, the outer surfaces of both the fixed magnetic chuck 6.2 and the moving magnetic chuck 6.1 are covered with a waterproof isolation layer. This helps protect the fixed magnetic chuck 6.2 and the moving magnetic chuck 6.1, extending their service life. In this embodiment, the waterproof isolation layer is made of a plastic shell, and the plastic shell covering the moving magnetic chuck 6.1 has bolt holes. The moving magnetic chuck 6.1 is fixedly mounted on the mounting plate 3.23 through the bolt holes on the plastic shell and the bolts. It should be noted that the waterproof isolation layer can also be a waterproof paint layer or a waterproof rubber layer, etc.

[0067] Furthermore, such as Figure 3 , Figure 4 , Figure 6 As shown, the other end of the main fence 3.1 is provided with a rearwardly extending mesh support rod 3.15. The blocking mesh 5 is located above the mesh support rod 3.15. There are multiple mesh support rods 3.15. During the rearward rotation of the other end of the main fence 3.1, the mesh support rod 3.15 blocks the mesh 5 from the support column, preventing the blocking mesh 5 from falling outside the mesh bag 1; thus, when the fence 3 resets, and the other end of the fence 3 rotates again towards the front cavity 1.1 under the action of the first elastic element and abuts against the limiting member 2.1, it is beneficial for the blocking mesh 5 to reset smoothly and block the escape port 4. In this embodiment, the mesh support rods 3.15 correspond one-to-one with the main fence rods 3.11, and each main fence rod 3.11 has a rearwardly extending mesh support rod 3.15 at its other end. Of course, it should be noted that it is also possible that some main fence rods 3.11 each have a rearwardly extending mesh support rod 3.15 at their other end.

[0068] Furthermore, such as Figure 3 As shown, the main fence 3.1 has several protrusions 3.14 on the side facing the front cavity 1.1. In this embodiment, each main fence bar 3.11 of the main fence 3.1 has several protrusions 3.14, and the protrusions 3.14 on the same main fence bar 3.11 are distributed sequentially along the axial direction of the main fence bar 3.11. In this embodiment, the protrusions 3.14 are spherical protrusions 3.14 or arc-shaped protrusions 3.14.

[0069] When the fish are pressed against the fence 3 by the impact of the water flow, the protrusion 3.14 can prevent the fish from sliding along the main fence 3.1. Thus, when the fish are pressed against the fence 3 by the impact of the water flow, the impact force of the water flow overcomes the force of the first elastic element and the attraction force between the fixed magnetic suction element 6.2 and the moving magnetic suction element 6.1, causing the other end of the main fence 3.1 to rotate backward by a set angle (for example, the other end of the main fence 3.1 rotates backward by 10 degrees). The second elastic element overcomes the attraction force between the fixed magnetic suction element 6.2 and the moving magnetic suction element 6.1, driving the other end of the secondary fence rod 3.21 to rotate in the direction of the rear cavity 1.2, thereby effectively increasing the gap of the fence 3 and eliminating the obstruction of the fish by the secondary fence 3.2. At this time, the protrusion 3.14 can prevent the fish from sliding along the main fence 3.1, which is more conducive to the fish pressed against the fence 3 passing through the fence 3 quickly.

[0070] In this specific embodiment, the remaining structure is the same as in specific embodiment two, except that...

[0071] like Figure 1 , Figure 3 As shown, when the other end of the main fence 3.1 abuts against the limiting member 2.1, the other end of the main fence 3.1 tilts forward (i.e., the other end of the main fence 3.1 tilts towards the front cavity 1.1), and the tilt angle of the main fence 3.1 is less than or equal to 10 degrees. In this embodiment, when the other end of the main fence 3.1 abuts against the limiting member 2.1, the tilt angle of the main fence 3.1 is 10 degrees.

[0072] When the other end of the main fence 3.1 abuts against the limiting member 2.1, the other end of the main fence 3.1 tilts forward, so as not to affect the fish passing through the fence 3. Furthermore, when the fish are pressed against the fence 3 by the impact of the water flow, the impact force of the water flow acts on the fence 3, thereby overcoming the force of the first elastic element and the attraction force of the fixed magnetic suction element 6.2 and the moving magnetic suction element 6.1. As the other end of the fence 3 rotates backward, when the other end of the main fence 3.1 has rotated backward by 10 degrees, before the other end of the main fence 3.1 has tilted backward, the second elastic element can overcome the attraction force of the fixed magnetic suction element 6.2 and the moving magnetic suction element 6.1, driving the other end of the secondary fence rod 3.21 to rotate in the direction of the rear cavity 1.2. This effectively increases the gap of the fence 3 and eliminates the obstruction of the fish by the secondary fence 3.2. Since the other end of the main fence 3.1 has not tilted backward at this time, the fish pressed against the fence 3 can quickly pass through the fence 3 without sliding down along the main fence 3.1 and passing through the escape opening 4. This is more conducive to the fish pressed against the fence 3 passing through the fence 3 quickly.

[0073] On the other hand, when the other end of the main fence 3.1 abuts against the limiting member 2.1, the other end of the main fence 3.1 tilts forward, and the tilt angle of the main fence 3.1 is less than or equal to 10 degrees. This tilt angle cannot be too large, otherwise when the sea turtle enters the trawl net, it will be blocked by the fence 3, which will affect the other end of the fence 3 from rotating backward, thus affecting the sea turtle's escape. Therefore, in this embodiment, when the other end of the main fence 3.1 abuts against the limiting member 2.1, the tilt angle of the main fence 3.1 is set to 10 degrees. In this way, when the sea turtle enters the trawl net and is blocked by the fence 3, the fence 3 can overcome the force of the first elastic element under the impact of the water flow, causing the other end of the fence 3 to rotate backward, and driving the shielding net 5 to gradually open the escape port 4, allowing the sea turtle to escape through the escape port 4.

[0074] In this specific embodiment four, the remaining structure is the same as in specific embodiment two, except that...

[0075] When the other end of the main fence 3.1 abuts against the limiting member 2.1, the other end of the main fence 3.1 tilts backward (i.e., the other end of the main fence 3.1 tilts towards the rear cavity 1.2, not shown in the figure), and the tilt angle of the main fence 3.1 is less than or equal to 10 degrees. In this embodiment, when the other end of the main fence 3.1 abuts against the limiting member 2.1, the tilt angle of the main fence 3.1 is 5 degrees.

[0076] When the other end of the main fence 3.1 abuts against the limiting member 2.1, the other end of the main fence 3.1 tilts back and forth, so as not to affect the fish passing through the fence 3. In addition, when the sea turtle enters the trawl net and is blocked by the fence 3, the fence 3 can overcome the force of the first elastic element under the impact of the water flow, which helps the other end of the fence 3 to rotate backward and drive the shielding net 5 to gradually open the escape opening 4, allowing the sea turtle to escape through the escape opening 4.

[0077] On the other hand, when the fish are pressed against the fence 3 by the impact of the water flow, the impact force of the water flow acts on the fence 3, thereby overcoming the force of the first elastic element and the attraction force of the fixed magnetic suction element 6.2 and the moving magnetic suction element 6.1. As the other end of the fence 3 rotates backward, when the other end of the main fence 3.1 rotates backward by 10 degrees, the angle of backward tilt of the other end of the main fence 3.1 is small. At this time, the second elastic element can overcome the attraction force of the fixed magnetic suction element 6.2 and the moving magnetic suction element 6.1, driving the other end of the secondary fence rod 3.21 to rotate in the direction of the rear cavity 1.2. This effectively increases the gap of the fence 3 and eliminates the obstruction of the fish by the secondary fence 3.2. Since the angle of backward tilt of the other end of the main fence 3.1 is small at this time, the fish pressed against the fence 3 can quickly pass through the fence 3.

[0078] The above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention in any way. Any simple modifications, alterations, and equivalent transformations made to the above embodiments based on the technical essence of the present invention shall still fall within the protection scope of the present invention.

Claims

1. A turtle escape dredging device comprising a net bag and a turtle escape device provided in the net bag, characterized in that, The turtle escape device comprises: a frame arranged on the net bag, and a limiting piece arranged on the frame; a fence separating the inner cavity of the net bag into two cavities, one end of the fence being rotatably arranged on the frame via a main shaft rod, the main shaft rod being a hollow structure; an escape opening arranged on the side wall of the net bag in the rear cavity and close to the limiting piece; a shielding net piece, a front side of the shielding net piece being connected to the other end of the fence, and a rear side of the shielding net piece being connected to the net bag behind the escape opening; a first elastic element, the other end of the fence being rotated to the front cavity direction under the action of the first elastic element and abutting against the limiting piece, at this time, the shielding net piece shields the escape opening; a secondary shaft rod rotatably arranged in the main shaft rod, a fence passing opening being arranged on the side wall of the main shaft rod, the fence comprising a main fence and a secondary fence, one end of the main fence being fixed on the main shaft rod, the other end of the main fence abutting against the limiting piece, one end of the secondary fence passing through the fence passing opening and being fixedly connected with the secondary shaft rod; a second elastic element, the other end of the secondary fence being rotated to the rear cavity direction under the action of the second elastic element; a fixed magnetic attraction piece and a movable magnetic attraction piece capable of being attracted to each other.

2. A turtle escape gillnet apparatus according to claim 1, characterised in that, The fixed magnetic attraction piece is fixed on the frame, and the movable magnetic attraction piece is fixed on the secondary shaft rod or the secondary fence; when the other end of the main fence abuts against the limiting piece, the fixed magnetic attraction piece and the movable magnetic attraction piece are attracted to each other and overcome the force of the second elastic element acting on the secondary fence, so that the other end of the secondary fence is rotated to the front cavity direction and overlaps with the main fence.

3. A turtle escape gillnet apparatus according to claim 2, characterised in that, When the main fence is rotated by a set angle T from the state of abutting against the limiting piece to the rear, the second elastic element will overcome the attraction force of the fixed magnetic attraction piece and the movable magnetic attraction piece to drive the other end of the secondary fence to rotate to the rear cavity direction.

4. A turtle escape dredging device according to claim 2 or 3, characterised in that, One end of the secondary shaft rod is provided with a mounting disc, and the movable magnetic attraction piece is fixed on the mounting disc.

5. A turtle escape gillnet apparatus according to claim 4, characterised in that, The mounting disc is located outside the net bag, and the movable magnetic attraction piece is fixed on the mounting disc via a bolt.

6. A turtle escape gillnet apparatus according to claim 2 or 3, characterised in that, The outer surfaces of the fixed magnetic attraction piece and the movable magnetic attraction piece are both coated with a waterproof isolation layer.

7. A turtle escape gillnet apparatus according to claim 2 or 3, characterised in that, The main fence comprises a plurality of main fence rods distributed along the axial direction of the main shaft rod in sequence, and the secondary fence comprises a plurality of secondary fence rods distributed along the axial direction of the secondary shaft rod in sequence, the main fence rods and the secondary fence rods being alternately distributed in sequence.

8. A turtle escape gillnet device according to claim 2 or 3, characterised in that, When the other end of the main fence abuts against the limiting piece, the other end of the main fence is inclined forward, and the inclination angle of the main fence is less than or equal to 10 degrees.

9. A turtle escape gillnet device according to claim 1 or 2 or 3, characterised in that, The fence is further provided with a plurality of protrusions on the side thereof facing the front cavity.

10. A turtle escape gillnet device according to claim 1 or 2 or 3, characterised in that, The other end of the fence is provided with a net piece supporting rod extending rearward, and the shielding net piece is located above the net piece supporting rod.

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