Bottom side tank structure of bulk cargo ship

Abstract

The invention relates to the technical field of cargo ships, in particular to a bottom side tank structure of a bulk cargo ship, which comprises a cabin, a cabin bottom mechanism is arranged at the bottom of the cabin, the cabin bottom mechanism comprises a lifting ejector rod, the lower end of the lifting ejector rod is fixedly connected with the bottom of the cabin, and the upper end of the lifting ejector rod is fixedly connected with a horizontal bottom plate; the side wall of the cabin is hinged to a side plate through a hinge shaft, and the end, away from the hinge shaft, of the side plate is in lap joint with the upper surface of the bottom plate and can slide along the upper surface. When the lifting ejector rod drives the bottom plate to ascend or descend, the end of the side plate slides on the bottom plate along with the lifting ejector rod, so that the side plate rotates around a hinge shaft to change the inclination angle of the side plate, and a dynamic supporting structure capable of changing along with loads is formed through sliding hinge connection between the side plate and the bottom plate. Therefore, high stress concentration caused by rigid connection is avoided, the risk caused by fatigue cracks is effectively reduced, and the safety and durability of the hull structure are improved.

Description

Technical Field

[0001] This invention relates to the field of cargo ship technology, and more specifically, to a bottom side tank structure for a bulk carrier. Background Technology

[0002] In the field of marine engineering, the structural design of bulk carriers has always faced a core challenge: how to ensure sufficient safety and durability of the hull under complex navigation conditions. Ships are continuously subjected to various dynamic loads during navigation, including but not limited to the periodic impact of waves, changes in weight distribution caused by cargo loading, unloading, and displacement, and thermal stress caused by temperature differences in different sea areas. These loads act together on the hull structure, and are particularly prone to causing significant stress concentrations in areas of abrupt structural changes.

[0003] Traditional ship hull compartments typically connect side compartments and the hull at right angles. While this design is simpler to manufacture, it has inherent mechanical drawbacks. At right-angle connections, the stress transfer path changes abruptly, leading to a high concentration of stress flow lines and making these areas highly susceptible to fatigue crack initiation and propagation. Under long-term alternating loads, these fatigue cracks will gradually extend, potentially causing severe structural strength degradation or even sudden failure, posing a direct threat to the ship's navigational safety.

[0004] Therefore, there is an urgent need for a bottom side tank structure for bulk carriers to improve the shortcomings of existing technologies. Summary of the Invention

[0005] The purpose of this invention is to provide a bottom side tank structure for a bulk carrier, which forms a dynamic, load-responsive support structure through a sliding hinge connection between the side plates and the bottom plate. This avoids the high stress concentration caused by rigid connections, effectively reduces the risk of fatigue cracks, and improves the safety and durability of the hull structure, thereby solving the problems mentioned in the background art. In traditional ship hulls, the side compartments and bottom compartments are usually connected at right angles. At right angles, the stress transmission path changes abruptly, causing stress flow lines to concentrate highly, making it an easy starting point for fatigue crack initiation and propagation.

[0006] To achieve the above objectives, the present invention provides a bottom side tank structure for a bulk carrier, including a ship compartment, the bottom of which is provided with a bottom mechanism, the bottom mechanism including a lifting rod, the lower end of which is fixedly connected to the bottom of the ship compartment, and the upper end of which is fixedly connected to a horizontal bottom plate. The side wall of the cabin is hinged with a side plate, the other end of which overlaps the upper surface of the bottom plate and can slide along the upper surface. When the lifting rod drives the base plate to rise or fall, the end of the side plate slides on the base plate, thereby causing the side plate to rotate about the hinge axis to change its tilt angle.

[0007] As a further improvement to this technical solution, the upper surface of the base plate is provided with a sliding groove extending along its length, the sliding groove being used to limit the maximum and minimum angles of rotation of the side plate.

[0008] The side plate has a pulley on its lower surface, which is housed in the groove and can roll along it. The lower ends of the side plate are fixed with two fixed seats, and a shaft is mounted between the two fixed seats. A scraper is fitted on the shaft and is located between the two fixed seats. The scraper has a through groove running through both ends, and the vertical dimension of the through groove is larger than the diameter of the shaft, so that the bottom of the scraper can always contact the upper surface of the bottom of the groove under its own weight.

[0009] As a further improvement to this technical solution, the side plate is fixedly connected with reinforcing ribs to enhance its structural strength, and the reinforcing ribs extend from top to bottom along the surface of the side plate.

[0010] As a further improvement to this technical solution, the peripheral sidewalls of the bottom plate slide in contact with the inner wall of the cabin, and a sealing strip is provided around the bottom plate to prevent cargo from falling into the gap between the bottom plate and the inner wall of the cabin.

[0011] As a further improvement to this technical solution, a first sealing element is provided on the upper edge of the side plate, and a second sealing element is provided on the side wall of the cabin at a position corresponding to the first sealing element. The upper surface of the first seal is adapted to the shape of the lower surface of the second seal, and is used to maintain the contact seal at the connection between the two during the rotation of the side plate.

[0012] As a further improvement to this technical solution, multiple lifting rods are provided and arranged in an array below the base plate, and the lower end of each lifting rod is fixedly connected to the bottom of the cabin through a base.

[0013] Compared with the prior art, the beneficial effects of the present invention are as follows: The bottom side tank structure of this bulk carrier, firstly, significantly optimizes stress distribution and enhances structural fatigue life. Traditional fixed bottom side tanks suffer from stress concentration at the bulkhead junction. The side plates and bottom plate are connected by a sliding hinge, forming a dynamic support structure that adapts to load changes. This design allows the connection to adapt to deformation through slight displacement and rotation under dynamic loads such as hull bending and wave impact, thus avoiding the high stress concentration caused by rigid connections, effectively reducing the risk of fatigue cracks, and improving the safety and durability of the hull structure. Attached Figure Description

[0014] Figure 1 This is a schematic diagram of the overall structure of the embodiment; Figure 2 This is a schematic diagram of the bottom structure of the embodiment; Figure 3 This is a schematic diagram of the lifting structure of the hull mechanism in an embodiment; Figure 4 This is a schematic diagram of the side plate structure in an embodiment; Figure 5 This is a partially enlarged structural diagram of an embodiment; Figure 6 This is a schematic diagram of the sealing mechanism structure in an embodiment; Figure 7 This is a schematic diagram of the inclined force structure of the side plate in an embodiment.

[0015] The meanings of the labels in the diagram are as follows: 100. Cabin; 200. Side plate; 210. Fixing seat; 211. Shaft; 212. Scraper; 220. Pulley; 230. Reinforcing rib; 300. Bottom mechanism; 310. Lifting rod; 320. Bottom plate; 330. Slide groove; 400. First seal; 410. Second seal. Detailed Implementation

[0016] 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.

[0017] Please see Figures 1-7 As shown, this embodiment provides a bottom side tank structure for a bulk carrier, including a tank 100. The bottom of the tank 100 is provided with a bottom tank mechanism 300. The bottom tank mechanism 300 includes a lifting rod 310. The lower end of the lifting rod 310 is fixedly connected to the bottom of the tank 100, and the upper end is fixedly connected to a horizontal bottom plate 320. The side wall of the cabin 100 is hinged to a side plate 200. The end of the side plate 200 away from the hinge axis overlaps the upper surface of the bottom plate 320 and can slide along the upper surface. When the lifting rod 310 drives the base plate 320 to rise or fall, the end of the side plate 200 slides on the base plate 320, thereby causing the side plate 200 to rotate about the hinge axis to change its tilt angle.

[0018] Currently, in traditional ship hull interiors, side compartments and bottom compartments are typically connected at right angles. At these right-angle connections, the stress transmission path changes abruptly, leading to a high concentration of stress flow lines and making these areas highly susceptible to fatigue crack initiation and propagation. To address this, multiple lifting masts 310 support the bottom plate 320, arranged in a rectangular array below it. The lower end of each lifting mast 310 is fixedly connected to the bottom of the hull compartment 100 via a base. Multiple masts collectively support the bottom plate 320 and the cargo load above it, distributing the concentrated force across multiple support points and avoiding structural deformation or instability that might occur with single-point support. Simultaneously, the base structure more evenly distributes the concentrated load from each mast to the bottom structure of the hull, preventing potential damage to the hull plates from point loads and significantly enhancing the connection strength and reliability between the entire propulsion system and the main hull structure.

[0019] When loading light cargo, the hydraulic pump operates to retract the lifting boom 310, causing the bottom plate 320 to descend. This allows the lower end of the side plate 200 to slide towards the side wall of the hull 100, and the side plate 200 as a whole retracts inward around the top hinge axis, forming a more upright posture. This state not only provides maximum cargo space, but more importantly, when the hull deforms due to the pressure of heavy cargo or the impact of waves, the hinge and sliding between the side plate 200 and the bottom plate 320 allows for changes in position and fine-tuning of the angle of the connection point between the side plate 200 and the bottom plate 320. It is no longer a fixed geometric node, but a node that can buffer and adapt to external deformation through small changes in its own configuration. This disperses the stress originally concentrated at one point to the side wall, hinge axis, side plate 200 body, and bottom plate 320, achieving a smooth transition and redistribution of stress.

[0020] During unloading or loading of heavy cargo, the hydraulic pump drives the lifting boom 310 to extend, lifting the bottom plate 320. The upper surface of the bottom plate 320 pushes the lower end of the side plate 200 outward, forcing the side plate 200 to unfold outward, forming a more inclined slope. This concentrates heavy cargo in the bottom area near the centerline of the hull, avoiding excessive weight distribution on both sides, thus effectively controlling the ship's center of gravity in a lower, more centered ideal position, ensuring navigational stability. This inclined state facilitates cargo sliding to the bottom of the hull during unloading, making unloading easier. In the event of hull torsion or bending, the inclined side plate 200 can absorb and release deformation energy through further fine-tuning of its angle, always avoiding rigid stress locking at the joints.

[0021] When the side panel 200 unfolds outward to form an inclined plane, the vertical pressure (F) from the cargo above is decomposed into two components on this inclined plane: a normal force (Fn) perpendicular to the panel surface and a tangential force (Ft) parallel to the panel surface. The normal force (Fn) perpendicular to the panel surface is mainly converted into a load that compresses the side panel and is efficiently transmitted along its body to the top rigid hinge shaft and side wall frame; while the tangential force (Ft) parallel to the panel surface is converted into a horizontal thrust and vertical pressure on the bottom plate through the pulley 220 at the lower end of the side panel, and is ultimately borne by the array of lifting rods 310.

[0022] Therefore, changing the tilt angle of the side plate 200 is essentially a dynamic adjustment. The more tilted the angle, the more vertical cargo weight is transferred through the bottom plate 320 path, effectively utilizing the strong longitudinal components at the bottom of the hull; at the same time, the lateral pressure borne by the sidewalls is optimized. This active load distribution based on actual loading conditions avoids the localized overload caused by the single and fixed load path in traditional structures, forcing more critical components of the hull to participate in load-bearing collaboratively, thereby significantly enhancing the overall rigidity and deformation resistance at the system level.

[0023] See Figures 2-5 As shown, the side plate 200 continuously bears the pressure from the cargo, the stress from the deformation of the hull, and the inertial force from its own movement under ship navigation and cargo loads. To prevent bending, vibration, or local instability, stiffening ribs 230 extending vertically from top to bottom are fixedly connected to the surface of the side plate 200. These stiffening ribs 230 greatly enhance the bending stiffness of the plate. When the side plate 200 is under load, the stress is effectively transferred to the stiffening ribs 230, which have higher stiffness, and is evenly distributed across the entire plate surface. This significantly suppresses the overall deformation and local buckling of the side plate 200, ensuring that it maintains a stable geometric shape at various tilt angles, providing a solid foundation for the entire movable mechanism.

[0024] An annular gap exists between the periphery of the base plate 320 and the fixed inner wall of the cabin 100. A sealing strip is installed around the periphery of the base plate 320. This sealing strip is made of elastic and wear-resistant rubber. Regardless of the position to which the base plate 320 rises or falls under the drive of the lifting rod 310, the sealing strip around its periphery always maintains sliding contact and elastic compression with the inner wall of the cabin 100. This effectively isolates cargo from the internal space of the mechanism, prevents the intrusion of foreign objects, and ensures a clean working environment and safe operation of the bottom drive mechanism.

[0025] On the upper surface of the base plate 320, a groove 330 extending along its length is provided, with its two ends above the bottom surface of the groove 330 forming physical stops. When the side plate 200 rotates under the lifting drive of the base plate 320, the movement of its lower end is restricted within the stroke range of the groove 330. The end of the groove 330 near the side wall of the cabin 100 determines the minimum angle at which the side plate 200 retracts inward and tends to be upright; while the other end of the groove 330 away from the side wall of the cabin 100 determines the maximum angle at which the side plate 200 unfolds outward.

[0026] A pulley 220 is provided on the lower surface of the side plate 200 to ensure that the lower end of the side plate 200 can slide smoothly and with low resistance in the slide groove 330. The pulley 220 is housed in the slide groove 330, which transforms sliding friction into rolling friction, ensuring that the mechanism can still respond flexibly to the drive when subjected to the pressure of the cargo.

[0027] A scraper 212 is fitted onto the shaft 211, positioned between the two fixed seats 210. As the side plate 200 moves, it travels within the chute 330. During this movement, the scraper 212, under its own weight and in contact with the chute 330, has its bottom edge pressed tightly against the upper surface of the chute bottom. During this travel, the scraper 212 continuously removes and cleans cargo particles, dust, or debris from the chute 330, effectively preventing clogging and ensuring the pulley 220 and the entire motion mechanism operate normally, thus greatly improving the system's reliability.

[0028] Additionally, see Figure 6As shown, a first seal 400 is provided on the upper edge of the side plate 200, while a second seal 410 is provided on the corresponding side wall of the fixed compartment 100. Together, these two form a crucial dynamic sealing interface. Regardless of how the side plate 200 rotates around its hinge axis to change its tilt angle, the first seal 400 and the second seal 410 always maintain a tight fit at the contact interface. This is achieved by designing the contact surfaces of both to be shaped to fit each other. This ensures that a sliding seal is maintained between the two seals throughout the entire rotation range of the side plate 200, effectively preventing fine cargo particles or dust from escaping from the joint between the side plate 200 and the fixed structure of the compartment 100, ensuring the airtightness of the cargo compartment, and preventing debris from falling into the hinge mechanism and affecting its movement.

[0029] In this embodiment, the bottom side tank structure of a bulk carrier, in practical use, firstly, a hydraulic pump drives the synchronous extension and retraction of multiple lifting masts 310 arranged in a rectangular array. These masts distribute the load to the hull through a base, jointly supporting and driving the horizontal bottom plate 320 to rise and fall vertically.

[0030] When unloading or loading lightweight cargo, the lifting boom 310 retracts, and the bottom plate 320 lowers accordingly. This forces the lower end of the side plate 200 to slide along the groove 330 on the upper surface of the bottom plate 320 towards the side wall of the hold 100, thereby causing the side plate 200 to retract inward around the hinge axis at the top, forming a more upright posture to provide the maximum square cargo space. Conversely, when loading heavy cargo, the lifting boom 310 extends, lifting the bottom plate 320. The bottom plate 320 pushes the lower end of the side plate 200 to slide outward along the groove 330, forcing the side plate 200 to unfold outward, forming a more inclined slope. This concentrates heavy cargo in the bottom area near the centerline of the hull, avoiding excessive weight distribution on both sides. This effectively controls the ship's center of gravity to a lower, more central position, ensuring navigational stability. During unloading, it also facilitates the complete sliding out of the cargo under gravity, effectively solving the problem of unloading the hold. Throughout the process, the two ends of the slide 330 act as physical stops, precisely limiting the maximum and minimum angles of rotation of the side plate 200.

[0031] The dynamic structure formed by the hinged connection between the side plate 200 and the side wall of the hull, and the sliding connection with the bottom plate 320, fundamentally solves the stress concentration problem at traditional right-angle connections. When the hull bends or twists due to wave impact or cargo load, the connection point between the side plate 200 and the bottom plate 320 is no longer a rigid node, but can adaptively buffer and absorb energy through small displacements and angle changes, smoothly distributing the originally highly concentrated stress to the hinge shaft, the side plate 200 body, the bottom plate 320, and the lifting rod 310, greatly reducing the risk of fatigue cracks. To ensure the reliability of this moving mechanism, the vertical reinforcing ribs 230 on the surface of the side plate 200 effectively enhance its rigidity and deformation resistance; at the same time, the scraper 212 moves with the side plate 200, automatically scraping away debris in the groove 330 to prevent blockage.

[0032] Finally, the sealing system ensures the cleanliness of the operating environment and the airtightness of the cargo hold. The sealing strip around the bottom plate 320 is always in sliding contact with the inner wall of the hold 100, forming a dynamic seal to prevent cargo from falling into the mechanical space below; while the first seal 400 at the top of the side plate 200 and the second seal 410 on the wall of the hold 100, due to their matching shapes, always maintain sliding contact throughout the entire rotation range of the side plate 200, together forming an effective dust barrier.

[0033] The foregoing has shown and described the basic principles, main features, and advantages of the present invention. Those skilled in the art should understand that the present invention is not limited to the above embodiments. The embodiments and descriptions in the specification are merely preferred examples and are not intended to limit the invention. Various changes and modifications can be made to the invention without departing from its spirit and scope, and all such changes and modifications fall within the scope of the present invention as claimed. The scope of protection of the present invention is defined by the appended claims and their equivalents.

Claims

1. A bottom side hold structure for a bulk carrier, comprising a hold (100), wherein the bottom of the hold (100) is provided with a bottom hold mechanism (300), characterized in that: The bottom mechanism (300) includes a lifting rod (310), the housing end of which is fixedly connected to the bottom of the cabin (100), and the piston rod end is fixedly connected to a horizontal bottom plate (320); the side wall of the cabin (100) is hinged with a side plate (200), the other end of which overlaps the upper surface of the bottom plate (320) and can slide along the upper surface; when the lifting rod (310) drives the bottom plate (320) to rise or fall, the side plate (200) rotates around the hinge axis to change the tilt angle of the side plate (200).

2. The bottom side tank structure of a bulk carrier according to claim 1, characterized in that: The upper surface of the base plate (320) is provided with a groove (330) extending along its length, the groove (330) being used to limit the maximum and minimum angles of rotation of the side plate (200).

3. The bottom side tank structure of a bulk carrier according to claim 2, characterized in that: The maximum angle between the side plate (200) and the horizontal plane is 65 degrees, and the minimum angle between the side plate (200) and the horizontal plane is 35 degrees.

4. The bottom side tank structure of a bulk carrier according to claim 3, characterized in that: The lower surface of the side plate (200) is provided with a pulley (220), which is housed in the groove (330) and can roll along it.

5. The bottom side tank structure of a bulk carrier according to claim 1, characterized in that: The lower ends of the side plate (200) are fixed with mounting bases (210), and a shaft (211) is mounted between the two mounting bases (210). A scraper (212) is fitted on the shaft (211). The scraper (212) is located between the two fixed seats (210) and is used to scrape the cargo at the bottom of the chute (330) to the bottom of the hold.

6. The bottom side tank structure of a bulk carrier according to claim 5, characterized in that: The scraper (212) has a through groove running through both ends. The vertical dimension of the through groove is larger than the diameter of the shaft (211), so that the bottom of the scraper (212) can always contact the upper surface of the bottom of the groove (330) under its own weight.

7. The bottom side tank structure of a bulk carrier according to claim 1, characterized in that: The side plate (200) has a reinforcing rib (230) fixedly connected to its surface to enhance its structural strength. The reinforcing rib (230) extends from top to bottom along the surface of the side plate (200).

8. The bottom side tank structure of a bulk carrier according to claim 1, characterized in that: The peripheral sidewall of the bottom plate (320) slides in contact with the inner wall of the cabin (100), and the periphery of the bottom plate (320) is provided with a sealing strip to prevent cargo from falling into the gap between the bottom plate (320) and the inner wall of the cabin (100).

9. The bottom side tank structure of a bulk carrier according to claim 1, characterized in that: The upper edge of the side plate (200) is provided with a first sealing element (400), and the side wall of the cabin (100) is provided with a second sealing element (410) at a position corresponding to the first sealing element (400). The upper surface of the first seal (400) is adapted to the shape of the lower surface of the second seal (410) to maintain a contact seal at the connection between the two during the rotation of the side plate (200).

10. The bottom side tank structure of a bulk carrier according to claim 1, characterized in that: Multiple lifting rods (310) are provided and arranged in an array below the base plate (320). The lower end of each lifting rod (310) is fixedly connected to the bottom of the cabin (100) through a base.

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