Connection method for port anchor chain, chain connector, and method of manufacturing the same

Abstract

To provide a connection method for a port anchor chain, a chain connector used for the connection method, and a method of efficiently manufacturing the same at low cost such that a long-sized chain can be easily manufactured, which is strong and reliable enough for use as a port anchor chain.SOLUTION: There is provided a connection method for port anchor chain that includes: using a chain connector which has a shaft body in a C link shape and a fastening part consisting of a first lid body and a second lid body; connecting end links, provided at ends of one single chain and the other single chain and having a shaft diameter d, with the shaft body; fitting the first lid body and second lid body to one end part and the other end part of the shaft body; and fixing the first lid body and second lid body integrally through mechanical fastening, wherein the shaft body has a shaft diameter of 1.1d to 1.2d, and the fastening part has an outer thickness of 1.2d to 1.4d.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a method for connecting harbor anchor chains that can be used to lengthen harbor anchor chains used in construction work such as floating breakwaters, floating piers, and mooring buoys, as well as a chain connector that can be used in the method for connecting harbor anchor chains, and a method for manufacturing the same. [Background technology]

[0002] Anchor chains are broadly divided into ship anchor chains and harbor anchor chains. The standard length of a single strand of ship chain is 25m or 27.5m, but harbor anchor chains are longer than ship anchor chains, with a single strand length of 50m or more. There is also a demand for long chains with a single strand length of up to 300m as harbor anchor chains used in construction of floating breakwaters, floating piers, mooring buoys, etc.

[0003] Such long chains are heavy and difficult to heat treat, making them difficult to manufacture as a single unit due to limitations on manufacturing plant capacity. For this reason, a method is used in which single-link chains of a specified length are connected to form a single long chain. For example, a 100-m long chain can be obtained by making four 25-m single-link chains and connecting the chains together with three connectors.

[0004] When connecting individual chains to form a long chain, the strength and reliability of the connector and the ease of the connecting operation are extremely important, and therefore various connectors have been proposed. For example, Patent Document 1 (Japanese Patent Publication No. 56-501134) discloses "a chain connecting link having a link-like assembly including at least one removable member, which allows the assembly to be attached to an end link of a continuous chain portion when the removable member is removed, and which provides a secure link between the chain portions when the removable member is attached, characterized in that the assembly includes at least one member having a flanged end adapted to be preloaded, which provides the link end when the assembly is assembled, and another member forms coupling means for connecting the flanged end, the flanged end being preloaded in compression, and the coupling means being preloaded in tension."

[0005] Previously, due to dimensional limitations imposed on connecting shackles, it was necessary to design the connecting parts so that only small radii could be used for the chamfers, which reduced stress at the internal discontinuities. However, these chamfers on the inside of the assembled shackle created high stress concentrations, resulting in failure under repeated loading after a fewer total number of cycles than would cause failure in a normal stud link chain. In contrast, the chain connecting link described in Patent Document 1 utilizes the principle of reducing stress at the chamfers, which are susceptible to fatigue, by applying a pre-load.

[0006] Furthermore, Patent Document 2 (Jitsu Zen Sho 53-075671) discloses a chain connecting link for connecting two chains or one chain to an anchor or other link, the connecting link having a main portion similar to the corresponding portion of the link of the chain used, with a gap on one side through which the link of the chain can be passed, protrusions protruding outward from the link on each side of the gap, a recess provided in each protrusion on the opposite side to the gap, and a device for freely swinging the link to engage with the protrusions, wherein pressure is applied to the connecting link against its elasticity while the closure member is moved to engage with the recess of the other protrusion, and the closure member and the protrusions have strength appropriate to share the load of tension applied when the chain is in use.

[0007] The chain connecting link described in Patent Document 2 above has the same main parts as each link of the chain to be connected and used, has a gap on one side to allow the link of the chain to be connected to pass through, has a protrusion that protrudes outward at one or both ends of the gap, and can securely attach a gap closing member, so it is said that after connection, it will not malfunction even when used in a capstan or sprocket wheel that operates and functions as one link of the chain. [Prior art documents] [Patent documents]

[0008] [Patent Document 1] Special Publication No. 56-501134 [Patent Document 2] Publication No. 53-075671 Summary of the Invention [Problem to be solved by the invention]

[0009] However, the chain connecting link in Patent Document 1 is for connecting ship anchor chains, and because it has thin-walled sections, it cannot be applied to connecting harbor anchor chains, which require higher strength and reliability than ship anchor chains.In addition, because the structure is complex, it is not suitable for work at construction sites such as floating breakwaters, floating piers, and mooring buoys, where simple operation is required.

[0010] Furthermore, the chain connecting link in Patent Document 2 is also used to connect ship anchor chains, and since it has thin-walled sections, it cannot be used to connect harbor anchor chains, which require higher strength and reliability than ship anchor chains.

[0011] In view of the problems with the prior art as described above, an object of the present invention is to provide a method for connecting harbor anchor chains that can easily produce long chains that are strong and reliable enough to withstand use as harbor anchor chains, a chain connector to be used in said method, and an inexpensive and efficient method for manufacturing the same. [Means for solving the problem]

[0012] In order to achieve the above-mentioned object, the inventors conducted extensive research into the structure of chain connectors, and discovered that it is extremely effective to use a connector that connects a C-link shaped shaft body with two cover bodies, and to set the shaft diameter of the connector to 1.1d to 1.2d based on the shaft diameter of the single-link chain to be connected, and to set the outer thickness of the fastening part (connector) to 1.2d to 1.4d, and thus arrived at the present invention.

[0013] That is, the present invention provides: A chain connector having a C-link shaped shaft and a fastening portion consisting of a first lid and a second lid is used, and end links having a shaft diameter of d provided at the ends of one single-link chain and the other single-link chain are connected by the shaft, and the first lid and the second lid are fitted onto one end and the other end of the shaft, and the first lid and the second lid are fixed together by mechanical fastening, The shaft diameter of the shaft body is set to 1.1d to 1.2d, The outer thickness of the fastening portion is 1.2d to 1.4d. The present invention provides a method for connecting anchor chains for ports, characterized by the above.

[0014] In the past, long harbor anchor chains were typically made by connecting individual link chains with connecting shackles. In this case, the head and pin of the connecting shackle would not fit into the standard link, so it was not possible to connect the standard links with the connecting shackle. Instead, an expansion link had to be attached to the end of the individual link, and a large terminal link had to be attached to the expansion link. In other words, two expansion links, two terminal links, and a connecting shackle were required for one connection, meaning that five or more additional parts were required.

[0015] In contrast, the harbor anchor chain connecting method of the present invention allows the ordinary links at the ends of single-link chains to be connected with a single chain connector, significantly reducing the material costs and labor required to obtain a long harbor anchor chain. Furthermore, when maintaining an existing mooring chain, if partial wear or other issues are found in the chain, conventional technology requires the use of connecting shackles to connect the chain, which means the entire chain subject to maintenance must be replaced. In contrast, the harbor anchor chain connecting method of the present invention allows ordinary links to be connected together, so the worn-out section can be cut off and only the cut-off section replaced and reconnected.

[0016] In addition, by setting the shaft diameter of the chain connector shaft to 1.1d to 1.2d and the outer thickness of the fastening part to 1.2d to 1.4d, based on the shaft diameter d of the links to be connected, the strength and reliability of the connecting part of single chains can be sufficiently ensured, making it suitable for use as a harbor anchor chain, which requires greater strength and reliability than ship anchor chains.A connector called a Kenta shackle is known for connecting ship chains, but the Kenta shackle has thin sections and is at high risk of breaking due to wear and tear from long-term use in a corrosive environment (underwater), so it cannot be used to connect harbor anchor chains.

[0017] In addition, in the method for connecting harbor anchor chains of the present invention, The outer length of the shaft is 6d to 8d. The outer width of the shaft is 3.5d to 5d. The length of the fastening portion is 3.4d to 4.5d, It is preferable that the gap width between the one end and the other end of the shaft body is 1.1d to 1.3d.

[0018] By making the shaft and fastening portion of the chain connector these dimensions, it is possible to achieve a higher level of strength and reliability in the single-link chain connecting portion without compromising workability when connecting single-link chains.

[0019] Furthermore, in the method for connecting a harbor anchor chain of the present invention, it is preferable that the end link is a normal link. The links connected in the method for connecting a harbor anchor chain of the present invention are not limited to normal links, and may be enlarged links or terminal links, but by connecting normal links together, enlarged links or terminal links are not necessary, which reliably reduces the material costs and labor required to obtain a long harbor anchor chain. In this invention, the term "end link" refers to a link located at the end of a single-link chain.

[0020] Furthermore, in the method for connecting harbor anchor chains of the present invention, it is preferable that the shaft and / or the fastening part are made of low alloy steel. There are no particular restrictions on the material of the shaft and / or fastening part of the chain connector as long as the effects of the present invention are not impaired, and various conventionally known materials such as steel for chains used in connecting shackles and chain links can be used, but by using low alloy steel, sufficient strength and reliability can be ensured compared to the single-link chains to be connected, without increasing the size of the chain connector.

[0021] Furthermore, in the method for connecting anchor chains for port use according to the present invention, it is preferable that the mechanical fastening portion is composed of a bolt and a nut, and that the bolt is made of stainless steel. By using a stainless steel bolt, changes in the fastening state of the first cover and the second cover due to corrosion can be suppressed. The stainless steel is not particularly limited as long as it does not impair the effects of the present invention, and various conventionally known stainless steels can be used, such as SUS304, SUS316, and SUS630. In particular, using SUS630, a high-strength material, can suppress shearing of the bolt.

[0022] In addition, in the connecting method of the harbor anchor chain of the present invention, it is preferable to plug the bolted parts with lead and / or weld them. By plugging the bolted parts with lead and / or weld them, loosening of the bolted parts can be effectively suppressed.

[0023] Furthermore, in the method of connecting harbor anchor chains of the present invention, it is preferable that the length of the one single-link chain and / or the other single-link chain is 50 m or more. By making the length of at least one of the connected single-link chains 50 m or more, a long harbor anchor chain can be obtained efficiently.

[0024] The present invention also provides a chain connector used in the harbor anchor chain connecting method of the present invention, The device has a C-link shaped shaft body and a fastening portion consisting of a first lid body and a second lid body, the first lid body and the second lid body are fixed together by a mechanical fastening portion in a state where they are fitted to one end and the other end of the shaft body, thereby enabling the one end and the other end to be fastened together; Also provided is a chain link characterized by:

[0025] The chain connector of the present invention has a shaft body shaped like a C-link and a fastening portion consisting of a first lid body and a second lid body. The first lid body and the second lid body are fitted onto one end and the other end of the shaft body and fixed together by mechanical fastening, thereby fastening one end of the shaft body to the other end.By passing the link at the end of the single-link chain to be connected through the shaft body, single-link chains can be connected together in an extremely simple and efficient manner.

[0026] The size of the chain coupler can be adjusted depending on the size and strength of the individual chains to be connected, and by setting the shaft diameter of the chain coupler's shaft to 1.1d to 1.2d and the outer thickness of the fastening part to 1.2d to 1.4d, based on the shaft diameter d of the connecting links, the strength and reliability of the connecting part of the individual chains can be sufficiently ensured, making it suitable for use as a harbor anchor chain, which requires higher strength and reliability than ship anchor chains.In addition, because the chain coupler does not have any component parts with complex shapes, it can be manufactured easily and inexpensively without using special equipment such as forging machines.

[0027] In addition, in the chain connector of the present invention, the shaft and / or the fastening portion are preferably made of low-alloy steel. The material of the shaft and / or the fastening portion of the chain connector is not particularly limited as long as it does not impair the effects of the present invention, and various conventionally known materials such as steel for chains used in connecting shackles and chain links can be used, but by using low-alloy steel, sufficient strength and reliability can be ensured compared to the single-link chains to be connected, without increasing the size of the chain connector.

[0028] Furthermore, in the chain connector of the present invention, it is preferable that the bolts be made of stainless steel. Using stainless steel bolts can prevent changes in the fastening state of the first and second lids due to corrosion. The stainless steel is not particularly limited as long as it does not impair the effects of the present invention, and various conventionally known stainless steels can be used, such as SUS304, SUS316, and SUS630. In particular, using SUS630, a high-strength material, can prevent shearing of the bolts.

[0029] In addition, the chain connector of the present invention is lighter than conventional connecting shackles, making it easier to handle during connecting work at the chain connecting site. More specifically, the lightweight chain connector makes it possible to connect single-link chains without using a crane or the like.

[0030] Furthermore, the present invention provides A method for manufacturing a chain connector of the present invention, comprising: a bending process for obtaining a shaft body having a C-link shape by bending a round steel bar; a machining step for obtaining the first lid body and the second lid body by machining the rolled steel material; Also provided is a method for manufacturing a chain link, characterized by:

[0031] Manufacturing a C-link shaft by die forging requires a forging die, resulting in high initial costs. Additionally, since there are dozens of different nominal chain diameters, manufacturing chain connectors for each chain requires a large number of forging dies, significantly increasing the initial cost. In contrast, machining a C-link shaft allows for the efficient production of chain connectors of various shapes and sizes.

[0032] Furthermore, by manufacturing the first and second lid bodies by machining rolled steel, the dimensional accuracy of the first and second lid bodies can be increased, and rattle can be suppressed when the first and second lid bodies and the shaft body are fixed together. [Effects of the Invention]

[0033] According to the present invention, it is possible to provide a method for connecting port anchor chains that can easily produce long chains that are strong and reliable enough to withstand use as port anchor chains, a chain connector used in said connecting method, and an inexpensive and efficient method for manufacturing the same. [Brief explanation of the drawings]

[0034] [Figure 1] 1 is a schematic diagram showing one embodiment of a chain connector of the present invention. [Figure 2] FIG. 10 is a schematic diagram showing another embodiment of the chain connector of the present invention. [Figure 3] FIG. 2 is a schematic diagram showing the size of the chain connector of the present invention. [Figure 4] FIG. 1 is a schematic diagram of a conventional single-link chain. [Figure 5] FIG. 1 is a schematic diagram showing a conventional method for connecting single-link chains. [Figure 6] 1 is a schematic diagram showing a method of connecting a single-link chain when using the chain connector of the present invention. FIG. [Figure 7] 2 is a schematic diagram of components of the chain connector 2. FIG. [Figure 8] 2 is a schematic diagram showing a state in which a first lid body 6 is fitted onto a shaft body 4. FIG. [Figure 9] FIG. 2 is a schematic diagram showing a state in which a fastening portion 10 has been formed. [Figure 10] 8 is a schematic diagram showing a state in which a first lid body 6 different from that in FIG. 7 is fitted onto a shaft body 4. FIG. [Figure 11] 8 is a schematic diagram showing a state in which a fastening portion 10 is formed by a first cover body 6 and a second cover body 8 different from those in FIG. 7. FIG. [Figure 12] 1 is a photograph showing the appearance of a resin chain connector. [Figure 13] This is a photograph of the appearance of regular links connected together using a resin chain connector. [Figure 14] This is the result of a stress analysis when a 2580kN load is applied to an SBC690 chain connector. [Figure 15] This is the result of a stress analysis when a 3690kN load is applied to an SBC690 chain connector. [Figure 16] This is the result of a stress analysis when a load of 2580kN is applied to a chain connector made of SCM435. [Figure 17] This is the result of a stress analysis when a load of 3690kN is applied to a chain connector made of SCM435. DETAILED DESCRIPTION OF THE INVENTION

[0035] Representative embodiments of the harbor anchor chain connecting method, chain connector, and manufacturing method thereof of the present invention will be described in detail below with reference to the drawings. However, the present invention is not limited to those shown in the drawings, and since each drawing is intended to conceptually explain the present invention, ratios and numbers may be exaggerated or simplified as necessary to make it easier to understand. Furthermore, in the following description, the same or equivalent parts will be given the same reference numerals, and duplicate explanations may be omitted.

[0036] 1. Chain connector 1 and 2 show schematic diagrams of one embodiment and another embodiment of the chain connector of the present invention, respectively. The chain connector 2 has a shaft 4 having a generally C-link shape and a fastening portion 10 consisting of a first cover 6 and a second cover 8. The first cover 6 and the second cover 8 are fitted to one end and the other end of the shaft 4 and fastened together with a bolt and nut, thereby fastening the one end and the other end. This configuration of the chain connector 2 eliminates the need for thick parts such as the head and pin of conventional connecting shackles, making on-site connecting work easier and more efficient.

[0037] The first lid body 6 and the second lid body 8 are provided with threaded portions 12, and by mechanically fastening the first lid body 6 and the second lid body 8 with screws or bolts while they are in face-to-face contact, a fastening portion 10 is obtained in which the first lid body 6 and the second lid body 8 are integrated. In the case of FIG. 1, the first lid body 6 is thicker than the second lid body 8, and the threaded portions 12 are arranged to line up in the axial direction of the shaft body 4. In the case of FIG. 2, the first lid body 6 and the second lid body 8 are approximately the same thickness, and the threaded portions 12 are arranged to line up in the radial direction of the shaft body 4.

[0038] It is preferable that one end and the other end of the shaft 4 and the first and second lids 6 and 8 have a concave-convex shape (stepped shape) so as to interlock with each other. The concave-convex shape allows the C-link shape to exhibit high resistance to a load applied in the opening direction in particular.

[0039] Furthermore, when the first and second lids 6 and 8 are fitted onto one end and the other end of the shaft 4 and fixed together with bolts and nuts, it is preferable that there are no gaps inside the fastening portion 10. The first and second lids 6 and 8 are in close contact with the shaft 4, and the first and second lids 6 and 8 are in close contact at the opening of the shaft 4, allowing the chain connector 2 as a whole to exhibit high strength and reliability.

[0040] The relationship between the size of the chain coupler 2 and the shaft diameter d of the linked links is shown in Figure 3. The shape and size of the chain coupler 2 can be determined according to the end links of the single-link chains to be linked, but by using the shaft diameter d of the linked links as a reference and setting the shaft diameter of the shaft body 4 to 1.1d to 1.2d and the outer thickness of the fastening part 10 to 1.2d to 1.4d, the strength and reliability of the linked parts of the single chains can be fully ensured, making it suitable for use as a harbor anchor chain, which requires greater strength and reliability than ship anchor chains.

[0041] It is also preferable that the outer length of the shaft 4 be 6d to 8d, the outer width of the shaft 4 be 3.5d to 5d, the length of the fastening portion 10 be 3.4d to 4.5d, and the gap width between one end of the shaft 4 be 1.1d to 1.3d. By setting the shaft 4 and fastening portion 10 of the chain connector 2 to these dimensions, it is possible to achieve a higher level of strength and reliability in the single-link chain connection portion without compromising the ease of connecting single-link chains. In particular, setting the outer length of the shaft 4 to 6d or more facilitates the connection of the links to be fastened, and setting it to 8d or less reduces the amount of deformation when a load is applied. Similarly, setting the outer width of the shaft 4 to 3.5d or more facilitates the connection of the links to be fastened, and setting it to 5d or less reduces the amount of deformation when a load is applied.

[0042] Here, harbor anchor chains are installed underwater for several years to over a decade, and are maintained in a severely corrosive environment for long periods of time. Therefore, a thin Kenta shackle cannot be used because it would break due to corrosion and wear. In contrast, the thickness of the fastening part 10 of the chain connector 2 is set large, taking into account corrosion and wear. Also, taking into account wear of the chain links due to the difference in hardness with the chain connector 2, it is preferable that the difference in hardness between the chain connector 2 and the chain links is not too large. Note that the use of chain parts made from materials one rank higher is permitted for anchor chains.

[0043] Furthermore, the shaft 4 and / or the fastening portion 10 (first cover 6 and second cover 8) are preferably made of low alloy steel. The material of the shaft 4 and / or the fastening portion 10 is not particularly limited as long as it does not impair the effects of the present invention, and various conventionally known materials such as steel for chains used in connecting shackles and chain links can be used, but by using low alloy steel, sufficient strength and reliability can be ensured compared to the single-link chains to be connected, without increasing the size of the chain coupler 2. Examples of low alloy steel that can be used include SCM435 and SNCM431.

[0044] Furthermore, the bolts for fastening the first cover 6, the second cover 8, and the shaft 4 together are preferably made of stainless steel. Using stainless steel bolts can prevent changes in the fastening state of the first cover 6 and the second cover 8 due to corrosion. The stainless steel is not particularly limited as long as it does not impair the effects of the present invention, and various conventionally known stainless steels can be used, such as SUS304, SUS316, and SUS630. In particular, using SUS630, which is a high-strength material, can prevent the bolts from shearing.

[0045] 2. Manufacturing method of chain connector The greatest feature of the chain connector manufacturing method of the present invention is that the first cover 6, second cover 8, and shaft 4 are manufactured by bending and machining steel material without using die forging. This eliminates the need to prepare forging dies, significantly reduces the initial processing costs, and enables efficient, low-cost manufacturing of a wide variety of small-lot chain connectors.

[0046] The method for manufacturing a chain connector of the present invention includes a bending process for obtaining a shaft body having a C-link shape by bending round steel, and a machining process for obtaining a first cover body and a second cover body by machining a rolled steel material. Here, it is preferable to give one end and the other end of the shaft a concave-convex shape (a stepped shape) by machining.

[0047] It is preferable to subject the materials of the first lid 6, the second lid 8, and the shaft 4 to an appropriate heat treatment. Machining may be performed either before or after the heat treatment, but high machining accuracy can be achieved by performing the machining after the heat treatment.

[0048] The shapes, sizes, materials, etc. of the first lid body 6, the second lid body 8, and the shaft body 4 are as described in "1. Chain connector."

[0049] 3.How to connect anchor chains for harbors Figure 4 is a schematic diagram of a connected single-link chain, and Figure 5 shows a conventional method for connecting single-link chains. In order to connect two single-link chains 20 together with a connecting shackle 22, the inner diameter of the links located at the ends of the single-link chain 20 must be sufficiently large, and this is generally configured as a normal link 24, an expansion link 26, and a terminal link 28. For this reason, the connecting section is composed of the connecting shackle 22, two expansion links 26, and two terminal links 28, requiring a total of five additional parts.

[0050] Therefore, when manufacturing a single-link chain 20 that is connected with connecting shackles 22, it is necessary to individually manufacture the enlarged links 26 and the terminal links 28 in addition to the regular links 24. Since the shaft diameters and dimensions of each link are all different, material costs and manufacturing man-hours increase.

[0051] Figure 6 shows how to connect single-link chains using the chain connector of the present invention. The shaft 4 of the chain connector 2 has a substantially uniform thickness throughout, and does not have a thickened head or pin like the connecting shackle 22, so it can connect ordinary links 24 together. As a result, the connecting section can be constructed using only the chain connector 2.

[0052] In addition, when comparing the weight of the connecting shackle 22 and the chain coupler 2 for a nominal diameter of 70 mm, the connecting shackle 22 weighs 80 kg and the chain coupler 2 weighs 50 to 60 kg. In other words, the chain coupler 2 of the present invention is 35 to 47% lighter than the conventional connecting shackle 22. As a result, the work of connecting single-link chains can sometimes be carried out without using a crane.

[0053] Here, the objects to be connected with the chain connector 2 are not limited to the normal links 24, but may also be connected as needed to the enlarged links 26 and terminal links 28. When connecting the enlarged links 26 and terminal links 28, the size and material of the chain connector 2 can be adjusted appropriately depending on the shaft diameter, strength, etc. of these links.

[0054] More specifically, by setting the shaft diameter of the shaft body 4 to 1.1d to 1.2d and the outer thickness of the fastening portion 10 to 1.2d to 1.4d, based on the shaft diameter d of the links connected by the chain connector 2, the strength and reliability of the connecting portion of the single-link chain can be fully ensured, making it suitable for use as a harbor anchor chain, which requires higher strength and reliability than ship anchor chains.

[0055] It is also preferable that the outer length of the shaft 4 be 6d to 8d, the outer width of the shaft 4 be 3.5d to 5d, the length of the fastening portion 10 be 3.4d to 4.5d, and the gap width between one end of the shaft 4 and the other be 1.1d to 1.3d. By setting the shaft 4 and fastening portion 10 of the chain connector 2 to these dimensions, it is possible to achieve a higher level of both strength and reliability in the connecting portion of the single link chains without compromising workability when connecting single link chains.

[0056] It is preferable to use lead plugs and / or welding to fasten the bolted portions that integrally fasten the first cover 6, the second cover 8, and the shaft 4. By using lead plugs and / or welding to fasten the bolted portions and making them fixed, loosening of the bolted portions can be effectively prevented.

[0057] Furthermore, by using the chain connector 2 to connect single-link chains each having a length of 50 m or more, a long harbor anchor chain can be efficiently obtained.

[0058] The method of using the chain connector 2 will be described in more detail below. FIG. 7 shows the shaft 4, first lid 6, second lid 8, bolt 30, and nut 32 that make up the chain connector 2. As shown in FIG. 8, the first lid 6 is fitted onto the shaft 4, and as shown in FIG. 9, the bottom surfaces of the first lid 6 and second lid 8 are brought into contact with each other to form a fastening portion 10. Next, the bolt 30 and nut 32 are inserted into the threaded portions 12 provided on the first lid 6 and second lid 8, thereby completing the chain connector 2 as a strong annular member. Here, one end and the other end of the shaft 4 are provided with a concave-convex shape (stepped shape), and the first lid 6 and / or second lid 10 are provided with a corresponding shape to fit into this.

[0059] 10 and 11 show cases where the shapes and sizes of the first lid body 6 and the second lid body 8 that make up the fastening portion 10 are different from those in FIG. 7. In the case of FIG. 7, most of the shaft body 4 is contained within the first lid body 6, and the second lid body 8 is thin. In contrast, in the case of FIG. 10, the first lid body 6 and the second lid body 8 have approximately the same thickness. Also, in the case of FIG. 7, the threaded portion 12 is provided in the axial direction of the shaft body 4, while in the case of FIG. 10, the threaded portion 12 is provided in the radial direction of the shaft body 4.

[0060] The method for connecting harbor anchor chains, the chain connector, and the method for manufacturing the same will be further explained below with reference to examples, but the present invention is not limited to these examples in any way. [Example]

[0061] <Model prototype of chain connector> A resin model of the chain connector shown in Figure 10 was produced using a resin layering 3D modeling device (i3 Mega manufactured by ANYCUBIC). The resin used was PLA resin (polylactic acid) manufactured by OVERTURE. The resulting resin model is shown in Figure 12.

[0062] Figure 13 shows the state of connecting standard links using the resulting resin model. After passing the standard links through the shaft, the shaft and cover are simply fitted together and fastened with bolts, demonstrating how simple it is to connect single-link chains together.

[0063] <Strength evaluation of chain connectors> A strength analysis was carried out on the chain connector having the shape shown in Figures 7 to 9 using a third-class material with a nominal diameter of 70 mm. The analysis was carried out using ANSYS Mechanical, a finite element analysis software made by ANSYS. The shaft, first lid, and second lid were all made of SBC690, and the shaft, first lid, and second lid were fixed together. The shaft diameter was 77 mm, the outer thickness of the fastening part consisting of the first and second lids was 98 mm, the outer length of the shaft was 525 mm, the outer width of the shaft was 280 mm, the length of the fastening part was 242 mm, and the gap width between one end of the shaft and the other end was 80 mm. The yield point of SBC690 was 410 N / mm 2 , tensile strength is 690N / mm 2 SBC690 assumes that the chain connector is made from the same material as the chain.

[0064] The analysis was carried out using load values ​​of 3690kN, which is the breaking load of a 70mm stud-equipped chain made of third-class material, and 2580kN, which is the yield strength. Figure 14 shows the state of the shaft when the yield strength load is applied. The maximum stress generated was 1318N / mm 2 The maximum displacement was 14.5 mm, and no fracture occurred. Figure 15 shows the state of the shaft when the breaking load was applied. The maximum stress was 1521 N / mm 2 The maximum displacement was 43.1 mm, and although the displacement was large, no breakage occurred, indicating that chain connectors made from SBC690 can be used as connectors for third-class material 70 mm stud-equipped chains.

[0065] The analysis was carried out on SCM435 chain connectors using load values ​​of 3690kN, which is the breaking load of a 70mm stud-equipped chain made of third-class material, and 2580kN, which is its yield strength. Other than using SCM435 as the material, the shape and size of the chain connectors were not changed. The yield point of SCM435 is 785N / mm 2 , tensile strength is 930N / mm 2 SCM435 is intended for cases where the chain connector is made of a material stronger than the chain.

[0066] The state of the shaft when the proof load is applied is shown in Figure 16. The maximum stress generated is 1974 N / mm 2 The maximum displacement was 4.3 mm, and although the local stress was high due to the resistance to deformation, no fracture occurred. Figure 17 shows the state of the shaft when a breaking load was applied. The maximum stress generated was 2233 N / mm 2 The maximum displacement was 7.9 mm, and although the local stress was even higher, no fractures occurred. It was also confirmed that by using SMC435, the deformation of the chain connector could be reduced to about one-fifth of that of SBC690. [Explanation of symbols]

[0067] 2. Chain connector, 4... shaft body, 6... First cover body, 8... Second cover body, 10. Fastening part, 12....Screw processing part, 20···Single-link chain, 22···Connecting shackle, 24...Normal link, 26... Expanded link, 28···Terminal link, 30 volts, 32···Nut.

Claims

1. A chain connector having a C-link shaped shaft and a fastening portion consisting of a first lid and a second lid is used, and end links having a shaft diameter of d provided at the ends of one single-link chain and the other single-link chain are connected by the shaft, and the first lid and the second lid are fitted onto one end and the other end of the shaft, and the first lid and the second lid are fixed together by mechanical fastening, The shaft diameter of the shaft body is 1.1d to 1.2d, The outer thickness of the fastening portion is 1.2d to 1.4d; A method for connecting anchor chains for use in ports, characterized by the above.

2. The outer length of the shaft is 6d to 8d. The outer width of the shaft is 3.5d to 5d, The length of the fastening portion is 3.4d to 4.5d, The gap width between the one end and the other end of the shaft is 1.1d to 1.3d; 2. The method for connecting anchor chains for use in harbors according to claim 1,

3. the end link is a normal link; 3. A method for connecting anchor chains for use in harbors according to claim 1 or 2.

4. The shaft body and / or the fastening portion are made of low alloy steel; 3. A method for connecting anchor chains for use in harbors according to claim 1 or 2.

5. The mechanical fastening is performed using stainless steel bolts.

3. A method for connecting anchor chains for use in harbors according to claim 1 or 2.

6. Lead plugging and / or welding of bolted joints; 6. The method for connecting anchor chains for use in harbors according to claim 5,

7. The length of the one single-link chain and / or the other single-link chain is 50 m or more; 3. A method for connecting anchor chains for use in harbors according to claim 1 or 2.

8. A chain connector used in the harbor anchor chain connecting method according to claim 1 or 2, a C-link shaped shaft body and a fastening portion consisting of a first lid body and a second lid body; the first lid body and the second lid body are fixed together by a mechanical fastening portion in a state where they are fitted to one end and the other end of the shaft body, thereby enabling the one end and the other end to be fastened together; A chain connector characterized by:

9. the shaft body and / or the fastening portion are made of low alloy steel; 9. The chain link according to claim 8,

10. The mechanical fastening portion is composed of a bolt and a nut, the bolt is made of stainless steel; 9. The chain link according to claim 8,

11. A method for manufacturing the chain connector according to claim 8, comprising the steps of: a bending process for obtaining a shaft body having a C-link shape by bending a round steel bar; a machining step for obtaining the first lid body and the second lid body by machining the rolled steel material; A method for manufacturing a chain connector, characterized by:

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