Assembly of casing and cap for fluid leak detector for marine hose, and fluid leak detection system for marine hose

Abstract

To provide an assembly of a casing and a cap, capable of improving durability of a detector, reducing a risk of damage on both a detector and an object due to contact therebetween, and ensuring an excellent radio communication state with the detector, and a fluid leak detection system of a marine hose comprising the same.SOLUTION: In a casing 18 in which a pressure sensor part 15 and an IC tag 12 are accommodated in a pressure holding chamber 18c formed by a base part 18a and a radio wave transmission part 18b, three or more metal projection parts 19 are made to protrude from the base part 18a above the radio wave transmission part 18b at intervals in a circumferential direction at positions on the outer peripheral side of the radio wave transmission part 18b in a plan view; the upper end parts of the projection parts 19 are spaced apart; and in a state where a resin or rubber annular cap 20 that continuously covers the upper end part of each projection part 19 in the circumferential direction in plan view is fixed to the casing 18, an inner peripheral side region and an outer peripheral side region of each protrusion part 19 communicate with each other through a gap between the lower end parts of the protrusion parts 19 circumferentially adjacent to each other.SELECTED DRAWING: Figure 5

Description

[Technical field]

[0001] The present invention relates to a casing and cap assembly for a marine hose fluid leak detector and a marine hose fluid leak detection system, and more specifically to a casing and cap assembly that improves the durability of the detector, reduces the risk of damage to both the detector and an object due to contact therebetween, and ensures good wireless communication with the detector, and a marine hose fluid leak detection system equipped with this assembly. [Background technology]

[0002] In marine hoses, a fluid retention layer is provided between reinforcing layers to temporarily store leaked fluid in the fluid retention layer and prevent it from leaking out of the hose. Various fluid leakage detection systems have been proposed to detect fluid leakage into the fluid retention layer (for example, see Patent Document 1).

[0003] In the fluid leak detection system proposed in Patent Document 1, the fluid retention layer can be connected to the detector via a communication pipe. When fluid flows into the fluid retention layer, the pressure in the pressure holding chamber formed inside the casing of the detector increases through the communication pipe. This pressure change can be obtained by a communication device using a return radio wave from a passive IC tag as detected pressure data by the pressure sensor unit, which is useful for reliably detecting fluid leaks while facilitating the work of checking for fluid leaks.

[0004] Since the pressure sensor unit and the IC tag are housed in the pressure chamber, the upper side of the pressure chamber in the casing is covered with a radio wave transparent portion. The radio wave transparent portion is arranged in an exposed state protruding from the surface of the marine hose in order to improve radio wave communication with the communication device. Therefore, when the marine hose is installed at sea, when it is retrieved on a ship, or when the marine hose is used at sea, there is a high risk that the radio wave transparent portion will be damaged by an external force from some object. On the other hand, simply installing a metal cover or the like around the upper periphery of the radio wave transparent portion for protection will impair the quality of radio wave communication. In addition, there is a risk that the object that comes into contact with the metal cover will be damaged. Therefore, there is room for improvement in order to improve the durability of the detector, reduce the risk of damage to both the detector and the object due to contact between them, and ensure good wireless communication with the detector. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Patent Publication No. 2021-46929 Summary of the Invention [Problem to be solved by the invention]

[0006] An object of the present invention is to provide a casing and cap assembly that improves the durability of a detector, reduces the risk of damage to both the detector and an object due to contact between them, and ensures good wireless communication with the detector, and a marine hose fluid leak detection system that includes this assembly. [Means for solving the problem]

[0007] In order to achieve the above object, the present invention provides an assembly of a casing and cap for a marine hose fluid leak detector, which is installed on the surface of a marine hose and connected so as to be capable of communicating with a fluid retention layer formed on the marine hose, and a cap fixed to the casing, wherein the casing has a metallic cylindrical base, a radio wave transparent portion that watertightly blocks the upper end side of the base, and three or more metallic protrusions that protrude from the base above the radio wave transparent portion, a pressure holding chamber is formed by being surrounded by the base and the radio wave transparent portion, and in a plan view, each of the protrusions is disposed at an outer circumferential side position of the radio wave transparent portion with intervals in the circumferential direction, and each of the The upper ends of the protrusions are spaced apart, and the pressure holding chamber houses a pressure sensor unit and a passive IC tag connected to the pressure sensor unit. The cap is an annular body made of resin or rubber that continuously covers the upper ends of each of the protrusions in a circumferential direction when viewed in a plane, and is formed with engagement portions that engage with the upper ends of each of the protrusions. When the engagement portions engage with the upper ends of each of the protrusions and the cap is positioned at the upper ends of each of the protrusions and fixed to the casing, the inner region of each of the protrusions and the outer region of each of the protrusions are connected through the circumferential gaps between the lower ends of circumferentially adjacent protrusions.

[0008] The marine hose fluid leak detection system of the present invention comprises a casing and cap assembly for the above-mentioned marine hose fluid leak detector, a detector having the pressure sensor unit and the IC tag housed in the pressure holding chamber, a connecting pipe extending over the surface of the marine hose to connect the fluid retention layer and the detector so as to enable communication between them, a check valve that allows flow only from the connecting pipe side to the pressure holding chamber side, and a radio wave transmitter and radio wave receiver arranged on the outside of the marine hose, and is characterized in that a reply radio wave is transmitted from the IC tag in response to the transmitted radio wave transmitted from the radio wave transmitter, and pressure data detected by the pressure sensor unit is sent by the reply radio wave and received by the radio wave receiver. Effect of the Invention

[0009] According to the assembly of the present invention, three or more metal protrusions protruding above the radio wave transparent portion are arranged at intervals in the circumferential direction on the outer periphery of the radio wave transparent portion in a plan view, and the upper surface of the radio wave transparent portion is protected by these protrusions. This is advantageous in reducing the risk of damage to the radio wave transparent portion and improving the durability of the detector. Furthermore, since each protrusion is arranged at intervals in the circumferential direction and the upper ends of each protrusion are spaced apart from each other in a plan view, the disadvantage of these protrusions impairing the quality of radio wave communication with the detector is avoided.

[0010] The upper end of each protrusion is covered by a cap, which is a resin ring-shaped body that is continuous in the circumferential direction in a plan view, so that even if the upper end of each metal protrusion comes into contact with some object, it is advantageous to reduce the risk of damage to both the detector and the object. Moreover, when the cap is fixed to the casing, the inner peripheral region of each protrusion and the outer peripheral region of each protrusion communicate with each other through the circumferential gap between the lower ends of the circumferentially adjacent protrusions, so that the force that the cap receives from waves is reduced, which is advantageous for stably fixing the cap to the casing for a long period of time. In addition, since the cap is a ring-shaped body, the upper surface of the radio wave transmission part is not entirely covered by the cap, and it is possible to avoid impairing the quality of radio wave communication with the detector.

[0011] According to the fluid leakage detection system of the present invention, good radio communication can be maintained for a long period of time between the radio wave transmitter and radio wave receiver arranged on the outside of the marine hose and the detector (IC tag). Therefore, the ease of checking for fluid leakage and the reliability of detection can be ensured for a long period of time. In addition, even if an object comes into contact with the detector, the risk of damage to both the detector and the object can be reduced for a long period of time. [Brief description of the drawings]

[0012] [Figure 1] FIG. 1 is an explanatory diagram illustrating a marine hose to which the present invention is applied. [Diagram 2] 1 is an explanatory diagram illustrating an embodiment of a fluid leak detection system in an enlarged longitudinal cross-sectional view of a portion of a marine hose. [Diagram 3] 3 is an explanatory diagram illustrating the detector of FIG. 2 as seen from the side; [Figure 4] 4 is an explanatory diagram illustrating the detector of FIG. 3 as viewed from above. [Diagram 5] 5 is an explanatory diagram illustrating a detector in a cross-sectional view taken along line AA in FIG. 4 (longitudinal cross-sectional view). [Figure 6] 6 is an explanatory diagram illustrating the inside of the pressure holding chamber in FIG. 5 as viewed from above. [Figure 7] 5 is an explanatory diagram illustrating the detector of FIG. 4 with the cap removed as viewed from above. FIG. [Figure 8] 8 is an explanatory diagram illustrating the casing in FIG. 7 as seen from the side. [Figure 9] 5 is an explanatory diagram illustrating the cap of FIG. 4 as viewed from the bottom. FIG. [Figure 10] 6 is an explanatory diagram illustrating a state in which the detector in FIG. 5 is disassembled. [Figure 11] 6 is an explanatory diagram illustrating a state in which a cap is attached to the casing in FIG. 5. FIG. [Figure 12] 1 is an explanatory diagram illustrating a vertical cross-sectional view of a detector communicating with a communication device; [Figure 13] FIG. 13 is an explanatory diagram showing a modified example of the assembly in vertical cross section. [Figure 14] 14 is an explanatory diagram illustrating a state in which the casing and the cap in FIG. 13 are separated. FIG. [Figure 15] 15 is an explanatory diagram illustrating the casing in FIG. 14 as viewed from above. [Figure 16] 15 is an explanatory diagram illustrating the cap of FIG. 14 as viewed from the bottom. FIG. [Figure 17] FIG. 13 is an explanatory diagram showing another modified example of the assembly in a vertical cross-sectional view. [Figure 18] 18 is an explanatory diagram illustrating a state in which the casing and the cap in FIG. 17 are separated. FIG. [Figure 19] 18 is an explanatory diagram illustrating the casing in FIG. 17 as viewed from above. [Figure 20]18 is an explanatory diagram illustrating the cap of FIG. 17 as viewed from the bottom. [Figure 21] 13 is an explanatory diagram illustrating a modified example of the casing as viewed from the side; FIG. [Figure 22] 22 is an explanatory diagram illustrating the casing in FIG. 21 as viewed from above. FIG. [Diagram 23] 22 is an explanatory diagram illustrating a detector using the assembly of the casing and the cap in FIG. 21 as seen from the side. FIG. [Figure 24] 24 is an explanatory diagram illustrating the detector of FIG. 23 as viewed from above. [Diagram 25] FIG. 1 is an explanatory diagram illustrating an embodiment of a fluid leak detection system using a drone in an enlarged longitudinal cross-sectional view of a portion of a marine hose. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0013] Below, the casing and cap assembly for a marine hose fluid leak detector (hereinafter referred to as assembly 21) and the marine hose fluid leak detection system (hereinafter referred to as the detection system) of the present invention will be described based on the embodiments shown in the figures.

[0014] The assembly 21 and detection system are used to detect the presence or absence of leakage of fluid L from a flow path 1a of a floating-type marine hose 1 as exemplified in Fig. 1. The marine hose 1 has connecting ends 2 at both longitudinal ends for connecting another marine hose 1. The connecting ends 2 have a nipple 2b extending in the longitudinal direction of the marine hose 1, and a flange 2a joined to one longitudinal end of the nipple 2b. Generally, about eight to ten marine hoses 1 are connected together for use.

[0015] 2, between the nipples 2b at both ends in the longitudinal direction of the marine hose 1, an inner surface layer 3, an inner periphery reinforcing layer 4, a main body wire layer 5, a fluid retention layer 7, an outer periphery reinforcing layer 6, a buoyancy layer 8, and an outer surface layer 9 are laminated in this order from the inner periphery to the outer periphery of the marine hose 1 on the outer periphery side of the flow path 1a. The inner periphery side of the inner surface layer 3 forms the flow path 1a for the fluid L. Examples of the fluid L include crude oil, heavy oil, gasoline, LPG, water, seawater, and chemicals (alcohols refined from gasoline).

[0016] The buoyancy layer 8 is made of a material such as sponge rubber or polyurethane foam that exerts buoyancy to float the marine hose 1 on the sea surface. The outer surface layer 9 is made of a water-impermeable material such as rubber, and has a line pattern or the like with excellent visibility on its surface.

[0017] The inner surface layer 3 is made of an appropriate material depending on the type of fluid L. When the fluid L is crude oil, the inner surface layer 3 is made of nitrile rubber, which has excellent oil resistance. The inner reinforcing layer 4 and the outer reinforcing layer 6 are each made by laminating a plurality of reinforcing cord layers in which reinforcing cords are covered with rubber. The main body wire layer 5 is made by winding a metal wire around the outer rubber of the inner reinforcing layer 4 in a spiral shape at a predetermined interval. The inner reinforcing layer 4, the main body wire layer 5, and the outer reinforcing layer 6 are fixed to the nipple 2b using nipple wires 4a, 5a, and 6a at one end of each layer and a fixing ring 2c protruding from the outer surface of the nipple 2b. The fluid retention layer 7 formed between the inner reinforcing layer 4 and the outer reinforcing layer 6 is a space for storing the fluid L leaked from the flow path 1a.

[0018] 2 includes a detector 11, a communication pipe 10 that extends on the surface of the marine hose 1 (the outer circumferential surface of the nipple 2b) and connects the fluid retention layer 7 and the detector 11 so as to be communicatively connected, a check valve 17, and a radio wave transmitter 24a and a radio wave receiver 24b that are disposed on the outside of the marine hose 1. An outgoing radio wave R1 is transmitted from the radio wave transmitter 24a to the detector 11, and a reply radio wave R2 is transmitted from the detector 11 to the radio wave receiver 24b.

[0019] The radio wave transmitting unit 24a and the radio wave receiving unit 24b are disposed outside the marine hose 1, separate from the marine hose 1. In this embodiment, a communication device 24 is used in which the radio wave transmitting unit 24a, the radio wave receiving unit 24b, and the computing device 25 are integrated together, but each of these may also be configured separately and independently. A known computer is used as the computing device 25, and the communication device 24 is equipped with, for example, a monitor.

[0020] As illustrated in Figures 3 to 11, the detector 11 has an assembly 21 composed of a casing 18 and a cap 20, and a pressure sensor unit 15 and a passive IC tag 12 housed in a pressure maintaining chamber 18c inside the casing 18.

[0021] As illustrated in Fig. 5, in this embodiment, the detector 11 is connected to the communication pipe 10 via a cylindrical metal adapter part 23. More specifically, a cylindrical pipe end connection part 10a at the end of the communication pipe 10 is screwed and connected to the adapter part 23. The adapter part 23 is connected to the base part 18a of the casing 18, and watertightness is ensured between the two by an annular seal material 18s (O-ring). The inside of the adapter part 23 is a watertight introduction chamber 23a. When the adapter part 23 is not used, the base part 18a and the pipe end connection part 10a are connected.

[0022] The casing 18 has a cylindrical metal base 18a, a radio wave transparent portion 18b that watertightly blocks the upper end side of the base 18a, and three or more metal protrusions 19 that protrude above the radio wave transparent portion 18b. In this embodiment, the casing 18 further has an annular fixing portion 18d. The base 18a and the protrusions 19 are basically one piece. The base 18a, the fixing portion 18d, and the protrusions 19 are formed of, for example, stainless steel.

[0023] As shown in Figures 5 and 10, the base 18a has inside thereof a large-diameter recess in which the radio wave transmitting portion 18b is disposed, and a small-diameter recess connected to the lower part of the large-diameter recess. The upper end of the check valve 17 attached to the lower end of the base 18a is exposed at the bottom of the small-diameter recess. An annular seal material 18s (O-ring) is disposed inside the base 18a (at the bottom of the large-diameter recess) and on the lower surface of the base 18a. The seal material 18s is disposed at a required position as appropriate.

[0024] In this embodiment, the radio wave transparent portion 18b is formed in a disk shape and has a depression on its lower surface. The depression on the lower surface of the radio wave transparent portion 18b and the small-diameter depression inside the base portion 18a are set to face each other vertically. The radio wave transparent portion 18b is installed on the base portion 18a with its lower surface abutting against the bottom surface of the large-diameter depression inside the base portion 18a.

[0025] Since a seal material 18s is interposed between the lower surface of the radio wave transmitting portion 18b and the bottom surface of the large-diameter recess inside the base 18a, the upper end side of the base 18a is sealed off watertight by the radio wave transmitting portion 18b. A pressure maintaining chamber 18c is formed surrounded by the base 18a and the radio wave transmitting portion 18b. That is, the watertight pressure maintaining chamber 18c is formed by the small-diameter recess inside the base 18a and the recess on the lower surface of the radio wave transmitting portion 18b.

[0026] The radio wave transmitting portion 18b has a notch that is circular in plan view on the outer edge of the upper surface. An annular fixing portion 18d is disposed in this notch. The outer peripheral surface of the fixing portion 18d is screwed into the inner peripheral surface of the upper end opening of the base 18a, and is detachable from the base 18a. The radio wave transmitting portion 18b is fixed to the base 18a in a state where the outer peripheral edge is pressed down from above by the fixing portion 18d that is screwed into the inner peripheral surface of the upper end opening of the base 18a. In this way, the radio wave transmitting portion 18b is fixed to the base 18a via the annular fixing portion 18d that engages with the outer edge of the radio wave transmitting portion 18b.

[0027] The relative dielectric constant of the radio wave transmitting portion 18b is set to 5.0 or less to facilitate the transmission of the outgoing radio wave R1 and the return radio wave R2, for example, 2.0 to 5.0, more preferably 2.5 to 3.0. Taking into consideration durability, impact resistance, and the like, the radio wave transmitting portion 18b is made of a material such as polycarbonate, polyamide, or epoxy resin.

[0028] The radio wave transparent portion 18b and the base portion 18a may have any specifications as long as they can form the pressure holding chamber 18c using the radio wave transparent portion 18b and the base portion 18a. Also, the radio wave transparent portion 18b may be fixed to the base portion 18a using another part instead of the fixing portion 18d, or using another part in addition to the fixing portion 18d.

[0029] The protrusions 19 are arranged at intervals in the circumferential direction on the outer circumferential side of the radio wave transparent portion 18b in a plan view. The protrusions 19 are preferably arranged at equal intervals in the circumferential direction of the radio wave transparent portion 18b, and for example, 3 to 8 protrusions 19 are arranged.

[0030] In this embodiment, the protrusions 19 extend straight upward, but are not limited to this shape. However, if the upper ends of the protrusions 19 are in contact (joined) with each other, good radio communication between the IC tag 12 and the communicator 24 cannot be ensured. Therefore, the upper ends of the protrusions 19 are spaced apart from each other.

[0031] The check valve 17 is installed between the pressure-maintaining chamber 18c and the introduction chamber 23a. The check valve 17 allows the fluid L and gas to flow only from the introduction chamber 23a to the pressure-maintaining chamber 18c, and regulates (blocks) the flow from the pressure-maintaining chamber 18c to the introduction chamber 23a. That is, the check valve 17 interposed between the communicating tube 10 and the pressure-maintaining chamber 18c allows the fluid L and gas to flow only from the communicating tube 10 to the pressure-maintaining chamber 18c, and regulates the flow from the pressure-maintaining chamber 18c to the communicating tube 10. Therefore, when the pressure P in the pressure-maintaining chamber 18c rises, the pressure state is maintained. A known check valve can be used as the check valve 17.

[0032] The IC tag 12 has an IC chip 13 and an antenna section 14 connected to the IC chip 13. The pressure sensor section 15 is connected to the IC tag 12 (IC chip 13). The size of the IC chip 13 is very small, for example, the vertical and horizontal dimensions are each 30 mm or less (equivalent to an outer diameter of 30 mm or less) and the thickness is 5 mm or less. The size of the antenna section 14 is also very small, for example, the vertical and horizontal dimensions are each 50 mm or less (equivalent to an outer diameter of 50 mm or less) and the thickness is 10 mm or less. In this embodiment, a ceramic antenna is used as the antenna section 14, making it very compact.

[0033] A plate-shaped metal ground section 16 is arranged in contact with the lower surface of the antenna section 14. In this embodiment, as illustrated in Figs. 5 and 6, the ground section 16 is placed on a C-shaped ring 18f that detachably fits into an annular groove formed in a recess on the lower surface of the radio wave transmitting section 18b, and the IC tag 12 and the pressure sensor section 15 are installed in the pressure maintaining chamber 18c with an annular spacer 18e arranged on the upper surface of the antenna section 14. The IC tag 12 and the pressure sensor section 15 may be installed in the pressure maintaining chamber 18c without using the C-shaped ring 18f. The spacer 18e can be provided as desired. Combining the antenna section 14 using a ceramic antenna with a small check valve 17 that can withstand high pressure (for example, 7 to 8 MPa) and the ground section 16 greatly contributes to making the detector 11 compact.

[0034] The ground portion 16 may be in contact with the metal base portion 18a. This allows the base portion 18a and the protrusion portion 19 to function as an antenna, making it easier to ensure good radio communication between the IC tag 12 and the communication device 24.

[0035] The pressure sensor unit 15 detects the pressure P in the pressure holding chamber 18c. The size of the pressure sensor unit 15 is approximately the same as that of the IC chip 13. In the drawings, the IC chip 13 and the pressure sensor unit 15 are shown in a suspended state, but they can also be placed flat like the antenna unit 14.

[0036] The larger the exposed area of ​​the upper surface of the radio wave transmitting portion 18b, the more advantageous it is for maintaining good radio wave communication between the IC tag 12 and the communicator 24, but the more disadvantageous it is for ensuring pressure resistance of the radio wave transmitting portion 18b. Therefore, as illustrated in FIG. 7, when the upper surface of the radio wave transmitting portion 18b is circular, the diameter Da is set to, for example, 40 mm or more and 70 mm or less. That is, the exposed area of ​​the upper surface of the radio wave transmitting portion 18b is set to a diameter Da of 40 mm or more and 70 mm or less. The gap Db between each of the protrusions 19 facing each other in a plan view is set to 100% or more of the diameter Da. Also, as illustrated in FIG. 10, the larger the thickness C of the upper surface of the radio wave transmitting portion 18b, the more advantageous it is for ensuring pressure resistance, but the more disadvantageous it is for maintaining good radio wave communication between the IC tag 12 and the communicator 24. Therefore, the thickness C of the upper surface of the radio wave transmitting portion 18b is set to, for example, 5 mm or more and 15 mm or less.

[0037] The specifications, number, and position of the protrusions 19 are premised on the fact that they can protect the radio wave transmitting portion 18b and can maintain good radio wave communication between the IC tag 12 and the communication device 24. In order to protect the radio wave transmitting portion 18b with the protrusions 19, it is preferable that the height H and thickness of the protrusions 19 are relatively large, but it is essential that the height H of the protrusions 19 is set so that the upper end of the protrusions 19 does not protrude above the flange 2a when the detector 11 is installed on the surface of the marine hose 1. In addition, if the height H and thickness of the protrusions 19 are excessively large, the space occupied by the protrusions 19 will be large, so the height H of the protrusions 19 is determined, for example, in the range of 15 mm to 40 mm, and the thickness is determined, for example, in the range of 3 mm to 8 mm. The height H of the protrusions 19 is preferably set to 35% to 45% of the diameter Da of the upper surface of the radio wave transmitting portion 18b. The width of the protrusions 19 is determined so that the interval W between adjacent protrusions in the circumferential direction is, for example, 10 mm or more, more preferably 15 mm or more.

[0038] The cap 20 is an annular body (cylindrical body) that continuously covers the upper ends of the protrusions 19 in the circumferential direction in a plan view, and is made of a known resin or rubber. The inner diameter of the cap 20 is, for example, 10 mm or more and 70 mm or less, and the outer diameter is 70 mm or more and 110 mm or less. The relative dielectric constant of the cap 20 is 1.0 or more and 8.0 or less.

[0039] Examples of resins for forming the cap 20 include ABS, polyvinyl chloride, polycarbonate, polyimide, and epoxy. Since the cap 20 is preferably excellent in weather resistance, it is formed from a resin or rubber with excellent weather resistance, or an antioxidant that improves the weather resistance of the resin or rubber used is mixed, or a paint with excellent weather resistance is applied to the surface of the cap 20. For example, paints such as acrylic silicone resin, polyurethane resin, acrylic resin, and vinyl chloride-based paints are used. Reinforcing fibers (short fibers) can be mixed into the resin or rubber used to improve durability. Known carbon fibers, glass fibers, and the like can be used as reinforcing fibers.

[0040] As illustrated in Fig. 9, the cap 20 is formed with a plurality of engagement portions 20d that engage with the upper ends of the respective protrusions 19. As illustrated in Fig. 5, the engagement portions 20d engage with the upper ends of the corresponding protrusions 19, and the cap 20 is disposed on the upper ends of the respective protrusions 19. In this embodiment, a plurality of holes that are spaced apart in the circumferential direction of the cap 20 and open on the bottom surface of the cap 20 are used as the engagement portions 20d. The holes that become the engagement portions 20d are formed in the cap 20 in a number and arrangement that corresponds to the respective protrusions 19.

[0041] The cap 20 may be colored in a color (such as orange) that stands out in the ocean. Although the surface of the cap 20 may be painted with a paint of a striking color, it is advantageous to manufacture the cap 20 from a material colored in a striking color in order to maintain the color for a longer period of time.

[0042] 3 to 5, when the cap 20 is disposed on the upper end of each protrusion 19 and fixed to the casing 18, the region on the inner periphery of each protrusion 19 and the region on the outer periphery of each protrusion 19 communicate with each other through the circumferential gap between the lower ends of circumferentially adjacent protrusions 19. That is, the cap 20 covers the upper ends of each protrusion 19 but does not cover the entire height of each protrusion 19. The height gap between the lower end of the cap 20 and the lower end of each protrusion 19 (the upper surface of the radio wave transparent portion 18b) is 10 mm or more, for example, 10 mm or more and 30 mm or less.

[0043] There are various specifications for fixing the cap 20 to the casing 18, but in this embodiment, screws 22 are used. Thus, the cap 20 is formed with a plurality of radially extending insertion holes 20a spaced apart in the circumferential direction. More specifically, as shown in Fig. 4 and Fig. 9, the insertion holes 20a are formed in the outer peripheral surface of the cap 20 so as to communicate with the respective engagement portions 20d.

[0044] 7 and 8, screw holes 19a are formed in the outer peripheral surfaces of the multiple protrusions 19. In this embodiment, screw holes 19a are formed in all of the protrusions 19, but it is sufficient that screw holes 19a are formed in multiple protrusions 19, and it is more preferable that screw holes 19a are formed in three or more protrusions 19. Furthermore, screw holes 22 do not necessarily need to penetrate protrusions 19 in the radial direction, and may extend partway from the outer peripheral surface to the inner peripheral surface of protrusions 19.

[0045] When the cap 20 is fixed to the casing 18, as illustrated in FIG. 11, the cap 20 is moved downward from above each of the protrusions 19, and the upper end of each of the protrusions 19 is inserted into the engagement portion 20d formed on the cap 20, and the cap 20 is disposed at the upper end of each of the protrusions 19. Next, as illustrated in FIGS. 3 to 5, screws 22 are inserted radially from the outer periphery side to the inner periphery side of the cap 20 into the insertion holes 20a communicating with the engagement portions 20d in which the tip ends of the protrusions 19 are accommodated and engaged. These screws 22 are screwed into the screw holes 19a arranged opposite to the insertion holes 20a, so that the cap 20 is firmly fixed to the casing 18. In this embodiment, the screws 22 are screwed into the screw holes 19a of all the protrusions 19, but for example, the cap 20 may be fixed to the casing 18 by screwing the screws 22 into the screw holes 19a of the protrusions 19 every other one in the circumferential direction. The head of the screw 22 is embedded in the insertion hole 20a without protruding outward from the outer circumferential surface of the cap 20.

[0046] An example of a detection procedure for determining whether or not leakage of the fluid L from the flow path 1a occurs using this detection system will be described below.

[0047] An operator approaches the marine hose 1 on a work boat or the like periodically or when necessary to check for leaks of the fluid L. Then, the operator operates the communication device 24, and as shown in FIG. 2, an outgoing radio wave R1 is transmitted from the radio wave transmitter 24a to the detector 11, and this outgoing radio wave R1 is used to generate power in the IC tag 12. The IC tag 12 transmits a reply radio wave R2 using this power, and this reply radio wave R2 is received by the radio wave receiver 24b. At this time, pressure data detected by the pressure sensor unit 15 is transmitted by the reply radio wave R2, and the detected pressure data received by the radio wave receiver 24b is input to the calculation device 25.

[0048] That is, the IC tag 12 and the communicator 24 constitute an RFID (Radio Frequency IDentification) system. The frequency and output of the radio waves R1, R2 used for communication are set appropriately, but because a passive IC tag 12 is used, the communication distance of the radio waves R1, R2 between the IC tag 12 and the communicator 24 is, for example, about several tens of centimeters to several meters. The frequency of the radio waves (R1, R2) used for wireless communication between the IC tag 12 and the communicator 24 is mainly in the UHF band (a range of 860 MHz to 930 MHz depending on the country, and 915 MHz to 930 MHz in Japan), and the HF band (13.56 MHz) is sometimes used.

[0049] A reference value Pc of the pressure P in the pressure holding chamber 18c for determining whether leakage of the fluid L from the flow path 1a occurs is stored in the computing device 25. In order to prevent erroneous detection, an appropriate range of the reference value Pc is determined in advance by conducting experiments and simulations while taking into consideration the specifications and operating conditions of the marine hose 1, and the reference value Pc is set within this appropriate range and stored in the computing device 25.

[0050] The computing device 25 compares the pressure value of the inputted detected pressure data with the reference value Pc. When the fluid L is not flowing into the fluid retention layer 7, there is no particularly large fluctuation in the pressure P in the pressure holding chamber 18c, so the pressure value of the detected pressure data is smaller than the reference value Pc. Therefore, the computing device 25 determines that the fluid L is not leaking from the flow path 1a, and notifies the result by monitor display or voice.

[0051] On the other hand, when the inner surface layer 3, the inner circumferential side reinforcing layer 4, etc. are damaged and the fluid L flows from the flow path 1a into the fluid retention layer 7, the pressure P in the pressure holding chamber 18c increases through the communicating pipe 10, the introduction chamber 23a, and the check valve 17, as illustrated in Fig. 12. This increased pressure P is retained by the check valve 17 and detected by the pressure sensor unit 15. Therefore, when the radio wave R1 is transmitted from the radio wave transmitter 24a to the detector 11 during the leak checking operation of the fluid L, the pressure value of the highest pressure P ever detected is received by the radio wave receiver 24b and input to the calculation device 25 as the pressure data detected by the pressure sensor unit 15.

[0052] The computing device 25 compares the pressure value of the input detected pressure data with the reference value Pc. If the pressure value of the detected pressure data is equal to or greater than the reference value Pc, it determines that the fluid L is leaking from the flow path 1a, and notifies the user of the result by monitor display or audio.

[0053] This detection system uses a passive IC tag 12, so there is no need to monitor the battery consumption. Also, by using the check valve 17 to maintain the pressure in the pressure chamber 18c and using the detected pressure data received by the radio wave receiving unit 24b from the pressure sensor unit 15 as an index, it becomes possible to more reliably determine whether or not the fluid L is leaking from the flow path 1a.

[0054] In this embodiment, the presence or absence of leakage of the fluid L from the flow path 1a is automatically determined by the calculation device 25. Alternatively, for example, the presence or absence of leakage of the fluid L can be determined by an operator comparing the pressure value of the detected pressure data received by the radio wave receiving unit 24b with a preset reference value Pc.

[0055] Other information can also be stored in the IC chip 13 and transmitted by the reply radio wave R2. For example, information such as specification information for the marine hose 1, manufacturing information, and the time when the IC tag 12 was attached to the marine hose 1 can be stored in the IC chip 13 and transmitted to the radio wave receiver 24b.

[0056] When this detector 11 is used, the upper surface of the radio wave transparent portion 18b is protected by the above-mentioned protrusions 19. This reduces the risk of damage to the radio wave transparent portion 18b, which is advantageous for improving the durability of the detector 11. Since the protrusions 19 are arranged at intervals in the circumferential direction and the upper ends of the protrusions 19 are spaced apart from each other in a plan view, the disadvantage of these protrusions 19 impairing the quality of radio wave communication between the IC tag 12 and the communicator 24 is avoided. This ensures ease of checking for fluid leakage and reliability of detection while protecting the upper surface of the radio wave transparent portion 18b.

[0057] Furthermore, because the upper end of each protrusion 19 is covered by the above-mentioned cap 20, even if the upper end of each metal protrusion 19 comes into contact with some object, this is advantageous in reducing the risk of damage to both the detector 11 and the object. For example, even if another marine hose, rope, or the like present around the detector 11 comes into contact with the detector, it is possible to reduce damage to the detector 11, the marine hose, or the rope. Furthermore, because the cap 20 is firmly fixed to the casing 18, it will not easily come off the casing 18 even if an object comes into contact with it.

[0058] When the cap 20 is fixed to the casing 18, the inner peripheral region of each protrusion 19 and the outer peripheral region of each protrusion 19 communicate with each other through the circumferential gap between the lower ends of circumferentially adjacent protrusions 19, allowing seawater to flow through this gap. This reduces the force that the cap 20 receives from waves, preventing the cap 20 from coming off the casing 18 due to wave force, which is advantageous for stably fixing the cap 20 to the casing 18 for a long period of time.

[0059] Furthermore, because the cap 20 is annular, the upper surface of the radio wave transmitting portion 18b is not entirely covered by the cap 20. This makes it possible to avoid impairing the quality of radio wave communication between the IC tag 12 and the communication device 24. The dielectric has the effect of making the holes through which radio waves pass appear larger (the wavelength of radio waves is shorter than in air), and this effect may be one of the factors that slightly improves the quality of radio wave communication by fixing the cap 20 to the casing 18.

[0060] In the assembly 21 illustrated in Figs. 13 to 16, the cap 20 is firmly fixed to the casing 18 by using the protruding thread portion 19b and the cap thread portion 20b. The cap 20 is formed with the cap thread portion 20b extending in the circumferential direction. More specifically, an annular groove that is continuous in the circumferential direction of the cap 20 and opens into the bottom surface of the cap 20 is used as the engagement portion 20d. The cap thread portion 20b extending in the circumferential direction is formed on the outer peripheral surface of the annular groove that becomes the engagement portion 20d. The protruding thread portion 19b extending in the circumferential direction is formed on the outer peripheral surface of each protrusion 19.

[0061] The cap 20 is rotated circumferentially around the central axis of the cap 20 (respective protrusions 19) in a plan view at the upper end of each protrusion 19, whereby the cap screw portion 20b and each protrusion screw portion 19b are screwed together. As the cap 20 is rotated, the engagement portion 20d engages with the upper end of each protrusion 19, and the cap 20 gradually moves downward, until it is fixed to the casing 18 in a state where it is positioned at the upper end of each protrusion 19.

[0062] In the assembly 21 illustrated in Figs. 17 to 20, the cap 20 is firmly fixed to the casing 18 by using the protruding fitting portion 19c and the cap fitting portion 20c. The cap 20 is formed with the cap fitting portion 20c. More specifically, a plurality of holes that are spaced apart in the circumferential direction of the cap 20 and open to the bottom surface of the cap 20 are used as the engaging portion 20d. The cap fitting portion 20c that protrudes radially inward is formed on the outer peripheral surface of the plurality of holes that serve as the engaging portion 20d.

[0063] A projection fitting portion 19c recessed radially inward is formed on the outer peripheral surface of the plurality of projections 19. When the cap 20 is pressed downward, each of the engagement portions 20d engages with the upper end portion of the corresponding projection 19, and the cap 20 is disposed on the upper end portion of each projection 19, whereby the cap fitting portion 20c and each of the projection fitting portions 19c fit together, and the cap 20 is fixed to the casing 18.

[0064] It is also possible to employ the cap fitting portion 20c recessed radially outward, and to employ the protruding fitting portion 19c protruding radially outward. Also, instead of the multiple holes spaced apart in the circumferential direction, it is also possible to employ an annular groove that is continuous in the circumferential direction of the cap 20 and opens into the bottom surface of the cap 20 as the engagement portion 20d.

[0065] An adhesive can also be used in combination to fix the cap 20 to the casing 18. That is, when fixing the cap 20 to the casing 18 by using each of the above-mentioned methods, the cap 20 and the tip end of each of the protrusions 19 can also be fixed to each other by using a known adhesive.

[0066] It is also possible to use in combination the above-mentioned method of fixing the cap 20 to the casing 18 using the screw 22 and the above-mentioned method of fixing the cap 20 to the casing 18 by screwing the protruding thread portion 19b and the cap thread portion 20b together. It is also possible to use in combination the above-mentioned method of fixing the cap 20 to the casing 18 using the screw 22 and the above-mentioned method of fixing the cap 20 to the casing 18 by fitting the protruding fitting portion 19c and the cap fitting portion 20c together.

[0067] Although the shape of the protrusions 19 is basically a shape that extends straight upward, a different shape can be adopted to improve the protective effect on the radio wave transparent portion 18b. As shown in Figures 21 and 22, each protrusion 19 can be bent halfway in the up-down direction and extended toward the center of the radio wave transparent portion 18b in a plan view.

[0068] However, the lower end of each protrusion 19 is positioned more radially outward than the outer periphery of the upper surface of the radio wave transparent portion 18b, and the height position at which it is bent midway is at a position 8 mm or more above the upper surface of the radio wave transparent portion 18b. Also, in plan view, the gap Db between the opposing bent upper ends of each protrusion 19 is 50% or more, preferably 70% or more, and more preferably 100% or more of the diameter Da of the upper surface of the radio wave transparent portion 18b. Also, in plan view, the gap W between adjacent bent upper ends of each protrusion 19 in the circumferential direction is preferably 3 mm or more, and more preferably 5 mm or more.

[0069] 21 and 22, the cap 20 can be fixed to the casing 18 in the same manner as the various caps 20 described above. That is, the casing 18 and the cap 20 can form an assembly 21 as shown in FIGS. 23 and 24.

[0070] In the detection system of the present invention, the work of checking for fluid leakage can be performed not only by an operator holding a handheld communication device 24, but also by mounting the communication device 24 on a drone 27 as illustrated in Fig. 25. Unlike the above-described embodiment, the detection system illustrated in Fig. 25 includes a drone 27 mounted with a communication device 24 (radio wave transmitter 24a and radio wave receiver 24b) and a camera device 26, and a computing device 25 to which the detected pressure data received by the radio wave receiver 24b and the image data acquired by the camera device 26 are input. The computing device 25 is located, for example, on a ship or in a management office in a remote location.

[0071] The camera device 26 acquires image data of the marine hose 1 from the airspace above the marine hose 1. As the camera device 26, various known digital cameras that acquire still or video image data Mr can be used.

[0072] A GNSS receiver 28 is installed in the drone 27, and the position coordinates of the drone 27 are grasped in real time by the GNSS receiver 28. Based on the successively acquired image data Mr, the pilot can move the drone 27 to the nearby airspace above the detector 11 (IC tag 12), or the position coordinates of the detector 11 can be input to a control unit of the drone 27, so that the drone 27 can be moved to the nearby airspace above the detector 11 (IC tag 12) by automatic control operation.

[0073] In this detection system, when checking for fluid leakage, a drone 27 is flown from a measurement base such as on land or on a ship and moved to a state in which it is located in the airspace above and near the detector 11 (IC tag 12) placed on the surface of the marine hose 1. In this state, wireless communication is performed between the IC tag 12 and the communication device 24, and the detected pressure data by the pressure sensor unit 15 and the image data Mr acquired by the camera device 26 are input to the calculation device 25.

[0074] The computing device 25 determines whether there is a fluid leak based on the detected pressure data, and also determines whether there is an abnormality outside the marine hose 1 based on the image data Mr. By using the drone 27, the worker does not need to approach the marine hose 1 when checking for leaks, further reducing the workload. In addition, if the cap 20 is a conspicuous color such as orange, it becomes easier to confirm the position of the detector 11 using the image data Mr from the camera device 26, making it easier to move the communication device 24 to the airspace above and near the detector 11 (IC tag 12).

[0075] The present disclosure includes the following inventions. [Invention 1]: An assembly of a casing for a fluid leak detector that is installed on a surface of a marine hose and is connected to a fluid retention layer formed on the marine hose so as to be capable of communicating with the fluid, and a cap that is fixed to the casing, the casing has a metallic cylindrical base, a radio wave transparent portion that watertightly blocks the upper end side of the base, and three or more metallic protrusions that protrude from the base above the radio wave transparent portion, a pressure holding chamber is formed surrounded by the base and the radio wave transparent portion, in a plan view, each of the protrusions is disposed at intervals in the circumferential direction at a position on the outer periphery of the radio wave transparent portion, and the upper ends of each of the protrusions are spaced apart from each other, and the pressure holding chamber accommodates a pressure sensor portion and a passive IC tag connected to the pressure sensor portion, The cap is an annular body made of resin or rubber that continuously covers the upper ends of the respective protrusions in a circumferential direction in a plan view, and has engagement portions formed thereon that engage with the upper ends of the respective protrusions, A casing and cap assembly for a marine hose fluid leak detector in which, when the engaging portion engages with the upper end portion of each of the protrusions and the cap is placed on the upper end portion of each of the protrusions and fixed to the casing, the inner region of each of the protrusions and the outer region of each of the protrusions are in communication through the circumferential gaps between the lower ends of circumferentially adjacent protrusions. [Invention 2]: The cap has a plurality of radially extending insertion holes formed at intervals in the circumferential direction, A screw hole is formed on the outer peripheral surface of each of the plurality of protrusions, a screw is inserted into each of the insertion holes in a radial direction from an outer circumferential side to an inner circumferential side of the cap, A casing and cap assembly for a marine hose fluid leak detector as described in [Invention 1], in which, with the engaging portions engaging with the upper ends of the respective protrusions and the cap being positioned at the upper ends of the respective protrusions, the screws inserted into each of the multiple insertion holes are screwed into the screw holes positioned opposite the respective insertion holes, thereby fixing the cap to the casing. [Invention 3]: The cap has a cap thread portion extending in a circumferential direction, A protruding thread portion is formed on the outer peripheral surface of each of the protruding portions and extends in the circumferential direction, The casing and cap assembly for a marine hose fluid leak detector described in [Invention 1] or [Invention 2], wherein the cap is fixed to the casing in a state in which the cap screw portion and each of the protrusion screw portions screw together by rotating the cap circumferentially on the upper ends of each of the protrusions, and the engaging portions engage with the upper ends of each of the protrusions, thereby positioning the cap at the upper ends of each of the protrusions. [Invention 4]: The cap is formed with a cap fitting portion, A protrusion fitting portion is formed on the outer peripheral surface of the plurality of protrusions, A casing and cap assembly for a marine hose fluid leak detector as described in [Invention 1] or [Invention 2], in which the engaging portion engages with the upper end portion of each of the protrusions and the cap is positioned on the upper end portion of each of the protrusions, thereby fitting the cap fitting portion to each of the protrusion fitting portions and fixing the cap to the casing. [Invention 5]: A marine hose fluid leak detector comprising: an assembly of a casing and a cap for a marine hose fluid leak detector according to any one of [Invention 1] to [Invention 4]; a detector having the pressure sensor unit and the IC tag housed in the pressure holding chamber; a communication pipe extending on the surface of the marine hose and connecting the fluid retention layer and the detector so as to be able to communicate with each other; a check valve which allows only flow from the communication pipe side to the pressure holding chamber side; and a radio wave transmitting unit and a radio wave receiving unit which are arranged on the outside of the marine hose; A marine hose fluid leak detection system configured such that a reply radio wave is transmitted from the IC tag in response to the transmitted radio wave transmitted from the radio wave transmitting unit, and pressure data detected by the pressure sensor unit is sent by the reply radio wave and received by the radio wave receiving unit. [Invention 6]: A marine hose fluid leakage detection system as described in [Invention 5], comprising a drone equipped with the radio wave transmitting unit, the radio wave receiving unit, and a camera device, and a computing device to which the detected pressure data received by the radio wave receiving unit and the image data acquired by the camera device are input. [Explanation of symbols]

[0076] 1 Marine hose 1a Flow path 2 Connecting end 2a Flange 2b nipple 2c Retaining ring 3 Inner layer 4 Inner reinforcing layer 4a nipple wire 5 Body Wire Layer 5a nipple wire 6 Outer reinforcing layer 6a nipple wire 7 Fluid retention layer 8 Buoyancy layer 9 Outer layer 10 Communication pipe 10a Pipe end connection 11 Detectors 12 IC Tags 13 IC chip 14 Antenna section 15 Pressure sensor section 16 Grounds 17 Check valve 18 Casing 18a base 18b Radio wave transmission part 18c Pressure holding chamber 18d Fixed part 18e Spacer 18f C-shaped ring 18s sealing material 19 Protrusion 19a Screw hole 19b Protruding screw part 19c Protrusion fitting part 20 Cap 20a Insertion hole 20b Cap screw part 20c Cap fitting part 20d Engagement part 21 Assembly 22 Bis 23 Adapter part 23a Introduction room 24 Communication Device 24a Radio wave transmission unit 24b Radio wave receiving unit 25 Arithmetic unit 26 Camera Equipment 27 Drone 28 GNSS receivers

Claims

1. An assembly including a casing for a fluid leak detector that is installed on a surface of a marine hose and is communicatively connected to a fluid retention layer formed on the marine hose, and a cap that is fixed to the casing, the casing has a metallic cylindrical base, a radio wave transparent portion that watertightly blocks the upper end side of the base, and three or more metallic protrusions that protrude from the base above the radio wave transparent portion, a pressure holding chamber is formed surrounded by the base and the radio wave transparent portion, in a plan view, each of the protrusions is disposed at intervals in the circumferential direction at a position on the outer periphery of the radio wave transparent portion, and the upper ends of each of the protrusions are spaced apart from each other, and the pressure holding chamber accommodates a pressure sensor portion and a passive IC tag connected to the pressure sensor portion, The cap is an annular body made of resin or rubber that continuously covers the upper ends of the respective protrusions in a circumferential direction in a plan view, and has engagement portions formed thereon that engage with the upper ends of the respective protrusions, A casing and cap assembly for a marine hose fluid leak detector in which, when the engaging portion engages with the upper end portion of each of the protrusions and the cap is placed on the upper end portion of each of the protrusions and fixed to the casing, the inner region of each of the protrusions and the outer region of each of the protrusions are in communication through the circumferential gaps between the lower ends of circumferentially adjacent protrusions.

2. The cap has a plurality of radially extending insertion holes formed at intervals in a circumferential direction, A screw hole is formed on the outer peripheral surface of each of the plurality of protrusions, a screw is inserted into each of the insertion holes in a radial direction from an outer circumferential side to an inner circumferential side of the cap, 2. The casing and cap assembly for a marine hose fluid leak detector as described in claim 1, wherein, with the engaging portion engaging with the upper end portion of each of the protrusions and the cap positioned on the upper end portion of each of the protrusions, the screws inserted into each of the multiple insertion holes are screwed into the screw holes positioned opposite each of the insertion holes, thereby fixing the cap to the casing.

3. The cap has a cap thread portion extending in a circumferential direction, A protruding thread portion is formed on the outer peripheral surface of each of the protruding portions and extends in the circumferential direction, 2. The casing and cap assembly for a marine hose fluid leak detector as described in claim 1, wherein the cap is fixed to the casing in a state in which the cap screw portion and each of the protrusion screw portions screw together by rotating the cap circumferentially around the upper ends of each of the protrusions, and the engaging portion engages with the upper ends of each of the protrusions, thereby positioning the cap on the upper ends of each of the protrusions.

4. The cap has a cap fitting portion formed thereon, A protrusion fitting portion is formed on the outer peripheral surface of the plurality of protrusions, 2. A casing and cap assembly for a marine hose fluid leak detector as described in claim 1, wherein the cap is positioned on the upper end of each of the protrusions by engaging the engagement portion with the upper end of each of the protrusions, thereby fixing the cap to the casing by engaging the cap fitting portion with each of the protrusion fitting portions.

5. a casing and cap assembly for a marine hose fluid leak detector according to any one of claims 1 to 4, a detector having the pressure sensor unit and the IC tag housed in the pressure holding chamber, a communication pipe extending on a surface of the marine hose to connect the fluid retention layer and the detector so as to be able to communicate with each other, a check valve which allows only flow from the communication pipe side to the pressure holding chamber side, and a radio wave transmitting unit and a radio wave receiving unit which are arranged on the outside of the marine hose, A marine hose fluid leak detection system configured such that a reply radio wave is transmitted from the IC tag in response to the transmitted radio wave transmitted from the radio wave transmitting unit, and pressure data detected by the pressure sensor unit is sent by the reply radio wave and received by the radio wave receiving unit.

6. 6. The marine hose fluid leakage detection system as described in claim 5, comprising: a drone equipped with the radio wave transmitting unit, the radio wave receiving unit, and a camera device; and a computing device to which the detected pressure data received by the radio wave receiving unit and the image data acquired by the camera device are input.

Images