Fluid leak sensing system for marine hoses and method of manufacturing the same

Abstract

The present application provides a fluid leakage sensing system for a marine hose capable of improving durability of a sensor while ensuring easiness of confirmation of fluid leakage and sensing reliability, and a manufacturing method thereof. A pressure sensor portion (15) and a passive IC tag (12) are housed in a pressure maintaining chamber (18c) formed by a metal cylindrical base portion (18a) of a housing (18) provided on a surface of a marine hose (1) and a wave-permeable portion (18b) which water-tightly partitions the upper end portion side thereof, the pressure maintaining chamber (18c) is communicated with a communication pipe (10) via a check valve (17) which allows fluid L to flow only from the communication pipe (10) side to the pressure maintaining chamber (18c) side, the IC tag (12) transmits sensing pressure data to a wave receiving portion (22b) through a reply wave (W2) according to a transmission wave (W1) from a wave transmission portion (22a), three or more metal protrusion portions (19) protruding upward more than the wave-permeable portion (18b) are arranged at an outer peripheral side position of the wave-permeable portion (18b) in plan view at intervals in the circumferential direction with each upper end portion spaced from each other.

Description

Technical Field

[0001] This invention relates to a fluid leakage sensing system for marine hoses and a method for manufacturing the same, and more specifically, to a fluid leakage sensing system for marine hoses and a method for manufacturing the same, which can improve the durability of the sensor while ensuring the ease of confirmation and the reliability of sensing fluid leakage in marine hoses. Background Technology

[0002] In marine hoses, a fluid retention layer is provided between reinforcing layers to temporarily store leaking fluid, thereby preventing it from leaking to the outside of the hose. Thus, various fluid leakage sensing systems have been proposed to detect fluid leakage into the fluid retention layer (for example, see Patent Document 1).

[0003] In the fluid leak sensing system proposed in Patent Document 1, when fluid flows into the fluid retention layer, the fluid passes through the connecting pipe and check valve, causing the pressure in the sensor's pressure chamber to rise. This pressure change can be obtained using a response radio wave from a passive IC tag in the form of sensed pressure data measured by the pressure sensor unit, thus facilitating reliable fluid leak detection while simplifying the confirmation process.

[0004] The upper surface of the pressure-holding chamber housing the pressure sensor and IC tag is covered by a radio wave transmission section. To improve radio wave communication, the radio wave transmission section is positioned to protrude beyond the surface of the marine hose. Therefore, the risk of damage to the radio wave transmission section from external forces increases when the marine hose is deployed at sea, retrieved onto the ship, or used at sea. On the other hand, simply providing protection by covering the area around the radio wave transmission section with a metal cap or similar material would compromise the quality of radio wave communication. Therefore, there is room for improvement in enhancing the sensor's durability while ensuring ease of fluid leakage detection and sensing reliability.

[0005] Existing technical documents

[0006] Patent documents

[0007] Patent Document 1: Japanese Patent Application Publication No. 2021-46929 Summary of the Invention

[0008] The problem that the invention aims to solve

[0009] The purpose of this invention is to provide a fluid leakage sensing system for marine hoses and a method thereof that can improve the durability of the sensor while ensuring the ease of confirmation and the reliability of sensing of fluid leakage in marine hoses.

[0010] Technical means to solve the problem

[0011] To achieve the above objectives, the fluid leakage sensing system for marine hoses of the present invention is configured to include: a connecting pipe communicating with a fluid retention layer formed on a marine hose having a buoyancy layer and extending to the surface of the marine hose; a sensor communicating with the connecting pipe and disposed on the surface of the marine hose; and a radio wave transmitting unit and a radio wave receiving unit disposed on the outside of the marine hose; the sensor having: a housing; a pressure holding chamber built into the housing; a check valve sandwiched between the connecting pipe and the pressure holding chamber, allowing flow only from the connecting pipe side to the pressure holding chamber side; and a pressure sensor unit and a passive IC connected to the pressure sensor unit. The IC tag is housed in the pressure-holding chamber; based on the transmitted radio waves sent from the radio wave transmitting unit, the IC tag sends a response radio wave, and transmits the sensed pressure data measured by the pressure sensor unit via the response radio wave, which is received by the radio wave receiving unit. The housing is characterized by having: a metal cylindrical base; a radio wave transmitting portion that watertightly blocks the upper end side of the base; and three or more metal protrusions protruding upwards from the radio wave transmitting portion; the pressure-holding chamber is formed by the base and the radio wave transmitting portion, such that, when viewed from above, each of the protrusions is circumferentially spaced at a position on the outer periphery of the radio wave transmitting portion, and each upper end is spaced apart from the other.

[0012] The manufacturing method of the fluid leakage sensing system for marine hoses of the present invention is characterized in that, as described above, it is a manufacturing method for the fluid leakage sensing system for marine hoses, and in the sensor specification determination step, the specifications, quantity, and position of each of the protrusions are combined in different ways to determine the intensity of the returned radio waves received by the radio wave receiving unit under the same specified conditions, and to determine the combinations in which the intensity of the determined returned radio waves is higher than a preset threshold.

[0013] In the sensor installation process, the sensor, which uses the determined combination, is connected to the connecting pipe and installed on the surface of the marine hose.

[0014] Invention Effects

[0015] According to the fluid leak sensing system for marine hoses of the present invention, when fluid flowing in the flow path flows into the fluid retention layer, the fluid passes through the connecting pipe and the check valve, causing the pressure in the pressure-holding chamber built into the housing to increase. This pressure is maintained by the check valve and sensed by the pressure sensor. The sensed pressure data measured by the pressure sensor can be obtained by receiving the response radio wave from the passive IC tag by the radio wave receiving unit. Therefore, fluid leaks can be reliably sensed while facilitating fluid leak confirmation operations.

[0016] Furthermore, when viewed from above, three or more metal protrusions protruding upwards from the radio wave transmitting section are arranged circumferentially at intervals on the outer periphery of the radio wave transmitting section, thus protecting the upper surface of the radio wave transmitting section. This reduces the risk of damage to the radio wave transmitting section and improves the sensor's durability. Moreover, since the protrusions are arranged circumferentially at intervals, and their upper ends are spaced apart when viewed from above, the disadvantage of these protrusions compromising the quality of radio wave communication is avoided. Therefore, ease of fluid leakage detection and reliable sensing are ensured.

[0017] According to the manufacturing method of the fluid leakage sensing system for marine hoses of the present invention, a sensor employing the combination determined in the above manner is disposed on the surface of the marine hose in communication with a connecting pipe. Therefore, it is advantageous to manufacture a fluid leakage sensing system with high precision, which improves sensor durability while ensuring ease of fluid leakage detection and sensing reliability. Attached Figure Description

[0018] Figure 1 This is an illustrative diagram of a marine hose for which a fluid leakage sensing system for marine hoses incorporating the present invention is applied.

[0019] Figure 2 This is an illustration of a fluid leak sensing system, presented as an example by magnifying a portion of a ship's hose in a longitudinal cross-sectional view.

[0020] Figure 3 This is an example shown from a side view. Figure 2 An explanatory diagram of the sensor.

[0021] Figure 4 This example is shown from the top view. Figure 3 An explanatory diagram of the sensor.

[0022] Figure 5 This is illustrated using a longitudinal section perspective. Figure 2 An explanatory diagram of the sensor.

[0023] Figure 6 This example is shown from the top view. Figure 5 An explanatory diagram of the interior of the pressure-holding chamber.

[0024] Figure 7 This example is shown from the top view. Figure 5 An explanatory diagram of the sensor after the cover has been removed.

[0025] Figure 8 This is an example. Figure 5 A diagram illustrating the disintegration state of the sensor.

[0026] Figure 9 This is an example to illustrate that... Figure 8 This diagram illustrates the state of the radio wave transmission part after it is assembled with the IC tag and pressure sensor part.

[0027] Figure 10 This is an example to illustrate that... Figure 9 This diagram illustrates the state of a component assembled from an electromagnetic wave transmission part, an IC tag, and a pressure sensor part, mounted on a base.

[0028] Figure 11 This is an explanatory diagram showing, from a longitudinal sectional view, the sensor and connector section in the state after being removed from the surface of the marine hose.

[0029] Figure 12 This is an explanatory diagram illustrating a sensor communicating with a communication device, shown from a longitudinal cross-sectional perspective.

[0030] Figure 13 This is an explanatory diagram showing an improved example of the sensor from a side view.

[0031] Figure 14 This example is shown from the top view. Figure 13 An explanatory diagram of the sensor.

[0032] Figure 15 This example uses a top-down view to illustrate the relationship between IC tags and... Figure 4 A diagram illustrating the circumferential positions of the various protrusions.

[0033] Figure 16 This is an example illustrating the relationship with... Figure 15 This diagram illustrates the state of the IC tag after each protrusion changes its circumferential position. Detailed Implementation

[0034] The fluid leakage sensing system (hereinafter referred to as the sensing system) for marine hoses of the present invention and its manufacturing method will be described below based on the embodiments shown in the figures.

[0035] The sensing system of the present invention is applied to Figure 1 In the example of the floating marine hose 1, the presence or absence of fluid L leaking from the flow path 1a is detected. The marine hose 1 has connecting ends 2 at both ends along its length for connecting to other marine hoses 1. The connecting end 2 has a pipe fitting 2b extending along the length of the marine hose 1, and a flange 2a engaging one end of the pipe fitting 2b along its length. Generally, about 8 to 10 marine hoses 1 are connected together for use.

[0036] like Figure 2As illustrated, between the pipe joints 2b at both ends of the marine hose 1 along its length, on the outer periphery of the flow path 1a, from the inner periphery to the outer periphery, are sequentially layered an inner surface rubber layer 3, an inner periphery reinforcing layer 4, a main body layer 5, a fluid retention layer 7, an outer periphery reinforcing layer 6, a buoyancy layer 8, and an outer skin layer 9. The inner periphery of the inner surface rubber layer 3 forms the flow path 1a for fluid L. Examples of fluid L include crude oil, heavy oil, gasoline, LPG (Liquefied Petroleum Gas), water, seawater, and chemicals (alcohols refined from gasoline).

[0037] The buoyancy layer 8 is made of materials such as sponge rubber and polyurethane foam, which provide buoyancy for the ship's hose 1 to float at sea. The outer skin layer 9 is made of non-permeable materials such as rubber, and its surface is decorated with visually distinctive lines and patterns.

[0038] The inner surface rubber layer 3 is made of an appropriate material depending on the type of fluid L. If the fluid L is crude oil, it is made of nitrile rubber or similar material with excellent oil resistance. The inner peripheral reinforcing layer 4 and the outer peripheral reinforcing layer 6 are each formed by stacking multiple reinforcing cord layers made of rubber-coated reinforcing cords. The main body cord layer 5 is formed by spirally winding metal wires at specified intervals around the outer peripheral rubber of the inner peripheral reinforcing layer 4. The inner peripheral reinforcing layer 4, the main body cord layer 5, and the outer peripheral reinforcing layer 6 are fixed to the pipe joint 2b using pipe joint lines 4a, 5a, and 6a at one end of each and a fixing ring 2c protruding from the outer peripheral surface of the pipe joint 2b. The fluid retention layer 7 formed between the inner peripheral reinforcing layer 4 and the outer peripheral reinforcing layer 6 is a space for storing the fluid L leaking from the flow path 1a.

[0039] The sensing system includes: a connecting tube 10, which, as shown in... Figure 2 As shown in the example, the hose 1 is connected to the fluid retention layer 7 and extends to the surface of the marine hose 1 (outer peripheral surface of the connector 2b); a sensor 11, which is connected to the connecting pipe 10 and disposed on the surface of the marine hose 1 (outer peripheral surface of the connector 2b); and a radio wave transmitting unit 22a and a radio wave receiving unit 22b. The radio wave transmitting unit 22a transmits a transmitted radio wave W1 to the sensor 11, and the sensor 11 transmits a returned radio wave W2 to the radio wave receiving unit 22b.

[0040] The radio wave transmitter 22a and the radio wave receiver 22b are separately disposed on the outside of the marine hose 1. In this embodiment, a communication device 22 is used that integrates the radio wave transmitter 22a, the radio wave receiver 22b, and the arithmetic unit 22c, but they can also be configured to be separate and independent. A known computer can be used as the arithmetic unit 22c, and a monitor, for example, can be attached to the communication device 22.

[0041] like Figures 3 to 8 As illustrated by an example, the sensor 11 includes: a housing 18, a pressure chamber 18c built into the housing 18, a check valve 17 disposed on the housing 18, and a pressure sensor section 15 and a passive IC tag 12 housed within the pressure chamber 18c. In this embodiment, a cover 20 is provided covering the upper part of the housing 18. The cover 20 can be arbitrarily disposed.

[0042] The sensor 11 is connected to the connecting pipe 10 via a metal cylindrical connector portion 21. Specifically, the cylindrical pipe end connector 10a at the end of the connecting pipe 10 is screwed into the connector portion 21. A ring-shaped seal 18s (O-ring) is clamped between the lower surface of the base 18a and the upper end of the connector portion 21 to ensure water tightness. The interior of the connector portion 21 forms a watertight inlet chamber 21a. The connector portion 21, communicating with the connecting pipe 10, is detachably mounted on the surface of the marine hose 1 (outer peripheral surface of the pipe connector 2b) via the pipe end connector 10a. The connector portion 21 is made of, for example, stainless steel.

[0043] The lower end of the housing 18 is screwed into the upper end of the connector portion 21 to connect the two. The housing 18 is detachably mounted on and connected to the connecting pipe 10 via the connector portion 21. The connector portion 21 can be used arbitrarily; if the connector portion 21 is not used, the lower end of the housing 18 is screwed into the pipe end connection portion 10a to connect the two.

[0044] The housing 18 has: a cylindrical metal base 18a; a radio wave transmitting portion 18b that watertightly blocks the upper end of the base 18a; and three or more metal protrusions 19 that protrude upwards from the radio wave transmitting portion 18b. In this embodiment, the housing 18 also has an annular fixing portion 18d. The base 18a and the protrusions 19 are essentially a single unit. The base 18a, the fixing portion 18d, and the protrusions 19 are formed, for example, of stainless steel.

[0045] like Figure 8 As illustrated, the base 18a has a large-diameter recess with an electromagnetic wave transmission portion 18b disposed therein, and a small-diameter recess connected to the lower part of the large-diameter recess. The upper end of the check valve 17, mounted on the lower end of the base 18a, protrudes from the bottom surface of the small-diameter recess. Circular seals 18s (O-rings) are disposed inside the base 18a (the bottom surface portion of the large-diameter recess) and on the lower surface of the base 18a. Furthermore, the seals 18s are appropriately positioned where necessary.

[0046] In this embodiment, the radio wave transmitting portion 18b is formed in the shape of a disk and has a recess on its lower surface. The recess on the lower surface of the radio wave transmitting portion 18b and the small-diameter recess inside the base 18a are set opposite to each other. The radio wave transmitting portion 18b is disposed on the base 18a by its lower surface abutting against the bottom surface portion of the large-diameter recess inside the base 18a.

[0047] Since the seal 18s is sandwiched 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 of the base 18a is watertightly isolated by the radio wave transmitting portion 18b. Furthermore, the pressure-holding chamber 18c is formed by the base 18a and the radio wave transmitting portion 18b. That is, the watertight pressure-holding 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.

[0048] The radio wave transmitting portion 18b has a circular cutout on its outer edge when viewed from above. An annular fixing portion 18d is disposed in this cutout. The outer peripheral surface of the fixing portion 18d engages with the inner peripheral surface of the upper opening of the base 18a, allowing it to be freely attached and detached from the base 18a. The radio wave transmitting portion 18b is fixed to the base 18a by pressing its outer peripheral edge in from above through the fixing portion 18d, which is screwed into the inner peripheral surface of the upper opening of the base 18a. Thus, the radio wave transmitting portion 18b is fixed to the base 18a via the annular fixing portion 18d that engages with its outer edge.

[0049] To facilitate the transmission of transmitted radio waves W1 and returned radio waves W2, the relative permittivity of the radio wave transmitting portion 18b is set to 5.0 or less, for example, to 2.0 or more and 5.0 or less, and more preferably to 2.5 or more and 3.0 or less. Considering durability, impact resistance, etc., the material of the radio wave transmitting portion 18b can be, for example, polycarbonate, polyamide, epoxy resin, etc.

[0050] Furthermore, the radio wave transmitting portion 18b and the base 18a are not limited to the shapes illustrated in this embodiment, as long as the radio wave transmitting portion 18b and the base 18a can form the pressure-holding chamber 18c. Additionally, other components may be used instead of the fixing portion 18d, or other components may be used besides the fixing portion 18d to fix the radio wave transmitting portion 18b to the base 18a. For example, to more reliably fix the radio wave transmitting portion 18b to the base 18a, a screw or the like may extend radially inward from the outer peripheral surface of the base 18a, with its front end engaging the outer peripheral surface of the radio wave transmitting portion 18b.

[0051] When viewed from above, each protrusion 19 is arranged at circumferential intervals on the outer periphery of the radio wave transmitting portion 18b. Preferably, each protrusion 19 is arranged at equal intervals in the circumferential direction of the radio wave transmitting portion 18b, for example, three or more but eight or fewer protrusions 19 are arranged.

[0052] In this embodiment, a protrusion 19 extending straight upwards is used, but the shape is not limited to this. However, if the upper ends of each protrusion 19 are in contact (engaged) with each other, the quality of radio wave communication between the IC tag 12 and the communicator 22 cannot be guaranteed. Therefore, the upper ends of each protrusion 19 are spaced apart from each other.

[0053] The cover 20 is radio-transparent and is formed of various resins such as polyvinyl chloride or rubber. The cover 20 is an integrally formed shape consisting of a cylindrical portion that is embedded along the entire length of each protrusion 19 and at least the upper end of the base 18a, and an end face that closes the upper end of the cylindrical portion. By mounting the cover 20 onto the housing 18, the inner peripheral region of each protrusion 19 above the radio-transparent portion 18b is watertightly isolated from the outside. The cover 20 can be made orange to make it conspicuous in the ocean.

[0054] A check valve 17 is disposed between the pressure holding chamber 18c and the inlet chamber 21a. The check valve 17 only allows the flow of fluid L and gas from the inlet chamber 21a side to the pressure holding chamber 18c side, and restricts (isolates) the flow from the pressure holding chamber 18c side to the inlet chamber 21a side. That is, the check valve 17, sandwiched between the connecting pipe 10 and the pressure holding chamber 18c, only allows the flow from the connecting pipe 10 side to the pressure holding chamber 18c side, and restricts the flow from the pressure holding chamber 18c side to the connecting pipe 10 side. Therefore, when the pressure P in the pressure holding chamber 18c rises, its pressure state will be maintained. Various known types of check valves can be used.

[0055] The IC (Integrated Circuit) tag 12 has an IC chip 13 and an antenna section 14 connected to the IC chip 13. A pressure sensor section 15 is connected to the IC tag 12 (IC chip 13). The IC chip 13 is very small, for example, with a vertical dimension and a horizontal dimension of 30 mm or less (30 mm or less in terms of outer diameter), and a thickness of 5 mm or less. The antenna section 14 is also very small, for example, with a vertical dimension and a horizontal dimension of 50 mm or less (50 mm or less in terms of outer diameter), and a thickness of 10 mm or less. In this embodiment, because a ceramic antenna is used as the antenna section 14, it becomes very compact.

[0056] A plate-shaped metal grounding portion 16 is disposed in contact with the lower surface of the antenna section 14. In this embodiment, the grounding portion 16 is mounted on a C-ring 18f that fits detachably into an annular groove formed in the recess of the lower surface of the radio wave transmitting portion 18b, and an annular spacer 18e is disposed on the upper surface of the antenna section 14. The IC tag 12 and the pressure sensor section 15 are disposed in the pressure holding chamber 18c. It is also possible to manufacture a structure in which the IC tag 12 and the pressure sensor section 15 are disposed in the pressure holding chamber 18c without using the C-ring 18f. The spacer 18e can be arbitrarily set. By combining the antenna section 14, which employs a ceramic antenna, the small check valve 17, which can withstand high pressure (e.g., 7-8 MPa), and the grounding portion 16, it is very helpful to make the sensor 11 compact.

[0057] Alternatively, it can be configured such that the grounding portion 16 contacts the metal base 18a. If configured in this way, the base 18a and the protrusion 19 can actively function as an antenna, thus easily ensuring excellent radio wave communication between the IC tag 12 and the communicator 22.

[0058] The pressure sensor unit 15 senses the pressure P in the pressure-holding chamber 18c. The size of the pressure sensor unit 15 is the same as that of the IC chip 13. In the accompanying drawings, the IC chip 13 and the pressure sensor unit 15 are in a suspended state, but they can also be in a flat state like the antenna unit 14.

[0059] The sensing system of the present invention is configured as follows: after the radio wave transmitter 22a transmits a transmitted radio wave W1, the IC tag 12 transmits a response radio wave W2 according to the transmitted radio wave W1, and the radio wave receiver 22b receives the response radio wave W2. That is, the IC tag 12 and the communicator 22 constitute an RFID (Radio Frequency Identification) system. The frequencies and outputs of the communicating radio waves W1 and W2 can be appropriately set, but since a passive IC tag 12 is used, the mutual communication distance between the IC tag 12 and the communicator 22 is, for example, about tens of centimeters to several meters.

[0060] The sensing system uses a response radio wave W2 to transmit the sensed pressure data of the pressure-holding chamber 18c sensed by the pressure sensor unit 15, which is then received by the radio wave receiver 22b. The sensed pressure data received by the radio wave receiver 22b is input into the processing unit 22c.

[0061] The calculation unit 22c stores a reference value Pc for determining whether fluid L leakage has occurred in the pressure chamber 18c of the flow path 1a. To prevent false sensing, an appropriate range is determined in advance by conducting experiments or simulations, taking into account the specifications and operating conditions of the marine hose 1. The reference value Pc is set within this appropriate range and stored in the calculation unit 22c in advance.

[0062] In this embodiment, the IC chip 13 stores location determination information that determines the placement position of the IC tag 12 in the marine hose 1. This location determination information is then transmitted to the radio wave receiver 22b via a response radio wave W2. Alternatively, other information can be pre-stored in the IC chip 13 and transmitted via the response radio wave W2. For example, information such as the specifications of the marine hose 1, manufacturing information, and the time when the IC tag 12 was placed in the marine hose 1 can be pre-stored in the IC chip 13 and transmitted to the radio wave receiver 22b.

[0063] The following is an example of the steps in the manufacturing method of this sensing system.

[0064] A marine hose 1 having a fluid retention layer 7 and a buoyancy layer 8 is manufactured using a known method. Alternatively, an existing marine hose 1 having a fluid retention layer 7 and a buoyancy layer 8 can also be used. Furthermore, a connecting pipe 10 communicating with the fluid retention layer 7 extends to the surface of the marine hose 1. A pipe end connection 10a is provided at the end of the connecting pipe 10 and fixed to the surface of the marine hose 1.

[0065] Regarding sensor 11, from Figure 8 Starting with the state shown in the example, such as Figure 9 As shown in the example, the IC tag 12 (IC chip 13, antenna 14), grounding part 16, and pressure sensor part 15 are assembled together with spacer 18e and C-ring 18f onto the radio wave transmission part 18b. Next, as... Figure 10 As shown in the example, components assembled from the radio wave transmitting part 18b, the IC tag 12, and the pressure sensor part 15 are disposed inside the base 18a. Next, as... Figure 11 As shown in the example, the outer peripheral surface of the fixing part 18d is screwed into the inner peripheral surface of the upper opening of the base 18a, and the radio wave transmitting part 18b is fixed relative to the base 18a via the fixing part 18d.

[0066] Next, in the sensor 11 installation process, the sensor 11 is installed on the surface of the marine hose 1 via the pipe end connection 10a, thereby becoming... Figure 5The example shown is as follows. In this embodiment, the sensor 11 (base 18a) is connected to the pipe end connection 10a via the connector 21. If the connector 21 is not used, the sensor 11 (base 18a) is connected to the pipe end connection 10a. Furthermore, regardless of whether the connector 21 is used or not, when the sensor 11 is placed on the surface of the marine hose 1, the upper end of the protrusion 19 is not allowed to protrude further upward than the flange 2a. The cover 20 can be mounted on the housing 18 at any time.

[0067] The sensing system manufactured by mounting the sensor 11 on the surface of the marine hose 1 can be as follows: Figure 12 Use it as illustrated in the example. The method of using this sensing system will be explained later.

[0068] During the manufacturing of this sensing system, a specification determination process for sensor 11 is performed. A larger exposed area on the upper surface of the radio wave transmitting portion 18b is more beneficial for maintaining good radio wave communication between the IC tag 12 and the communication device 22, but less beneficial for ensuring the pressure resistance of the radio wave transmitting portion 18b. Therefore, if the upper surface of the radio wave transmitting portion 18b is circular, the diameter A 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 be equivalent to a diameter A of 40 mm or more and 70 mm or less. Furthermore, a larger thickness C on the upper surface of the radio wave transmitting portion 18b is more beneficial for ensuring pressure resistance, but less beneficial for maintaining good radio wave communication between the IC tag 12 and the communication device 22. 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.

[0069] In this specification determination process, the combination of the specifications (height H, thickness, shape), quantity, and position of each protrusion 19 is determined. The specifications, quantity, and position of the protrusions 19 are based on the premise of being able to protect the radio wave transmission part 18b and to maintain good radio wave communication between the IC tag 12 and the communication device 22.

[0070] To protect the radio wave transmitting portion 18b by the protrusion 19, the height H and thickness of the protrusion 19 are preferably large enough, but it is necessary to ensure that the height is such that, when the sensor 11 is mounted on the surface of the marine hose 1, the upper end of the protrusion 19 does not protrude further upward than the flange 2a. Furthermore, if the height H and thickness of the protrusion 19 are too large, the space occupied will be too large. Therefore, the height H of the protrusion 19 is set within, for example, a range of 15 mm to 40 mm, and the thickness is set within, for example, a range of 3 mm to 8 mm. The height H of the protrusion 19 can be set to be 35% to 45% of the diameter A of the upper surface of the radio wave transmitting portion 18b.

[0071] The number and arrangement of the protrusions 19 are as described above, with for example, 3 to 8 protrusions 19 arranged at equal intervals in the circumferential direction of the radio wave transmission portion 18b. The width of the protrusions 19 is determined such that the circumferential interval W between adjacent protrusions is, for example, 10 mm or more, more preferably 15 mm or more.

[0072] The protrusion 19 can generally be shaped to extend straight upwards, but other shapes can be used to improve the protection of the radio wave transmission portion 18b. For example... Figure 13 , Figure 14 As illustrated by example, each protrusion 19 can also be shaped to bend at a midpoint in the vertical direction and extend to the center side of the radio wave transmission portion 18b when viewed from above.

[0073] However, the lower end of each protrusion 19 is positioned further outward than the outer periphery of the upper surface of the radio wave transmitting portion 18b, and the height of the mid-bend is set at a position at least 8 mm from the upper surface of the radio wave transmitting portion 18b. Furthermore, when viewed from above, the gap D between the curved upper ends of each protrusion 19 is at least 50%, preferably at least 70%, and more preferably at least 100% of the diameter A of the upper surface of the radio wave transmitting portion 18b. Additionally, when viewed from above, the circumferential gap W between adjacent curved upper ends of each protrusion 19 is preferably at least 3 mm, and more preferably at least 5 mm.

[0074] The specifications of each protrusion 19 are substantially the same. However, protrusions 19 with different specifications may also coexist. For example, one protrusion 19 of two different heights H may be arranged alternately along the circumference.

[0075] In this specification determination process, different combinations of the height H, width, thickness, shape, number, and arrangement of the protrusions 19 are made within the aforementioned range to determine the strength of the response radio wave W2 received by the radio wave receiver 22b when the transmitted radio wave W1 is sent from the radio wave transmitter 22a to the IC tag 12 under the same specified conditions. For example, the communication device 22 is positioned approximately 1m directly above the distance sensor 11 to determine the strength of the response radio wave W2.

[0076] Then, it is determined that the strength of the received radio wave W2 is higher than a preset threshold (a value that can maintain good radio wave communication between IC tag 12 and communicator 22). In the sensor 11 setting process, the sensor 11 with the determined combination is connected to the connecting pipe 10 and set on the surface of the marine hose 1.

[0077] If connector 21 is used, the position of sensor 11 relative to marine hose 1 changes depending on the length of connector 21. This can sometimes affect the radio communication between IC tag 12 and communicator 22. Therefore, the length of connector 21 should be determined in advance to ensure good radio communication between IC tag 12 and communicator 22, and set to a length that can maintain good radio communication.

[0078] The circumferential position of the IC tag 12 (antenna portion 14) relative to each protrusion 19 when viewed from above can sometimes affect the radio communication between the IC tag 12 and the communicator 22. Therefore, for a sensor 11 using the combination determined in the above manner, it is necessary to further determine the circumferential position of the IC tag 12 (antenna portion 14) relative to each protrusion 19 when viewed from above.

[0079] Therefore, as Figure 15 , Figure 16 As illustrated in the example, the circumferential position of the IC tag 12 (antenna portion 14) can be varied when viewed from above relative to each protrusion 19 to determine the strength of the returned radio wave W2 received by the radio wave receiver 22b when a transmitted radio wave W1 is sent from the radio wave transmitter 22a to the IC tag 12 under the same specified conditions. For example, a communication device 22 can be positioned approximately 1 m directly above the distance sensor 11 to determine the strength of the returned radio wave W2. The determination of the strength of the returned radio wave W2 can be performed beforehand during the specification determination process of the sensor 11, or it can be performed during the installation process of mounting the sensor 11 on the surface of the marine hose 1.

[0080] In the process of setting up the sensor 11, the IC tag 12 (antenna part 14) is fixed at the circumferential position where the intensity of the received radio wave W2 is relatively strong (strongest) in multiple different circumferential positions, and the sensor 11 is connected to the connecting pipe 10 and set on the surface of the marine hose 1.

[0081] The following describes an example of a sensing step that uses this sensing system to determine whether a fluid L leak has occurred in flow path 1a.

[0082] For confirming a leak in fluid L, the operator periodically, or at necessary times, approaches the vessel's hose 1 via a work vessel or similar vessel. Then, the communication device 22 is activated, such as... Figure 2As illustrated in the example, a transmitted radio wave W1 is sent from the radio wave transmitter 22a toward the sensor 11, and this transmitted radio wave W1 powers the IC tag 12. The IC tag 12 then transmits a response radio wave W2 via this power, which is received by the radio wave receiver 22b. At this time, the sensed pressure data measured by the pressure sensor unit 15 is transmitted via the response radio wave W2, and the sensed pressure data received by the radio wave receiver 22b is input to the arithmetic unit 22c. In the communication device 22, it can also be configured to display the pressure value of the received sensed pressure data.

[0083] The calculation unit 22c compares the pressure value of the input sensed pressure data with the reference value Pc. When fluid L does not flow into the fluid retention layer 7, the pressure P in the pressure holding chamber 18c does not change significantly, therefore the pressure value of the sensed pressure data is less than the reference value Pc. Therefore, the calculation unit 22c determines that fluid L is not leaking from the flow path 1a, and notifies the result through the monitor display and sound.

[0084] On the other hand, if the inner surface rubber layer 3 or the inner peripheral reinforcing layer 4 is damaged, causing fluid L to flow from the flow path 1a into the fluid retention layer 7, then, as Figure 12 As illustrated, fluid L passes through the connecting pipe 10, the inlet chamber 21a, and the check valve 17, causing the pressure P in the pressure-holding chamber 18c to rise. This increased pressure P is maintained by the check valve 17 and sensed by the pressure sensor unit 15. Therefore, during a leak detection operation of fluid L, a transmitted electrical signal is sent from the radio wave transmitter 22a toward the sensor 11.

[0085] After wave W1, the pressure value of the highest pressure P previously measured by the pressure sensor unit 15 will be received by the radio wave receiver 22b and input into the calculation unit 22c as the sensed pressure data.

[0086] The arithmetic unit 22c compares the pressure value of the input sensed pressure data with a reference value Pc. If the pressure value of the sensed pressure data is above the reference value Pc, it is determined that fluid L is leaking from flow path 1a, and this result is announced via display and sound from the monitor. If the pressure value of the sensed pressure data is below the reference value Pc, it is determined that fluid L is not leaking from flow path 1a, and this result is announced via display and sound from the monitor. In this way, the presence or absence of fluid L leakage can be determined based on the sensed pressure data (the magnitude of the sensed pressure) received by the radio wave receiver 22b.

[0087] If the fluid L flowing in flow path 1a is water, when it flows into pressure chamber 18c and submerges IC tag 12 (antenna section 14), the radio communication between radio wave transmitter 20a and IC tag 12 is cut off. Therefore, even if radio wave W1 is transmitted from radio wave transmitter 20a, the sensed pressure data received by radio wave receiver 22b will be zero (sensed pressure data cannot be received). Therefore, if fluid L is water, it needs to be preset so that, for example, if a reply radio wave W2 cannot be received even if radio wave W1 is transmitted, it is determined that fluid L is leaking from flow path 1a. It should be noted that although the radio communication between radio wave transmitter 20a and IC tag 12 is not cut off even when IC tag 12 (antenna section 14) is submerged in oil, it is necessary to know in advance the type of fluid L that will cut off the radio communication, and set it so that when fluid L is a fluid that will cut off the communication, the judgment of whether there is a leak is performed in the same way as in the case of water.

[0088] The sensing system uses a passive IC tag 12, thus eliminating the need to monitor battery consumption. Furthermore, by maintaining the pressure in the pressure chamber 18c using a check valve 17 and using the pressure data received by the radio wave receiver 22b and measured by the pressure sensor 15 as an indicator, it is possible to more reliably determine whether fluid L is leaking from the flow path 1a.

[0089] That is, since a passive IC tag 12 is used, it is not possible to continuously monitor the sensed pressure data measured by the pressure sensor unit 15, but it is possible to monitor the highest pressure P in the pressure holding chamber 18c generated before the fluid leak confirmation operation. If a fluid L leak occurs from the flow path 1a, there will be an excessively large value in the historical record of pressure P. Moreover, even if a fluid L leak occurs, it is possible for the following situation to occur: for example, fluid L flows out from the fluid retention layer 7, causing the pressure P at the time of the confirmation operation to decrease. In such cases, although a sensing system using a passive IC tag 12 is used, it is still possible to reliably determine whether there is a fluid L leak.

[0090] In this embodiment, the calculation unit 22c automatically determines whether fluid L is leaking from the flow path 1a. Alternatively, for example, the operator can compare a preset reference value Pc with the pressure value of the sensed pressure data received by the radio wave receiving unit 22b to determine whether fluid L is leaking.

[0091] For confirming fluid leaks, the operation can be carried out by an operator holding a portable communication device 22, or the communication device 22 can be mounted on a drone. If a drone is used, the operator does not need to approach the ship's hose 1 during the confirmation operation.

[0092] In this sensor 11, the upper surface of the radio wave transmitting portion 18b is protected by the aforementioned protrusions 19. Therefore, this reduces the risk of damage to the radio wave transmitting portion 18b and improves the durability of the sensor 11. The protrusions 19 are spaced apart circumferentially, and when viewed from above, the upper ends of each protrusion 19 are spaced apart from each other. Therefore, these protrusions 19 prevent the impairment of radio wave communication between the IC tag 12 and the communicator 22. Thus, while protecting the upper surface of the radio wave transmitting portion 18b, it is possible to ensure ease of fluid leakage detection and reliable sensing.

[0093] Furthermore, according to the manufacturing method of the sensing system described above, the sensor 11, with the specifications (height H, width, thickness, shape), quantity, and arrangement of each protrusion 19 determined in the above manner, is connected to the connecting pipe 10 and installed on the surface of the marine hose 1. Therefore, it is advantageous to manufacture a sensing system with high precision that improves the durability of the sensor 11 while ensuring ease of confirmation of fluid leakage and sensing reliability.

[0094] In this embodiment, since the upper surface of the radio wave transmitting portion 18b is flat, it is advantageous to reduce the protrusion height H of the upwardly projecting protrusion 19, which is used to protect the radio wave transmitting portion 18b. The radio wave transmitting portion 18b is not limited to having a flat upper surface. For example, the radio wave transmitting portion 18b can also be made into an upwardly projecting dome shape (approximately hemispherical). The dome-shaped radio wave transmitting portion 18b easily improves its resistance to pressure from external sources.

[0095] After the cover 20 is installed on the housing 18, marine biofouling (attachment of marine organisms) can be prevented from damaging the upper surface of the radio wave transmission portion 18b. Generally speaking, it is more beneficial to maintain the good radio wave communication between the IC tag 12 and the communicator 22 than to install the cover 20. However, depending on the specifications of the cover 20 (e.g., made of polyvinyl chloride with a thickness of about 1 mm to 3 mm), sometimes the radio wave communication can be even better. The dielectric has the effect of making the aperture through which radio waves pass appear larger (the wavelength of the radio waves becomes shorter compared to air), so it is speculated that installing the cover 20 on the housing 18 will improve the radio wave communication as one of the reasons.

[0096] Compared to traditional marine hoses with oil tanks, this sensing system can be constructed simply by preparing an IC tag 12, a pressure sensor unit 15, a check valve 17, and a communication unit 22. Therefore, it also has the advantage of being usable directly without modifying existing marine hoses.

[0097] In this embodiment, location determination information, which determines the placement position of the IC tag 12 in the marine hose 1, is transmitted via a response radio wave W2 sent from the IC tag 12. Therefore, by analyzing the response radio wave W2 (location determination information) received by the radio wave receiver 22b, the location where a fluid L leak has occurred can be determined more easily and reliably.

[0098] Explanation of reference numerals in the attached figures

[0099] 1: Marine hoses

[0100] 1a: Flow path

[0101] 2: Connecting end

[0102] 2a: Flange

[0103] 2b: Pipe fitting

[0104] 2c: Fixing ring

[0105] 3: Inner rubber layer

[0106] 4: Inner peripheral reinforcing layer

[0107] 4a: Pipe fitting line

[0108] 5: Body line layer

[0109] 5a: Pipe fitting line

[0110] 6: Peripheral reinforcement layer

[0111] 6a: Pipe fitting line

[0112] 7: Fluid retention layer

[0113] 8: Buoyancy layer

[0114] 9: Outer layer

[0115] 10: Connecting pipe

[0116] 10a: Pipe end connection

[0117] 11: Sensor

[0118] 12: IC tag

[0119] 13: IC Chips

[0120] 14: Antenna section

[0121] 15: Pressure Sensor Section

[0122] 16: Grounding part

[0123] 17: Check valve

[0124] 18: Shell

[0125] 18a: Base

[0126] 18b: Radio wave transmission section

[0127] 18c: Pressure holding chamber

[0128] 18d: Fixed part

[0129] 18e: Spacer

[0130] 18f: C-shaped ring

[0131] 18s: Seals

[0132] 19: Protrusion

[0133] 20: cover

[0134] 21: Connector section

[0135] 21a: Induction Chamber

[0136] 22: Communication equipment

[0137] 22a: Radio wave transmitting unit

[0138] 22b: Radio wave receiving unit

[0139] 22c: Arithmetic Unit

Claims

1. A fluid leakage sensing system for a marine hose, comprising: a connecting pipe communicating with a fluid retention layer formed on a marine hose having a buoyancy layer and extending to the surface of the marine hose; a sensor communicating with the connecting pipe and disposed on the surface of the marine hose; and an electromagnetic wave transmitting unit and an electromagnetic wave receiving unit disposed on the outside of the marine hose. The sensor includes: a housing; a pressure holding chamber housed within the housing; a check valve sandwiched between the connecting pipe and the pressure holding chamber, allowing flow only from the connecting pipe side to the pressure holding chamber side; and a pressure sensor portion and a passive IC tag connected to the pressure sensor portion, housed within the pressure holding chamber. Based on the transmitted radio wave from the radio wave transmitting unit, the IC tag transmits a response radio wave, and transmits the sensed pressure data measured by the pressure sensor unit via the response radio wave, which is then received by the radio wave receiving unit. The characteristic of this method is that... The housing has: a cylindrical metal base; a watertight portion that blocks the upper end of the base from radio wave transmission; and three or more metal protrusions that protrude upwards from the radio wave transmission portion; the pressure chamber is formed by the base and the radio wave transmission portion, such that when viewed from above, each of the protrusions is circumferentially spaced at a position on the outer periphery of the radio wave transmission portion, and each upper end is spaced apart from the other.

2. The fluid leakage sensing system for marine hoses according to claim 1, wherein, The housing has an annular fixing part that engages with the outer edge of the radio wave transmitting part, and the radio wave transmitting part is fixed relative to the base via the fixing part.

3. The fluid leakage sensing system for marine hoses according to claim 1 or 2, wherein, The upper surface of the radio wave transmission part is flat.

4. The fluid leakage sensing system for marine hoses according to claim 1 or 2, wherein, Each of the protrusions bends at a midpoint in the vertical direction and extends to the center side of the radio wave transmission portion when viewed from above.

5. The fluid leakage sensing system for marine hoses according to claim 1 or 2, comprising an electromagnetically permeable cover integrally formed of a cylindrical portion externally embedded in at least the upper end of each of the protrusions and the base and an end face closing the upper end of the cylindrical portion, wherein the inner peripheral region of each of the protrusions above the electromagnetically permeable portion is watertightly isolated from the outside through the cover.

6. The fluid leakage sensing system for a marine hose according to claim 1 or 2, comprising a connector portion that communicates with the connecting pipe and is detachably mounted on the surface of the marine hose, wherein the housing is detachably mounted on the upper end of the connector portion, and the connecting pipe is connected to the housing via the connector portion.

7. A method for manufacturing a fluid leakage sensing system for marine hoses, wherein the manufacturing method is the method for manufacturing a fluid leakage sensing system for marine hoses as described in any one of claims 1 to 6. In the sensor specification determination process, the specifications, quantity, and position of each of the protrusions are combined in different ways to determine the intensity of the returned radio waves received by the radio wave receiving unit under the same specified conditions. The combination in which the intensity of the returned radio waves is determined to be higher than a preset threshold is determined. In the sensor installation process, the sensor using the determined combination is connected to the connecting pipe and installed on the surface of the ship hose.

8. The method for manufacturing a fluid leakage sensing system for marine hoses according to claim 7, wherein, The circumferential position of the IC tag can be varied relative to each of the protrusions when viewed from above, so as to determine the intensity of the returned radio wave received by the radio wave receiving unit under the same specified conditions. In the setting process, while the IC tag is fixed at the circumferential position where the intensity of the determined returned radio wave is relatively strong, the sensor is connected to the connecting pipe and set on the surface of the marine hose.

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