Tension monitoring device

Abstract

To provide a tension monitoring device which can be introduced at a low cost, can be attached to an arbitrary position of a mooring rope, and is hardly displaced or detached even if the tension of the mooring rope changes.SOLUTION: A mooring device includes a pair of locking tools that are spaced apart from each other in a longitudinal direction and detachably locked to a mooring rope for a ship, and a measuring tool that measures an amount of change from an initial value of a separation distance between the locking tools, wherein the locking tool includes a tightening mechanism that tightens the mooring rope in accordance with a change in a diameter of the mooring rope, and is locked to the mooring rope via the tightening mechanism.SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] The present invention relates to a tension monitoring device. [Background technology]

[0002] Mooring ropes that moor ships to ports when anchored can be subject to significant tension due to the ship's hull rising due to cargo handling and tides, and the ship's tilt due to wind and waves. If the ropes break, it can result in a serious accident that could result in loss of life. Furthermore, if the tension becomes too low, there is a risk that the ship may collide with the quay or other ships anchored there. For this reason, it is necessary to monitor and adjust the tension.

[0003] On large ships, this is addressed by incorporating a mechanism to automatically control the tension in the winch that winds up the mooring rope, but on small ships, since it is not possible to spend the same amount of money as on large ships, workers check the tension by kicking the mooring rope with their foot and watching the recoil, which is an extremely dangerous method of relying on intuition.

[0004] In view of this situation, Patent Document 1 discloses a tension meter that can be introduced at low cost. This tension meter has a structure in which a pair of support rollers that press down on one radial side of the mooring rope and a tension roller that presses down on the other radial side of the mooring rope, which is interposed between the pair of support rollers, are axially fixed to a single plate-like casing. This makes it possible to attach it to any position on the mooring rope and install it near the winch, making it easy to use.

[0005] However, because the tension meter is designed to be fixed to the mooring rope while it is under a certain amount of tension, it can shift position or come off if the tension slackens, which is a major problem for mooring ropes used on ships, where the tension frequently changes due to the tilt of the ship's hull caused by wind and waves. [Prior art documents] [Patent documents]

[0006] [Patent Document 1] Japanese Patent Application Publication No. 51-93086 Summary of the Invention [Problem to be solved by the invention]

[0007] Therefore, the main objective of the present invention is to provide a tension monitoring device that can be introduced at low cost, can be attached at any position on the mooring rope, and is unlikely to shift position or come off even if the tension of the mooring rope changes. [Means for solving the problem]

[0008] The tension monitoring device of the present invention comprises a pair of fastening devices that are detachably fastened to a mooring rope for a ship at a longitudinal distance from each other, and a measuring device that measures the amount of change in the distance between the fastening devices from an initial value, and is installed between the fastening devices to measure the amount of change in the distance between the fastening devices from an initial value, and the fastening devices are equipped with a tightening mechanism that tightens the mooring rope in response to changes in the diameter of the mooring rope, and are fastened to the mooring rope via the tightening mechanism.

[0009] According to the present invention, the measuring tool is attached to the mooring rope using a pair of fastening devices, allowing for easy attachment to any position on the mooring rope. Furthermore, the mooring rope expands and contracts as its tension changes, but the fastening device is equipped with a tightening mechanism, ensuring that it remains firmly fixed even when the diameter changes. This makes it less likely for the fastening device to shift position or come off even when tension changes. As a result, the amount of change in the distance between the two fastening devices can be accurately determined.

[0010] This change indicates the elongation rate of the mooring rope between the two anchors. The elongation rate is known to be correlated with the load, which is an indicator of tension. Therefore, knowing the elongation rate allows you to monitor the tension of the mooring rope.

[0011] A specific embodiment of the tightening mechanism is one in which the tightening mechanism elastically tightens the mooring rope.

[0012] To make installation easier, the tightening mechanism may include a pair of clamping pieces that resiliently clamp the mooring rope. With this configuration, the mooring rope can be secured simply by clamping it between the pair of clamping pieces.

[0013] However, if the measuring tool is a non-contact sensor, since mooring ropes are basically used at sea, there is a risk that salt from seawater will adhere to the lens, making it impossible to make measurements.

[0014] Therefore, it is preferable that the measuring tool is installed between the two fastening tools. With this configuration, measurements can be continued even if salt adheres to the measuring tool.

[0015] A specific embodiment of this type of measuring tool is one that includes a gauge body fixed to one fastening device and a slider fixed to the other fastening device and slidable relative to the gauge body, and measures the amount of change based on the amount of movement of the slider relative to the gauge body.

[0016] According to this configuration, the amount of change can be measured with a simple structure.

[0017] Another specific embodiment of the installation type measuring tool is one in which the measuring tool is provided with a strain-generating body that is interposed between the two fastening tools and pulled by the fastening tools, and the amount of change is measured based on the degree of distortion of the strain-generating body.

[0018] As mentioned above, it is generally known that there is a correlation between load and elongation, and it is believed that this correlation follows Hooke's law. However, when the applicant conducted tests to measure the relationship between load and elongation using mooring ropes sold by various manufacturers in developing the present invention, he found that the relationship does not simply follow Hooke's law, as shown in the graph in Figure 6, for example. Then, through repeated tests, he found that mooring ropes of the same specifications sold by various manufacturers show approximately the same correlation between load and elongation.

[0019] Therefore, the device may further include a correlation data storage unit that stores correlation data for each type of mooring rope that indicates the correlation between the amount of change and the load applied to the mooring rope interposed between the two fastening devices, and a conversion unit that converts the amount of change measured by the measuring device into a load based on the correlation data.

[0020] With this configuration, the tension can be measured accurately by acquiring correlation data in advance for each type of mooring rope sold by each manufacturer. [Effects of the Invention]

[0021] The present invention configured in this manner can be introduced at low cost, can be attached at any position on the mooring rope, and is less likely to shift position or come off even if the tension on the mooring rope changes. [Brief explanation of the drawings]

[0022] [Figure 1] 1 is a schematic diagram showing a state in which a tension monitoring device according to an embodiment is attached to a mooring rope. [Figure 2] 1 is a side view schematically showing a state in which a tension monitoring device according to an embodiment is attached to a mooring rope. [Figure 3] FIG. 2 is a block diagram schematically illustrating a control unit in the tension monitoring device according to the embodiment. [Figure 4]2 is a cross-sectional view taken along the line AA, showing a state in which the tension monitoring device of the embodiment is attached to a mooring rope. FIG. [Figure 5] FIG. 10 is a side view schematically showing a state in which a tension monitoring device of another embodiment is attached to a mooring rope. [Figure 6] 1 is a graph showing the results of actual measurements of the relationship between the load and elongation of a mooring rope. DETAILED DESCRIPTION OF THE INVENTION

[0023] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of a tension monitoring device according to the present invention will be described below with reference to the drawings.

[0024] The tension monitoring device according to the present invention is used by being attached to the mooring rope of a large ship or a small ship.

[0025] 1, a tension monitoring device 100 according to this embodiment is used by being attached to the middle of a mooring rope R that is pulled out from a winch W of a ship S and stretched across a mooring post P. As shown in FIGS. 2 and 3, this tension monitoring device 100 includes a pair of fastening devices 10 that are detachably fastened to the mooring rope R, and a measuring device 20 that is stretched between the fastening devices 10.

[0026] The pair of fastening devices 10 are fastened to the mooring rope R at a distance from each other in the longitudinal direction. That is, the pair of fastening devices 10 are each fastened to two locations on the mooring rope R. When attached to the mooring rope R, both fastening devices 10 protrude in the radial direction of the mooring rope R, and the measuring device 20 is hung across this protruding portion.

[0027] The measuring tool 20 measures the amount of change from the initial value of the distance between the two fastening devices 10. In other words, the distance between the two fastening devices 10 at the timing of locking the fastening devices 10 is set as the initial value, and the amount of change in the distance between the two fastening devices 10 thereafter is measured. Here, examples of the locking timing include a timing when no tension is applied to the mooring rope R or a timing immediately after the mooring rope R is stretched.

[0028] The measuring tool 20 of this embodiment is a so-called slide gauge. Specifically, it includes a gauge body 21a fixed to one of the fastening devices 10, a slider 21b fixed to the other fastening device 10 and slidable relative to the gauge body 21a, and a sensor (not shown) that measures the amount of movement of the slider 21b relative to the gauge body 21a, and measures the amount of change based on the measurement value of this sensor.

[0029] In this embodiment, the gauge body 21a is cylindrical, the slider 21b is rod-shaped and inserted into the cylindrical gauge body 21a, and a sensor is attached so as to be interposed between the inner surface of the gauge body 21a and the outer surface of the slider 21b.

[0030] The sensor may be, for example, a capacitance type in which the electrical signal changes according to the change in the area of ​​the opposing metal plates attached to the gauge body 21a and the slider 21b, but is not limited to this and may be of another type.

[0031] This measuring tool 21b is attached to the mooring rope R so that the sliding direction of the slider 21b relative to the gauge body 21a is along the longitudinal direction of the mooring rope R.

[0032] The tension monitoring device 100 of this embodiment further includes a control unit C, a display D, and an informing mechanism A. In this embodiment, these are housed in a casing B provided on the outer surface of the gauge main body 21a, forming an integrated structure.

[0033] The control unit C includes a CPU, memory, input means, etc., and is connected to the measuring tool 20 to receive the amount of change measured by the measuring tool 20. Based on the program stored in the memory, the control unit C at least functions as a correlation data storage unit C1, a locking timing load storage unit C2, a conversion unit C3, a display control unit C4, and a notification control unit C5, as shown in FIG. Below, the operation of the control unit C will be explained together with an explanation of each unit.

[0034] The correlation data storage unit C1 is installed in a predetermined area of ​​the memory and stores correlation data that indicates the correlation between the load and the change in the mooring rope R. Examples of the correlation data include table data and calculation formulas.

[0035] This correlation data storage unit C1 stores correlation data for each type of mooring rope R. Therefore, the worker can select correlation data that matches the mooring rope R to which the device 100 is attached.

[0036] Here, the type of mooring rope R can be classified according to its specifications, for example, by taking into consideration the material, thickness, and weaving method of the fibers that make up the mooring rope R, as well as the thickness of the mooring rope R itself. Note that mooring ropes R sold by different manufacturers have different specifications for each product, so they can also be classified by product. This is easier to use, as workers can specify correlation data simply by looking up the model number of the mooring rope R they are using.

[0037] The locking timing load data storage unit C2 is installed in a predetermined area of ​​the memory and stores locking timing load data that indicates the load applied to the mooring rope R for each predetermined locking timing. For example, if the locking timing is before the mooring rope R is laid, the load will be 0, but if it is after the laying, the load will not be 0. In this way, if the locking timing differs, the load applied to the mooring rope R may differ. Therefore, the load applied to the mooring rope R at each locking timing is measured in advance and stored as locking timing load data.

[0038] The conversion unit C3 converts the amount of change received from the measuring tool 21b into a load based on the correlation data and the locking timing load data. More specifically, the conversion unit C3 refers to the locking timing load data, identifies the initial load related to the locking timing input by the worker via the input means, and calculates the load using this initial load, amount of change, and correlation data. Note that the conversion unit C3 in this embodiment receives the amount of change from the measuring tool 21b in real time and converts it into a load. The load obtained by conversion by the conversion unit C3 is then displayed on the display D in real time by the display control unit C4.

[0039] The notification control unit C5 controls the notification mechanism A to notify the worker when the load converted by the conversion unit C3 becomes equal to or greater than a threshold value. This threshold value is stored in a predetermined area of ​​the memory, similar to the correlation data, and is set to a value smaller than the breaking load of the mooring rope R. Note that the notification mechanism A may be one that notifies the worker by sound, light, or vibration, for example. The notification control unit C5 may also be configured to notify the worker when the load converted by the conversion unit C3 becomes smaller than the threshold value.

[0040] Therefore, as shown in Figure 4, the fastening device 10 of this embodiment is equipped with a tightening mechanism 11 that tightens the mooring rope R in accordance with changes in the diameter of the mooring rope R, and is fastened to a predetermined location on the mooring rope R via this tightening mechanism 11.

[0041] The tightening mechanism 11 of this embodiment elastically tightens the mooring rope R. More specifically, the tightening mechanism 11 is scissor-shaped and includes a pair of clamping pieces 11a that clamp the mooring rope R from the radial direction, and a biasing mechanism 11b that biases the clamping pieces 11a in a closing direction.

[0042] The clamping pieces 11a have contact surfaces 11s that are curved to fit along the outer surface of the mooring rope R, and this contact surface 11s may be provided with an anti-slip surface to prevent it from slipping on the mooring rope R. The biasing mechanism 11b is, for example, a substantially C-shaped elastic body that clamps both clamping pieces 11a from the outer surface side.

[0043] According to the tension monitoring device 100 of this embodiment, the fastening device 10 is fastened to the mooring rope R via the tightening mechanism 11, so that changes in the tension applied to the mooring rope R interposed between the two fastening devices 10 can be monitored.

[0044] More specifically, the mooring rope R expands and contracts in response to changes in tension, and the diameter changes as the rope expands and contracts. Therefore, if the fastening device 10 does not have the tightening mechanism 11, for example, when the mooring rope R expands and its diameter becomes smaller, the fastening device 10 will shift position relative to the mooring rope R. As a result, it becomes impossible to measure how much the separation distance between the two fastening devices 10 has changed from its initial value.

[0045] On the other hand, by engaging the fastening device 10 with the mooring rope R via the tightening mechanism 11 as in the tension monitoring device 100 of this embodiment, even if the mooring rope R becomes thinner, the fastening device 10 is fixed without shifting from the initial position of the mooring rope R. As a result, the amount of change can be measured accurately.

[0046] Furthermore, by locking with the tightening mechanism 11, the mooring rope R is less likely to come off even if the tension thereon changes.

[0047] Furthermore, by configuring the tightening mechanism 11 to have a pair of clamping pieces 11a, it can be easily attached and detached to any position on the mooring rope.

[0048] <Modification> Figure 5 shows a modification of the tension monitoring device 100. The measuring tool 20 of this device 100 measures the amount of change based on the degree of distortion of a flexure body 22a located between both fasteners 10. Specifically, it includes a flexure body 22a located between both fasteners 10, and an elastic body 22b provided between at least one of the fasteners 10 and the flexure body 22a, elastically connecting the flexure body 22a to that fastener 10. When the separation distance between the two fasteners 10 changes from its initial value, the force with which the elastic body 22b pulls the flexure body 22a changes accordingly, and the degree of distortion of the flexure body 22b changes accordingly. Because there is a correlation between the degree of distortion and the amount of change, the amount of change is measured from the degree of distortion.

[0049] In this device 100, the entire measuring tool 20 is housed in a casing B, which is provided with a control unit C, a display D, and an alarm mechanism A. The casing B is formed with a long hole h through which the tip ends of both locking tools 10, which are provided with tightening mechanisms 11, can protrude, and the device 100 is fastened to the mooring rope R by the tightening mechanisms 11 of the locking tools 10 protruding from this long hole h.

[0050] Other Embodiments The tension monitoring device 100 according to the present invention is not limited to the above-described embodiment. For example, in the above-described embodiment, the tightening mechanism includes a pair of clamping pieces, but is not limited to this. For example, an elastic ring may be used to tighten the mooring rope. In this case, the mooring rope must be passed through the elastic ring, which makes installation somewhat more difficult, but it can tighten the mooring rope in accordance with its diameter, similar to the tightening mechanism of the above-described embodiment. An example of the elastic ring is a rubber ring with a diameter smaller than the diameter of the mooring rope.

[0051] In the above embodiment, the tightening mechanism is configured to elastically tighten the mooring rope, but it may also be configured to tighten mechanically, for example, by operating a pair of clamping pieces with a motor.

[0052] Furthermore, in the measuring tool of the above embodiment, the change in the distance between the two fastening devices is measured using a mechanism that employs a slide gauge or a strain generator, but the present invention is not limited to this and other mechanisms may also be used for measurement.

[0053] Although the measuring tool in the above embodiment is a type that is installed between both fasteners, this measuring tool may also be a non-contact type. In this case, for example, a laser emitter and a receiver are installed on one of the fasteners, and the laser that is emitted from the emitter to the other fastener and reflected is received by the receiver, and the distance can be measured from the time it takes for the laser to go back and forth.

[0054] In the above embodiment, the control unit, display, and notification mechanism are integrally formed with the measuring tool, but this is not limiting. For example, a separate terminal connected to the measuring tool wirelessly or via a wired connection may include the control unit, display, and notification mechanism. Examples of the separate terminal include a smartphone, tablet, and PC, with a mobile terminal being preferred. Furthermore, some of the components constituting the control unit may be handled by a first control unit attached to the measuring tool, and the remaining components may be handled by a separate terminal.

[0055] Furthermore, the present invention is not limited to the above-described embodiment, and it goes without saying that various modifications are possible without departing from the spirit of the present invention. [Explanation of symbols]

[0056] 100 Tension monitoring device 10. Locking device 11. Clamping mechanism 11a Clamping piece 20 Measuring Tools 21a Gauge body 21b slider 22a Strain body C control section C1 Correlation data storage section C3 conversion unit

Claims

1. a pair of fastening devices that are detachably fastened to a mooring rope for a ship while being spaced apart in the longitudinal direction; a measuring tool for measuring a change in the distance between the two fastening devices from an initial value, A tension monitoring device characterized in that the locking device is equipped with a tightening mechanism that tightens the mooring rope in response to changes in the diameter of the mooring rope, and is locked to the mooring rope via the tightening mechanism.

2. 2. The tension monitor of claim 1, wherein the tightening mechanism elastically tightens the mooring rope.

3. 2. A tension monitor according to claim 1, wherein the tightening mechanism comprises a pair of clamping pieces that elastically clamp the mooring rope.

4. 2. A tension monitor according to claim 1, wherein the measuring tool is installed between the two fastening tools.

5. 5. A tension monitor according to claim 4, wherein the measuring tool comprises a gauge body fixed to one of the fastening tools and a slider fixed to the other fastening tool and slidable relative to the gauge body, and the amount of change is measured based on the amount of movement of the slider relative to the gauge body.

6. 5. A tension monitoring device according to claim 4, wherein the measuring tool includes a strain-generating body that is interposed between the two fastening tools and pulled by the fastening tools, and the amount of change is measured based on the degree of strain of the strain-generating body.

7. a correlation data storage unit that stores correlation data indicating the correlation between the amount of change and the load acting on the mooring rope interposed between the two fastening devices for each type of mooring rope; The tension monitoring device according to claim 1, further comprising a conversion unit that converts the amount of change measured by the measuring tool into a load based on the correlation data.

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