Mooring chain link length measurement device and measurement method

Abstract

A mooring chain link length measurement device, comprising a base (1), a chain feeding device (2), jacking devices (3), and an external traction device. The jacking devices (3) include a first jacking device (31) and a second jacking device (32). The first jacking device (31) is located on two sides of one end of a groove, and is mounted on the base (1). The second jacking device (32) is located on two sides of the other end of the groove, and is slidingly connected to the base (1). A tensioning device (4) used for controlling the second jacking device (32) to slide is arranged beside the second jacking device (32). A measurement device (5) is arranged between the two jacking devices (3). When the first jacking device (31) works to fix a chain link, the second jacking device (32) stops sliding of the chain link, or an external traction device works to straighten and tension a mooring chain, and the measurement device (5) measures the length of a mooring chain link. The problem of the measurement precision being greatly reduced due to the vibration and displacement of the mode of clamping a chain link by movable calipers and clamping jaws is solved. The length of any number of chain link combinations can be measured, the measurement speed is high, and the flexibility is high. Further disclosed is a method for measuring the length of a mooring chain.

Description

A mooring chain link length measuring device and a measuring method thereof Technical Field

[0001] The present invention relates to the technical field of length measurement, and in particular to a mooring chain link length measuring device and a measuring method thereof. Background Art

[0002] Mooring chains are crucial to the safety of ships and marine engineering projects. These include marine mooring chains used on various vessels and those used in offshore projects such as oil drilling and single-point mooring systems. The mooring chain is retracted and extended by the engagement of the windlass's sprocket with the chain links. To ensure proper engagement between the sprocket and the chain links, the sum of the lengths (L5) of any five links in the mooring chain must be measured. The tolerance for L5 is + / - 2.5% of L5 to prevent accidents such as chain breakage during the engagement of the mooring chain with the windlass's sprocket.

[0003] Currently, laser sensors are often used to measure the length of mooring chain links. Patent CN201210111069.2 discloses a chain length measuring device. This device uses a horizontal chain tension tester to tighten the anchor chain. A movable caliper descends to press against the outermost ends of the first and last links of the anchor chain. A laser length measuring instrument emits a laser beam for measurement. After the measurement is completed, a pair of movable calipers rise, and the horizontal chain tension tester removes the previous set of links and measures the next set. However, this solution uses a horizontal chain tension tester to tighten the anchor chain. After each measurement, the fixed position of the horizontal chain tension tester and the anchor chain must be continuously adjusted to tighten the next set of links. This method requires repeated manual operation, is time-consuming and labor-intensive, and has low efficiency. Furthermore, during the tightening process using the horizontal chain tension tester, the anchor chain is suspended, which inevitably causes vibration during the anchor chain measurement process, thereby affecting measurement accuracy. Patent CN201610366496.3 discloses a method for vertically measuring chain links using an infrared rangefinder. A tensile testing machine straightens the chain link, and a right-angled claw is placed at each end of the chain link. The two claws are brought close to each other, and the infrared rangefinder starts measuring when they touch the cross-section of the outer ring. However, this solution causes the chain link to swing in the process of straightening the chain link using a tensile testing machine, so that the claws do not touch the cross-section of the outer ring. At this time, the measurement result of the infrared rangefinder is inaccurate. At the same time, the vibration and displacement generated by the tensile testing machine after breaking the chain will greatly reduce the measurement accuracy. Patent CN201310003546.8 discloses a measurement method that accurately captures the crown apex of the chain link in the first and second directions of the anchor chain or mooring chain, and converts the measurement of the single-link length and five-link length of the anchor chain or mooring chain into the measurement of the straight-line travel distance of the moving trolley. However, this approach requires finding the plane of symmetry in the first and second directions during measurement, and adjusting the laser sensor so that the laser light emitted lies precisely within the plane of symmetry. This approach inevitably causes the chain link to vibrate under the tension of the tensioning device, causing the planes of symmetry in the first and second directions to constantly shift, making it difficult to precisely capture the plane of symmetry at a given moment, thus affecting measurement accuracy. Furthermore, adjusting the laser sensor so that the laser light emitted lies precisely within the plane of symmetry is a cumbersome process.

[0004] Summary of the Invention

[0005] Purpose of the invention: The present invention aims to provide a measuring device suitable for different mooring chain specifications, which improves the measurement efficiency of mooring chain loop length and reduces the workload of workers. Another purpose of the present invention is to provide a method for measuring the length of a mooring chain.

[0006] Technical solution: The mooring chain link length measuring device described in the present invention includes a base, a chain feeding device, a top-up device and an external traction device. The base is provided with a groove for the mooring chain to pass through. The chain feeding device is arranged in the groove. The top-up device includes a first top-up device and a second top-up device. The first top-up device is located on both sides of one end of the groove and is installed on the base; the second top-up device is located on both sides of the other end of the groove and is slidably connected to the base. A tensioning device for controlling the sliding of the second top-up device is provided next to the second top-up device; a measuring device is provided between the two top-up devices; when the first top-up device works to fix the chain link, the second top-up device fixes the chain link and slides or the external traction device works to straighten and tension the mooring chain, and the measuring device measures the length of the mooring chain link.

[0007] Furthermore, the second top device is composed of two symmetrically arranged hydraulic devices, which include a fixed seat, a support shaft seat and a hydraulic cylinder. The fixed seat is installed on the base, and the support shaft seat and the hydraulic cylinder are installed on the inner and outer sides of the fixed seat respectively. The piston rod of the hydraulic cylinder passes through the through hole of the support shaft seat.

[0008] Furthermore, the tensioning device includes a fixed frame, a hydraulic cylinder and a pressure sensor. The fixed frame is installed on the base, the hydraulic cylinder is arranged on the fixed seat, the front end of the piston rod of the hydraulic cylinder is provided with a flange, the pressure sensor is arranged in the positioning hole of the flange, and the flange is fixedly connected to the fixed seat.

[0009] Furthermore, the chain feeding device includes a motor, a synchronous wheel belt structure, a guide rail, a placement plate and a cylinder. The driving wheel of the synchronous wheel belt structure is connected to the output shaft of the motor through a coupling and an output shaft, the driven wheel and the guide rail are respectively fixed on the inner wall of the groove, and the synchronous belt is connected to the slider that cooperates with the guide rail through a pressure plate; the placement plate is connected to the guide rail through a slider, and the cylinder is arranged on the placement plate, and the piston rod of the cylinder is used to move the mooring chain.

[0010] Furthermore, the measuring device includes a first measuring device for measuring the length of the chain link in the horizontal direction and a second measuring device for measuring the length of the chain link in the vertical direction, which are symmetrically arranged on both sides of the groove.

[0011] Furthermore, the first measuring device and the second measuring device both include a bracket, a fixing frame, a linear slide module and a multi-point laser sensor. The bracket is fixed on the base, the linear slide module is installed on the inner side of the top of the bracket through the fixing frame, the linear slide module includes two modules, and the multi-point laser sensor is fixed on the slider of each module through a connecting block.

[0012] Furthermore, the bracket is a "C"-shaped structure, including a connecting part, a supporting part perpendicular to the base, and a fixing part. The angle between the supporting part and the fixing part is a right angle, and the fixing part is installed on the base. The angle between the connecting part and the supporting part of the first bracket of the first measuring device is 60°, and the angle between the connecting part and the supporting part of the second bracket of the second measuring device is 30°.

[0013] Furthermore, the connecting block is a right-angled trapezoidal structure, and the multi-point laser sensor is installed on the inclined surface of the connecting block.

[0014] Furthermore, rollers are provided at both ends of the base.

[0015] The method for measuring the length of a mooring chain according to the present invention comprises the following steps:

[0016] (1) Pass the mooring chain through the roller at the front end, straighten it and place it in the groove in the middle of the base. The horizontal and vertical rings of the mooring chain are perpendicular to each other. The first link of the mooring chain is placed at the second top-up device and connected to the external traction device;

[0017] (2) Control the linear slide module so that the first link is located between the two multi-point laser sensors of the first measuring device, and the distance between the two multi-point laser sensors in the first and second measuring devices is 9d, where d is the nominal size of the mooring chain;

[0018] (3) The two hydraulic cylinders in the first jacking device extend synchronously and lock into the link at one end of the mooring chain;

[0019] (4) Determine whether the mooring chain passes through the rear roller. If not, the external traction device tensions the mooring chain and proceeds to step (6). If it passes, the two hydraulic cylinders in the second jacking device extend synchronously and lock in the chain link at the other end of the mooring chain.

[0020] (5) The two hydraulic cylinders in the tensioning device extend synchronously, pushing against the second push-up device, causing it to move outward along the guide rail. The mooring chain is straightened and tensioned. According to the mooring chain specifications, the tensioning device applies the tensile load F required by GB_T 20848-2017;

[0021] (6) Measure two adjacent links, two adjacent links are grouped as a group, denoted as M; the first measuring device measures the horizontal length of the mooring link l H The second measuring device measures the vertical length of the mooring chain link l V ;

[0022] (7) The computer counts i starting from 0. After each set of M measurements, set i+2;

[0023] (8) If the mooring chain is tensioned by an external traction device, the tensioning force is canceled and the process proceeds to step (10); if the mooring chain is tensioned by a second top-up device, the hydraulic cylinder in the tensioning device contracts and resets, causing the mooring chain to lose its tensioning force;

[0024] (9) The hydraulic cylinder in the second jacking device retracts and resets, loosening the chain link here;

[0025] (10) The hydraulic cylinder in the first jacking device retracts and resets, loosening the chain link here;

[0026] (11) Determine whether the computer count i reaches the total number of chain links n; when i=n, ​​all chain links are detected and the process goes to step (14); when i≠n, there are still chain links that have not been detected and the process goes to step (12).

[0027] (12) Determine whether the mooring chain has passed the rear roller; if not, the external traction mooring chain moves two links, and the process proceeds to step (3); if it has passed, the piston rod of the cylinder in the chain feeding device is extended and pushed into the horizontally placed link, driving the mooring chain to move the length of two links along the direction of the second push-up device, and the process proceeds to step (13);

[0028] (13) The piston rod of the cylinder is shortened, and the cylinder is reset to its initial position and enters step (3);

[0029] (14) Calculate the length of any single link of the mooring chain as:

[0030] The length of any five links of the mooring chain is: l=(l H(i+1) +l V(i+2) +l H(i+3) +l V(i+4) +l H(i+5) )-8D,

[0031] Wherein, i=0, 2, 4, ..., n, n is the total number of mooring chain links, and D is the actual diameter of the mooring chain.

[0032] Beneficial effects: Compared with the prior art, the present invention has the following significant advantages: 1. The present invention solves the problem that the vibration and displacement of the tensile machine caused by clamping the chain link with the movable caliper and the claw will greatly reduce the measurement accuracy through the close reciprocating cooperation between the top device, the tensioning device, and the chain feeding device. The mooring chain of the present invention is safe and stable during movement, does not produce movement fluctuations, and has a high safety factor. During the measurement of the mooring chain, the various parts cooperate compactly and continuously, and the measurement efficiency is high; 2. The present invention can simultaneously measure a group of adjacent chain links through two pairs of multi-point laser sensors, and can measure the length of any number of chain link combinations, with fast measurement speed and strong flexibility; 3. The present invention can detect the length of mooring chains of different specifications through an adjustable measuring device, and the use of a multi-point laser sensor can find the crown apex of the chain link without finding the measuring surface of the chain link, thereby ensuring measurement accuracy while reducing operational difficulty. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] FIG1 is a schematic diagram of the overall structure of the present invention;

[0034] Figure 2 is a schematic diagram of the base structure;

[0035] Figure 3 is a schematic diagram of the base structure;

[0036] Figure 4 is a schematic diagram of the support platform structure;

[0037] Figure 5 is a schematic diagram of the chain feeding device and the base structure;

[0038] Figure 6 is a schematic structural diagram of a chain feeding device;

[0039] Figure 7 is a schematic structural diagram of the chain feeding device;

[0040] Figure 8 is a schematic diagram of the top-up device structure;

[0041] Figure 9 is a schematic structural diagram of the tensioning device;

[0042] Figure 10 is a schematic structural diagram of the tensioning device;

[0043] Figure 11 is a schematic structural diagram of a measuring device;

[0044] FIG12 is a schematic structural diagram of a first measuring device;

[0045] FIG13 is a schematic structural diagram of a second measuring device;

[0046] FIG14 is a flow chart of a method for measuring the length of a mooring chain. DETAILED DESCRIPTION

[0047] The present invention will be further described below with reference to the accompanying drawings.

[0048] The mooring chain link length measuring device of the present invention includes a base 1, a chain feeding device 2, a top-up device 3 and an external traction device. The base 1 is provided with a groove for a mooring chain 6 to pass through. The chain feeding device 2 is arranged in the groove. The top-up device 3 includes a first top-up device 31 and a second top-up device 32. The first top-up device 31 is located on both sides of one end of the groove and is installed on the base 1; the second top-up device 32 is located on both sides of the other end of the groove and is slidably connected to the base 1. A tensioning device 4 for controlling the sliding of the second top-up device 32 is provided next to the second top-up device 32; a measuring device 5 is provided between the two top-up devices; when the first top-up device is working to fix the chain link, the second top-up device fixes the chain link and slides or the external traction device is working to straighten and tension the mooring chain, and the measuring device measures the length of the mooring chain link.

[0049] As shown in Figure 2, the base 1 consists of a support platform 12 and a base 11. As shown in Figure 4, the support platform 12 consists of a fixed platform 121 and rollers 122. The fixed platform 121 is cast concrete and has a rectangular shape. It has a trapezoidal recess at each end and a rectangular recess just outside the trapezoidal recess. Anchor bolts are embedded within the fixed platform 121. Anchor bolts are embedded in the middle of the fixed platform 121. The rollers 122 are fixed in the rectangular recesses by anchor bolts. As shown in Figure 3, the base 11 is cast iron and consists of two left and right parts. Both parts are L-shaped. The left and right parts of the base 11 are separated by a certain distance to form a groove, giving the base 11 an overall "convex" shape. The left part of the base 11 has a rectangular groove near the front left platform. The side of the boss facing the rectangular groove has a rectangular through-groove. The lower end of the rectangular through-groove is threaded with holes. The right end face of the left part of the base 11 is threaded with holes. The right side face of the left part of the base 11 is threaded with holes. Base 11 is surrounded by through-holes and threaded holes. These holes correspond to pre-buried anchor bolts in the center of fixed platform 121 of support platform 12. These anchor bolts secure base 11 to fixed platform 121 of support platform 12. Mooring chain 6 is passed through roller 122 at the front end and straightened, then placed in the groove in the center of base 11, ensuring that adjacent links of mooring chain 6 are vertical.

[0050] As shown in Figure 11, the measuring device 5 is composed of a first measuring device 51 and a second measuring device 52. As shown in Figure 12, the first measuring device 51 is composed of a first bracket 511, a first fixed bracket 512, a first linear slide module 513, and a multi-point laser sensor 514. The first bracket 511 is generally "C"-shaped. Its upper end is a 60° outward inclined surface with threaded holes. Its lower end is 90° and has through holes, which correspond to the threaded holes on the base 11 of the base 1. The first bracket 511 is fixed to the base 11 of the base 1 by screws. The first fixed bracket 512 is generally rectangular, with threaded holes at both ends and in the middle. The bottom surface of the first fixed bracket 512 is provided with through holes, which correspond to the threaded holes on the upper inclined surface of the first bracket 511. The first fixed bracket 512 is fixed to the first bracket 511 by screws. The first linear slide module 513 is composed of a first module 5131, a second module 5132 and a connecting block 5133. The two ends of the first module 5131 are fixed to the left half of the first fixed frame 512 by screws. The two ends of the second module 5132 are fixed to the right half of the first fixed frame 512 by screws, aligned with the first module 5131. The connecting block 5133 is a right-angled trapezoid as a whole, with through holes on its bottom surface and threaded holes on the inclined surface. The through holes on the connecting block 5133 correspond to the threaded holes on the sliders of the first module 5131 and the second module 5132. The inclined surfaces of the two connecting blocks 5133 are placed opposite each other, and the two connecting blocks 5133 are fixed to the two modules respectively by screws. The multi-point laser sensor 514 is provided with a through hole, which corresponds to the threaded hole on the inclined surface of the connecting block 5133. The multi-point laser sensor 514 is fixed to the inclined surface of the connecting block 5133 by screws.

[0051] As shown in Figure 13, the second measuring device 52 consists of a second bracket 521, a second fixed frame 522, a second linear slide module 523, and a multi-point laser sensor 524. The second bracket 521 is generally C-shaped. Its upper end is a 30° outward inclined surface with threaded holes. Its lower end is 90° and has through holes, which correspond to the threaded holes on the base 11 of the base 1. The second bracket 521 is fixed to the base 11 of the base 1 by screws and is spaced half a chain link away from the first fixed frame 512. The second fixed frame 522 is generally rectangular, with threaded holes at both ends and in the middle. The bottom surface of the second fixed frame 522 is provided with through holes, which correspond to the threaded holes on the upper inclined surface of the second bracket 521. The second fixed frame 522 is fixed to the second bracket 521 by screws. The second linear slide module 523 is composed of a third module 5231, a fourth module 5232, and a connecting block 5233. The third module 5231 is fixed to the left half of the second fixing frame 522 with screws at both ends. The fourth module 5232 is fixed to the right half of the second fixing frame 522 with screws at both ends, aligned with the third module 5231. The connecting block 5233 is a rectangular trapezoid with through holes on its bottom surface and threaded holes on its inclined surface. The through holes on the connecting block 5233 correspond to the threaded holes on the sliders of the third module 5231 and the fourth module 5232. The inclined surfaces of the two connecting blocks 5233 are positioned opposite each other and are fixed to the two modules respectively with screws. The multi-point laser sensor 524 is also provided with through holes that correspond to the threaded holes on the inclined surface of the connecting block 5233. The multi-point laser sensor 524 is fixed to the inclined surface of the connecting block 5233 with screws. The first linear slide module 513 is controlled to set the distance between the two sensors in the first measuring device 51 to 9d, and the second linear slide module 523 is controlled to set the distance between the two sensors in the second measuring device 52 to 9d. Using computer-visualized data, the first linear slide module 513 is controlled to place the first link between the two sensors in the first measuring device 51, and the second linear slide module 523 is controlled to place the second link between the two sensors in the second measuring device 52. At this point, the measuring devices are adjusted.

[0052] As shown in Figure 8, the jacking device 3 consists of a first jacking device 31 and a second jacking device 32. The first jacking device 31 is a symmetrical structure comprising a first hydraulic device 311 and a second hydraulic device 312. The first hydraulic device 311 consists of a first fixing seat 3112, a first support shaft seat 3113, and a first hydraulic cylinder 3111. The first fixing seat 3112 is generally L-shaped, with a circular through-hole in the center of its left side and threaded holes evenly distributed around the through-hole. Threaded holes and through-holes are arranged on the right platform of the first fixing seat 3112. The through-holes on the first fixing seat 3112 correspond to the threaded holes on the base 11 of the base 1, and the first fixing seat 3112 is fixed to the base 11 of the base 1 using screws. The first support shaft seat 3113 has through-holes on its bottom surface, which correspond to the threaded holes on the right platform of the first fixing seat 3112. The first support shaft seat 3113 is fixed to the first fixing seat 3112 using screws. The through hole on the front end flange of the first hydraulic cylinder 3111 corresponds to the threaded holes around the through hole of the first fixing seat 3112. The first hydraulic cylinder 3111 is fixed to the first fixing seat 3112 by screws, and its piston rod extends inward into the first support shaft seat 3113.

[0053] The second hydraulic device 312 has the same structure as the first hydraulic device 311 and is fixed to the base 11 of the base 1 in a mirror-symmetrical manner. The second top-up device 32 is a symmetrical structural device including a third hydraulic device 321 and a fourth hydraulic device 322. The third hydraulic device 321 is composed of a third fixed seat 3212, a third support shaft seat 3213, a guide rail slider assembly 3214 and a third hydraulic cylinder 3211. The third fixed seat 3212 is generally "L"-shaped, with a circular through hole in the middle of its left side, and threaded holes are evenly distributed around the through hole. Threaded holes and through holes are distributed on the right platform of the third fixed seat 3212, and a circle of threaded holes is evenly distributed in the middle of the front face. The bottom surface of the third support shaft seat 3213 is provided with through holes, which correspond to the threaded holes on the third fixed seat 3212. The third support shaft seat 3213 is fixed to the third fixed seat 3212 by screws. The through-holes on the front flange of the third hydraulic cylinder 3211 correspond to the threaded holes around the through-holes of the third fixing seat 3212. The third hydraulic cylinder 3211 is fixed to the third fixing seat 3212 via screws, with its piston rod extending inwardly into the third support shaft seat 3213. The through-holes on the guide rail in the guide rail slider assembly 3214 correspond to the threaded holes on the base 11 of the base 1. The guide rail in the guide rail slider assembly 3214 is fixed to the base 11 of the base 1 via screws. The threaded holes on the slider in the guide rail slider assembly 3214 correspond to the through-holes on the third fixing seat 3212. The third fixing seat 3212 is fixed to the slider in the guide rail slider assembly 3214 via screws. The fourth hydraulic device 322 is identical in structure to the third hydraulic device 321 and is fixed to the base 11 of the base 1 in a mirror-image manner. The two hydraulic cylinders in the first jacking device 31 extend synchronously and lock into the vertical link V at one end of the mooring chain 6.

[0054] As shown in Figure 10, the tensioning device 4 is a symmetrical structure device including a first tensioning device 41 and a second tensioning device 42. The first tensioning device 41 is composed of a fixing frame 411, a hydraulic cylinder 412 and a pressure sensor 413. The fixing frame 411 is generally in the shape of a "convex" character, with a circular through hole in the middle position, and threaded holes are evenly distributed around the through hole. Through holes are distributed around the bottom surface of the fixing frame 411, and the through holes correspond to the threaded holes distributed on the base 11 of the base 1. The fixing frame 411 is fixed to the base 11 of the base 1 by screws. The piston rod of the hydraulic cylinder 412 is directed toward the third hydraulic device 321 of the second top device 32 in the top device. The through holes on the flange of the hydraulic cylinder 412 correspond to the threaded holes around the through hole of the fixing frame 411, and the hydraulic cylinder 412 is fixed to the fixing frame 411 by screws. The through-hole on the front flange of the piston rod of hydraulic cylinder 412 corresponds to the threaded hole on the front face of the third hydraulic device 321 of the second jacking device 32 in the jacking device 3. The front flange of the piston rod of hydraulic cylinder 412 is fixed to the third hydraulic device 321 of the second jacking device 32 in the jacking device 3 by screws. A pressure sensor 413 is screwed into the front flange of hydraulic cylinder 412, protruding a distance from the flange plane. The second tensioning device 42 is identical in structure to the first tensioning device 41 and is fixed to the base 11 of the base 1 in a mirror-image manner. The two hydraulic cylinders in the tensioning device 4 extend synchronously, pressing against the second jacking device 32, forcing it to move outward along the guide rails, straightening and tensioning the mooring chain 6. Based on the specifications of the mooring chain 6 being tested and the force sensor data, the tensioning device applies a tensile load F of 10% (in compliance with GB_T 20848-2017 requirements).

[0055] As shown in Figure 7, the chain feeding device 2 consists of a planetary reduction stepper motor 21, a coupling 22, a bearing seat 23, a transmission shaft 24, a flange shaft 210, a second synchronous pulley 25, a cylinder 27, a placement plate 28, a synchronous belt 26, a first synchronous pulley 29, and a guide rail slider assembly 211. The through hole on the flange shaft 210 corresponds to the threaded hole on the right side of the left portion of the base 11 of the base 1. The flange shaft 210 is fixed to the center of the right side of the left portion of the base 11 of the base 1 using screws. The first synchronous belt 29 is fixed to the flange shaft 210 using set screws. The planetary reduction stepper motor 21 is fixed to the rectangular groove in the left portion of the base 11 of the base 1 using screws. The transmission shaft 24 is connected to the output shaft of the planetary reduction stepper motor 21 via the coupling 22. The second synchronous pulley 25 is fixed to the transmission shaft 24 using set screws. A bearing seat 23 is placed in the middle of the drive shaft 24 and is fixed to the rectangular through-groove in the left portion of the base 11 of the base 1 by screws. One end of the synchronous belt 26 is wound around the first synchronous pulley 29, and the other end is wound around the second synchronous pulley 25, and both are kept taut. The through holes on the guide rail of the guide rail slider assembly 211 correspond to the threaded holes on the right side of the left portion of the base 11 of the base 1. The guide rail in the guide rail slider assembly 211 is fixed to the base 11 of the base 1 by screws. The placement plate 28 is rectangular in shape and has through holes around its perimeter and in its middle. The through holes around its perimeter correspond to the threaded holes on the slider in the guide rail slider assembly 211. The placement plate 28 is fixed to the slider in the guide rail slider assembly 211 by screws. The threaded holes on the cylinder 27 correspond to the through holes in the middle of the placement plate 28. The cylinder 27 is fixed to the placement plate 28 by screws. The synchronous belt 26 is fixed to the inner side of the slider in the guide rail slider assembly 211 by a synchronous belt pressure plate.

[0056] The method for measuring the length of a mooring chain according to the present invention comprises the following steps:

[0057] (1) Pass the mooring chain through the roller at the front end, straighten it and place it in the groove in the middle of the base so that each adjacent link of the mooring chain is in a vertical state.

[0058] (2) Place the first link of the mooring chain at the second top-up device and fix the first link to the external traction device.

[0059] (3) Input the total number of chain links N, the nominal size d of the mooring chain and the actual diameter D of the mooring chain into the system.

[0060] (4) The distance between the two sensors in the first measuring device is set to 9d by controlling the linear slide module.

[0061] (5) The distance between the two sensors in the second measuring device is set to 9d by controlling the linear slide module.

[0062] (6) Through computer visualization data, the linear slide module is controlled to place the first link between the two sensors of the first measuring device. At this time, the measuring device is adjusted.

[0063] (7) The two hydraulic cylinders in the first jacking device extend synchronously and lock inside the link at one end of the mooring chain.

[0064] (8) Determine whether the mooring chain passes the rear roller (1: passed, 0: not passed). If it is 0, the mooring chain is tensioned externally and execution starts from (10); if it is 1, the two hydraulic cylinders in the second top-up device are extended synchronously and locked in the chain link at the other end of the mooring chain.

[0065] (9) The two hydraulic cylinders in the tensioning device extend synchronously, pushing against the second push-up device, causing it to move outward along the guide rail, straightening and tensioning the mooring chain. Based on the specifications of the mooring chain being tested and the force sensor data, the tensioning device applies a tensile load F of 10% of the national standard (GB_T 20848-2017).

[0066] (10) The measuring device starts measuring, measuring two adjacent links at a time, that is, two adjacent links are grouped as a group, which is recorded as M. Taking the first measuring device as an example, the base is used as the reference plane, and one of the multi-point laser sensors is used as the origin, the width direction of the mooring chain is the x-axis, and the length direction is the y-axis, to establish a plane rectangular coordinate system. Assume that the distance between the front end of the first module and the end of the second module in the first linear slide module is b1, and the coordinates of the multi-point laser sensor of the first module are (0,0). The distance sensor on the first module measures the actual distance L1 from the multi-point laser sensor to the front end of the first module; at this time, the multi-point laser sensor of the second module is moved to the coordinate position (9d-b1-L1, 0), and the distance sensor on the second module is used to measure the actual distance L2 from the multi-point laser sensor to the end of the second module. The multi-point laser sensor obtains the distances between the apex positions of the left and right rings of the mooring chain as a1 and a2 respectively. The angles formed by the laser of the multi-point laser sensor passing through the crown vertex and the straight line passing through the crown vertex and perpendicular to the y-axis are θ1 and θ2 respectively. The first measuring device measures the horizontal mooring chain length l H =L1+L2+b1-a1sinθ1-a2sinθ2.

[0067] The second measuring device is similar, and is used to measure the vertical chain link V. Assume that the distance between the front end of the fourth module and the end of the third module in the second linear slide module is b2. The distance sensor on the fourth module measures the actual distance L3 from the multi-point laser sensor to the front end of the fourth module; the distance sensor on the third module measures the actual distance L4 from the multi-point laser sensor to the end of the third module. The multi-point laser sensor obtains the distances between the apex positions of the left and right ring crowns of the mooring chain, which are a3 and a4 respectively. The angles formed by the laser of the multi-point laser sensor passing through the apex position of the ring crown and the straight line passing through the apex of the ring crown and perpendicular to the y-axis are θ3 and θ4 respectively, so the second measuring device measures the vertical mooring chain link length l V =L3+L4+b2-a3sinθ3-a4sinθ4.

[0068] (11) The computer counter i starts from 0. After each measurement of a group of M, the counter i+2.

[0069] (12) At this time, if it is external traction, the tensioning force is canceled and the process starts from (14). If it is traction by the chain feeding device, the hydraulic cylinder in the tensioning device shrinks and resets, causing the mooring chain to lose tension.

[0070] (13) The hydraulic cylinder in the second jacking device contracts and resets, loosening one end of the chain link.

[0071] (14) The hydraulic cylinder in the first jacking device retracts and resets, loosening the chain link at the other end.

[0072] (15) The computer counts whether the number i reaches the total number of chain links n. When i = n, it means that all chain links have been detected, and the execution is (18); when i ≠ n, it means that there are still chain links that have not been detected, and the execution is (16).

[0073] (16) Determine whether the mooring chain passes the rear roller (1: passed, 0: not passed). If it is 0, the external traction mooring chain moves the length of two assembled chain links, that is, 10d, where d is the diameter of the mooring chain. At this time, execute from (7). If it is 1, the cylinder in the chain feeding device extends and pushes into the horizontally placed chain link. At this time, the motor rotates and drives the cylinder fixed on the synchronous belt to move the length of two assembled chain links along the direction of the second push-up device, that is, 10d. At this time, execute (17)

[0074] (17) The cylinder in the chain feeding device is shortened and reset, and the motor is reversed to reset the cylinder to its initial position. Execute from (7) onwards.

[0075] (18) The length of any single link of mooring chain is:

[0076] The length of any five links of the mooring chain is: l=(l H(i+1) +l V(i+2) +lH(i+3) +l V(i+4) +l H(i+5) )-8D,

[0077] Where i = 0, 2, 4, ..., n, n is the total number of mooring chain links, D is the actual diameter of the mooring chain, l H Horizontal link length, l V Vertical chain link length.

Claims

1. A mooring chain link length measuring device, characterized in that: The invention comprises a base (1), a chain feeding device (2), a top-up device (3) and an external traction device. The base (1) is provided with a groove for a mooring chain (6) to pass through. The chain feeding device (2) is arranged in the groove. The top-up device (3) comprises a first top-up device (31) and a second top-up device (32). The first top-up device (31) is located on both sides of one end of the groove and is installed on the base (1). The second top-up device (32) is located on both sides of the other end of the groove and is slidably connected to the base (1). A tensioning device (4) for controlling the sliding of the second top-up device (32) is arranged beside the second top-up device (32). A measuring device (5) is arranged between the two top-up devices. When the first top-up device works to fix the chain link, the fixed chain link of the second top-up device slides or the external traction device works to straighten and tension the mooring chain, and the measuring device measures the length of the mooring chain link.

2. The mooring chain link length measuring device according to claim 1, characterized in that: The second top device is composed of two symmetrically arranged hydraulic devices, which include a fixed seat, a supporting shaft seat and a hydraulic cylinder. The fixed seat is installed on the base, and the supporting shaft seat and the hydraulic cylinder are respectively installed on the inner and outer sides of the fixed seat. The piston rod of the hydraulic cylinder passes through the through hole of the supporting shaft seat.

3. The mooring chain link length measuring device according to claim 2, characterized in that: The tensioning device includes a fixing frame, a hydraulic cylinder and a pressure sensor. The fixing frame is installed on a base, the hydraulic cylinder is arranged on a fixing seat, a flange is arranged at the front end of the piston rod of the hydraulic cylinder, the pressure sensor is arranged in a positioning hole of the flange, and the flange is fixedly connected to the fixing seat.

4. The mooring chain link length measuring device according to claim 1, characterized in that: The chain feeding device includes a motor, a synchronous wheel belt structure, a guide rail, a placement plate and a cylinder. The driving wheel of the synchronous wheel belt structure is connected to the output shaft of the motor through a coupling and an output shaft, the driven wheel and the guide rail are respectively fixed on the inner wall of the groove, and the synchronous belt is connected to the slider matching the guide rail through a pressure plate; the placement plate is connected to the guide rail through a slider, and the cylinder is arranged on the placement plate, and the piston rod of the cylinder is used to move the mooring chain.

5. The mooring chain link length measuring device according to claim 1, characterized in that: The measuring device comprises a first measuring device for measuring the length of the chain link in the horizontal direction and a second measuring device for measuring the length of the chain link in the vertical direction, which are symmetrically arranged on both sides of the groove.

6. The mooring chain link length measuring device according to claim 5, characterized in that: The first measuring device and the second measuring device both include a bracket, a fixing frame, a linear slide module and a multi-point laser sensor. The bracket is fixed on a base, the linear slide module is installed on the inner side of the top of the bracket through the fixing frame, the linear slide module includes two modules, and the multi-point laser sensor is respectively fixed on the slider of each module through a connecting block.

7. The mooring chain link length measuring device according to claim 6, characterized in that: The bracket is a "C"-shaped structure, including a connecting portion, a supporting portion perpendicular to the base, and a fixing portion, the supporting portion and the fixing portion are at a right angle, and the fixing portion is installed on the base. The connecting portion of the first bracket of the first measuring device has an angle of 60° with the supporting portion, and the connecting portion of the second bracket of the second measuring device has an angle of 30° with the supporting portion.

8. The mooring chain link length measuring device according to claim 6, characterized in that: The connecting block is a right-angle trapezoidal structure, and the multi-point laser sensor is installed on the inclined surface of the connecting block.

9. The mooring chain link length measuring device according to claim 1, characterized in that: Rollers are arranged at both ends of the base.

10. A method for measuring the length of a mooring chain, characterized in that: The steps include: (1) The mooring chain is passed through the roller at the front end, straightened and placed in the groove in the middle of the base. The horizontal ring and vertical ring of the mooring chain are perpendicular to each other. The first link of the mooring chain is placed at the second top-up device and connected to the external traction device; (2) Control the linear slide module so that the first link is located between the two multi-point laser sensors of the first measuring device, and the distance between the two multi-point laser sensors in the first / second measuring device is 9d, and the distance between the front multi-point laser sensors of the first / second measuring device is always 4.5d, where d is the nominal specification of the mooring chain; (3) The two hydraulic cylinders in the first jacking device extend synchronously and lock in the chain link at one end of the mooring chain; (4) Determine whether the mooring chain passes through the roller at the rear end. If not, the external traction device tensions the mooring chain and proceeds to step (6). If it passes, the two hydraulic cylinders in the second jacking device extend synchronously and lock in the chain link at the other end of the mooring chain. (5) The two hydraulic cylinders in the tensioning device extend synchronously to support the second push device, causing it to move outward along the guide rail. The mooring chain is straightened and tensioned. According to the mooring chain specifications, the tensioning device applies the tensile load F required by GB_T 20848-2017; (6) Measure two adjacent links. Two adjacent links are grouped as a group and are denoted as M. The first measuring device measures the horizontal length of the mooring link l H The second measuring device measures the vertical length of the mooring chain link l V ; (7) The computer counts i starting from 0. After each set of M measurements, i+2 is added; (8) If the mooring chain is tensioned by an external traction device, the tensioning force is canceled and the process proceeds to step (10); if the mooring chain is tensioned by a second top-up device, the hydraulic cylinder in the tensioning device is retracted and reset, so that the mooring chain loses its tensioning force; (9) The hydraulic cylinder in the second jacking device retracts and resets, loosening the chain link here; (10) The hydraulic cylinder in the first jacking device is retracted and reset, loosening the chain link here; (11) Determine whether the computer count i reaches the total number of chain links n; when i=n, ​​all chain links are detected and go to step (14); when i≠n, there are still chain links that have not been detected, and go to step (12). (12) Determine whether the mooring chain has passed through the rear roller; if not, the mooring chain is externally pulled to move two links, and the process proceeds to step (3); if it has passed, the piston rod of the cylinder in the chain feeding device is extended to push into the horizontally placed link, driving the mooring chain to move the length of two links in the direction of the second push device, and the process proceeds to step (13); (13) The piston rod of the cylinder is shortened, and the cylinder is reset to its initial position and enters step (3); (14) Calculate the length of any single link of the mooring chain as: The length of any five links of the mooring chain is: l＝(l H(i+1) +l V(i+2) +l H(i+3) +l V(i+4) +l H(i+5) )-8D， Wherein, i=0, 2, 4, ..., n, n is the total number of mooring chain links, and D is the actual diameter of the mooring chain.

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