Windlass protection system

Abstract

A windlass protection system (1) according to one embodiment includes a windlass (2) including a chain drum, a hydraulic motor (25), and a brake (3) for winding and unwinding an anchor chain. The windlass protection system (1) also includes: a processing circuit (71) which causes an alarm (81) to generate an alarm sound when an effective pressure of the hydraulic motor (25) during winding of the anchor chain exceeds a first threshold value, and causes the alarm (81) to generate an alarm sound and brings the brake (3) into a constrained state in which rotation of the chain drum is prohibited when the effective pressure exceeds a second threshold value which is higher than the first threshold value.

Description

Windlass Protection System

[0001] The present disclosure relates to a windlass protection system including a windlass mounted on a ship.

[0002] Large marine vessels such as cargo ships, ferries, and cruise ships are equipped with a windlass that hoists and pays out anchor chains. Windlasses are classified into electrically driven types and hydraulically driven types. Generally, a windlass includes a chain drum, an electric motor or a hydraulic motor that rotates the chain drum, and a brake switchable between a released state that permits rotation of the chain drum and a restrained state that prohibits rotation of the chain drum.

[0003] For example, Patent Document 1 describes that when the windlass hoists an anchor chain, in order to prevent unexpected payout of the anchor chain, the brake of the windlass is switched to the restrained state when the load on the driving device of the windlass increases. Patent Document 1 describes methods for measuring the load of the driving device, including measurement based on the power consumption of the driving device and measurement using a force transducer.

[0004] Japanese Patent Laid-Open No. 2019-509941

[0005] However, when the brake is switched from the released state to the restrained state when the load on the driving device increases as described in Patent Document 1, the stop of rotation of the chain drum generates an impact on the vessel, which may catch crew members off guard.

[0006] Therefore, an object of the present disclosure is to provide a windlass protection system capable of notifying crew members in advance of switching the brake to the restrained state when hoisting an anchor chain.

[0007] This disclosure provides a windlass protection system comprising, in a first aspect, a windlass including a chain drum, a hydraulic motor, and a brake for winding up and unwinding an anchor chain; a first pressure sensor for detecting the pressure of hydraulic fluid supplied to the hydraulic motor when the anchor chain is being wound up; a second pressure sensor for detecting the pressure of hydraulic fluid discharged from the hydraulic motor when the anchor chain is being wound up; and a processing circuit that, when the effective pressure of the hydraulic motor (which is the difference between the pressure detected by the first pressure sensor and the pressure detected by the second pressure sensor) or the pressure detected by the first pressure sensor exceeds a first threshold, generates an alarm sound in the alarm device and sets the brake to a restrained state that prohibits the rotation of the chain drum when the effective pressure of the hydraulic motor or the pressure detected by the first pressure sensor exceeds a second threshold that is higher than the first threshold.

[0008] This disclosure, in a second aspect, provides a windlass protection system comprising: a windlass including a chain drum, a hydraulic motor, and a brake for winding up and unwinding an anchor chain; a first pressure sensor for detecting the pressure of hydraulic fluid supplied to the hydraulic motor when the anchor chain is being wound up; a second pressure sensor for detecting the pressure of hydraulic fluid discharged from the hydraulic motor when the anchor chain is being wound up; and a processing circuit that generates an alarm sound in an alarm device when the effective pressure of the hydraulic motor, which is the difference between the pressure detected by the first pressure sensor and the pressure detected by the second pressure sensor, or the amount of change in the pressure detected by the first pressure sensor over a first threshold, when the effective pressure of the hydraulic motor or the pressure detected by the first pressure sensor over a second threshold, and generates an alarm sound in the alarm device and sets the brake to a restrained state that prohibits the rotation of the chain drum.

[0009] According to this disclosure, a windlass protection system is provided that can notify the crew in advance of the switch to a brake-locked state when the anchor chain is being hoisted up.

[0010] Figure 1 is a schematic diagram of a windlass protection system according to one embodiment. Figure 2 is a side view of the windlass. Figure 3 is a graph showing the change over time of the effective pressure of the hydraulic motor when the anchor chain is hoisted up.

[0011] Figure 1 shows a windlass protection system 1 according to one embodiment. The windlass protection system 1 includes a windlass 2 that winds up and unwinds the anchor chain, and a control device 7.

[0012] As shown in Figure 2, the windlass 2 includes a chain drum 21 around which the anchor chain is wound, and a support structure 23 that rotatably supports a rotating shaft 22 that passes through the chain drum 21. In this embodiment, since the windlass 2 is large, the support structure 23 also rotatably supports a drive shaft 24 located to the side of the rotating shaft 22. Power transmission is performed by the meshing of a drive gear with an ON / FF power transmission switching function attached to the drive shaft 24 and a driven gear attached to the chain drum 21. In the case of a small windlass, power transmission is performed by the meshing of a claw-type clutch with an ON / OFF power transmission function attached to the drive shaft 24 and a claw-type boss attached to the boss portion of the chain drum 21.

[0013] Furthermore, the windlass 2 includes a hydraulic motor 25 shown in Figure 1 that rotates the chain drum 21 via a drive shaft 24 and a rotating shaft 22, and a brake 3 that can be switched between a restrained state that prohibits the rotation of the chain drum 21 and a released state that allows the rotation of the chain drum 21.

[0014] The hydraulic motor 25 is supplied with hydraulic fluid from the hydraulic pump 41. A directional control valve 45, which also serves as a flow control valve, is interposed between the hydraulic pump 41 and the hydraulic motor 25. The hydraulic pump 41 is connected to the directional control valve 45 by a pump line 42, and the directional control valve 45 is connected to a tank by a tank line 43. A check valve 44 with a cracking pressure set slightly higher is provided in the tank line 43.

[0015] Furthermore, the directional control valve 45 is connected to the hydraulic motor 25 by a hoisting supply line 51 and a payout supply line 52. The hoisting supply line 51 is provided with a counterbalance valve 53 for load holding and speed control when the anchor chain is paid out.

[0016] Furthermore, the hoisting supply line 51 and the unwinding supply line 52 are connected by a relay line 54, and the relay line 54 is equipped with a relief valve 55 that opens when the pressure in the hoisting supply line 51 exceeds the relief pressure. In other words, the relief valve 55 is for the hydraulic fluid supplied to the hydraulic motor 25 when the anchor chain is hoisted up.

[0017] In this embodiment, the hydraulic motor 25 is a variable displacement motor. The capacity of the hydraulic motor 25 is changed by the regulator 56 according to the higher of the pressure in the hoisting supply line 51 and the unwinding supply line 52. However, the hydraulic motor 25 may also be a fixed displacement motor. The hydraulic motor 25 is connected to the tank line 43 described above by a drain line 57.

[0018] The brake 3 is a band brake and includes a brake drum that rotates with the chain drum 21 and a pair of arc-shaped bands that run along the outer surface of the brake drum. One end of each band is pivotably connected to the other end via a pin. Furthermore, as shown in Figure 2, the brake 3 includes a hydraulic cylinder 31 connected to the other end of the pair of bands via a link mechanism 32 and a handle 33 for manually operating the brake 3.

[0019] The hydraulic cylinder 31 is single-acting. In this embodiment, as shown in Figure 1, hydraulic fluid is supplied to the hydraulic cylinder 31 from a hydraulic pump 61 separate from the hydraulic pump 41 for the hydraulic motor 25, but hydraulic fluid may also be supplied to the hydraulic cylinder 31 from the hydraulic pump 41. When hydraulic fluid is not supplied to the hydraulic cylinder 31, the brake 3 is maintained in a restrained state, and when hydraulic fluid is supplied to the hydraulic cylinder 31, the brake 3 is switched to a released state.

[0020] A switching valve 65 is interposed between the hydraulic pump 61 and the hydraulic cylinder 31. The hydraulic pump 61 is connected to the switching valve 65 by a pump line 62, and the switching valve 65 is connected to a tank by a tank line 64. A pressure reducing valve 63 is provided in the pump line 62 to maintain a constant pressure of the hydraulic fluid supplied to the hydraulic cylinder 31. The switching valve 65 is also connected to the hydraulic cylinder 31 by a supply and discharge line 66.

[0021] The switching valve 65 can be switched between a neutral position that connects the supply and discharge line 66 to the tank line 64 and an operating position that connects the supply and discharge line 66 to the pump line 62. The switching valve 65 is electromagnetic and is electrically connected to the control device 7.

[0022] The control device 7 includes a processing circuit 71 that controls the switching valve 65. The control device 7 is electrically connected to both the alarm 81 and the display 82. The display 82 may also be incorporated into the control device 7 as a touchscreen that also functions as an input device.

[0023] The functions of the elements disclosed herein can be performed using circuits or processing circuits, including general-purpose processors, dedicated processors, integrated circuits, ASICs (Application Specific Integrated Circuits), conventional circuits, and / or combinations thereof, configured or programmed to perform the disclosed functions. A processor is considered a processing circuit or circuit because it includes transistors and other circuits. In this disclosure, a circuit, unit, or means is hardware that performs the enumerated functions, or hardware programmed to perform the enumerated functions. The hardware may be hardware disclosed herein, or other known hardware that is programmed or configured to perform the enumerated functions. If the hardware is a processor, which is considered a type of circuit, then the circuit, means, or unit is a combination of hardware and software, and the software is used to configure the hardware and / or the processor.

[0024] The control device 7 is electrically connected to both the first pressure sensor 91 and the second pressure sensor 92. Note that in Figure 1, some signal lines are omitted for the sake of simplicity.

[0025] The first pressure sensor 91 is installed in the hoisting supply line 51 and detects the pressure of the hydraulic fluid supplied to the hydraulic motor 25 when the anchor chain is hoisted up. The second pressure sensor 92 is installed in the unwinding supply line 52 and detects the pressure of the hydraulic fluid discharged from the hydraulic motor 25 when the anchor chain is hoisted up.

[0026] It is desirable that the windlass 2 or the ship's deck be provided with a cover to protect the first pressure sensor 91 and the second pressure sensor 92 from blue waves, as this will provide weather resistance.

[0027] Before starting to unwind the anchor chain and before starting to wind up the anchor chain, the processing circuit 71 switches the switching valve 65 to the operating position to release the brake 3. When winding up the anchor chain, the processing circuit 71 generates an alarm sound in the alarm device 81 when the effective pressure Pa (= P1 - P2) of the hydraulic motor 25, which is the difference between the pressure P1 detected by the first pressure sensor 91 and the pressure P2 detected by the second pressure sensor 92, exceeds the first threshold α.

[0028] The first threshold α is determined based on the supply pressure to the hydraulic motor 25 corresponding to the design rated load when the anchor chain is hoisted up. For example, the first threshold α is in the range of 50% to 80% of the relief pressure of the relief valve 55.

[0029] Subsequently, when the effective pressure Pa of the hydraulic motor 25 exceeds a second threshold β which is higher than the first threshold α, the processing circuit 71 generates an alarm sound in the alarm device 81 and switches the switching valve 65 to the neutral position to lock the brake 3. It is desirable that the alarm sound when the effective pressure Pa of the hydraulic motor 25 exceeds the second threshold β is different from the alarm sound when the effective pressure Pa of the hydraulic motor 25 exceeds the first threshold α, but it may be the same as the alarm sound when the effective pressure Pa of the hydraulic motor 25 exceeds the first threshold α.

[0030] The second threshold β is determined based on the relief pressure of the relief valve 55. For example, the second threshold β is within the range of 90% to 100% of the relief pressure.

[0031] Furthermore, when the anchor chain is being hoisted, the processing circuit 71 displays the change in the effective pressure Pa of the hydraulic motor 25 over time, along with the first threshold α and the second threshold β, as a graph on the display unit 82 as shown in Figure 3.

[0032] Furthermore, in this embodiment, the processing circuit 71 predicts the fluctuation range R of the effective pressure Pa of the hydraulic motor 25 when the anchor chain is hoisted up, based on wave information, and generates an alarm sound in the alarm device 81 when the fluctuation range R reaches a first threshold α. For example, the processing circuit 71 may acquire wave information from a wave height meter or a GNSS (Global Navigation Satellite Systems) compass. The processing circuit 71 also displays the fluctuation range R as a graph on the display device 82, as shown in Figure 3.

[0033] As described above, in the windlass protection system 1 of this embodiment, an alarm sound is generated before the brake 3 is switched to the restrained state when the anchor chain is being reeled in, that is, when the effective pressure Pa of the hydraulic motor 25 exceeds the first threshold α which is lower than the second threshold β. This allows the crew to be notified in advance of the switch to the restrained state of the brake 3.

[0034] Furthermore, in this embodiment, an alarm sound is also generated when the fluctuation range R of the effective pressure Pa of the hydraulic motor 25 reaches a first threshold α. In other words, since the alarm sound is generated in two stages before the brake 3 switches to the restrained state, the crew can adjust their attention depending on whether the alarm sound is heard first or second.

[0035] Furthermore, in this embodiment, the change in the effective pressure Pa of the hydraulic motor 25 over time is displayed on the display 82 along with the first threshold α and the second threshold β. Therefore, even before an alarm sound is generated, the crew can predict when the brake 3 will activate by looking at the display 82.

[0036] <Modifications> This disclosure is not limited to the embodiments described above, and various modifications are possible without departing from the gist of this disclosure.

[0037] For example, the processing circuit 71 may generate an alarm sound in the alarm device 81 when the pressure P1 detected by the first pressure sensor 91 during the winding of the anchor chain exceeds a first threshold α, and when the pressure P1 exceeds a second threshold β, it may generate an alarm sound in the alarm device 81 and switch the switching valve 65 to the neutral position to restrain the brake 3. In this case as well, the same effects as in the above embodiment can be obtained.

[0038] If the processing circuit 71 generates an alarm sound in the alarm device 81 when the pressure P1 exceeds a first threshold α during anchor chain winding, the processing circuit 71 may predict the pressure fluctuation range R of the hydraulic fluid supplied to the hydraulic motor 25 during anchor chain winding based on wave information, and generate an alarm sound in the alarm device 81 when the fluctuation range R reaches the first threshold α. Alternatively, the processing circuit 71 may display the change in pressure P1 over time along with the first threshold α and the second threshold β on the display device 82.

[0039] Alternatively, the processing circuit 71 may generate an alarm sound in the alarm device when the time rate of change of the effective pressure Pa of the hydraulic motor 25 or the pressure P1 detected by the first pressure sensor 91 exceeds a first threshold γ during the winding of the anchor chain. When the time rate of change of the effective pressure Pa of the hydraulic motor 25 exceeds the first threshold γ, it means that the effective pressure Pa of the hydraulic motor 25 has not yet exceeded a second threshold β, and when the time rate of change of pressure P1 exceeds the first threshold γ, it means that pressure P1 has not yet exceeded a second threshold β. In this case as well, the same effects as in the above embodiment can be obtained.

[0040] Furthermore, the processing circuit 71 may determine the effective pressure Pa of the hydraulic motor 25 or the upper limit of the normal value of the hydraulic fluid pressure ε based on the water depth information of the current position of the vessel on which the windlass 2 is installed and the length of the anchor chain extended. If the water depth information of the current position of the vessel and the length of the anchor chain extended are known, it is possible to calculate the load that should be there, i.e., the weight of the anchor chain and anchor considering buoyancy. The effective pressure Pa of the hydraulic motor 25 or the upper limit of the normal value of the hydraulic fluid pressure ε is a value obtained by adding, for example, a 10% error to the hydraulic fluid pressure corresponding to the load that should be there. Note that the water depth information of the current position of the vessel can be detected by a depth gauge, and the length of the anchor chain extended can be calculated from the amount of rotation of the rotating shaft 22 of the windlass 2, the amount of rotation of the drive shaft 24, or the amount of rotation of the boss portion which is part of the chain drum 21.

[0041] Subsequently, the processing circuit 71 may generate an alarm sound in the alarm device 81 when the effective pressure Pa of the hydraulic motor 25 or the pressure P1 detected by the first pressure sensor 91 exceeds the upper limit ε of the normal value during the winding of the anchor chain. With this configuration, when attempting to move the ship to the anchor position using the force of the windlass 2, an alarm sound is generated when the effective pressure Pa of the hydraulic motor 25 or the pressure P1 exceeds the upper limit ε of the normal value, prompting the captain to move the ship using the propulsion system.

[0042] <Summary> As a first aspect, from a first viewpoint, the present disclosure provides a windlass protection system comprising: a windlass including a chain drum, a hydraulic motor, and a brake that winds and pays out an anchor chain; a first pressure sensor that detects the pressure of hydraulic oil supplied to the hydraulic motor when winding the anchor chain; a second pressure sensor that detects the pressure of hydraulic oil discharged from the hydraulic motor when winding the anchor chain; and a processing circuit that, when winding the anchor chain, causes an alarm to generate an alarm sound when the effective pressure of the hydraulic motor, which is the difference between the pressure detected by the first pressure sensor and the pressure detected by the second pressure sensor, or the pressure detected by the first pressure sensor exceeds a first threshold value, and when the effective pressure of the hydraulic motor or the pressure detected by the first pressure sensor exceeds a second threshold value higher than the first threshold value, causes the alarm to generate an alarm sound and places the brake in a restrained state that prohibits rotation of the chain drum.

[0043] According to the above configuration, an alarm sound is generated before the brake is switched to the restrained state when winding the anchor chain, so that seafarers can be notified in advance of the switching of the brake to the restrained state.

[0044] As a second aspect, in the first aspect, the processing circuit may predict, based on wave information, a fluctuation range of the effective pressure of the hydraulic motor when winding the anchor chain, or a fluctuation range of the pressure of hydraulic oil supplied to the hydraulic motor when winding the anchor chain, and cause the alarm to generate an alarm sound when the fluctuation range reaches the first threshold value. According to this configuration, alarm sounds are generated in two stages before the brake is switched to the restrained state, so that seafarers can adjust their level of attention depending on whether the alarm sound is the first or the second.

[0045] In a third embodiment, in the first or second embodiment, the processing circuit may display the time-dependent change in the effective pressure of the hydraulic motor or the pressure detected by the first pressure sensor on the display unit along with the first and second threshold values. With this configuration, even before an alarm sound is generated, the crew can predict when the brakes will be switched to the locked state by looking at the display unit.

[0046] In a fourth embodiment, in any of the first to third embodiments, the windlass protection system may further include a cover to protect the pressure sensor from blue waves. This configuration provides weather resistance.

[0047] In a fifth embodiment, in any of the first to fourth embodiments, the first threshold is determined based on the supply pressure to the hydraulic motor corresponding to the design rated load when the anchor chain is being hoisted up, and the processing circuit determines the normal upper limit of the effective pressure of the hydraulic motor or the hydraulic fluid pressure based on the water depth information of the current position of the vessel on which the windlass is installed and the length of the anchor chain being paid out, and an alarm sound may be generated in the alarm device when the effective pressure of the hydraulic motor or the pressure detected by the first pressure sensor exceeds the normal upper limit when the anchor chain is being hoisted up. With this configuration, when attempting to move the vessel to the anchor position using the force of the windlass, the effective pressure of the hydraulic motor or the hydraulic fluid pressure exceeds the normal upper limit and an alarm sound is generated, prompting the captain to move the vessel using the propulsion system.

[0048] In a sixth aspect, from a second aspect, the present disclosure provides a windlass protection system comprising: a windlass including a chain drum, a hydraulic motor and a brake, that winds and pays out an anchor chain; a first pressure sensor that detects a pressure of hydraulic oil supplied to the hydraulic motor when the anchor chain is being wound; a second pressure sensor that detects a pressure of hydraulic oil discharged from the hydraulic motor when the anchor chain is being wound; and a processing circuit configured to cause an alarm to generate an alarm sound when an effective pressure of the hydraulic motor, which is a difference between a pressure detected by the first pressure sensor and a pressure detected by the second pressure sensor during winding of the anchor chain, or a time-varying amount of the pressure detected by the first pressure sensor exceeds a first threshold value, and when the effective pressure of the hydraulic motor or the pressure detected by the first pressure sensor exceeds a second threshold value, cause the alarm to generate an alarm sound and place the brake in a restrained state that prohibits rotation of the chain drum.

[0049] According to the above configuration, an alarm sound is generated before the brake is actuated, so that a crew member can be notified in advance of the switching of the brake to the restrained state.

[0050] 1: windlass protection system, 2: windlass, 21: chain drum, 25: hydraulic motor, 3: brake, 31: hydraulic cylinder, 7: control device, 71: processing circuit, 81: alarm, 82: display, 91: first pressure sensor, 92: second pressure sensor

Claims

1. A windlass protection system comprising: a windlass including a chain drum, a hydraulic motor, and a brake for winding up and unwinding an anchor chain; a first pressure sensor for detecting the pressure of the hydraulic fluid supplied to the hydraulic motor when the anchor chain is being wound up; a second pressure sensor for detecting the pressure of the hydraulic fluid discharged from the hydraulic motor when the anchor chain is being wound up; and a processing circuit that, when the effective pressure of the hydraulic motor (which is the difference between the pressure detected by the first pressure sensor and the pressure detected by the second pressure sensor) or the pressure detected by the first pressure sensor exceeds a first threshold, generates an alarm sound in an alarm device, and when the effective pressure of the hydraulic motor or the pressure detected by the first pressure sensor exceeds a second threshold higher than the first threshold, generates an alarm sound in the alarm device and sets the brake to a restrained state that prohibits the rotation of the chain drum.

2. The windlass protection system according to claim 1, wherein the processing circuit predicts, based on wave information, the range of fluctuations in the effective pressure of the hydraulic motor when the anchor chain is hoisted up, or the range of fluctuations in the pressure of the hydraulic fluid supplied to the hydraulic motor when the anchor chain is hoisted up, and generates an alarm sound in the alarm device when the range of fluctuations reaches the first threshold.

3. The windlass protection system according to claim 1 or 2, wherein the processing circuit displays the time-dependent change in the effective pressure of the hydraulic motor or the pressure detected by the first pressure sensor on a display unit together with the first threshold and the second threshold.

4. The windlass protection system according to claim 1 or 2, further comprising a cover that protects the pressure sensor from blue waves.

5. The windlass protection system according to claim 1 or 2, wherein the first threshold is determined based on the supply pressure to the hydraulic motor corresponding to the design rated load when the anchor chain is being hoisted, the processing circuit determines a normal upper limit for the effective pressure of the hydraulic motor or the hydraulic fluid pressure based on the water depth information of the current position of the vessel on which the windlass is installed and the length of the anchor chain being paid out, and when the effective pressure of the hydraulic motor or the pressure detected by the first pressure sensor exceeds the normal upper limit when the anchor chain is being hoisted, an alarm sound is generated in the alarm device.

6. A windlass protection system comprising: a windlass including a chain drum, a hydraulic motor, and a brake for winding up and unwinding an anchor chain; a first pressure sensor for detecting the pressure of the hydraulic fluid supplied to the hydraulic motor when the anchor chain is being wound up; a second pressure sensor for detecting the pressure of the hydraulic fluid discharged from the hydraulic motor when the anchor chain is being wound up; and a processing circuit that, when the effective pressure of the hydraulic motor (which is the difference between the pressure detected by the first pressure sensor and the pressure detected by the second pressure sensor) or the amount of change in the pressure detected by the first pressure sensor over a first threshold, generates an alarm sound in the alarm and sets the brake to a restrained state that prohibits the rotation of the chain drum when the effective pressure of the hydraulic motor or the pressure detected by the first pressure sensor over a second threshold.

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