Two-section gangway ladder and control method thereof

Abstract

The invention relates to a two-section gangway ladder and a control method thereof.The two-section gangway ladder comprises an upper-section gangway ladder winch and a lower-section gangway ladder winch which are independent, the upper-section gangway ladder is controlled by the upper-section gangway ladder winch through a variable-frequency motor, and the lower-section gangway ladder is controlled by the lower-section gangway ladder winch through a non-variable-frequency marine motor; an adjusting switch is arranged on the stand column, the adjusting switch is arranged at the horizontal extending end point of the upper section gangway ladder, and the adjusting switch is triggered to act when the upper section gangway ladder horizontally extends to the end point; the adjusting switch and the first contactor form a closed loop; a first contact of the first contactor is arranged in a frequency control loop of the frequency converter, and the frequency of the frequency converter is adjusted based on the power-on / power-off state of the first contactor. The two-section gangway ladder is suitable for a large ship, the upper section gangway ladder and the lower section gangway ladder are substantially independent, and in order to enable the relatively independent gangway ladders to synchronously complete actions such as overturning, lifting and descending, synchronous operation of the gangway ladders is achieved through frequency conversion control of the winch of the upper section gangway ladder.

Description

Technical Field

[0001] The invention belongs to the technical field of ship automation, and in particular relates to a two-section gangway ladder and a control method thereof. Background Art

[0002] The gangway is an important device that connects the ship and the dock for people to board and leave the ship when the ship is at the port. It is mainly composed of the gangway body and accessories such as the retracting and releasing mechanism, the fixing and locking mechanism, and the handrails. It is generally set above the bulkhead or freeboard deck, in the passage where the side is not closed by the hull outer plate. With the rapid development of the international shipping market and the continuous increase in trade and transportation demand, ships are gradually turning to larger sizes. The increase in the main dimensions of the ship has made the layout position of the gangway higher and higher, which has led to the continuous increase in the length of the gangway, and the two-section gangway has also come into being.

[0003] Two-section gangway ladders are usually operated mechanically, using a pulley block to achieve synchronous operation through the travel distance of the wire rope. This method has high requirements for precision, which makes debugging difficult, and it is very easy to make errors in subsequent operations, resulting in damage to the gangway ladder. Summary of the invention

[0004] A first object of the present invention is to provide a two-section gangway ladder.

[0005] To achieve the above object, the present invention adopts the following technical solutions:

[0006] A two-section gangway ladder comprises a column, an upper gangway ladder, a lower gangway ladder and an intermediate platform connecting the upper and lower gangway ladders, and an independent upper gangway ladder winch and a lower gangway ladder winch, wherein the upper gangway ladder is controlled by the upper gangway ladder winch through a variable frequency motor, and the lower gangway ladder is controlled by the lower gangway ladder winch through a non-variable frequency marine motor;

[0007] The column is provided with an adjustment switch, which is arranged at the end point of the horizontal extension of the upper gangway ladder, and the adjustment switch is triggered when the upper gangway ladder is horizontally extended to the end point;

[0008] The regulating switch and the first contactor form a closed loop; the first contact of the first contactor is arranged in the loop of the frequency control of the inverter, and the frequency of the inverter is adjusted based on the power-on / power-off state of the first contactor.

[0009] As a preferred embodiment, the upper gangway ladder is provided with a first limit switch, which is disconnected after the upper gangway ladder is horizontally extended to the end point, and the lower gangway ladder is provided with a second limit switch, which is disconnected after the lower gangway ladder is horizontally extended to the end point;

[0010] The first limit switch is connected in series with the first branch for controlling the rise of the lower motor, and then connected in parallel with the second branch for controlling the descent of the lower motor, to form a control loop for the lower motor; the second limit switch is connected in series with the third branch for controlling the rise of the upper motor, and then connected in parallel with the fourth branch for controlling the descent of the upper motor, to form a control loop for the lower motor;

[0011] The second, third, fourth and fifth contactors are connected in series in the first, second, third and fourth branches respectively; the fourth and fifth contacts controlled by the fourth and fifth contactors are connected in parallel and connected to the control end of the frequency regulation of the frequency converter.

[0012] As a preferred implementation manner, the second and third contactors are interlocked and controlled; the fourth and fifth contactors are interlocked and controlled.

[0013] As a preferred implementation, corresponding ascending / descending process control buttons are respectively connected in series in the first, second, third and fourth branches.

[0014] As a preferred embodiment, the frequency converter is pre-set with a regulating frequency f2, which is determined based on the travel L1 of the steel wire rope of the upper gangway ladder and the travel L2 of the steel wire rope of the lower gangway ladder, and is calculated as follows:

[0015]

[0016] Where n1 is the speed of the variable frequency motor when the gangway is flipped; p is the number of motor poles.

[0017] As a preferred implementation, the first contact point controlled by the first contactor is connected to the sliding contact of the potentiometer, the two fixed ends of the potentiometer are connected to the frequency converter, and the frequency conversion is controlled by the change of the resistance value of the potentiometer;

[0018] The fourth and fifth contacts controlled by the fourth and fifth contactors are connected in parallel and connected to a fixed end of a potentiometer.

[0019] Furthermore, the sliding contact of the potentiometer is located at a preset position; the preset position is determined based on the stroke of the steel wire rope of the upper gangway ladder and the stroke of the steel wire rope of the lower gangway ladder.

[0020] As a preferred implementation, the regulating switch is a limit switch.

[0021] As a preferred implementation, the non-frequency-converting marine motor is a marine three-phase asynchronous motor.

[0022] A second object of the present invention is to provide a control method for the above-mentioned two-section gangway ladder, comprising:

[0023] (1) Obtain the travel L1 of the steel wire rope of the upper gangway ladder and the travel L2 of the steel wire rope of the lower gangway ladder; calculate the inverter adjustment frequency f2 based on the following formula:

[0024]

[0025] In the formula, n1 is the speed of the variable frequency motor when the gangway is turned over, and the corresponding frequency is f1; p is the number of motor poles;

[0026] Based on the calculation results, the adjustment frequency f2 is pre-set in the frequency converter;

[0027] (2) Activate the gangway;

[0028] When the gangway is lowered:

[0029] When the gangway is turned over, the speed and frequency of the variable frequency motor are consistent with those of the marine motor;

[0030] After flipping into place, the first limit switch and the second limit switch are disconnected, and the gangway is locked in the horizontal position;

[0031] The upper gangway triggers the regulating switch to operate, the first contact operates, and the frequency of the inverter changes to f2;

[0032] The first and second limit switches are closed, and the upper and lower gangways are lowered to their proper positions;

[0033] When the gangway is raised:

[0034] The upper gangway is raised to the flip position at f2;

[0035] The first and second limit switches are disconnected, the regulating switch is actuated, the first contact is actuated, and the frequency of the inverter is changed to f1;

[0036] The first and second limit switches are closed, and the upper and lower gangways are flipped into place.

[0037] When the gangway of the present invention is working, firstly, when the gangway moves from the storage locking position to the horizontal position, the turning operation of the two sections of the gangway must be synchronized, and one cannot be fast and the other slow, otherwise it is easy to cause the upper and lower sections to twist and overturn. Secondly, when the gangway is lowered from the horizontal position to the maximum use angle, the rotation center positions of the two sections of the gangway are different. In order to maintain the synchronization of the gangway lowering process and prevent the two sections from hindering each other, the speed needs to be set so that the lower section is faster than the upper section. The upper and lower sections of the gangway need to be set according to the stroke, so as not to cause the gangway to twist and deform. The frequency conversion control method of the upper section of the gangway is used to match the rotation speed of the lower section of the gangway, thereby ensuring synchronous operation during the descent or lifting process.

[0038] The present invention is applicable to the two-section gangway ladder used in large ships. The upper and lower gangway ladders are substantially independent. In order to make the relatively independent gangway ladders synchronously complete the actions of turning over, lifting, and lowering, the upper gangway ladder winch is controlled by frequency conversion to achieve synchronous operation. The present invention has been used in 5800-lane-meter roll-on / roll-off ships. Comprehensively using the conditions, it can realize the turning over, lifting, and lowering of the two-section gangway ladder very stably and effectively. The present invention can also be applied to other projects. It only needs to adjust the frequency of the upper gangway ladder based on the travel of the steel wire ropes of the two gangway ladders. BRIEF DESCRIPTION OF THE DRAWINGS

[0039] Figure 1 It is a schematic diagram of the structure of a two-section gangway of a ro-ro ship.

[0040] Figure 2 It is the control schematic diagram of the ro-ro ship gangway (control console loop).

[0041] Figure 3 This is the control schematic diagram of the ro-ro ship gangway (inverter control loop). DETAILED DESCRIPTION

[0042] The technical solution of the present invention is further described below in conjunction with the accompanying drawings and specific implementation methods.

[0043] Example 1

[0044] like Figure 1-3 The two-section gangway ladder shown includes a column, an upper gangway ladder, a lower gangway ladder, an intermediate platform connecting the upper and lower gangway ladders, and an independent upper gangway ladder winch and a lower gangway ladder winch. The upper gangway ladder is controlled by the upper gangway ladder winch through a variable frequency motor, and the lower gangway ladder is controlled by the lower gangway ladder winch through a non-variable frequency marine motor; an adjustment switch (a limit switch is used in the embodiment) is provided on the column, and the adjustment switch is set at the end point of the horizontal extension of the upper gangway ladder, and the adjustment switch is triggered when the upper gangway ladder is horizontally extended to the end point.

[0045] The upper gangway ladder is provided with a first limit switch, which is disconnected after the upper gangway ladder is horizontally extended to the end point, and the lower gangway ladder is provided with a second limit switch, which is disconnected after the lower gangway ladder is horizontally extended to the end point;

[0046] The first limit switch is connected in series with the first branch for controlling the rise of the lower motor, and then connected in parallel with the second branch for controlling the descent of the lower motor, to form a control loop for the lower motor; the second limit switch is connected in series with the third branch for controlling the rise of the upper motor, and then connected in parallel with the fourth branch for controlling the descent of the upper motor, to form a control loop for the lower motor;

[0047] The second, third, fourth and fifth contactors and corresponding rising / falling process control buttons are respectively connected in series in the first, second, third and fourth branches; the fourth and fifth contacts controlled by the fourth and fifth contactors are connected in parallel to the control end of the frequency converter frequency adjustment.

[0048] The regulating switch and the first contactor form a closed loop; the first contact of the first contactor is arranged in the loop of the frequency control of the frequency converter, and the frequency converter frequency is adjusted based on the power-on / power-off state of the first contactor.

[0049] like Figure 2 As shown, the second and third contactors are interlocked and controlled; the fourth and fifth contactors are interlocked and controlled.

[0050] The frequency converter is pre-set with the adjustment frequency f2, which is determined based on the travel L1 of the upper gangway ladder wire rope and the travel L2 of the lower gangway ladder wire rope. The calculation method is as follows:

[0051]

[0052] Where n1 is the speed of the variable frequency motor when the gangway is flipped; p is the number of motor poles.

[0053] In this embodiment, Figure 3 As shown, the first contact controlled by the first contactor is connected to the sliding contact of the potentiometer, the two fixed ends of the potentiometer are connected to the frequency converter, and the frequency conversion is controlled by the change of the resistance value of the potentiometer. The sliding contact of the potentiometer is located at a preset position; the preset position is determined based on the above-mentioned adjustment frequency.

[0054] Example 2

[0055] The present invention is applied to the multi-position gangway described in ISO 5488 (Specification 4.1.2). In Example 2, a 5,800-lane-meter ro-ro ship is taken as an example to specifically illustrate the technical solution of the present invention.

[0056] Gangway down

[0057] 1. Gangway reversal: The speeds of the two gangways must be consistent. The lower gangway maintains a fixed speed of 890rpm, and the upper gangway also runs at a motor speed of n1=890rpm, with a frequency of f1=890*4 / 60=59.3Hz (motor level P=4);

[0058] 2. After flipping into place, an adjustment switch is installed on the column, which serves as the signal source for adjusting the frequency of the upper gangway;

[0059] 3. The upper gangway stroke of this project is L1=5226mm, the lower gangway stroke is L2=10452mm, n2=L1 / L2*n1, so keep n2=445rpm, f2= n2*p / 60 corresponding to frequency 29.7Hz;

[0060] 4. Gangway descent: Adjust the switch action, and the upper gangway will run at the set frequency of 29.7Hz until it descends into place.

[0061] Gangway up

[0062] 1. Gangway ascending: The upper gangway runs at the set frequency of 29.7 Hz until it rises to the flip position;

[0063] 2. Adjust the switch action, the upper gangway receives the signal, changes the motor frequency to 59.3Hz, and the speed to 890rpm;

[0064] 3. Gangway flipping: The two sections of the gangway move at the same speed and flip into place.

[0065] When the gangway is locked in the horizontal position, the adjustment switch does not operate, KM5 is closed and does not operate, and the gangway maintains 59.3Hz operation;

[0066] When the gangway is descending or ascending, the regulating switch is actuated, KM5 is disconnected, and the gangway operates at 29.7 Hz.

Claims

1. A two-section gangway ladder, comprising a column, an upper gangway ladder, a lower gangway ladder and an intermediate platform connecting the upper and lower gangway ladders, characterized in that: It also includes an independent upper gangway ladder winch and a lower gangway ladder winch, wherein the upper gangway ladder is controlled by the upper gangway ladder winch through a variable frequency motor, and the lower gangway ladder is controlled by the lower gangway ladder winch through a non-variable frequency marine motor; The column is provided with an adjustment switch, which is arranged at the end point of the horizontal extension of the upper gangway ladder, and the adjustment switch is triggered when the upper gangway ladder is horizontally extended to the end point; The regulating switch and the first contactor form a closed loop; the first contact of the first contactor is arranged in the loop of the frequency control of the inverter, and the frequency of the inverter is adjusted based on the power-on / power-off state of the first contactor.

2. The two-section gangway ladder according to claim 1, characterized in that: The upper gangway ladder is provided with a first limit switch, which is disconnected after the upper gangway ladder is horizontally extended to the end point, and the lower gangway ladder is provided with a second limit switch, which is disconnected after the lower gangway ladder is horizontally extended to the end point; The first limit switch is connected in series with the first branch for controlling the rise of the lower motor, and then connected in parallel with the second branch for controlling the descent of the lower motor, to form a control loop for the lower motor; the second limit switch is connected in series with the third branch for controlling the rise of the upper motor, and then connected in parallel with the fourth branch for controlling the descent of the upper motor, to form a control loop for the lower motor; The second, third, fourth and fifth contactors are connected in series in the first, second, third and fourth branches respectively; the fourth and fifth contacts controlled by the fourth and fifth contactors are connected in parallel and connected to the control end of the frequency regulation of the frequency converter.

3. The two-section gangway ladder according to claim 2, characterized in that: The second and third contactors are interlocked and controlled; the fourth and fifth contactors are interlocked and controlled.

4. The two-section gangway ladder according to claim 2, characterized in that: The first, second, third and fourth branches are respectively connected in series with corresponding ascending / descending process control buttons.

5. The two-section gangway ladder according to claim 1, characterized in that: The frequency converter is pre-set with a regulating frequency f 2. The adjustment frequency is based on the travel of the upper gangway ladder wire rope L 1 and the travel of the wire rope of the lower gangway ladder L 2 is determined, and the calculation method is as follows: ； In the formula, n 1 is the speed of the variable frequency motor when the gangway is turned over; p is the number of motor pole pairs.

6. The two-section gangway ladder according to claim 2, characterized in that: The first contact point controlled by the first contactor is connected to the sliding contact of the potentiometer, and the two fixed ends of the potentiometer are connected to the frequency converter, and the frequency conversion is controlled by the change of the resistance value of the potentiometer; The fourth and fifth contacts controlled by the fourth and fifth contactors are connected in parallel and connected to a fixed end of a potentiometer.

7. The two-section gangway ladder according to claim 6, characterized in that: The sliding contact of the potentiometer is located at a preset position; the preset position is determined based on the stroke of the steel wire rope of the upper gangway ladder and the stroke of the steel wire rope of the lower gangway ladder.

8. The two-section gangway ladder according to claim 1, characterized in that: The regulating switch is a limit switch.

9. The two-section gangway ladder according to claim 1, characterized in that: The non-frequency-converting marine motor is a marine three-phase asynchronous motor.

10. The control method of the two-section gangway ladder according to any one of claims 1 to 9, characterized in that: include: (1) Obtain the travel of the wire rope of the upper gangway ladder L 1 and the travel of the wire rope of the lower gangway ladder L 2; Calculate the inverter adjustment frequency based on the following formula f 2: ； In the formula, n 1 is the speed of the variable frequency motor when the gangway is turned over, and the corresponding frequency is f 1; p is the number of motor pole pairs; Based on the calculation results, the adjustment frequency is pre-set in the inverter f 2; (2) Activate the gangway; When the gangway is lowered: When the gangway is turned over, the speed and frequency of the variable frequency motor are consistent with those of the marine motor; After flipping into place, the first limit switch and the second limit switch are disconnected, and the gangway is locked in the horizontal position; The upper gangway triggers the regulating switch to operate, the first contact operates, and the frequency of the inverter changes to f 2; The first and second limit switches are closed, and the upper and lower gangways are lowered to their proper positions; When the gangway is raised: Upper gangway f 2 rises to the flip position; The first and second limit switches are disconnected, the regulating switch is actuated, the first contact is actuated, and the inverter frequency changes to f 1; The first and second limit switches are closed, and the upper and lower gangways are flipped into place.

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