Active and passive motion compensation trestle luffing system and trestle

Abstract

The present invention discloses an active and passive motion compensating trestle luffing system, comprising a servo valve PS, an active oil cylinder, an active and passive oil cylinder, an accumulator and a high-pressure nitrogen bottle group; the active oil cylinder is a single-acting hydraulic cylinder, and its oil chamber is chamber a; the active and passive oil cylinders are double-acting hydraulic cylinders, and its rod chamber is chamber b, and its rodless chamber is chamber c; the accumulator is arranged on the active and passive oil cylinders, and the oil end of the accumulator is connected to the chamber c of the active and passive oil cylinders through an isolation valve group, and the gas end of the accumulator is connected to the high-pressure nitrogen bottle group; the servo valve PS is used to control the active oil cylinder and the active and passive oil cylinders, and the servo valve PS is connected to a hydraulic accumulator group. The present invention also discloses a trestle including the active and passive motion compensating trestle luffing system. The present invention adopts a double hydraulic cylinder instead of a three-chamber composite oil cylinder to solve the defects and shortcomings existing in the prior art.

Description

Technical Field

[0001] The invention relates to a trestle luffing system, and more particularly to an active and passive motion compensation trestle luffing system and a trestle. Background Art

[0002] Most of the personnel transportation in offshore projects such as offshore platforms and wind power operation and maintenance is carried out by trestles. Affected by wind and waves, offshore trestles should have passive or active motion compensation functions. The compensation capacity of passive motion compensation is not high and cannot meet the requirements of strong wind and wave environment. Active motion compensation was applied relatively early in foreign trestles, which is divided into full-power active motion compensation and active and passive motion compensation.

[0003] Full-power active motion compensation requires a high-power configuration, which is costly and energy-intensive.

[0004] Active and passive motion compensation (such as trestle luffing) generally uses a three-chamber composite cylinder. The cylinder a and b chambers are used to control the cylinder telescopic movement, and the c chamber is used to balance the horizontal static load of the trestle, which is connected to the high-pressure nitrogen bottle. In this way, a and b are only equivalent to about 30% of the load of the full-power compensation mode, which is economical and energy-saving. However, the three-chamber composite cylinder compensation mode is not widely used in China, and the cylinder application design is in the hands of foreign-funded enterprises, which is costly. Summary of the invention

[0005] In view of the above-mentioned defects in the prior art, the purpose of the present invention is to provide an active and passive motion compensation trestle luffing system and its trestle, which adopts double hydraulic cylinders instead of three-chamber compound oil cylinders to solve the defects and shortcomings in the prior art.

[0006] To achieve the above object, the present invention adopts the following technical solution:

[0007] On the one hand, an active and passive motion compensation trestle luffing system includes a servo valve PS, an active cylinder, an active and passive cylinder, an accumulator and a high-pressure nitrogen bottle group;

[0008] The active oil cylinder is a single-acting hydraulic cylinder, and its oil chamber is chamber a;

[0009] The active and passive oil cylinders are double-acting hydraulic cylinders, the rod chamber is chamber b, and the rodless chamber is chamber c;

[0010] The accumulator is arranged on the active and passive oil cylinders, the oil end of the accumulator is connected to the C chamber of the active and passive oil cylinders through an isolation valve group, and the gas end of the accumulator is connected to the high-pressure nitrogen cylinder group;

[0011] The servo valve PS is used to control the active cylinder and the active and passive cylinders, and the servo valve PS is connected to a hydraulic accumulator group.

[0012] Preferably, the accumulator is a piston accumulator.

[0013] Preferably, the accumulator is provided with a displacement sensor for detecting the piston position of the accumulator.

[0014] Preferably, the high-pressure nitrogen cylinder group is equipped with a safety valve and a relief valve at the top, and an inflation valve at the bottom.

[0015] On the other hand, a trestle including the active and passive motion compensation trestle luffing system also includes a base, a slewing mechanism, a trestle boom, a telescopic mechanism and a telescopic suspension ladder;

[0016] The base is arranged on the mounting tower;

[0017] The rotating mechanism is arranged on the base, and an upper rotating body is arranged on the rotating mechanism;

[0018] The rear end of the trestle arm is connected to the upper rotating body;

[0019] The active and passive motion compensation trestle luffing system is respectively connected to the upper slewing body and the trestle boom;

[0020] The telescopic suspension ladder is arranged on the trestle arm, and is driven to move along the telescopic movement of the trestle arm by a telescopic mechanism.

[0021] Preferably, the base is arranged on the mounting tower through a traction mechanism.

[0022] Preferably, the trestle boom and the upper rotary body are hinged, and the active and passive motion compensation trestle luffing system and the upper rotary body and the trestle boom are hinged.

[0023] Preferably, the active cylinder and the active and passive cylinders are arranged in parallel;

[0024] The bottom of the active oil cylinder and the bottom of the active and passive oil cylinders are hinged to the upper rotating body, and the piston rod of the active oil cylinder and the piston rod of the active and passive oil cylinders are hinged to the lower part of the trestle arm.

[0025] Preferably, a lap joint mechanism is provided on the front end portion of the telescopic suspension ladder.

[0026] The active and passive motion compensation trestle luffing system and trestle provided by the present invention have the following beneficial effects:

[0027] 1) Use traditional oil cylinders, which have low oil cylinder costs;

[0028] 2) Adopt active and passive motion compensation mode to save energy;

[0029] 3) It has a redundant safety design, fully considering human safety issues and avoiding accidents. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] Figure 1 It is a schematic diagram of the framework structure of the active and passive motion compensation trestle luffing system of the present invention;

[0031] Figure 2 It is a structural schematic diagram of the trestle of the present invention;

[0032] Figure 3 yes Figure 2 A magnified schematic diagram of the M position in the figure. DETAILED DESCRIPTION

[0033] In order to better understand the above technical solution of the present invention, the technical solution of the present invention is further described below in conjunction with the accompanying drawings and embodiments.

[0034] Combination Figure 1 As shown, an active and passive motion compensation trestle luffing system provided by the present invention includes a servo valve PS, an active cylinder 1, active and passive cylinders 2, an accumulator 3 and a high-pressure nitrogen bottle group 4.

[0035] The active oil cylinder 1 adopts a single-acting hydraulic cylinder, and its oil chamber is chamber a;

[0036] The active and passive oil cylinder 2 adopts a double-acting hydraulic cylinder, the rod chamber is chamber b, and the rodless chamber is chamber c;

[0037] The accumulator 3 is a piston accumulator, which is arranged on the active and passive oil cylinders 2. The oil end of the accumulator 3 is connected to the C chamber of the active and passive oil cylinders through the isolation valve group 16, and the gas end of the accumulator 3 is connected to the high-pressure nitrogen bottle group 4. The accumulator 3 is provided with a displacement sensor for detecting the piston position of the accumulator 3.

[0038] The pressure setting value of chamber c is used to balance the load applied to the cylinder when the trestle is in a horizontal state. The servo valve PS is used to control the movement of chambers a and b. The valve group design on chambers a and b must also meet the passive compensation and safety requirements of the cylinder. The servo valve PS is connected to a hydraulic accumulator group 17.

[0039] During the movement of the cylinder, in order to ensure that the pressure change range of chamber C is small, a nitrogen cylinder group with corresponding volume needs to be configured, and the volume is selected after calculation.

[0040] The upper part of the high-pressure nitrogen cylinder group 4 is provided with a safety valve 5 and a discharge valve 6, and the lower part is provided with a charging valve 7.

[0041] Combination Figure 2 As shown, the present invention also provides a trestle including the active and passive motion compensation trestle luffing system of the present invention, which also includes a base 8, a slewing mechanism 9, a trestle arm 10, a telescopic mechanism 11 and a telescopic suspension ladder 12.

[0042] The base 8 is mounted on the mounting tower 13 via a traction mechanism, and can be adjusted up and down along the mounting tower 13 .

[0043] The rotating mechanism 9 is arranged on the base 8 , and an upper rotating body 14 is arranged on the rotating mechanism 9 .

[0044] The rear end of the trestle arm 10 is hinged to the upper rotating body 14 .

[0045] The active and passive motion compensation trestle luffing system of the present invention is respectively hinged to the upper slewing body 14 and the trestle arm 10 .

[0046] The telescopic suspension ladder 12 is arranged on the trestle arm 10 , and the telescopic suspension ladder 12 is driven to telescopically move along the trestle arm 10 by a telescopic mechanism 11 , and the telescopic mechanism 11 is arranged at the lower part of the trestle arm 10 .

[0047] The telescopic mechanism 11 comprises a telescopic winch and a steel wire rope wound around the telescopic winch, and a tensioning mechanism is provided on the steel wire rope.

[0048] A lap joint mechanism 15 is provided on the front end of the telescopic suspension ladder 12 .

[0049] The active oil cylinder 1 is arranged in parallel with the active and passive oil cylinders 2 .

[0050] The bottom of the active cylinder 1 and the bottom of the active and passive cylinders 2 are hinged to the upper rotating body 14 , and the piston rod of the active cylinder 1 and the piston rod of the active and passive cylinders 2 are hinged to the lower part of the trestle arm 10 .

[0051] Combination Figure 3 As shown, the trestle arm 10 is hinged to the upper rotating body 14 at point O; the active cylinder 1 is hinged to the upper rotating body 14 at point A, and is hinged to the trestle arm 10 at point B; the active and passive cylinders 2 are hinged to the upper rotating body 14 at point C, and are hinged to the trestle arm 10 at point D. In this way, the triangle OAB and the triangle OCD form similar triangles. Through reasonable cylinder selection and design, the flow through the a chamber of the active cylinder 1 and the flow through the b chamber of the active and passive cylinder 2 can be approximately equal when the amplitude is changed. This design is conducive to the selection of servo valve specifications and the calculation and design of cylinder loads.

[0052] Recombination Figure 2As shown, the active cylinder 1 and the active and passive cylinders 2 are arranged in the upper and lower parts of the central plane of the trestle arm 10 to prevent the cylinders from being overloaded. The active cylinder 1 is a single-acting type and is arranged in the upper part; the active and passive cylinders 2 are double-acting types and are arranged in the lower part. The passive c-chamber bears the passive load, and the active a-chamber and b-chamber are used to control the amplitude variation motion. During the design, the flow through the active a-chamber and b-chamber is approximately equal when the amplitude variation is achieved through the cylinder selection and structural arrangement, which brings convenience to the valve selection and servo flow control. Since the passive c-chamber load is set to a larger approximate constant load, the approximate constant is calculated by the change of the P / V curve of the nitrogen bottle, and the general fluctuation is controlled within ±10%. The initial value of this load is equal to the static load applied to the cylinder when the trestle is in the horizontal state. The active force provided by the active a-chamber and b-chamber accounts for 30% of the passive c-chamber load, so the required power for the active and passive motion compensation of the amplitude variation can be greatly reduced.

[0053] Since the oil cylinder is selected by the pressure difference (servo valve a, b ports) corresponding to the trestle load, and the cylinder design pressure is determined by the system pressure, the system pressure is higher than the pressure difference between the servo valve a and b ports, and the passive chamber c pressure Pc is usually lower than the system pressure. In an emergency, the system oil supply is cut off, the cylinder Pc and Pa are restored to the system safety pressure, and Pb is ignored. It can be seen from the following formula that the bearing capacity F is significantly increased.

[0054] F=P c A c +(kP a A a -P b A b )

[0055] F: Load applied by the trestle to the semi-compensated cylinder

[0056] P c A c : Calculation load of oil cylinder C chamber

[0057] P a A a : Calculated load of cylinder chamber a

[0058] P b A b : Calculated load of cylinder chamber b

[0059] k: The coefficient of converting the calculated load of chamber a of the active cylinder to the semi-compensated cylinder

[0060] The working principle of trestle of the present invention is as follows:

[0061] After the ship equipped with the trestle of the present invention approaches the lap target, the ship's attitude is adjusted, and the trestle is manually controlled to overlap with the target. After the lap is completed, the trestle motion compensation function is turned on. The amplitude change, rotation, and telescopic enter the active and passive motion compensation state, and the servo valve is controlled by the control signal calculated by the MRU and other detection signals, and oil is supplied to each actuator according to actual needs, so that the actuator performs corresponding actions to achieve the purpose of motion compensation.

[0062] The active and passive motion compensation of the trestle of the present invention is as follows:

[0063] The oil cylinder type active and passive motion compensation is a combination of active compensation and passive compensation. This compensation type can be switched between passive and active. Its working principle is: the passive part is composed of a pressure vessel and the c chamber of the active and passive oil cylinder 2. The pressure of the pressure vessel can be adjusted by a compressor or an exhaust valve. The pressure vessel to be used for operation is selected by opening or closing the valve, and then the pressure is supplied to the c chamber of the active and passive oil cylinder 2 through the piston accumulator 3. An isolation valve group 16 is provided between the piston accumulator 3 and the active and passive oil cylinder 2 so that the oil cylinder can be locked. Through the isolation valve group 16, the oil in the c chamber of the active and passive oil cylinder 2 and the piston accumulator 3 can also be filled, discharged and safely overflowed.

[0064] The active part is composed of a hydraulic pump device, which controls the servo valve PS through the calculated control signal of MRU and other detection signals, and supplies oil to the a chamber of the active cylinder 1 and the b chamber of the active and passive cylinders 2 according to actual needs, so that the cylinders make corresponding movements to achieve the purpose of motion compensation. The active part is equipped with a hydraulic accumulator group 17, which can keep the system oil supply pressure relatively stable and buffer the impact. The a chamber of the active cylinder 1 and the b chamber of the active and passive cylinder 2 are connected by the bypass valve in the valve group. In the active mode, the bypass valve is closed, and the a chamber is not connected to the b chamber; when the bypass valve is open, the active part is invalid, and the system acts as a passive compensator, such as Figure 1 shown.

[0065] Those skilled in the art should recognize that the above embodiments are only used to illustrate the present invention, and are not intended to limit the present invention. As long as they are within the spirit of the present invention, any changes or modifications to the above embodiments will fall within the scope of the claims of the present invention.

Claims

1. An active and passive motion compensation trestle luffing system for a trestle, characterized by: Including servo valve, active cylinder, active and passive cylinder, accumulator and high-pressure nitrogen bottle group; The active oil cylinder is a single-acting hydraulic cylinder, and its oil chamber is chamber a; The active and passive oil cylinders are double-acting hydraulic cylinders, the rod chamber is chamber b, and the rodless chamber is chamber c; The accumulator is arranged on the active and passive oil cylinders, the oil end of the accumulator is connected to the C chamber of the active and passive oil cylinders through an isolation valve group, and the gas end of the accumulator is connected to the high-pressure nitrogen cylinder group; The servo valve is used to control the active cylinder and the active and passive cylinders. The servo valve is connected to a hydraulic accumulator group. The accumulator is a piston accumulator, through which pressure is supplied to the C chamber of the active and passive oil cylinders. The trestle includes a base, a slewing mechanism, a trestle arm, a telescopic mechanism and a telescopic suspension ladder; An upper rotating body is provided on the rotating mechanism; The trestle arm is hinged to the upper rotating body at point O; the active oil cylinder is hinged to the upper rotating body at point A, and is hinged to the trestle arm at point B; the active and passive oil cylinders are hinged to the upper rotating body at point C, and are hinged to the trestle arm at point D, and the triangle OAB and the triangle OCD form a similar triangle; The active oil cylinder and the active and passive oil cylinders are arranged on the upper and lower sides of the central plane of the trestle arm, with the active oil cylinder being arranged on the upper side and the active and passive oil cylinders being arranged on the lower side; The chamber a of the active oil cylinder is connected to the chamber b of the active and passive oil cylinders via a bypass valve in the valve group; In active mode, the bypass valve is closed, and chamber a and chamber b are not connected; When the bypass valve is open, the active portion is ineffective and the system acts as a passive compensator; The oil in the C chamber of the active and passive oil cylinders and the piston accumulator can be charged, discharged and safely overflowed through the isolation valve group.

2. The active and passive motion compensation trestle luffing system for a trestle according to claim 1, characterized in that: The accumulator is provided with a displacement sensor for detecting the piston position of the accumulator.

3. The active and passive motion compensation trestle luffing system for a trestle according to claim 1, characterized in that: The upper part of the high-pressure nitrogen cylinder group is equipped with a safety valve and a discharge valve, and the lower part is equipped with a charging valve.

4. A trestle comprising the active and passive motion compensation trestle luffing system for a trestle as claimed in any one of claims 1 to 3, characterized in that: It also includes a base, a slewing mechanism, a trestle arm, a telescopic mechanism and a telescopic suspension ladder; The base is arranged on the mounting tower; The rotating mechanism is arranged on the base, and an upper rotating body is arranged on the rotating mechanism; The rear end of the trestle arm is connected to the upper rotating body; The active and passive motion compensation trestle luffing system is respectively connected to the upper slewing body and the trestle boom; The telescopic suspension ladder is arranged on the trestle arm, and is driven to move along the telescopic movement of the trestle arm by a telescopic mechanism.

5. The trestle according to claim 4, characterized in that: The base is arranged on the mounting tower through a traction mechanism.

6. The trestle according to claim 4, characterized in that: The trestle arm and the upper rotating body, the active and passive motion compensation trestle luffing system and the upper rotating body, and the active and passive motion compensation trestle luffing system and the trestle arm are all hinged.

7. The trestle according to claim 6, characterized in that: The active oil cylinder is arranged in parallel with the active and passive oil cylinders; The bottom of the active oil cylinder and the bottom of the active and passive oil cylinders are hinged to the upper rotating body, and the piston rod of the active oil cylinder and the piston rod of the active and passive oil cylinders are hinged to the lower part of the trestle arm.

8. The trestle according to claim 4, characterized in that: A lap joint mechanism is arranged on the front end portion of the telescopic suspension ladder.

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