LNG tank car loading and unloading arm and its driving mechanism size optimization method

Abstract

The application discloses a LNG tank truck loading and unloading arm and a size optimization method of a driving mechanism thereof. The loading and unloading arm comprises at least five joints, four hydraulic cylinder driving mechanisms and a hydraulic motor driving mechanism; the five joints comprise joint 1 to joint 5; wherein joint 1 to joint 4 are driven by the four hydraulic cylinder driving mechanisms respectively, and joint 5 is driven by the hydraulic motor driving mechanism. The distance from joint 5 to joint 1 to the flange at the end of the loading and unloading arm gradually increases, and the required driving torque of the joint gradually increases; the joint 5 is selected to be driven by a hydraulic motor so that the structure of the loading and unloading arm is compact, and the joints 4 to 1 are selected to be driven by hydraulic cylinders so as to increase the driving force arm and in turn increase the driving torque; the rotary joint of the joint 2 is supported on the upper and lower sides, the known cantilever beam structure is improved, and the bending moment burden of the second rotary joint is reduced; the hydraulic cylinder driving mechanism is a triangular driving mechanism, and by optimizing the size parameters of the triangular side length, the maximum force arm of the hydraulic cylinder can be obtained, and thus the required hydraulic cylinder driving force is minimized.

Description

Technical Field

[0001] This invention belongs to the technical field of fluid loading and unloading equipment, and in particular, a method for optimizing the dimensions of an LNG tank truck loading and unloading arm and its drive mechanism. Background Technology

[0002] LNG tanker loading booms are key specialized pieces of equipment connecting stationary storage tanks with mobile tankers for the safe and efficient transport of liquefied natural gas. A loading boom typically consists of multiple rotating joints and rigid pipes, driven by hydraulic cylinders, hydraulic motors, or electric motors. By controlling the rotation angle of each joint, the loading boom's end flange connects to the tanker's flange, thus completing the transport of liquefied natural gas.

[0003] Patent application number 202411010527.2 discloses a land-based LNG loading arm, where each joint is driven by a servo motor. Due to the small driving arm, the required motor driving torque is relatively large. Patent application number 202010925026.2 discloses a semi-automatic tank truck loading and unloading arm, where joints 1, 3, and 4 are driven by hydraulic cylinders. Due to the large vertical distance from the hydraulic cylinder to the joint axis, the lever arm is large, thus requiring a relatively small hydraulic cylinder driving force. However, joint 2 is driven by a hydraulic motor, which still suffers from the problem of a small driving arm. Furthermore, the aforementioned patent documents do not address the optimal dimensions of the driving mechanisms such as hydraulic cylinders. Summary of the Invention

[0004] The purpose of this invention is to address the shortcomings of the existing LNG tanker loading and unloading arms by providing an LNG tanker loading and unloading arm and a method for optimizing the dimensions of the LNG tanker loading and unloading arm drive mechanism.

[0005] The technical solution to achieve the purpose of this invention is as follows: On the one hand, an LNG tanker loading and unloading arm is provided, the loading and unloading arm includes at least five joints, four hydraulic cylinder drive mechanisms and one hydraulic motor drive mechanism; the five joints include joints 1 to 5; wherein joints 1 to 4 are driven by four hydraulic cylinder drive mechanisms respectively, and joint 5 is driven by a hydraulic motor drive mechanism.

[0006] Furthermore, the loading and unloading arm also includes a column, a tank interface, a boom, a forearm, a docking arm, a spring balancing mechanism, and five rotary joints; the four hydraulic cylinder drive mechanisms include a first hydraulic cylinder drive mechanism, a second hydraulic cylinder drive mechanism, a third hydraulic cylinder drive mechanism, and a fourth hydraulic cylinder drive mechanism; the five rotary joints include a first rotary joint, a second rotary joint, a third rotary joint, a fourth rotary joint, and a fifth rotary joint.

[0007] The tank interface is fixedly connected to one end of the first right-angle extended elbow. One side of the first right-angle extended elbow is fixedly connected to the column. The other end of the first right-angle extended elbow is rotatably connected to one end of the first right-angle support elbow via a first rotary joint. One end of the first right-angle support elbow is rotatably connected to the connecting plate on the column. The other end of the first right-angle support elbow is fixedly connected to one end of the boom. The other end of the boom is fixedly connected to one end of the second right-angle elbow. The other end of the second right-angle elbow is rotatably connected to one end of the second right-angle support elbow via a second rotary joint. The other end of the second right-angle support elbow is connected to one end of the third right-angle elbow via a third rotary joint. The second right-angle support elbow is rotatably connected to the support base. The support base is fixedly connected to the upper arm through the lower reinforcing rib of the upper arm. The other end of the third right-angle elbow is fixedly connected to one end of the forearm. The forearm achieves diameter change through a tapered tube. The other end of the forearm is fixedly connected to one end of the fourth right-angle elbow. The other end of the fourth right-angle elbow is rotatably connected to one end of the fifth right-angle extended elbow through the fourth rotary joint. The other end of the fifth right-angle extended elbow is rotatably connected to one end of the right-angle elbow adjusting arm through the fifth rotary joint. The other end of the right-angle elbow adjusting arm is fixedly connected to one end of the docking arm. The other end of the docking arm is fixedly connected to the tank car docking interface.

[0008] All four hydraulic cylinder drive mechanisms are triangular drive mechanisms;

[0009] One end of the first hydraulic cylinder drive mechanism is connected to the column, and the other end is connected to the boom;

[0010] One end of the second hydraulic cylinder drive mechanism is connected to the boom, and the other end is connected to the second rotary joint;

[0011] One end of the third hydraulic cylinder drive mechanism is connected to the forearm, and the other end is connected to the third rotary joint;

[0012] One end of the fourth hydraulic cylinder drive mechanism is connected to the forearm, and the other end is connected to the fourth rotary joint.

[0013] One end of the spring balancing mechanism is connected to the forearm, and the other end is connected to the third rotary joint.

[0014] Furthermore, one end of the first hydraulic cylinder drive mechanism is hinged to one end of the first hydraulic cylinder support column, the other end of the first hydraulic cylinder support column is fixedly connected to the column, and the other end of the first hydraulic cylinder drive mechanism is fixedly connected to the boom through the first hydraulic cylinder connecting plate.

[0015] One end of the second hydraulic cylinder drive mechanism is hinged to one end of the second hydraulic cylinder support column, the other end of the second hydraulic cylinder support column is connected to the boom, and the other end of the second hydraulic cylinder drive mechanism is connected to the second rotary joint through the second hydraulic cylinder connecting plate.

[0016] One end of the third hydraulic cylinder drive mechanism is hinged to one end of the third hydraulic cylinder support column, the other end of the third hydraulic cylinder support column is fixedly connected to the forearm, and the other end of the third hydraulic cylinder is fixedly connected to the third rotary joint through the third hydraulic cylinder connecting plate.

[0017] One end of the fourth hydraulic cylinder drive mechanism is hinged to one end of the fourth hydraulic cylinder support column, the other end of the fourth hydraulic cylinder support column is fixedly connected to the forearm, and the other end of the fourth hydraulic cylinder is fixedly connected to the fourth rotary joint through the fourth hydraulic cylinder connecting plate.

[0018] Furthermore, the other end of the first hydraulic cylinder drive mechanism is hinged to one end of the first hydraulic cylinder connecting plate, and the other end of the first hydraulic cylinder connecting plate is fixedly connected to the boom; the other end of the second hydraulic cylinder drive mechanism is hinged to one end of the second hydraulic cylinder connecting plate, and the other end of the second hydraulic cylinder connecting plate is connected to the second rotary joint; the other end of the third hydraulic cylinder is hinged to the third hydraulic cylinder connecting plate, and the other end of the third hydraulic cylinder connecting plate is fixedly connected to the third rotary joint; the other end of the fourth hydraulic cylinder is hinged to one end of the fourth hydraulic cylinder connecting plate, and the other end of the fourth hydraulic cylinder connecting plate is fixedly connected to the fourth rotary joint.

[0019] Furthermore, one end of the spring balancing mechanism is hinged to the third hydraulic cylinder support column, the other end of the third hydraulic cylinder support column is fixedly connected to the forearm, and the other end of the spring balancing mechanism is fixedly connected to the third rotary joint through the balancing spring cylinder connecting plate.

[0020] Furthermore, the other end of the balance spring cylinder is hinged to one end of the balance spring cylinder connecting plate, and the other end of the balance spring cylinder connecting plate is fixedly connected to the third rotary joint.

[0021] Furthermore, one side of the first right-angle extended elbow is fixedly connected to the column via a lower connecting plate.

[0022] In one embodiment, a method for optimizing the size of the drive mechanism of the LNG tanker loading / unloading boom is provided, the method comprising the following steps:

[0023] Step 1: Establish the coordinate system of the LNG tanker loading / unloading boom and determine the range of motion of each joint angle; the coordinate system includes the fixed coordinate system of the loading / unloading boom. and the coordinate systems of each joint , , , , ;

[0024] Step 2, determine the dimensional parameters of each joint drive mechanism; for a certain joint 2, this includes: the length of the corresponding hydraulic cylinder drive mechanism is... , The corresponding vertex is vertex Of the two sides, the shorter side is denoted as . The longer side is denoted as , coordinate axes of the joint The included angle is ;

[0025] Step 3: Determine the height of the triangle of the hydraulic cylinder drive mechanism. With drive mechanism size parameters , , The relationship between them;

[0026] Step 4: Optimize the dimensional parameters of the hydraulic cylinder drive mechanism based on the boundary conditions. The optimization objective is: The height of the triangle on the side The larger the value, the less the thrust required by the hydraulic cylinder under the same driving torque at the joint.

[0027] Furthermore, step 3 specifically includes:

[0028] According to the Law of Cosines:

[0029]

[0030] According to the formula for the area of ​​a triangle:

[0031]

[0032] Solving the two formulas above, and Then we have:

[0033] .

[0034] Furthermore, step 4 specifically includes:

[0035] (1) If , It is a fixed value, and , The dimensions to be optimized;

[0036] The system of equations is listed below:

[0037]

[0038] In the above system of equations, when given , After obtaining the specific values, solve them using numerical methods. , Specific values; included angle No impact , The value of is determined by the included angle. The loading and unloading arm's movement space does not interfere with the adaptive selection of appropriate values;

[0039] In the formula, , They are respectively The lower limit and the upper limit, , They are respectively The lower limit and the upper limit, , They are respectively The lower limit and the upper limit; , represents the range of angle variation of joint 2. , The rotation angles of joint 2 are respectively The lower limit and the upper limit;

[0040] (2) If , It is a fixed value, and , The dimensions to be optimized;

[0041] Under the premise of satisfying the following system of equations, it should be that As small as possible;

[0042]

[0043] (3) If upper limit and lower limit For fixed values, , The size parameters being optimized, and ;

[0044] In the system of equations (1) above, when given , After obtaining the specific values, solve them using numerical methods. , Specific values; included angle No impact , The value of is determined by the included angle. The loading and unloading arm's movement space does not interfere with the adaptive selection of appropriate values;

[0045] (4) If upper limit and lower limit For fixed values, , The size parameters being optimized, and ;

[0046] Solving the system of equations in (2) above, we get:

[0047]

[0048] (5) If upper limit and lower limit , All are fixed values. The dimensions to be optimized;

[0049] Solving the system of equations in (1) above, we get:

[0050]

[0051] In the formula, , There are two solutions; we choose the correct one. If both solutions are positive, the larger positive solution is selected. If the larger positive solution is difficult to implement in actual installation, the smaller positive solution is selected.

[0052] Compared with the prior art, the significant advantages of this invention are:

[0053] (1) The distance from joint 5 to joint 1 to the end flange of the loading and unloading arm gradually increases, and the required driving torque of the joint gradually increases. Joint 5 is driven by a hydraulic motor to make the loading and unloading arm structure compact. Joint 4 to joint 1 is driven by a hydraulic cylinder to increase the driving arm and thus increase the driving torque.

[0054] (2) The rotary joint of joint 2 is supported at both the top and bottom, which can improve the known cantilever beam structure and thus reduce the bending moment load of the second rotary joint.

[0055] (3) The hydraulic cylinder drive mechanism is a triangular drive mechanism. By optimizing the side length parameters of the triangle, the lever arm of the hydraulic cylinder can be maximized, thereby minimizing the required hydraulic cylinder drive force.

[0056] The present invention will now be described in further detail with reference to the accompanying drawings. Attached Figure Description

[0057] Figure 1 This is a schematic diagram (axiom view) of the overall structure of the loading and unloading arm of the present invention in one embodiment.

[0058] Figure 2 This is a schematic diagram (top view) of the overall structure of the loading and unloading arm in one embodiment.

[0059] Figure 3 This is the coordinate system of the LNG tanker loading / unloading arm in one embodiment.

[0060] Figure 4 This is a schematic diagram of the dimensional parameters of the loading arm joint 1 drive mechanism in one embodiment.

[0061] Figure 5 This is a schematic diagram of the dimensional parameters of the loading arm joint 2 drive mechanism in one embodiment.

[0062] Figure 6 This is a schematic diagram of the dimensional parameters of the loading arm joint 3 drive mechanism in one embodiment.

[0063] Figure 7 This is a schematic diagram of the dimensional parameters of the loading arm joint 4 drive mechanism in one embodiment.

[0064] The following labels are marked on the image:

[0065] 1. Column, 2. Lower connecting plate of column, 3. Tank interface, 4. First right-angle extended elbow, 5. First rotary joint, 6. First right-angle support elbow, 7. Upper connecting plate of column, 8. Upper reinforcing rib of boom, 9. First hydraulic cylinder support column, 10. First hydraulic cylinder, 11. Second hydraulic cylinder support column, 12. Boom, 13. Second right-angle elbow, 14. Second rotary joint, 15. Balance spring cylinder, 16. Forearm, 17. Fourth hydraulic cylinder support column, 18. Fourth hydraulic cylinder, 19. Fourth right-angle elbow, 20. Fourth rotary joint, 21. Hydraulic motor, 22. Straight 23. Angle elbow adjusting arm, 24. Docking arm, 25. Gear, 26. Fifth rotary joint, 27. Tank car docking interface, 28. Fifth right-angle extended elbow, 29. Fourth hydraulic cylinder connecting plate, 30. Tapered pipe, 31. Third hydraulic cylinder support column, 32. Third hydraulic cylinder, 33. Third rotary joint, 34. Third hydraulic cylinder connecting plate, 35. Second right-angle support elbow, 36. Support base, 37. Balance spring cylinder connecting plate, 38. Second hydraulic cylinder connecting plate, 39. Third right-angle elbow, 40. Second hydraulic cylinder, 41. First hydraulic cylinder connecting plate, 42. Lower reinforcing rib of the boom. Detailed Implementation

[0066] To make the objectives, technical solutions, and advantages of this application clearer, the following detailed description is provided in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the scope of this application.

[0067] It should be noted that if the embodiments of the present invention involve directional indicators (such as up, down, left, right, front, back, etc.), the directional indicators are only used to explain the relative positional relationship and movement of the components in a certain specific posture (as shown in the figure). If the specific posture changes, the directional indicators will also change accordingly.

[0068] Furthermore, if the embodiments of this invention involve descriptions such as "first" or "second," these descriptions are for descriptive purposes only and should not be construed as indicating or implying their relative importance or implicitly specifying the number of technical features indicated. Therefore, a feature defined with "first" or "second" may explicitly or implicitly include at least one of those features. Additionally, the technical solutions of the various embodiments can be combined with each other, but this must be based on the ability of those skilled in the art to implement them. If the combination of technical solutions is contradictory or impossible to implement, it should be considered that such a combination of technical solutions does not exist and is not within the scope of protection claimed by this invention.

[0069] In one embodiment, combined Figure 1 and Figure 2 An LNG tanker loading arm is provided, the loading arm including at least five joints, four hydraulic cylinder drive mechanisms and one hydraulic motor drive mechanism 21; the five joints include joints 1 to 5; wherein joints 1 to 4 are driven by four hydraulic cylinder drive mechanisms respectively, and joint 5 is driven by a hydraulic motor drive mechanism.

[0070] Furthermore, in one embodiment, the loading and unloading arm further includes a column 1, a tank interface 3, a boom 12, a forearm 16, a docking arm 23, a spring balancing mechanism 15, and five rotary joints; the four hydraulic cylinder drive mechanisms include a first hydraulic cylinder drive mechanism 10, a second hydraulic cylinder drive mechanism 18, a third hydraulic cylinder drive mechanism 31, and a fourth hydraulic cylinder drive mechanism 38; the five rotary joints include a first rotary joint 5, a second rotary joint 14, a third rotary joint 32, a fourth rotary joint 20, and a fifth rotary joint 25.

[0071] The storage tank interface 3 is fixedly connected to one end of the first right-angle extended elbow 4. One side of the first right-angle extended elbow 4 is fixedly connected to the column 1. The other end of the first right-angle extended elbow 4 is rotatably connected to one end of the first right-angle support elbow 6 through the first rotary joint 5. One end of the first right-angle support elbow 6 is rotatably connected to the column connecting plate 7 on the column 1. The other end of the first right-angle support elbow 6 is fixedly connected to one end of the boom 12. The other end of the boom 12 is fixedly connected to one end of the second right-angle elbow 13. The other end of the second right-angle elbow 13 is rotatably connected to one end of the second right-angle support elbow 34 through the second rotary joint 14. The other end of the second right-angle support elbow 34 is rotatably connected to one end of the third right-angle elbow 38 through the third rotary joint 32. The supporting part of the second right-angle support elbow 34 is rotatably connected to the support base 35. The support base 35 is fixedly connected to the upper arm 12 through the lower reinforcing rib 41 of the upper arm. The other end of the third right-angle elbow 38 is fixedly connected to one end of the lower arm 16. The lower arm 16 achieves diameter change through the tapered tube 29. The other end of the lower arm 16 is fixedly connected to one end of the fourth right-angle elbow 19. The other end of the fourth right-angle elbow 19 is rotatably connected to one end of the fifth right-angle extended elbow 27 through the fourth rotary joint 20. The other end of the fifth right-angle extended elbow 27 is rotatably connected to one end of the right-angle elbow adjusting arm 22 through the fifth rotary joint 25. The other end of the right-angle elbow adjusting arm 22 is fixedly connected to one end of the docking arm 23. The other end of the docking arm 23 is fixedly connected to the tank car docking interface 26.

[0072] All four hydraulic cylinder drive mechanisms are triangular drive mechanisms;

[0073] One end of the first hydraulic cylinder drive mechanism 10 is connected to the column 1, and the other end is connected to the boom 12;

[0074] One end of the second hydraulic cylinder drive mechanism 39 is connected to the boom 12, and the other end is connected to the second rotary joint 14;

[0075] One end of the third hydraulic cylinder drive mechanism 31 is connected to the forearm 16, and the other end is connected to the third rotary joint 32;

[0076] One end of the fourth hydraulic cylinder drive mechanism 18 is connected to the forearm 16, and the other end is connected to the fourth rotary joint 20;

[0077] One end of the spring balancing mechanism 15 is connected to the forearm 16, and the other end is connected to the third rotary joint 32.

[0078] Preferably, in some embodiments, one end of the first hydraulic cylinder drive mechanism 10 is hinged to one end of the first hydraulic cylinder support column 9, the other end of the first hydraulic cylinder support column 9 is fixedly connected to the column 1, and the other end of the first hydraulic cylinder drive mechanism 10 is fixedly connected to the boom 12 through the first hydraulic cylinder connecting plate 40.

[0079] One end of the second hydraulic cylinder drive mechanism 39 is hinged to one end of the second hydraulic cylinder support column 11, the other end of the second hydraulic cylinder support column 11 is connected to the boom 12, and the other end of the second hydraulic cylinder drive mechanism 39 is connected to the second rotary joint 14 through the second hydraulic cylinder connecting plate 37.

[0080] One end of the third hydraulic cylinder drive mechanism 31 is hinged to one end of the third hydraulic cylinder support column 30, the other end of the third hydraulic cylinder support column 30 is fixedly connected to the forearm 16, and the other end of the third hydraulic cylinder 31 is fixedly connected to the third rotary joint 32 through the third hydraulic cylinder connecting plate 33.

[0081] One end of the fourth hydraulic cylinder drive mechanism 18 is hinged to one end of the fourth hydraulic cylinder support column 17, the other end of the fourth hydraulic cylinder support column 17 is fixedly connected to the forearm 16, and the other end of the fourth hydraulic cylinder 18 is fixedly connected to the fourth rotary joint 20 through the fourth hydraulic cylinder connecting plate 28.

[0082] Preferably, in some embodiments, the other end of the first hydraulic cylinder drive mechanism 10 is hinged to one end of the first hydraulic cylinder connecting plate 40, and the other end of the first hydraulic cylinder connecting plate 40 is fixedly connected to the boom 12; the other end of the second hydraulic cylinder drive mechanism 39 is hinged to one end of the second hydraulic cylinder connecting plate 37, and the other end of the second hydraulic cylinder connecting plate 37 is connected to the second rotary joint 14; the other end of the third hydraulic cylinder 31 is hinged to the third hydraulic cylinder connecting plate 33, and the other end of the third hydraulic cylinder connecting plate 33 is fixedly connected to the third rotary joint 32; the other end of the fourth hydraulic cylinder 18 is hinged to one end of the fourth hydraulic cylinder connecting plate 28, and the other end of the fourth hydraulic cylinder connecting plate 28 is fixedly connected to the fourth rotary joint 20.

[0083] Preferably, in some embodiments, the spring balancing mechanism 15 is hinged to one end of the third hydraulic cylinder support column 30, the other end of the third hydraulic cylinder support column 30 is fixedly connected to the forearm 16, and the other end of the spring balancing mechanism 15 is fixedly connected to the third rotary joint 32 through the balance spring cylinder connecting plate 36.

[0084] Preferably, in some embodiments, the other end of the balance spring cylinder 15 is hinged to one end of the balance spring cylinder connecting plate 36, and the other end of the balance spring cylinder connecting plate 36 is fixedly connected to the third rotary joint 32.

[0085] Preferably, in some embodiments, one side of the first right-angle extended elbow 4 is fixedly connected to the column 1 via the column lower connecting plate 2.

[0086] In one embodiment, a method for optimizing the size of the drive mechanism of the LNG tanker loading / unloading boom is provided, the method comprising the following steps:

[0087] Step 1: Establish the coordinate system of the LNG tanker loading / unloading boom and determine the range of motion of each joint angle; for example... Figure 3 As shown, establish a fixed coordinate system for the loading and unloading arm. and the coordinate systems of each joint , , , , Based on the coordinate system, establish the loading and unloading arm DH parameter table, as shown in Table 1.

[0088] Table 1 Parameter Table of Loading and Unloading Arm DH of the Invention

[0089]

[0090] In Table 1, , , , , , The DH parameter of the loading / unloading boom is determined by the boom's structural form and dimensions, and is a constant. , , , , Let be the rotation angle of each joint, which is a variable. The range of variation for each joint angle is as follows: , , , , ,in yes The upper limit, yes The lower limit.

[0091] Step 2: Determine the dimensional parameters of each joint drive mechanism; this invention optimizes the dimensional parameters of the drive mechanisms for joints 1 to 4; the dimensional parameters of the drive mechanisms for joints 1 to 4 are as follows: Figures 4 to 7 As shown;

[0092] Let's take joint 2 as an example. The length of the hydraulic cylinder drive mechanism corresponding to joint 2 is... , The corresponding vertex is vertex Of the two sides, the shorter side is denoted as . The longer side is denoted as , coordinate axes of the joint The included angle is ;

[0093] Step 3: Determine the height of the triangle of the hydraulic cylinder drive mechanism. With drive mechanism size parameters , , The relationship between them;

[0094] Step 4: Optimize the dimensional parameters of the hydraulic cylinder drive mechanism based on the boundary conditions. The optimization objective is: The height of the triangle on the side The larger the value, the less the thrust required by the hydraulic cylinder under the same driving torque at the joint.

[0095] Furthermore, in one embodiment, step 3 specifically includes:

[0096] According to the Law of Cosines, we have...

[0097] (1)

[0098] According to the formula for the area of ​​a triangle, we have...

[0099] (2)

[0100] Solving equations (1) and (2) simultaneously, and Then there is

[0101] (3)

[0102] Furthermore, in one embodiment, step 4 specifically includes:

[0103] (1) If , It is a fixed value, and , For the optimized size parameters

[0104] (4)

[0105] Pick ,but Solving this equation yields .

[0106] And because ,so, exist Monotonically increasing, in Monotonically decreasing above, in The maximum value is obtained at the location. .

[0107] Considering It is a transformation quantity, and its lower limit is The upper limit is To ensure that superior, If the minimum value reaches the maximum, then set exist value at ,equal, exist value at Based on this, the system of equations is listed below.

[0108] (5)

[0109] In system of equations (5), there are six equations and six unknowns. The number of equations is equal to the number of unknowns. , Once the specific values ​​are obtained, they can be solved using numerical methods. , The specific value. The included angle in joint 2. No impact , The value of can be determined based on the included angle. The movement space of the loading and unloading arm should not interfere with each other; choose appropriate values.

[0110] (2) If , It is a fixed value, and , These are the dimensional parameters to be optimized.

[0111] Then formula (3) can be transformed into:

[0112] (6)

[0113] At this point, we have:

[0114] (7)

[0115] because ,so Always negative, exist The upper bound is monotonically decreasing. Therefore, under the premise of satisfying the system of equations (8), it should be made that... As small as possible.

[0116] (8)

[0117] (3) If upper limit and lower limit For fixed values, , The size parameters being optimized, and

[0118] In system of equations (5), there are six equations and six unknowns. The number of equations is equal to the number of unknowns. , Once the specific values ​​are obtained, they can be solved using numerical methods. , The specific value. The included angle in joint 2. No impact , The value of can be determined based on the included angle. The movement space of the loading and unloading arm should not interfere with each other; choose appropriate values.

[0119] (4) If upper limit and lower limit For fixed values, , The size parameters being optimized, and

[0120] In this case, solving the system of equations (9) yields:

[0121] (9)

[0122] (5) If upper limit and lower limit , All are fixed values. For the optimized size parameters

[0123] Solving the system of equations (5) yields:

[0124] (10)

[0125] In the formula, , There are two solutions; we choose the correct one. If both solutions are positive, the larger positive solution is selected. If the larger positive solution is difficult to implement in actual installation, the smaller positive solution is selected.

[0126] The foregoing has shown and described the basic principles, main features, and advantages of the present invention. Those skilled in the art should understand that the present invention is not limited to the above embodiments. The embodiments and descriptions in the specification are merely illustrative of the principles of the invention. Any modifications, equivalent substitutions, or improvements made within the spirit and principles of the present invention without departing from its spirit and scope should be included within the protection scope of the present invention.

Claims

1. An LNG tanker loading / unloading boom, characterized in that, The loading and unloading arm includes at least five joints, four hydraulic cylinder drive mechanisms and one hydraulic motor drive mechanism (21); the five joints include joints 1 to 5; wherein joints 1 to 4 are driven by four hydraulic cylinder drive mechanisms respectively, and joint 5 is driven by a hydraulic motor drive mechanism.

2. The LNG tanker loading / unloading boom according to claim 1, characterized in that, The loading and unloading arm also includes a column (1), a tank interface (3), a boom (12), a forearm (16), a docking arm (23), a spring balancing mechanism (15), and five rotary joints; the four hydraulic cylinder drive mechanisms include a first hydraulic cylinder drive mechanism (10), a second hydraulic cylinder drive mechanism (18), a third hydraulic cylinder drive mechanism (31), and a fourth hydraulic cylinder drive mechanism (38); the five rotary joints include a first rotary joint (5), a second rotary joint (14), a third rotary joint (32), a fourth rotary joint (20), and a fifth rotary joint (25); The tank interface (3) is fixedly connected to one end of the first right-angle extended elbow (4). One side of the first right-angle extended elbow (4) is fixedly connected to the column (1). The other end of the first right-angle extended elbow (4) is rotatably connected to one end of the first right-angle support elbow (6) through the first rotary joint (5). One end of the first right-angle support elbow (6) is rotatably connected to the column connecting plate (7) on the column (1). The other end of the first right-angle support elbow (6) is fixedly connected to one end of the boom (12). The other end of the boom (12) is fixedly connected to one end of the second right-angle elbow (13). The other end of the second right-angle elbow (13) is rotatably connected to one end of the second right-angle support elbow (34) through the second rotary joint (14). The other end of the second right-angle support elbow (34) is rotatably connected to one end of the third right-angle elbow (38) through the third rotary joint (32). The support part of the right-angle support elbow (34) is rotatably connected to the support base (35). The support base (35) is fixedly connected to the upper arm (12) through the lower reinforcing rib (41) of the upper arm. The other end of the third right-angle elbow (38) is fixedly connected to one end of the lower arm (16). The lower arm (16) achieves diameter change through the tapered tube (29). The other end of the lower arm (16) is fixedly connected to one end of the fourth right-angle elbow (19). The other end of the fourth right-angle elbow (19) is rotatably connected to one end of the fifth right-angle extended elbow (27) through the fourth rotary joint (20). The other end of the fifth right-angle extended elbow (27) is rotatably connected to one end of the right-angle elbow adjusting arm (22) through the fifth rotary joint (25). The other end of the right-angle elbow adjusting arm (22) is fixedly connected to one end of the docking arm (23). The other end of the docking arm (23) is fixedly connected to the tank car docking interface (26). All four hydraulic cylinder drive mechanisms are triangular drive mechanisms; One end of the first hydraulic cylinder drive mechanism (10) is connected to the column (1), and the other end is connected to the boom (12). One end of the second hydraulic cylinder drive mechanism (39) is connected to the boom (12), and the other end is connected to the second rotary joint (14). One end of the third hydraulic cylinder drive mechanism (31) is connected to the forearm (16), and the other end is connected to the third rotary joint (32). One end of the fourth hydraulic cylinder drive mechanism (18) is connected to the forearm (16), and the other end is connected to the fourth rotary joint (20). One end of the spring balancing mechanism (15) is connected to the forearm (16), and the other end is connected to the third rotary joint (32).

3. The LNG tanker loading / unloading boom according to claim 2, characterized in that, One end of the first hydraulic cylinder drive mechanism (10) is hinged to one end of the first hydraulic cylinder support column (9), the other end of the first hydraulic cylinder support column (9) is fixedly connected to the column (1), and the other end of the first hydraulic cylinder drive mechanism (10) is fixedly connected to the boom (12) through the first hydraulic cylinder connecting plate (40). One end of the second hydraulic cylinder drive mechanism (39) is hinged to one end of the second hydraulic cylinder support column (11), the other end of the second hydraulic cylinder support column (11) is connected to the boom (12), and the other end of the second hydraulic cylinder drive mechanism (39) is connected to the second rotary joint (14) through the second hydraulic cylinder connecting plate (37). One end of the third hydraulic cylinder drive mechanism (31) is hinged to one end of the third hydraulic cylinder support column (30), the other end of the third hydraulic cylinder support column (30) is fixedly connected to the forearm (16), and the other end of the third hydraulic cylinder (31) is fixedly connected to the third rotary joint (32) through the third hydraulic cylinder connecting plate (33). One end of the fourth hydraulic cylinder drive mechanism (18) is hinged to one end of the fourth hydraulic cylinder support column (17), the other end of the fourth hydraulic cylinder support column (17) is fixedly connected to the forearm (16), and the other end of the fourth hydraulic cylinder (18) is fixedly connected to the fourth rotary joint (20) through the fourth hydraulic cylinder connecting plate (28).

4. The LNG tanker loading / unloading boom according to claim 3, characterized in that, The other end of the first hydraulic cylinder drive mechanism (10) is hinged to one end of the first hydraulic cylinder connecting plate (40), and the other end of the first hydraulic cylinder connecting plate (40) is fixedly connected to the boom (12); the other end of the second hydraulic cylinder drive mechanism (39) is hinged to one end of the second hydraulic cylinder connecting plate (37), and the other end of the second hydraulic cylinder connecting plate (37) is connected to the second rotary joint (14); the other end of the third hydraulic cylinder (31) is hinged to the third hydraulic cylinder connecting plate (33), and the other end of the third hydraulic cylinder connecting plate (33) is fixedly connected to the third rotary joint (32); the other end of the fourth hydraulic cylinder (18) is hinged to one end of the fourth hydraulic cylinder connecting plate (28), and the other end of the fourth hydraulic cylinder connecting plate (28) is fixedly connected to the fourth rotary joint (20).

5. The LNG tanker loading / unloading boom according to claim 2, characterized in that, The spring balancing mechanism (15) is hinged to one end of the third hydraulic cylinder support column (30), and the other end of the third hydraulic cylinder support column (30) is fixedly connected to the forearm (16). The other end of the spring balancing mechanism (15) is fixedly connected to the third rotary joint (32) through the balance spring cylinder connecting plate (36).

6. The LNG tanker loading / unloading boom according to claim 5, characterized in that, The other end of the balance spring cylinder (15) is hinged to one end of the balance spring cylinder connecting plate (36), and the other end of the balance spring cylinder connecting plate (36) is fixedly connected to the third rotary joint (32).

7. The LNG tanker loading / unloading boom according to claim 2, characterized in that, One side of the first right-angle extended elbow (4) is fixedly connected to the column (1) through the lower connecting plate (2) of the column.

8. A method for optimizing the dimensions of the drive mechanism of the LNG tanker loading / unloading boom according to any one of claims 1 to 7, characterized in that, The method includes the following steps: Step 1: Establish the coordinate system of the LNG tanker loading / unloading boom and determine the range of motion of each joint angle; the coordinate system includes the fixed coordinate system of the loading / unloading boom. and the coordinate systems of each joint , , , , ; Step 2, determine the dimensional parameters of each joint drive mechanism; for a certain joint 2, this includes: the length of the corresponding hydraulic cylinder drive mechanism is... , The corresponding vertex is vertex Of the two sides, the shorter side is denoted as . The longer side is denoted as , coordinate axes of the joint The included angle is ; Step 3: Determine the height of the triangle of the hydraulic cylinder drive mechanism. With drive mechanism size parameters , , The relationship between them; Step 4: Optimize the dimensional parameters of the hydraulic cylinder drive mechanism based on the boundary conditions. The optimization objective is: The height of the triangle on the side The larger the value, the less the thrust required by the hydraulic cylinder under the same driving torque at the joint.

9. The method for optimizing the size of the drive mechanism according to claim 8, characterized in that, Step 3 specifically includes: According to the Law of Cosines: According to the formula for the area of ​​a triangle: Solving the two formulas above, and Then we have: 。 10. The method for optimizing the size of the drive mechanism according to claim 9, characterized in that, Step 4 specifically includes: (1) If , It is a fixed value, and , The dimensions to be optimized; The system of equations is listed below: In the above system of equations, when given , After obtaining the specific values, solve them using numerical methods. , Specific values; included angle No impact , The value of is determined by the included angle. The loading and unloading arm's movement space does not interfere with the adaptive selection of appropriate values; In the formula, , They are respectively The lower limit and the upper limit, , They are respectively The lower limit and the upper limit, , They are respectively The lower limit and the upper limit; , represents the range of angle variation of joint 2. , The rotation angles of joint 2 are respectively The lower limit and the upper limit; (2) If , It is a fixed value, and , The dimensions to be optimized; Under the premise of satisfying the following system of equations, it should be that As small as possible; (3) If upper limit and lower limit For fixed values, , The size parameters being optimized, and ; In the system of equations (1) above, when given , After obtaining the specific values, solve them using numerical methods. , Specific values; included angle No impact , The value of is determined by the included angle. The loading and unloading arm's movement space does not interfere with the adaptive selection of appropriate values; (4) If upper limit and lower limit For fixed values, , The size parameters being optimized, and ; Solving the system of equations in (2) above, we get: (5) If upper limit and lower limit , All are fixed values. The dimensions to be optimized; Solving the system of equations in (1) above, we get: In the formula, , There are two solutions; we choose the correct one. If both solutions are positive, the larger positive solution is selected. If the larger positive solution is difficult to implement in actual installation, the smaller positive solution is selected.

Images