Main bowden cable and method of manufacturing the same

Abstract

This invention provides a main chord tube and its manufacturing method, relating to the field of marine engineering equipment. The main chord tube provided by this invention includes a rack plate and a main body. The main body includes two tube bodies, which are symmetrically arranged on both sides of the rack plate. The interior of each tube body has a porous structure, which is connected to the inner wall of the tube body. The main chord tube of this invention can reduce the amount of steel used, reduce its own weight, and save construction costs.

Description

Technical Field

[0001] This invention relates to the field of marine engineering equipment, specifically to a main chord tube and its manufacturing method. Background Technology

[0002] The legs of self-elevating platforms can be divided into truss-type legs and cylindrical legs according to their structural form, with truss-type legs being the most commonly used type. Truss-type legs are mainly composed of welded main chord tubes, horizontal bracing tubes, and diagonal bracing tubes. The main chord tubes connect the horizontal bracing tubes and diagonal bracing tubes, making the connection between the legs more stable.

[0003] The existing main chord pipe has a circular arc structure with a certain thickness. It is usually die-cast using a large press, which is dependent on the mold device and consumes a lot of steel. The steel used for the main chord pipe is high-strength steel with a minimum yield strength of 690MPa. The price of this steel is around $3,000 per ton, making the construction cost relatively high. Summary of the Invention

[0004] Therefore, the technical problem to be solved by the present invention is the defect that the main chord tube consumes a lot of steel material and has a high construction cost in the prior art. The present invention provides a main chord tube and its manufacturing method that reduces the amount of steel material used, lightens its own weight, and saves construction costs.

[0005] To address the above problems, the present invention provides a main string tube, comprising:

[0006] rack and pinion;

[0007] The main body includes two tubes, which are symmetrically arranged on both sides of the rack plate. The interior of each tube has a porous structure, which is connected to the inner wall of the tube.

[0008] As a preferred technical solution for the main chord tube, the porous structure includes a plurality of staggered holes, the axial direction of which is perpendicular to the rack plate.

[0009] As a preferred technical solution for the main chord tube, all the holes have the same side length.

[0010] As a preferred technical solution for the main chord tube, the cross-sectional shape of the perforation perpendicular to the axial direction is hexagonal, triangular, or rectangular.

[0011] As a preferred technical solution for the main chord tube, all the holes have the same sidewall thickness, which is 2-4 mm.

[0012] A method for manufacturing a main chord pipe, wherein the main chord pipe is as described above, and the method for manufacturing the main chord pipe includes the following steps:

[0013] The outer dimensions of the rack plate of the main chord tube are determined, and the plate substrate is cut and polished according to the outer dimensions to produce the rack plate;

[0014] Using the rack plate as a substrate, additive manufacturing is performed by depositing layers on the rack plate using pulsed laser to form the main body of the main chord tube. 。

[0015] As a preferred technical solution for the manufacturing method of the main chord tube, the step of using the rack plate as a substrate and performing additive manufacturing by layer-by-layer deposition on the rack plate using pulsed laser to form the main body of the main chord tube includes a preheating stage. In the preheating stage, the substrate is preheated by a preheating device, and the heat preservation temperature of the preheating device is 150-230 degrees Celsius.

[0016] In the preferred technical solution of the manufacturing method of the main chord tube, in the step of using the rack plate as a substrate and performing additive manufacturing by depositing layers on the rack plate with pulsed laser to form the main body of the main chord tube, the deposition layer height is 2-4 mm and the width is 1.8-2.2 mm when using pulsed laser for layer-by-layer deposition.

[0017] In the preferred technical solution of the manufacturing method of the main chord tube, the step of using the rack plate as a substrate and performing additive manufacturing by depositing layers on the rack plate with pulsed laser to form the main body of the main chord tube adopts a single-layer multi-pass lap welding method with an lap rate of 50%-55%.

[0018] In a preferred embodiment of the manufacturing method of the main chord tube, in the step of using the rack plate as a substrate and performing additive manufacturing by depositing layers on the rack plate using pulsed laser to form the main body of the main chord tube, a protective device is provided around the main chord tube to isolate the main chord tube from oxygen.

[0019] The technical solution of this invention has the following advantages:

[0020] 1. The main chord tube provided by this invention includes a rack plate and a main body. The main body includes two tubes symmetrically arranged on both sides of the rack plate. The interior of each tube has a porous structure, which is connected to the inner wall of the tube. This invention, by incorporating a porous structure inside the tube, saves steel material, effectively reduces the wall thickness and overall weight of the main chord tube, saves construction costs, and simultaneously provides high compressive strength to meet usage requirements.

[0021] 2. The main chord tube provided by the present invention has a porous structure comprising a plurality of staggered holes, the axial direction of which is perpendicular to the rack plate. By setting a plurality of holes with the axial direction perpendicular to the rack plate, the supporting force on the main chord tube body is improved, and the compressive strength of the main chord tube is increased.

[0022] 3. The manufacturing method of the main chord tube provided by the present invention includes the following steps: determining the external dimensions of the rack plate of the main chord tube, and cutting and grinding the plate substrate according to the external dimensions to form the rack plate; using the rack plate as a substrate, performing additive manufacturing by layer-by-layer deposition on the rack plate using pulsed laser to form the main body of the main chord tube. By using pulsed laser to perform additive manufacturing of the main chord tube by layer-by-layer deposition on the rack plate, large molds are not required, reducing construction costs and improving molding efficiency. It also has advantages such as uniform texture, better mechanical properties, and no structural or material limitations. The main chord tube manufactured by additive manufacturing process can effectively reduce the wall thickness and overall weight, save construction costs, and has high compressive strength to meet usage requirements. Attached Figure Description

[0023] To more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the specific embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0024] Figure 1 This is a schematic diagram of the existing main chord tube structure;

[0025] Figure 2 This is a schematic diagram of the main chord tube of the present invention;

[0026] Figure 3 This is a perspective view of the main string tube of the present invention;

[0027] Figure 4 This is a schematic diagram of the porous structure of the main chord tube of the present invention. Figure 1 ;

[0028] Figure 5 This is a schematic diagram of the porous structure of the main chord tube of the present invention. Figure 2 ;

[0029] Figure 6 This is a schematic diagram of the porous structure of the main chord tube of the present invention. Figure 3 ;

[0030] Figure 7 This is a schematic diagram of the installation of the main chord tube of the present invention;

[0031] Figure 8 for Figure 7 Enlarged view of point A in the middle;

[0032] Figure 9 This is a flowchart of the manufacturing method of the main string tube of the present invention;

[0033] Figure 10 This is a frequency response curve of the main string tube of the present invention.

[0034] Explanation of reference numerals in the attached figures:

[0035] 1. Main chord tube; 101. Toothed plate; 102. Tube body; 103. Porous structure; 2. Pile leg; 201. Support tube. Detailed Implementation

[0036] The technical solution of the present invention will now be clearly and completely described with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0037] In the description of this invention, it should be noted that the terms "center," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing the invention and for simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on the invention. Furthermore, the terms "first," "second," and "third" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0038] In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0039] Furthermore, the technical features involved in the different embodiments of the present invention described below can be combined with each other as long as they do not conflict with each other.

[0040] This invention proposes a main chord tube for use in leg 2. Leg 2 is a truss-type leg, used in conjunction with a lifting device. The lifting device has a meshing structure, such as gears; leg 2 has teeth, so the lifting device can move up and down in the height direction of leg 2 through the meshing of the meshing structure and teeth. The truss-type leg is mainly composed of a main chord tube 1 and a support tube 201 welded together. The main chord tube 1 is connected to the support tube 201, so the end face where the main chord tube 1 and the support tube 201 are connected is squeezed by the support tube 201, which can easily damage the connection between the main chord tube 1 and the support tube 201, resulting in damage to leg 2. The towing variable load of a self-elevating platform is one of the core indicators determining the platform's performance, and reducing the weight of leg 2 is the most effective way to increase the towing variable load.

[0041] like Figure 1 As shown, the traditional main chord tube has a circular arc-shaped structure with a certain thickness. It is usually die-cast using a large press, which is dependent on mold equipment, consumes a lot of steel, has a high construction cost, and is heavy. It also has a low towing variable load, which affects the performance of the self-elevating platform.

[0042] like Figure 2-8 The diagram shows a preferred embodiment of the main chord tube of the present invention. The main chord tube 1 of this embodiment includes a rack plate 101 and a main body. The main body includes two tube bodies 102, which are symmetrically arranged on both sides of the rack plate 101. The interior of the tube body 102 is a porous structure 103, which is connected to the inner wall of the tube body 102.

[0043] The main chord tube provided by this invention does not require the use of large molds, which can reduce the amount of steel used, save construction costs, reduce its own weight, increase the variable load of towing, and thus improve the performance of the self-elevating platform.

[0044] The aforementioned main chord tube 1 has a porous structure 103 inside the tube body 102. This porous structure 103 can save steel material, effectively reduce the wall thickness and overall weight of the main chord tube 1, save construction costs, and at the same time has high compressive strength to meet the usage requirements.

[0045] In a preferred embodiment, the porous structure 103 includes a plurality of staggered holes, the axis of which is perpendicular to the rack plate 101. Specifically, as shown... Figure 2 and 3 As shown, the axes of several holes are parallel, and the axis of each hole is perpendicular to the rack plate 101. By setting several holes with their axes perpendicular to the rack plate 101, the supporting force on the tube body 102 of the main chord tube 1 is increased, thereby increasing the compressive strength of the main chord tube 1.

[0046] The rack plate 101 includes a connecting plate and at least two racks. The connecting plate is disposed between two tubes 102. The racks are arranged along the length of the tubes 102 and one end is connected to the connecting plate. The racks have a plurality of teeth that mesh with a meshing structure on the lifting device. Since the structure of the rack plate 101 is known to those skilled in the art, it will not be described in detail.

[0047] The materials of the tube body 102, the rack plate 101 and the porous structure 103 are all ASTM A517 Q or E690 or F690 (depending on the design temperature), with a yield strength of 690MPa, a tensile strength of 790-930MPa and a carbon equivalent of about 0.7%.

[0048] In a preferred embodiment, all the perforated cells have the same side length; the side length of the perforated cells is 40-45mm. In this embodiment, the side length of the perforated cells is 45mm. This structure allows for a more rational spatial arrangement of the porous structure 103, facilitates the calculation of the perforated cell area and the internal area of ​​the tube body 102, and the fact that all sides have the same length makes manufacturing easier and saves production costs.

[0049] In other embodiments, the side length of the lattice is any value in the range of 40mm, 41mm, 42mm, or 40-45mm.

[0050] In a preferred embodiment, the cross-sectional shape of the perforated grid perpendicular to the axial direction is hexagonal, triangular, or rectangular. For example... Figure 2 and 3 As shown, in this embodiment, the cross-sectional shape of the perforated grid perpendicular to the axial direction is a regular hexagon. This is because, when using polygons such as hexagons, triangles, or rectangles to enclose an area, the sum of all edges is the smallest, resulting in a regular hexagon. Furthermore, the regular hexagonal perforated grid is isotropic. Isotropicity refers to the characteristic that the physical, chemical, and other properties of an object do not change with different directions; that is, the performance values ​​of an object measured in different directions are exactly the same, also known as homogeneity. Due to these characteristics, the regular hexagonal porous structure 103 possesses excellent eccentric stiffness, thereby improving the supporting force on the tube body 102 and increasing the compressive strength of the main chord tube 1. In other embodiments, such as... Figure 5 and 6 The cross-sectional shape of the pores in the porous structure 103 can also be an equilateral triangle or a square.

[0051] Three porous structures 103, in shapes of regular hexagons, equilateral triangles, and squares, were modeled as a honeycomb structure in 3D software. All structures had the same thin-wall width and a uniform overall height of 20mm. The basic unit dimensions were then designed to share a common outer circle with a diameter of 15mm, within a uniform 50x50 area. Volume, mass, and other parameters were measured. The resulting hexagonal porous structure 103 had a mass of 0.105kg and a volume of 13437mm². 3The equilateral triangular porous structure 103 has a mass of 0.139 kg and a volume of 17689.086 mm². 3 The square porous structure 103 has a mass of 0.116 kg and a volume of 14742.874 mm². 3 From the above data, it can be concluded that within the same area, the volume and mass of a regular hexagon are the smallest. Therefore, it can be concluded that the porous structure of a regular hexagon is the most material-efficient and cost-effective.

[0052] In a preferred embodiment, all the holes have the same sidewall thickness, which is 2-4 mm. In this embodiment, the sidewall thickness of the holes is 2 mm.

[0053] In other embodiments, the sidewall thickness of the lattice is any value in the range of 2.5 mm, 3 mm, or 2-4 mm.

[0054] The following comparison of the mass and finite element static analysis of the main chord tube 1 in this embodiment with that of a traditional main chord tube will illustrate the performance of the main chord tube in this embodiment.

[0055] The quality of the main chord tube 1 in this embodiment is compared with that of a conventional main chord tube: For example... Figure 1 As shown, the traditional main chord pipe has a circular arc-shaped wall with a certain thickness, and bevels are set on both sides of the wall to achieve a certain degree of weight reduction. Through local modeling and quality assessment in 3D software, the traditional main chord pipe has a wall thickness of 67mm and a mass of 32.085kg; the porous structure 103 has a wall thickness of 8mm and a mass of 5.466kg, and a wall thickness of 8mm and a mass of 8.816kg. Therefore, the total mass of the main chord pipe 1 in this embodiment is 14.282kg. Compared with the traditional main chord pipe, the mass of the main chord pipe 1 in this embodiment is only half that of the traditional main chord pipe, which saves steel material, effectively reduces the wall thickness and overall mass of the main chord pipe 1, saves construction costs, and improves the compressive strength of the main chord pipe 1 to meet usage requirements.

[0056] This embodiment compares the static finite element analysis of the main chord tube 1 with that of a traditional main chord tube: A three-dimensional model of the selected research object is created using modeling software, generating a file format compatible with and importable from general finite element analysis software. Typically, modeling software can include CATIA, Pro / Engineer, etc., and the three-dimensional model file can be in STP format. The three-dimensional model is then imported into finite element analysis software (e.g., ANSYS, ABAQUS). Static load calculations are performed on the three-dimensional models of both the traditional main chord tube and the main chord tube 1 of this embodiment. Finite element meshes are generated, fixed constraints are added at the bottom, and the same pressure is applied at the top, yielding the strain, stress, and Y-direction displacement changes of both the traditional and the main chord tube 1 of this embodiment. These results are shown in Table 1 below.

[0057]

[0058] As shown in Table 1, under the same pressure, the strain, stress and Y-direction displacement of the main chord tube 1 in this embodiment are all smaller than those of the traditional main chord tube. That is, under the same external force, the deformation of the main chord tube 1 in this embodiment is small, the strength and stiffness are large, the toughness is good, the service life is long, the specific strength is higher, it is safer on a macroscopic scale, and it has a significant vibration reduction effect.

[0059] The vibration response (vibration velocity mm / s) of the top of the pile leg 2 under a simulated seismic load (100N along the +Y direction) was compared between the main chord tube 1 of this embodiment and a conventional main chord tube. The results are as follows: Figure 10 As shown.

[0060] According to numerical analysis and comparison, the main chord tube 1 with a porous structure 103 inside the tube body 102 of this embodiment eliminates the third vibration response peak (around 70Hz) of the traditional main chord tube, and has a significant vibration reduction effect.

[0061] The traditional manufacturing process for the main chord tube generally involves the following steps: cutting and grinding the rack plate 101; cutting the half-chord plate; hot-pressing the half-chord plate to form the half-chord tube; welding the half-chord plate to the rack plate 101; and extending the main chord tube. This process involves significant heat input and multiple thermal cycles. Especially during the hot processing of the half-chord tube, uncontrollable human intervention (cutting and welding) occurs, leading to localized microscopic changes in the material properties of the main chord tube components. This, in turn, results in complex strain and stress unevenness in the weld metal and heat-affected zone of the main chord tube material.

[0062] like Figure 9 As shown, this embodiment provides a method for manufacturing a main chord tube, wherein the main chord tube 1 is the aforementioned main chord tube 1, and the method for manufacturing the main chord tube 1 includes the following steps:

[0063] Step S01: Determine the external dimensions of the rack plate 101 of the main chord tube 1, and cut and grind the plate substrate according to the external dimensions to make the rack plate 101.

[0064] Specifically, the external dimensions of the rack plate 101 are determined based on the shape of the meshing structure of the lifting equipment. The thickness and width of the rack plate 101 are mainly determined based on the section modulus of the main chord tube 1 required for the strength analysis of the pile leg 2, while also taking into account the technical requirements of the lifting equipment. The width of the rack of the main chord tube 1 is determined based on the width of the steel plate (i.e., the plate substrate) used to cut the rack of the main chord tube 1. After the width of the rack plate 101 and the width of the rack are determined, the width of the connecting plate is obtained by subtracting the width of two racks from the width of the rack plate 101. The thickness of the connecting plate is determined by the required section modulus of the main chord tube 1. The rack plate 101 is pre-processed according to the above dimensional data. By setting two separate racks on both sides of the connecting plate, when cutting the racks on the steel plate used to cut the racks, they can be cut in pairs along the tooth profile in one go, effectively avoiding material waste.

[0065] In step S02, the rack plate 101 is used as a substrate, and additive manufacturing is performed by depositing layers on the rack plate 101 using a pulsed laser to form the main body of the main chord tube 1.

[0066] Specifically, the diameter and wall thickness of the semi-chord tube are mainly determined based on the section modulus of the main chord tube 1 required for the strength analysis of the pile leg 2. The diameter and wall thickness of the semi-chord tube are determined according to the required section modulus. After the diameter and wall thickness of the semi-chord tube are determined, the rack plate 101 is used as the substrate for subsequent additive manufacturing. Additive manufacturing is performed on the rack plate 101 by layer-by-layer deposition using a pulsed laser, employing a single-layer multi-pass lap welding method with an lap rate of 50%-55%. Welds with a weld leg size less than 8mm are typically completed using single-layer multi-pass welding (one layer, multiple welds). The electrode diameter is selected within the range of 3-5mm depending on the steel plate thickness. During welding, the rack plate 101 (as a substrate) is fixed on the machine tool, and the welding wire is fed to the laser head through the wire feeding mechanism. The wire feeding mechanism can feed welding wires with diameters of 1.0 mm and 1.2 mm. The robotic arm drives the robotic hand carrying the laser head to move along the path trajectory, and the laser is deposited layer by layer until the shape is completed. The height of a single laser deposition layer is about 2-4 mm and the width is about 1.8-2.2 mm. In this embodiment, a single-layer two-pass laser overlapping method is adopted. The height of a single laser deposition layer is 2 mm and the width is 2 mm, with an overlap rate of 50%.

[0067] When performing multi-pass cladding, the overlap rate is the ratio of the overlap width between adjacent cladding passes to the width of a single cladding layer. When the overlap rate is too small (less than 50%), a noticeable depression will appear between adjacent cladding passes, but the heights of the two cladding passes will be the same. When the overlap rate is moderate (50%-55%), the cladding effect is good, and the heights of the two cladding passes are the same. When the overlap rate is too large (greater than 55%), a bulge will appear in the overlap area, and the heights of the two cladding passes will be different. If the cladding continues, the defects will be further amplified, making it impossible to form a cladding layer.

[0068] After additive manufacturing is completed, the main chord tube 1 is extended. Specifically, in actual construction, depending on the site and equipment capabilities, the pile leg 2 is generally fabricated in segments ranging from 5 to 8 meters. For example... Figure 7 and 8 As shown, the main chord tube 1 connects various support tubes 201 together to form segments, and multiple segments are joined together to form the pile leg 2.

[0069] In other embodiments, the height of the laser single-pass deposition layer is any value within the range of 2.5 mm, 3 mm, or 2-4 mm, the width is any value within the range of 1.9 mm, 2.1 mm, or 1.8-2.2 mm, and the overlap rate is any value within the range of 51%, 52%, or 50%-55%.

[0070] In a preferred embodiment, a preheating stage is included, in which the substrate is preheated by a preheating device, and the holding temperature of the preheating device is 150-230 degrees Celsius. Specifically, during the additive molding process, the rack plate 101 needs to be preheated by placing heating elements at the bottom or around the rack plate 101 to heat it. In this embodiment, the holding temperature of the heating elements is 200 degrees Celsius.

[0071] In other embodiments, the heating element is kept at a temperature of 150 degrees Celsius, 230 degrees Celsius, or any value within the range of 150-230 degrees Celsius.

[0072] In a preferred embodiment, a protective device is provided around the main chord tube 1 to isolate it from oxygen. Specifically, the protective device includes a protective cover that encloses the entire welding area and the robotic arm. The protective cover has an inflation port. First, carbon dioxide is injected into the protective cover through the inflation port to purge the air. Then, a protective gas is injected. In this embodiment, the protective gas is argon. Argon is injected to purge the carbon dioxide. After the protective atmosphere is formed, oxidation can be prevented from occurring in the molten pool and within 100 mm of its horizontal surface, thus improving the additive manufacturing effect.

[0073] In other embodiments, protective gas can be directly delivered to the molten metal pool during welding via copper pipes.

[0074] The mechanical properties and grain size of the main chord tube 1 produced by the manufacturing method of this embodiment will be tested and compared with those produced by conventional manufacturing methods to illustrate the performance of the main chord tube produced by the manufacturing method of the main chord tube 1 of this embodiment.

[0075] Mechanical property testing:

[0076] Four samples of the main chord tubes produced by the conventional manufacturing method were taken: two longitudinal samples, designated T / 2 and T / 4 (denoted as L2 and L4 respectively); and two transverse samples, designated T / 2 and T / 4 (denoted as T2 and T4 respectively). Standard cylindrical specimens were used for tensile testing, with 20mm diameter clamping portions at both ends and 10mm diameter tensile portion in the middle, for a total length of 140mm, of which the tensile portion was no less than 50mm. The test results are shown in Table 2 below.

[0077]

[0078] Four samples of the main chord tube 1 produced by the main chord tube manufacturing method of this embodiment were taken and labeled as 1-1, 1-2, 1-3 and 1-4, respectively, for tensile testing. The test results are shown in Table 3 below.

[0079]

[0080]

[0081] As can be seen from the above mechanical property tests, in terms of tensile strength, yield strength and elongation after fracture, the mechanical properties of the main chord tube 1 produced by the main chord tube manufacturing method of this embodiment are better than those of the main chord tube produced by the conventional manufacturing method.

[0082] Grain size detection:

[0083] Three samples of main chord tubes produced by two different manufacturing methods were taken from each sample. Following GB / T 6394-2017 "Method for Determination of Average Grain Size of Metals", the test surfaces of the samples were ground and polished, then etched with an etchant solution to test the grain size. The grain size of the main chord tubes produced by the two manufacturing methods was measured, and the average value was taken. The test results are shown in Table 4 below.

[0084]

[0085] As demonstrated by the above grain size test, the grain size of the main chord tube 1 produced by the main chord tube manufacturing method of this embodiment is superior to that produced by the traditional manufacturing method. In summary, the main chord tube 1 produced by the main chord tube manufacturing method of this embodiment avoids the influence of human factors and manual operation. Through automated additive manufacturing using machine programming, the material's heat input is lower, the grain size is finer, stress distribution is more uniform, the process is controllable, and the design is feasible. This effectively reduces the tube wall thickness and overall weight, saves construction costs, and simultaneously provides high compressive strength, meeting usage requirements.

[0086] Obviously, the above embodiments are merely illustrative examples for clear explanation and are not intended to limit the implementation. Those skilled in the art will recognize that other variations or modifications can be made based on the above description. It is neither necessary nor possible to exhaustively list all possible implementations here. However, obvious variations or modifications derived therefrom are still within the scope of protection of this invention.

Claims

1. A main chord pipe, characterized in that, include: rack plate (101); The main body includes two tubes (102), which are symmetrically arranged on both sides of the rack plate (101). The interior of each tube (102) is a porous structure (103), which is connected to the inner wall of the tube (102). The porous structure (103) includes a plurality of staggered holes, the axial direction of which is perpendicular to the rack plate (101). Using a rack plate (101) as a substrate, additive manufacturing is performed by depositing layers on the rack plate (101) using a pulsed laser to form the main body of the main chord tube (1).

2. The main chord pipe according to claim 1, characterized in that, All the lattice cells have the same side length.

3. The main chord pipe according to claim 2, characterized in that, The cross-sectional shape of the perforated grid perpendicular to the axial direction is hexagonal, triangular, or rectangular.

4. The main chord pipe according to any one of claims 1-3, characterized in that, All the aforementioned lattice cells have the same sidewall thickness, which is 2-4 mm.

5. A method for manufacturing a main chord pipe, characterized in that, The main chord tube (1) is the main chord tube (1) according to any one of claims 1 to 4, and the manufacturing method of the main chord tube (1) includes the following steps: Determine the external dimensions of the rack plate (101) of the main chord tube (1), and cut and polish the plate substrate according to the external dimensions to make the rack plate (101). Using the rack plate (101) as a substrate, additive manufacturing is performed by depositing layers on the rack plate (101) using pulsed laser to form the main body of the main chord tube (1); The step of using the rack plate (101) as a substrate and performing additive manufacturing by depositing layers on the rack plate (101) with pulsed laser to form the main body of the main chord tube (1) includes a preheating stage. In the preheating stage, the substrate is preheated by a preheating device, and the heat preservation temperature of the preheating device is 150-230 degrees Celsius.

6. The method for manufacturing the main chord tube according to claim 5, characterized in that, In the step of using the rack plate (101) as a substrate and performing additive manufacturing by depositing layers on the rack plate (101) with pulsed laser to form the main body of the main chord tube (1), the deposition layer height is 2-4 mm and the width is 1.8-2.2 mm when using pulsed laser for layer-by-layer deposition.

7. The method for manufacturing the main chord tube according to claim 5, characterized in that, In the step of using the rack plate (101) as a substrate and using pulsed laser to deposit material layer by layer on the rack plate (101) to form the main body of the main chord tube (1), a single-layer multi-pass lap welding method is adopted, with an lap rate of 50%-55%.

8. The method for manufacturing the main chord tube according to any one of claims 5-7, characterized in that, In the step of using the rack plate (101) as a substrate and performing additive manufacturing by depositing layers on the rack plate (101) with pulsed laser to form the main body of the main chord tube (1), a protective device is provided around the main chord tube (1). The protective device is used to isolate the main chord tube (1) from oxygen.

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