Hollow bolt ball, grid node and manufacturing and using method

Abstract

The application discloses a hollow bolt ball, a net rack node and a manufacturing and using method, which comprises a first layer hollow ball, a second layer hollow ball, a third layer hollow ball and a net rack node connector, the first layer hollow ball is located outside the second layer hollow ball, the second layer hollow ball is located outside the third layer hollow ball, the third layer hollow ball is internally provided with an inner rib plate, the first layer hollow ball and the second layer hollow ball are provided with through holes at the same position, the first layer hollow ball, the second layer hollow ball and the third layer hollow ball are provided with bolt holes and process holes at the same position, and the net rack node connector is fixedly connected with the three layer hollow balls. The combination of the three layer hollow balls and the inner rib plate overcomes the problems of large deformation of the hollow bolt ball, insufficient bolt anchoring length and insufficient bearing capacity, meanwhile, the net rack node is simple in structure, convenient to manufacture, small in welding quantity on site, capable of being repeatedly used and low in cost.

Description

Technical Field

[0001] This invention belongs to the field of building steel structures, specifically relating to hollow bolt balls, space frame nodes, and their manufacturing and usage methods. Background Technology

[0002] Steel space frame structures are widely used in engineering due to their advantages such as high integrity, high stiffness, and excellent seismic performance. Connection nodes are key factors determining the mechanical properties of steel space frame structures; common connection node types include welded hollow sphere space frame nodes and solid bolted sphere space frame nodes.

[0003] In existing welded hollow sphere connection joints, the steel pipe is welded to the hollow sphere. In these joints, excessive welding leads to excessive residual stress in the hollow sphere. To facilitate on-site welding, the hollow sphere is generally large. Furthermore, this connection joint is unsuitable for high-altitude assembly; it is often welded on the ground and then hoisted into the air, making it difficult to guarantee the connection's precision. Once the structure is damaged, this connection joint is difficult to reuse, resulting in significant economic losses. In existing solid bolted sphere connection joints, high-strength bolts are used to connect the solid bolted sphere and the rod. The bolt head is located inside the rod, and the bolt extends from the end of the rod and is inserted into the solid bolted sphere for rotational fixing. In this connection joint, the solid bolted sphere forging process is complex, and sphere forming is difficult. Additionally, this connection joint requires high precision.

[0004] To address these issues, hollow bolt spheres were developed. However, hollow bolt spheres may suffer from problems such as excessive sphere deformation, insufficient anchorage length, and insufficient load-bearing capacity. These issues will hinder the further promotion and application of steel space frame structures. Summary of the Invention

[0005] To overcome the problems of large deformation of hollow bolted spheres and insufficient bolt anchorage length and bearing capacity, and to optimize the structural form of space frame nodes, this invention proposes a hollow bolted sphere and a hollow bolted sphere space frame node, which has the advantages of simple structure, convenient manufacturing, small amount of on-site welding, and multiple reuses.

[0006] To achieve the above objectives, the present invention provides a hollow bolted sphere and a hollow bolted sphere space frame node. The hollow bolted sphere includes a shell, which comprises a first layer of hollow spheres, a second layer of hollow spheres, and a third layer of hollow spheres. Each of the first, second, and third hollow spheres is formed by splicing two hemispheres. The first layer of hollow spheres is located outside the second layer of hollow spheres, and the second layer of hollow spheres is located outside the third layer of hollow spheres. An inner rib is provided on the inner side of the third layer of hollow spheres. Through holes are provided in the first and second layers of hollow spheres at the same position. Through bolt holes and process holes are provided in the first, second, and third layers of hollow spheres at the same position. There are multiple bolt holes, at least two of which have different diameters. A pre-set connector is installed in the process hole.

[0007] The hollow bolt ball space frame node includes a hollow bolt ball and a space frame node connector. The hollow bolt ball is fastened to the space frame node connector. The space frame node connector includes a high-strength bolt, a sleeve, a fastening screw, and a rod. The sleeve is disposed between the first layer of hollow balls and the rod. A first limiting hole is radially formed on the side wall of the sleeve. A second limiting hole is formed at a corresponding position on the high-strength bolt. Fastening screws are installed in the first and second limiting holes. The high-strength bolt is gap-connected to the sleeve. A rod pre-drilled hole is formed on the side of the rod near the sleeve, and the high-strength bolt is inserted into the rod pre-drilled hole.

[0008] Furthermore, the distance between the inner surface of the first hollow sphere and the outer surface of the second hollow sphere does not exceed 2 mm, and the distance between the inner surface of the second hollow sphere and the outer surface of the third hollow sphere does not exceed 2 mm.

[0009] Furthermore, the diameter of the through holes in the first layer of hollow spheres is 1.5 times the thickness of the first layer of hollow spheres, and the distance between the through holes in the first layer of hollow spheres is greater than 5 times the thickness of the first layer of hollow spheres and less than or equal to 15 times the thickness of the first layer of hollow spheres. The diameter of the through holes in the second layer of hollow spheres is 1.5 times the thickness of the second layer of hollow spheres, and the distance between the through holes in the second layer of hollow spheres is greater than 5 times the thickness of the second layer of hollow spheres and less than or equal to 15 times the thickness of the second layer of hollow spheres.

[0010] Furthermore, the first, second, and third hollow spheres are all formed by welding two hemispheres together.

[0011] Furthermore, the angle between the plane containing the weld seam of the first hollow sphere and the plane containing the weld seam of the second hollow sphere is not less than 30 degrees, and the angle between the plane containing the weld seam of the second hollow sphere and the plane containing the weld seam of the third hollow sphere is not less than 30 degrees.

[0012] Furthermore, the total thickness of the hollow bolt ball is not less than 1.1 times the anchorage length of the high-strength bolt or the maximum bolt hole diameter.

[0013] A method for manufacturing a multi-layer hollow bolted spherical space frame node includes: S1: Select a stamping die with the appropriate radius to stamp the two hemispheres of each layer of hollow spheres, and then weld the inner rib plate to the inside of the two hemispheres of the third layer of hollow spheres; S2: Weld the two hemispheres of the third hollow sphere into a whole sphere using single-sided bevel butt welding, and then grind the weld of the third hollow sphere smooth. S3: Place the two hemispheres of the second hollow sphere on the outside of the third hollow sphere, and weld them into a whole sphere using single-sided bevel butt welding. Grind the weld of the second hollow sphere smooth. Then, use plug welding to fix the third hollow sphere to the second hollow sphere at the through hole of the second hollow sphere. Then grind the weld of the through hole smooth. S4: Place the two hemispheres of the first layer of hollow spheres on the outside of the second layer of hollow spheres, and weld them into a whole sphere using single-sided bevel butt welding. Grind the weld of the first layer of hollow spheres smooth. Then, use plug welding to fix the second layer of hollow spheres to the first layer of hollow spheres at the through holes of the first layer of hollow spheres. Finally, grind the weld of the through holes smooth to form a multi-layer hollow sphere. S5: Multi-layer hollow spheres are clamped on the milling machine indexing head using process holes. The process holes serve as reference holes. Then, bolt holes are made according to the designed bolt hole diameter and angle. S6: Remove the multi-layer hollow sphere from the machine tool, and then screw the preset connector into the process hole to seal the process hole.

[0014] A method for using a hollow bolt spherical grid joint includes: a. Screw the high-strength bolt into the pre-drilled hole in the rod, and then attach the sleeve to the high-strength bolt; b. Align the first limiting hole on the sleeve with the second limiting hole of the high-strength bolt, and then insert the fastening screw to fix the high-strength bolt. c. Tighten the sleeve to connect the high-strength bolt and the multi-layer hollow bolt ball; d. Repeat the above steps multiple times until the hollow bolt ball grid node is installed.

[0015] Compared with the prior art, the present invention has the following beneficial effects: This invention employs a three-layer hollow bolt ball structure, with an inner rib plate welded inside the third hollow ball. This optimizes the structural form of the space frame node and overcomes the problems of large deformation of the hollow bolt ball, insufficient bolt anchorage length, and insufficient bearing capacity. Furthermore, this multi-layer hollow bolt ball space frame node has a simple structure, is easy to manufacture, requires minimal on-site welding, can be reused, and reduces costs. Attached Figure Description

[0016] Figure 1 This is a cross-sectional schematic diagram of a multi-layer hollow bolted ball grid node according to an embodiment of the present invention; Figure 2 This is an assembly diagram of a multi-layer hollow bolt ball grid node according to an embodiment of the present invention; Figure 3 This is a cross-sectional schematic diagram of a multi-layer hollow bolt ball according to an embodiment of the present invention; Figure 4 This is a schematic diagram illustrating the fabrication of a multi-layer hollow bolt ball according to an embodiment of the present invention; Figure 5 This is a flowchart illustrating the manufacturing process of the multi-layer hollow bolt ball according to an embodiment of the present invention.

[0017] Explanation of reference numerals in the attached diagram: 1. First layer hollow sphere, 2. Second layer hollow sphere, 3. Third layer hollow sphere, 4. Bolt hole, 5. Through hole, 6. High-strength bolt, 7. Process hole, 8. Weld, 81. Weld of the first layer hollow sphere, 82. Weld of the second layer hollow sphere, 83. Weld of the third layer hollow sphere, 9. Rod, 10. Sleeve, 11. Fastening screw, 12. Inner rib plate. Detailed Implementation

[0018] To better understand the above-mentioned objectives, features, and advantages of the present invention, the present invention will be further described below in conjunction with the accompanying drawings and embodiments. It should be noted that, unless otherwise specified, the embodiments and features described in these embodiments can be combined with each other. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without inventive effort are within the scope of protection of the present invention.

[0019] 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.

[0020] In this invention, unless otherwise explicitly specified and limited, the terms "connection," "fixed," etc., should be interpreted broadly. For example, "fixed" can mean a fixed connection, a detachable connection, or an integral part; it can mean a mechanical connection or an electrical connection; it can mean a direct connection or an indirect connection through an intermediate medium; it can mean the internal communication of two components or the interaction between two components, unless otherwise explicitly limited. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0021] 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 meaning of "and / or" throughout the text includes three parallel solutions; for example, "A and / or B" includes solution A, solution B, or a solution where both A and B are satisfied simultaneously. Furthermore, 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. When 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.

[0022] Example 1 like Figure 3 As shown, this invention provides a hollow bolt ball, comprising a shell, which includes a first hollow ball 1, a second hollow ball 2, and a third hollow ball 3. The first hollow ball 1 is located outside the second hollow ball 2, and the second hollow ball 2 is located outside the third hollow ball 3. An inner rib plate 12 is welded to the inner side of the third hollow ball 3. The inner rib plate 12 is annular in shape and made of the same material as the base material, thereby increasing the load-bearing capacity and deformation resistance of the shell. The first hollow ball 1, the second hollow ball 2, and the third hollow ball 3 are made of steel plate, and the material of the steel plate is not lower than Q355B steel. The thickness of each hollow ball can be the same or different. By adopting a three-layer bolt ball structure and inner rib plate, the problems of large deformation of the hollow bolt ball, insufficient bolt anchorage length, and insufficient load-bearing capacity are overcome.

[0023] The first layer of hollow spheres 1 and the second layer of hollow spheres 2 have through holes 5 at the same position. Each layer of hollow spheres 1 and 2 has multiple through holes 5. The diameter of the through hole 5 in the first layer of hollow spheres 1 is 1.5 times the thickness of the first layer of hollow spheres 1. The distance between the through holes 5 in the first layer of hollow spheres 1 is greater than 5 times the thickness of the first layer of hollow spheres 1 and less than or equal to 15 times the thickness of the first layer of hollow spheres 1. The diameter of the through hole 5 in the second layer of hollow spheres 2 is 1.5 times the thickness of the second layer of hollow spheres 2. The distance between the through holes 5 in the second layer of hollow spheres 2 is greater than 5 times the thickness of the second layer of hollow spheres 1 and less than or equal to 15 times the thickness of the second layer of hollow spheres 2, so as to ensure that the through holes 5 in the first layer of hollow spheres 1 and the through holes 5 in the second layer of hollow spheres 2 are in the same position. The through hole 5 is used for plug welding to fix the relative positions between different hollow spheres, preventing misalignment between the first layer hollow sphere 1, the second layer hollow sphere 2, and the third layer hollow sphere 3, so as to ensure that the central axes of the bolt holes 4 of the three layers of hollow spheres coincide. To facilitate plug welding, the through hole 5 of the first layer hollow sphere 1 is slightly larger than the through hole 5 of the second layer hollow sphere 2.

[0024] The first layer of hollow spheres 1, the second layer of hollow spheres 2, and the third layer of hollow spheres 3 are provided with through bolt holes 4 and process holes 7 at the same position. There are multiple bolt holes 4, and at least two bolt holes 4 have different diameters, so that different bolts can be connected in different construction sites. The process hole 7 is a reference hole, which is used to locate the position of the bolt hole 4 when it is made. After the bolt ball is manufactured, the process hole 7 is sealed with a high-strength bolt 6. The use of high-strength bolt 6 is conducive to the promotion of multi-layer hollow bolt ball grid nodes.

[0025] Specifically, the first layer of hollow sphere 1, the second layer of hollow sphere 2, and the third layer of hollow sphere 3 are all made of two hemispheres spliced ​​together. The angle between the plane where the weld seam 81 of the first layer of hollow sphere is located and the plane where the weld seam 82 of the second layer of hollow sphere is located is not less than 30 degrees. The angle between the plane where the weld seam 82 of the second layer of hollow sphere is located and the plane where the weld seam 83 of the third layer of hollow sphere is located is not less than 30 degrees. Two hollow hemispheres are welded together to form a hollow whole sphere. In order to avoid different spheres being damaged in the same direction when under tension, the weld seam angle between different spheres is designed to be not less than 30 degrees, so as to improve the stress strength of the entire hollow bolt ball.

[0026] Specifically, the distance between the inner surface of the first hollow sphere 1 and the outer surface of the second hollow sphere 2 does not exceed 2mm, the distance between the inner surface of the second hollow sphere 2 and the outer surface of the third hollow sphere 3 does not exceed 2mm, and a gap of no more than 2mm is left between each layer of hollow spheres to facilitate plug welding, thereby facilitating accurate plug welding operation and improving the positioning accuracy between different layers of hollow spheres.

[0027] Specifically, the total thickness of the hollow bolt ball is not less than the anchorage length of the high-strength bolt 6 or 1.1 times the diameter of the maximum bolt hole 4, so that the hollow bolt ball has sufficient bearing capacity and ensures that the high-strength bolt 6 has sufficient anchorage length.

[0028] Example 2 This embodiment provides a hollow bolt ball space frame node, including a hollow bolt ball and a space frame node connector. The hollow bolt ball is the hollow bolt ball provided in Embodiment 1.

[0029] like Figure 1-2As shown, the hollow bolt ball and the space frame node connector are fastened together by high-strength bolts 6. The space frame node connector includes high-strength bolts 6, sleeves 10, fastening screws 11, and rods 9. A pre-drilled hole is provided on the side of the rod 9 near the sleeve 10. The nut portion of the high-strength bolt 6 is inserted into the pre-drilled hole of the rod 9. The nut portion of the high-strength bolt 6 is larger than the diameter of the pre-drilled hole, ensuring that the high-strength bolt 6 will not detach from the rod 9 during connection. The sleeve 10 is positioned between the first layer of hollow balls 1 and the rod 9, primarily to increase protection against loosening and vibration, enhance bolt tightening strength, provide compressive strength, and facilitate disassembly and replacement. The sleeve 10 is gap-connected to the high-strength bolt 6, which passes through the sleeve 10. A first limiting hole is radially provided on the side wall of the sleeve 10, and a second limiting hole is provided at a corresponding position on the high-strength bolt 6. Fastening screws 11 are installed in both the first and second limiting holes to fix the high-strength bolt 6 to the sleeve 10. The thread on the high-strength bolt 6 matches the thread on the bolt hole 4. The high-strength bolt 6 passes through the lower end of the rod 9 and is connected to the sleeve 10. It extends through the bolt hole 4 into the interior of the multi-layer hollow bolt ball, so that the rod 9 and the multi-layer hollow bolt ball are tightly connected.

[0030] Example 3 This embodiment provides a method for manufacturing a hollow bolt ball. The hollow bolt ball used is the one provided in Embodiment 1, such as... Figure 4 As shown, it includes the following steps: S1: Select a stamping die with the corresponding radius to stamp the two hemispheres of each layer of hollow spheres, and then open through holes 5 at the same positions of the two hemispheres of the first layer of hollow sphere 1 and the two hemispheres of the second layer of hollow sphere 2. S2: Weld the inner rib plate 12 to the inner side of the two hemispheres of the third hollow sphere 3, then weld the two hemispheres of the third hollow sphere 3 into a whole sphere using single-sided bevel butt welding, and then grind the weld 83 of the third hollow sphere flat. S3: Place the two hemispheres of the second hollow sphere 2 on the outside of the third hollow sphere 3, and weld them into a whole sphere using single-sided bevel butt welding. Grind the weld 82 of the second hollow sphere flat. The angle between the plane where the weld 82 of the second hollow sphere is located and the plane where the weld 83 of the third hollow sphere is located is not less than 30 degrees. Then, use plug welding at the through hole 5 of the second hollow sphere 2 to fix the third hollow sphere 3 to the second hollow sphere 2. Then grind the welded part of the through hole 5 flat. S4: Place the two hemispheres of the first layer hollow sphere 1 on the outside of the second layer hollow sphere 2, and weld them into a whole sphere using single-sided bevel butt welding. Grind the weld 81 of the first layer hollow sphere flat. The angle between the plane of the first layer hollow sphere weld 81 and the plane of the second layer hollow sphere weld 82 is not less than 30 degrees. Then, use plug welding to fix the second layer hollow sphere 2 to the first layer hollow sphere 1 at the through hole 5 of the first layer hollow sphere 1. Then grind the weld of the through hole 5 flat to form a multi-layer hollow sphere. S6: Clamp the prepared multi-layer hollow spheres on the lathe chuck. According to the requirements of different sphere diameters, the dimensional relationship between the datum plane and the sphere centerline, make the datum plane cutting mark blocks on the machine tool guide rail. Then, process the datum plane, and then drill and tap. S7: The multi-layer hollow sphere is clamped on the milling machine indexing head using process hole 7 to machine the bolt hole plane; S8: Mark the center of all bolt holes 4 on the multi-layer hollow sphere, use the bolt hole plane and the marked center to locate, and then drill, chamfer and tap on the machine tool according to the designed bolt hole diameter and angle to complete the machining of all bolt holes 4 on the multi-layer hollow sphere. S9: Remove the multi-layer hollow sphere from the machine tool, and then screw in the high-strength bolt 6 into the process hole 7 to seal the process hole 7.

[0031] Specifically, the two hemispheres of each hollow sphere are welded into a whole sphere using single-sided bevel butt welding because it can improve the strength and sealing of the weld, reduce the stress of the weld, and ensure good weld quality, high strength, and reliable sealing.

[0032] Example 4 This embodiment provides a method for using a hollow bolt ball grid node. The hollow bolt ball grid node adopts the hollow bolt ball grid node provided in Embodiment 2, including: a. Screw the high-strength bolt 6 into the reserved hole of the rod 9, and then put the sleeve 10 onto the high-strength bolt 6; b. Align the first limiting hole on the sleeve 10 with the second limiting hole of the high-strength bolt 6, and then insert the fastening screw 11 to fix the high-strength bolt 6. c. Tighten sleeve 10 to connect high-strength bolt 6 and multi-layer hollow bolt ball; d. Repeat the above steps multiple times until the hollow bolt ball grid node is installed.

Claims

1. A hollow bolt ball, comprising a shell, characterized in that, The shell comprises a first hollow sphere, a second hollow sphere, and a third hollow sphere. Each of the three hollow spheres is formed by splicing two hemispheres together. The first hollow sphere is located outside the second hollow sphere, and the second hollow sphere is located outside the third hollow sphere. An inner rib is provided on the inner side of the third hollow sphere. Through holes are provided in the first and second hollow spheres at the same positions. Through bolt holes and process holes are provided in the first, second, and third hollow spheres at the same positions. There are multiple bolt holes, at least two of which have different diameters. A pre-set connector is installed in the process hole.

2. A hollow bolt ball according to claim 1, characterized in that, The distance between the inner surface of the first hollow sphere and the outer surface of the second hollow sphere does not exceed 2 mm, and the distance between the inner surface of the second hollow sphere and the outer surface of the third hollow sphere does not exceed 2 mm.

3. A hollow bolt ball according to claim 1, characterized in that, The diameter of the through holes in the first layer of hollow spheres is 1.5 times the thickness of the first layer of hollow spheres, and the distance between the through holes in the first layer of hollow spheres is greater than 5 times the thickness of the first layer of hollow spheres and less than or equal to 15 times the thickness of the first layer of hollow spheres. The diameter of the through holes in the second layer of hollow spheres is 1.5 times the thickness of the second layer of hollow spheres, and the distance between the through holes in the second layer of hollow spheres is greater than 5 times the thickness of the second layer of hollow spheres and less than or equal to 15 times the thickness of the second layer of hollow spheres.

4. A hollow bolt ball according to claim 1, characterized in that, The first, second, and third hollow spheres are all formed by welding two hemispheres together.

5. A hollow bolt ball according to claim 4, characterized in that, The angle between the plane containing the weld seam of the first hollow sphere and the plane containing the weld seam of the second hollow sphere is not less than 30 degrees, and the angle between the plane containing the weld seam of the second hollow sphere and the plane containing the weld seam of the third hollow sphere is not less than 30 degrees.

6. A hollow bolted spherical grid node, characterized in that, The invention includes a hollow bolt ball as described in any one of claims 1 to 5, and a space frame node connector. The hollow bolt ball is fastened to the space frame node connector. The space frame node connector includes a high-strength bolt, a sleeve, a fastening screw, and a rod. The sleeve is disposed between the first layer of hollow balls and the rod. A first limiting hole is radially formed on the side wall of the sleeve. A second limiting hole is formed at a corresponding position on the high-strength bolt. A fastening screw is installed in the first limiting hole and the second limiting hole. The high-strength bolt is gap-connected to the sleeve. A rod pre-drilled hole is formed on the side of the rod near the sleeve. The high-strength bolt is inserted into the rod pre-drilled hole.

7. A hollow bolt ball grid node according to claim 6, characterized in that, The total thickness of the hollow bolt ball shall not be less than 1.1 times the anchorage length of the high-strength bolt or the maximum bolt hole diameter.

8. A method for manufacturing a hollow bolt ball according to any one of claims 1 to 5, characterized in that, include: S1: Select a stamping die with the appropriate radius to stamp the two hemispheres of each layer of hollow spheres, and then weld the inner rib plate to the inside of the two hemispheres of the third layer of hollow spheres; S2: Weld the two hemispheres of the third hollow sphere into a whole sphere using single-sided bevel butt welding, and then grind the weld of the third hollow sphere smooth. S3: Place the two hemispheres of the second hollow sphere on the outside of the third hollow sphere, and weld them into a whole sphere using single-sided bevel butt welding. Grind the weld of the second hollow sphere smooth. Then, use plug welding to fix the third hollow sphere to the second hollow sphere at the through hole of the second hollow sphere. Then grind the weld of the through hole smooth. S4: Place the two hemispheres of the first layer of hollow spheres on the outside of the second layer of hollow spheres, and weld them into a whole sphere using single-sided bevel butt welding. Grind the weld of the first layer of hollow spheres smooth. Then, use plug welding to fix the second layer of hollow spheres to the first layer of hollow spheres at the through holes of the first layer of hollow spheres. Finally, grind the weld of the through holes smooth to form a multi-layer hollow sphere. S5: Multi-layer hollow spheres are clamped on the milling machine indexing head using process holes. The process holes serve as reference holes. Then, bolt holes are made according to the designed bolt hole diameter and angle. S6: Remove the multi-layer hollow sphere from the machine tool, and then screw the preset connector into the process hole to seal the process hole.

9. A method of using the hollow bolt ball grid node according to any one of claims 6 to 7, characterized in that, include: a. Screw the high-strength bolt into the pre-drilled hole in the rod, and then attach the sleeve to the high-strength bolt; b. Align the first limiting hole on the sleeve with the second limiting hole of the high-strength bolt, and then insert the fastening screw to fix the high-strength bolt. c. Tighten the sleeve to connect the high-strength bolt and the multi-layer hollow bolt ball; d. Repeat the above steps multiple times until the hollow bolt ball grid node is installed.

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