Joint structure by bolt

Abstract

To provide a joint structure by bolt capable of joining members with higher tensile strength.SOLUTION: A joint structure 100 by bolt of members used in a wind power generation supporting object includes: a first member 1 having a first extension part 10 extending in one direction and a first flange part 11 extending in a second direction orthogonal to the first direction from the first extension part 10; a second member 2 having a second extension part 20 extending in the first direction, and a second flange part 21 extending in the second direction from the second extension part 20, and arranged adjacent to the first flange part 11 in the first direction; first mounting holes 13, 23 and second mounting holes 14, 24 formed in communication with the first flange part 11 and the second flange part 21 in the first direction, and arranged in the second direction with an interval; bolts 31, 32 inserted in the first mounting holes 13, 23 and the second mounting holes 14, 24 respectively; and nuts 36, 37 fastened to the bolts 31, 32.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a bolted joint structure. [Background technology]

[0002] Joint structures using high-strength bolts have been known for some time (see Patent Document 1 below). For the tower joints of wind power generation supports and the joints between the tower and foundation, a method of joining L-shaped or T-shaped flanges with bolts is sometimes used. Also, for the joints between transition pieces (TP) and monopiles (MP) in offshore wind power generation, grout joints are sometimes used. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Publication No. 7-331756 Summary of the Invention [Problem to be solved by the invention]

[0004] However, the large flanges and large-diameter bolts used in wind turbine supports must be certified by the Ministry of Economy, Trade and Industry or the Ministry of Land, Infrastructure, Transport and Tourism. These certified products have size restrictions, and when the load becomes large, the method of joining L-shaped flanges with a single row of bolts may not be able to withstand the load.

[0005] The present invention has been made in view of the above circumstances, and provides a bolted joint structure that can achieve joining with higher tensile strength. [Means for solving the problem]

[0006] In order to achieve the above object, the present invention employs the following means. That is, the bolted joint structure of the present invention is a bolted joint structure for components used in a wind power generation support, and comprises: a first member having a first extension portion extending in a first direction and a first flange extending from the first extension portion in a second direction perpendicular to the first direction; a second member having a second extension portion extending in the first direction and a second flange extending in the second direction from the second extension portion and arranged adjacent to the first flange in the first direction; first and second mounting holes formed in the first and second flanges so as to communicate with each other in the first direction and arranged at a distance in the second direction; bolts inserted into the first and second mounting holes, respectively; and nuts fastened to the bolts.

[0007] In this bolted joint structure, the first flange of the first member and the second flange of the second member are joined in two rows with bolts and nuts inserted through first and second mounting holes spaced apart in the second direction, thereby enabling the first and second members to be joined with higher tensile strength.

[0008] Furthermore, in the bolt joining structure according to the present invention, the first extension portion and the second extension portion may be formed in an annular shape when viewed from the first direction, and the first mounting hole and the second mounting hole may be formed at intervals in the circumferential direction of the first extension portion and the second extension portion, respectively.

[0009] In this bolted joint structure, the annular first and second flanges are joined together with bolts and nuts spaced apart in the circumferential direction, allowing the first and second flanges to be joined together with high tensile strength in the circumferential direction.

[0010] In addition, in the bolt joining structure of the present invention, the first extension portion and the second extension portion are formed in a cylindrical shape with the first direction as the axial direction, and the first flange portion extends radially inward from the first extension portion, and the second flange portion extends radially inward from the second extension portion.

[0011] In a bolted joint structure configured in this way, the bolts and nuts can be fastened from the inside of the first and second members, eliminating the need for scaffolding, as is the case when the bolts and nuts are fastened from the outside of the first and second members, and improving workability. [Effects of the Invention]

[0012] According to the bolt joint structure of the present invention, joints can be made with higher tensile strength. [Brief explanation of the drawings]

[0013] [Figure 1] 1 is a cross-sectional view showing a bolted joint structure according to an embodiment of the present invention. [Figure 2] FIG. 10 is a diagram showing an example of bolt arrangement. [Figure 3] FIG. 10 is a diagram showing the relationship between axial force and flange separation displacement (comparison between single-row and double-row systems). [Figure 4] FIG. 2 is a vertical cross-sectional view showing the analysis model. [Figure 5] FIG. 1 is a diagram illustrating an analytical model. [Figure 6] FIG. 1A is a plan view showing an analytical model of an embodiment, and FIG. 1B is a vertical cross-sectional view showing the analytical model of an embodiment. [Figure 7] FIG. 10 is a diagram showing an analysis result of the analysis model of the example. [Figure 8] FIG. 1A is a plan view showing an analytical model of a comparative example (single row system), and FIG. 1B is a vertical cross-sectional view showing the analytical model of a comparative example (single row system). [Figure 9] FIG. 10 is a diagram showing the analysis results of an analysis model of a comparative example (single-row system). DETAILED DESCRIPTION OF THE INVENTION

[0014] A bolted joint structure according to one embodiment of the present invention will be described with reference to the drawings. Fig. 1 is a cross-sectional view showing a bolted joint structure according to one embodiment of the present invention, and Fig. 2 is a diagram showing an example of bolt arrangement. 1 and 2, the bolted joint structure 100 is a joint structure between members used in a wind power generation support. A first member 1 and a second member 2 are joined by the bolted joint structure 100. As shown in Fig. 1, the bolted joint structure 100 includes the first member 1, the second member 2, first mounting holes 13, 23, second mounting holes 14, 24, bolts 31, 32, and nuts 36, 37.

[0015] In the illustrated example, the first member 1 and the second member 2 are cylindrical members extending in an axial direction (first direction) O. The axial direction O is aligned with the up-down direction. The first member 1 is disposed above the second member 2.

[0016] The first member 1 has a first extension portion 10 and a first flange portion 11. The first extension portion 10 is a cylindrical member extending in the axial direction O. The first flange portion 11 extends from the lower end of the first extension portion 10 in a radial direction, i.e., in a direction (second direction) perpendicular to the axial direction O. The first flange portion 11 extends radially inward from the lower end of the first extension portion 10. The first flange portion 11 is formed in an annular shape when viewed from the axial direction O. Note that the first flange portion 11 may be configured to protrude from the first extension portion 10 at multiple locations spaced apart in the circumferential direction.

[0017] The second member 2 has a second extension portion 20 and a second flange portion 21. The second extension portion 20 is a cylindrical member extending in the axial direction O. The second extension portion 20 is arranged coaxially with the first extension portion 10. The second extension portion 20 is arranged below the first extension portion 10. The second flange portion 21 extends radially inward from the upper end of the first extension portion 10. The second flange portion 21 is formed in an annular shape when viewed from the axial direction O. The second flange portion 21 may be configured to protrude from the second extension portion 20 at multiple locations with intervals in the circumferential direction. The second flange portion 21 is arranged adjacent to the lower side of the first flange portion 11.

[0018] The outer peripheral surface 1a of the first member 1, which is the outer peripheral surface of the first extension portion 10, and the outer peripheral surface 2a of the second member 2, which is the outer peripheral surface of the second extension portion 20, are arranged on the same plane. Note that the outer peripheral surface 1a of the first member 1 and the outer peripheral surface 2a of the second member 2 may be arranged with a radial offset.

[0019] The inner circumferential surface 1b of the first member 1, which is the extending end face of the first flange portion 11, and the inner circumferential surface 2b of the second member 2, which is the extending end face of the second flange portion 21, are arranged on the same plane. Note that the inner circumferential surface 1b of the first member 1 and the inner circumferential surface 2b of the second member 2 may be arranged with a radial offset.

[0020] The lower surface 11d of the first flange portion 11 and the upper surface 21u of the second flange portion 21 are in contact with each other.

[0021] The first flange portion 11 is formed with a plurality of first mounting holes 13 and second mounting holes 14 that penetrate in the up-down direction. The first mounting holes 13 are formed at positions closer to the inner periphery of the first flange portion 11 and spaced apart in the circumferential direction. The second mounting holes 14 are formed at positions closer to the outer periphery of the first flange portion 11 and spaced apart in the circumferential direction. The first mounting holes 13 and the second mounting holes 14 are arranged at intervals in the radial direction.

[0022] A plurality of first mounting holes 23 and second mounting holes 24 are formed in the second flange portion 21, penetrating in the up-down direction. The first mounting holes 23 are formed at positions closer to the inner periphery of the second flange portion 21, spaced apart in the circumferential direction. The second mounting holes 24 are formed at positions closer to the outer periphery of the second flange portion 21, spaced apart in the circumferential direction. The first mounting holes 23 and the second mounting holes 24 are arranged at intervals in the radial direction.

[0023] The first mounting hole 23 of the second flange portion 21 communicates with the first mounting hole 13 of the first flange portion 11. The second mounting hole 24 of the second flange portion 21 communicates with the second mounting hole 14 of the first flange portion 11.

[0024] The bolt 31 is inserted from the underside of the second flange portion 21 into the first mounting hole 23 and the first mounting hole 13 of the first flange portion 11. The bolt 32 is inserted from the underside of the second flange portion 21 into the second mounting hole 24 and the second mounting hole 14 of the first flange portion 11.

[0025] Nut 36 is fastened to the upper end of bolt 31 protruding upward from first mounting hole 13. Nut 37 is fastened to the upper end of bolt 32 protruding upward from second mounting hole 14.

[0026] In addition, the bolts 31, 32 may be inserted into the first mounting hole 13 and the second mounting hole 14 from the upper side of the first flange portion 11, and nuts 36, 37 may be fastened to the lower ends of the bolts 31, 32 protruding downward from the first mounting hole 23 and the second mounting hole 24.

[0027] 2, the inner circumferential side bolts 31 and the outer circumferential side bolts 32 are arranged with a circumferential offset. Note that the inner circumferential side bolts 31 and the outer circumferential side bolts 32 may be arranged without a circumferential offset.

[0028] 1, the bolted joint structure 100 is a two-row type in which bolts 31, 32 are arranged in two rows radially in a so-called L-shaped flange that is formed by the first extension portion 10 and the first flange portion 11 (and the second extension portion 20 and the second flange portion 21) in a vertical cross section. By arranging the bolts 31, 32 in two rows, a tensile bolt joint with greater strength can be achieved.

[0029] FIG. 3 is a diagram showing the relationship between axial force and flange separation displacement (comparison between the single-row system and the double-row system). As shown in Figure 3, it can be seen that the axial force (bearing strength of the joint) in the joint structure 100 using the double-row bolts of this embodiment is approximately 1.5 to 1.8 times greater than that in the single-row bolt joint in which bolts are joined in a single row in the radial direction.

[0030] FIG. 4 is a vertical cross-sectional view showing the analytical model. FIG. 5 is a diagram showing the analytical model. FIG. 6(a) is a plan view showing the analytical model of the embodiment, and FIG. 6(b) is a vertical cross-sectional view showing the analytical model of the embodiment. FIG. 7 is a diagram showing the analysis results of the analytical model of the embodiment. FIG. 8(a) is a plan view showing the analytical model of the comparative example (single row system), and FIG. 8(b) is a vertical cross-sectional view showing the analytical model of the comparative example (single row system). FIG. 9 is a diagram showing the analysis results of the analytical model of the comparative example (single row system). 7 and 9, it can be seen that the von Mises stress acting on the bolts 31 and 32 can be suppressed.

[0031] In the bolted joint structure 100 configured in this manner, the first flange portion 11 of the first member 1 and the second flange portion 21 of the second member 2 are joined in a double row manner by bolts 31, 32 and nuts 36, 37 inserted through first mounting holes 13, 23 and second mounting holes 14, 24 formed at intervals in the radial direction of the first flange portion 11 and the second flange portion 21. This allows the first member 1 and the second member 2 to be joined with higher tensile strength.

[0032] The annular first flange portion 11 and second flange portion 21 are joined together by bolts 31, 32 and nuts 36, 37 that are spaced apart in the circumferential direction. This allows the first flange portion 11 and the second flange portion 21 to be joined together with high tensile strength in the circumferential direction.

[0033] Furthermore, if the first extension portion 10 (second extension portion 20) is provided with a T-flange on both the inner and outer periphery, scaffolding is required on the outer periphery. In the bolted joint structure 100, the bolts 31, 32 and nuts 36, 37 can be fastened from the inside of the first member 1 and the second member 2, eliminating the need for scaffolding and improving workability.

[0034] Furthermore, the bolts 31, 32 are disposed inside the first member 1 and the second member 2 and are not affected by the outside air, making it easy to take anti-corrosion measures, which is particularly effective offshore where salt damage is strong.

[0035] Furthermore, even in offshore wind power projects where grout joints are unavoidable due to strength reasons, flange-bolt joints may be possible by adopting the bolt joint structure 100. This will enable shortening of construction time and reduction of costs.

[0036] The shapes and combinations of the components shown in the above-described embodiment are merely examples, and various modifications can be made based on design requirements, etc., within the scope of the present invention. [Explanation of symbols]

[0037] 1 volt 1 First member 2 Second member 10 1st extension part 11 First flange 13,23 First mounting hole 14,24 Second mounting hole 20 Second extension part 21 Second flange 31,32 volts 36,37 Nut 100 bolt joint structure

Claims

1. A bolted joint structure between members used in wind power generation supports, a first extending portion extending in a first direction; a first member having a first flange portion extending from the first extension portion in a second direction perpendicular to the first direction; a second extending portion extending in the first direction; a second member having a second flange portion extending in a second direction from the second extension portion and disposed adjacent to the first flange portion in the first direction; a first mounting hole and a second mounting hole formed in the first flange portion and the second flange portion so as to communicate with each other in the first direction and spaced apart from each other in the second direction; a bolt inserted through each of the first mounting hole and the second mounting hole; A bolted joint structure comprising: a nut fastened to the bolt.

2. The first flange portion and the second flange portion are formed in an annular shape when viewed from the first direction, The bolt joint structure according to claim 1 , wherein the first mounting hole and the second mounting hole are formed at intervals in the circumferential direction of the first extension portion and the second extension portion, respectively.

3. The first extension portion and the second extension portion are formed in a cylindrical shape with an axial direction aligned with the first direction, 3. The bolted joint structure according to claim 1, wherein the first flange portion extends radially inward from the first extension portion, and the second flange portion extends radially inward from the second extension portion.

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