Lighting fixture installation support and design method of same

Abstract

To provide a lighting fixture installation support, which has sufficient strength for installing a lighting fixture, can be manufactured relatively easily without requiring a dedicated manufacturing device, and can also meet the requirements of government ordinances.SOLUTION: Provided is a support for installing a lighting fixture, consisting of a plurality of steel pipe columns 4-7 of different diameters joined vertically with the diameter increasing from higher to lower. The plurality of steel pipe columns 4-7 are welded together via through diaphragms 10 respectively, and the plate thicknesses of the through diaphragms are set so that the out-of-plane stress generated therein is equal to or less than the short-term allowable stress level, allowing a maximum misalignment of 50 mm on one side between the upper steel pipe column and the steel pipe column below it.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to a support for installing lighting fixtures and a design method thereof, and more specifically to a support having a simple structure and sufficient strength performance, which is used mainly for installing lighting fixtures in stadiums, soccer fields, etc., and a design method thereof. [Background technology]

[0002] Lighting equipment is essential for athletics stadiums, soccer fields, baseball stadiums, etc. In such cases, each lighting fixture is quite heavy, so the poles for installing them must also be strong enough to withstand the weight. A typical lighting fixture installation pole has a special shape, with the entire pole or joints made of tapered steel pipes, so its manufacture requires specialized manufacturing equipment, and since there are only a limited number of manufacturers, costs are high and delivery times tend to be long.

[0003] Generally, lighting fixture installation poles are over 15m in height, and poles of this height are subject to regulation as structures (reinforced concrete poles, etc.) based on Article 88, paragraph 1 of the Building Standards Act and Article 138, paragraph 1, item 2 of the Building Standards Act Enforcement Order (Cabinet Order). This type of pole does not have the same diameter over its entire length, with the lower member having a larger diameter than the upper member, but the above regulation stipulates that the misalignment of the welds at the joints (the misalignment between the reference surfaces of the base materials to be welded) should be 5mm or less.

[0004] Although it is a common method to use a diaphragm to connect square steel pipe columns, this is mainly a method for connecting H-shaped steel beams to square steel pipe columns, and is not a design method for connecting square steel pipe columns vertically (Patent Publication No. 2023-23809, etc.). In addition, there is a proposal for a joint structure for steel columns with different diameters (Patent Publication No. 2000-8482), but the joint structure uses a specially shaped column core equivalent to a diaphragm, and is not common. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Patent Publication No. 2023-23809 [Patent Document 2] JP 2000-8482 A Summary of the Invention [Problem to be solved by the invention]

[0006] As described above, conventional general lighting fixture installation poles require specialized manufacturing equipment, and because there are only a limited number of manufacturers, they are expensive and take a long time to deliver. The present invention has been made in consideration of the problems of the conventional technology, and aims to provide a lighting fixture installation pole and a design method thereof that has sufficient strength to support the installation of lighting fixtures, can be manufactured relatively easily without specialized manufacturing equipment, and also meets the requirements of the above government ordinance. [Means for solving the problem]

[0007] The invention described in claim 1 for solving the above problem is a support for installing lighting fixtures, which is made by vertically joining multiple steel pipe poles of different diameters so that the diameter of the poles in the lower tier is larger, The multiple steel pipe columns are each welded together via a through diaphragm, and the plate thickness of the through diaphragm is set so that the out-of-plane stress generated therein is below the short-term allowable stress level, thereby resulting in a support column for installing lighting fixtures that is designed to allow a maximum misalignment of 50 mm on one side between the upper steel pipe column and the lower steel pipe column.

[0008] In one embodiment, the fact that the out-of-plane stress generated in the through diaphragm is equal to or less than the short-term allowable stress is confirmed by the following formula (1). TIFF2025041363000002.tif26170Here iMy: Out-of-plane bending moment around the y-axis at point i (unit: Nmm) jMz: Out-of-plane bending moment around the z-axis at point j (unit: Nmm) iZy: Section modulus of the y-axis cross section at point i (unit: mm 3 ) jZz: Section modulus in the z-axis direction at point j (unit: mm 3 ) iQz: Out-of-plane shear force in the Z-axis direction at point i (unit: N) jQy: Out-of-plane shear force in the y-axis direction at point j (unit: N) iAy: Cross-sectional area in the y-axis direction at point i (unit: mm 2 ) jAz: Cross-sectional area in the z-axis direction at point j (unit: mm 2 ) i: Any distance from the center of the diaphragm in the z-axis direction (the direction toward the compression flange is positive) (unit: mm) j: Any distance from the center of the diaphragm in the y-axis direction (absolute value) (unit: mm) y-axis: The direction perpendicular to the maximum wind direction of the lighting pole z-axis: Maximum wind direction of the lighting pole F: Allowable tensile stress of the diaphragm (unit: N / mm 2 )

[0009] In one embodiment, the uppermost steel pipe column is a circular steel pipe column equipped with a top plate for installing a lighting fixture at the upper end, and the other steel pipe columns are square steel pipe columns. In one embodiment, the column cross section of each of the steel pipe columns changes depending on the distance from the top so that the effective slenderness ratio is 200 or less. In another embodiment, the square steel pipe columns are made adjustable in length.

[0010] The invention described in claim 5 for solving the above problem is a method for designing a support for installing a lighting fixture, which is manufactured by vertically welding a plurality of steel pipe columns having different diameters via a through diaphragm so that the diameter of the lower row is larger, This is a method for designing a support for installing lighting fixtures, characterized in that the thickness of the through diaphragm is set so that the out-of-plane stress generated therein is equal to or less than the short-term allowable stress level.

[0011] In one embodiment, it is confirmed that the out-of-plane stress generated in the through diaphragm is equal to or less than the short-term allowable stress by the formula (1) described in claim 2. Effect of the Invention

[0012] The lighting fixture installation support and its design method according to the present invention are as described above. By joining the upper and lower steel pipe posts via a through diaphragm that is set so as to satisfy the above formula (1), it is possible to produce a lighting fixture installation support having sufficient strength to accommodate the installation of a lighting fixture without the need for dedicated manufacturing equipment. [Brief description of the drawings]

[0013] [Figure 1] 1 is a perspective view showing an overall configuration of a lighting fixture installation pole according to the present invention; [Diagram 2] 1 is a perspective view showing a configuration of a through diaphragm of a lighting fixture installation pole according to the present invention; [Diagram 3] 1 is a perspective view showing a method for elongating a square steel pipe column in a support for installing a lighting fixture according to the present invention. FIG. [Figure 4] 1A to 1C are diagrams showing a method of replacing an upper steel pipe in a support for installing a lighting fixture according to the present invention. [Diagram 5] FIG. 1 shows a classification of replacement plates. [Figure 6] FIG. 1 illustrates a modeled through diaphragm. [Figure 7] FIG. 13 illustrates the stresses generated in a modeled through diaphragm. [Figure 8] FIG. 13 is a diagram showing the out-of-plane bending moment of a through diaphragm. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0014] The embodiment of the present invention will be described in detail with reference to the attached drawings. The lighting fixture installation support pole of the present invention is formed by vertically joining a plurality of steel pipe poles of different diameters so that the lower one has a larger diameter, and the plurality of steel pipe poles are welded together via a through diaphragm, and the plate thickness of the through diaphragm is set so that the out-of-plane stress generated therein is equal to or less than the short-term allowable stress level, thereby allowing a maximum misalignment of 50 mm on one side between the upper steel pipe pole and the lower steel pipe pole. The reason why a maximum misalignment of 50 mm on one side is allowed here is because it was considered that a maximum misalignment of 50 mm on one side is optimal in order to comply with the upper limit (100 mm) of the plate thickness of the through diaphragm.

[0015] FIG. 1 is an overall configuration diagram of a lighting fixture installation support 1 according to the present invention. The topmost steel pipe pillar among the steel pipe pillars joined in multiple stages is a circular steel pipe 4 with a top plate 3 for installing a lighting fixture 2 at the upper end, and the other three steel pipe pillars are square steel pipes 5, 6, and 7. In the illustrated example, the square steel pipes 5, 6, and 7 are in three stages, but there are also cases where there are two stages or four or more stages. In the illustrated example, the square steel pipe pillar 6 is formed by joining two steel pipe pillars 6a and 6b of the same diameter at four sides with a splice plate 11 and high-strength bolts (see FIG. 3). This configuration is adopted when the pillar is segmented for the convenience of manufacturing and transporting the pillar and joined at the installation site.

[0016] The column cross section of each steel pipe column 4-7 is changed so that the effective slenderness ratio is 200 or less according to the distance from the top. A column base plate 8 is installed at the lower end of the lowest square steel pipe column 7. The column base plate 8 and the through diaphragm 10 described later are made of SN490C, which has the highest strength among materials standardized as steel materials for construction, or TMCP steel of equivalent quality. One reason why the lowest stage is a square steel pipe column 7 is that, since the foundation (column base plate 8) is generally rectangular, it is easy to align the direction with the foundation. The square steel pipes 5 and 6 above it are aligned with the square steel pipe column 7. In addition, since the angle of the lighting and the angle of the foundation may differ, the steel pipe in the top stage to which the lighting fixture 2 is attached is a circular steel pipe 4.

[0017] The circular steel pipe 4 and the square steel pipe 5, as well as the square steel pipes 5, 6, and 7, are welded together via through diaphragms 10. The welding is by full penetration welding. As mentioned above, the lighting fixture installation pole 1 exceeds 15 m in height and is regulated by the Building Standards Act Enforcement Ordinance, which stipulates that the weld misalignment at the joint (the misalignment between the reference surfaces of the base materials to be welded) should be 5 mm or less.

[0018] The lighting fixture installation pillar 1 of the present invention changes its column cross section depending on the distance from the top so that the effective slenderness ratio is 200 or less, and the part where the column cross section changes is welded together via a through diaphragm 10. The members joined to the upper and lower sides of the through diaphragm 10 are allowed to have a maximum misalignment of 50 mm on each side. However, since this allowable range of misalignment conflicts with the above-mentioned Cabinet Order, it is necessary to confirm safety in accordance with the proviso stipulated in the notification of the above-mentioned Cabinet Order.

[0019] As a result of the inventor's intensive research and development in order to comply with the above-mentioned Cabinet Order, he discovered that by adopting a design method in which the plate thickness of the through diaphragm 10 is set so that the out-of-plane stress generated in the through diaphragm 10 is equal to or less than the short-term allowable stress level, it is possible to satisfy the proviso stipulated in the notification of the above-mentioned Cabinet Order, namely, "This does not apply if appropriate reinforcement is made so that the strength of the steel material in the connection part is greater than or equal to the strength of the part calculated based on the allowable stress levels for long-term and short-term forces.", and thus completed the present invention.

[0020] The design method is described in detail below. In the present invention, the reinforcement of the misalignment is performed by confirming that the through diaphragm 10 is within the short-term allowable stress against the out-of-plane stress, and this confirmation is performed by using the formula (1) described later, and the plate thickness at each point of the through diaphragm 10 is set to satisfy the formula (1). The design procedure for the through diaphragm 10 is as follows.

[0021] 1) The circular steel tube 4 and the square steel tube 5 are converted into a cross section made up of four identical plates with equivalent cross-sectional area and section modulus (see Figure 4). To replace the square steel tube 5, find b (width of the four plates: mm) and uD (depth of the rectangle formed by the four plates: mm) that satisfy the following conditions. TIFF2025041363000003.tif37170 The replacement of circular steel pipe 4 satisfies the following conditions ut 3 Calculate a (thickness of the 4 plates: mm), b (width of the 4 plates: mm), and uD (area of ​​the rectangle formed by the 4 plates: mm). TIFF2025041363000004.tif36170

[0022] 2) Two sets of plates with the thickness direction parallel to the load direction are used as flanges, and two sets of plates with the width direction parallel to the load direction are used as webs (see Figure 5).

[0023] 3) The through diaphragm 10 is placed on a simply supported beam in the horizontal load direction and perpendicular to the horizontal load direction, which is supported by pins at the lower square steel pipe position (see Figure 6).

[0024] 4) For the simple beam in the load direction, the axial force acting on the flanges of the four plates replacing the upper member is taken as the external force, and for the simple beam in the direction perpendicular to the load, the axial force acting on the webs of the four plates replacing the upper member is taken as the load to determine the stress. The stress from the web is divided into the compression side and tension side, and is considered to act on the compression side diaphragm and tension side diaphragm, each of which has a width of half the effective width of the diaphragm (see Figure 7).

[0025] It is necessary to confirm that the combined stress intensity of bending stress and shear stress in the horizontal load direction and the perpendicular direction is equal to or less than the short-term allowable stress intensity of the through diaphragm 10, which can be confirmed by the following formula (1). The stress generated in the through diaphragm 10 at each point of the through diaphragm 10 must satisfy formula (1).

[0026] TIFF2025041363000005.tif26170Here iMy: Out-of-plane bending moment around the y-axis at point i (unit: Nmm) jMz: Out-of-plane bending moment around the z-axis at point j (unit: Nmm) iZy: Section modulus of the y-axis cross section at point i (unit: mm 3 ) jZz: Section modulus in the z-axis direction at point j (unit: mm 3 ) iQz: Out-of-plane shear force in the Z-axis direction at point i (unit: N) jQy: Out-of-plane shear force in the y-axis direction at point j (unit: N) iAy: Cross-sectional area in the y-axis direction at point i (unit: mm 2 ) jAz: Cross-sectional area in the z-axis direction at point j (unit: mm 2 ) i: Any distance from the center of the diaphragm in the z-axis direction (the direction toward the compression flange is positive) (unit: mm) j: Any distance from the center of the diaphragm in the y-axis direction (absolute value) (unit: mm) y-axis: The direction perpendicular to the maximum wind direction of the lighting pole z-axis: Maximum wind direction of the lighting pole F: Allowable tensile stress of the diaphragm (unit: N / mm 2 )

[0027] The above iMy, jMz, iQz, and jQy can be calculated using the following formulas. TIFF2025041363000006.tif123170Here uL: The value obtained by subtracting the equivalent plate thickness ut' from the cross-sectional area uD of the upper member, which is a set of four identical plate materials arranged symmetrically about two axes. uL=uD-ut' (unit: mm) LL: The value obtained by subtracting the plate thickness Lt from the thickness LD of the lower rectangular steel pipe LL=LD-Lt (single mm) NL: Column axial force at the examination height (unit: N) Nf: Axial force acting on the upper member flange due to bending moment around the y-axis at the examination height (unit: N) Nw: Axial force acting on the upper member web due to bending moment around the y-axis at the examination height (unit: N)

[0028] Using the above formula (1), it can be confirmed that the values ​​of the stress in the principal axis direction due to the bending moment around the y-axis iMy, the bending moment around the z-axis jMz, the shear force in the z-axis direction iQz, and the shear force in the y-axis direction jQy at any point (i,j) on the through diaphragm 10 do not exceed the allowable tensile stress of the diaphragm. Regarding this point, a structural performance evaluation has been obtained as an evaluation of the design method (ERI-K22004). [Industrial Applicability]

[0029] The lighting fixture installation support and its design method according to the present invention are as described above. By joining the upper and lower steel pipe posts via a through diaphragm that is set to satisfy a specified formula, it is possible to create a lighting fixture installation support that has sufficient strength to accommodate the installation of a lighting fixture without the need for dedicated manufacturing equipment, and the industrial applicability of this method is great. [Explanation of symbols]

[0030] 1 Support for lighting equipment installation 2. Lighting equipment 3 Top Plate 4. Circular steel pipe columns 5,6,7 Square steel pipe column 8 Column base plate 10 through diaphragm

Claims

1. A support for installing lighting fixtures, which is made by joining multiple steel pipe poles of different diameters vertically so that the lower ones have larger diameters, A support for installing lighting fixtures, characterized in that the multiple steel pipe columns are each welded together via a through diaphragm, and the plate thickness of the through diaphragm is set so that the out-of-plane stress generated therein is equal to or less than the short-term allowable stress level, thereby allowing a maximum misalignment of 50 mm on one side between the upper steel pipe column and the lower steel pipe column.

2. 2. The support for installing a lighting fixture according to claim 1, wherein the out-of-plane stress generated in the through diaphragm is equal to or less than the short-term allowable stress level, as confirmed by the following formula (1). Here iMy: Out-of-plane bending moment around the y-axis at point i (unit: Nmm) jMz: Out-of-plane bending moment around the z-axis at point j (unit: Nmm) iZy: Section modulus of the y-axis cross section at point i (unit: mm ３ ) jZz: Section modulus of the z-axis cross section at point j (unit: mm ３ ) iQz: Out-of-plane shear force in the Z-axis direction at point i (unit: N) jQy: Out-of-plane shear force in the y-axis direction at point j (unit: N) iAy: Cross-sectional area of ​​the y-axis cross section at point i (unit: mm ２ ) jAz: Cross-sectional area in the z-axis direction at point j (unit: mm ２ ) i: Any distance from the center of the diaphragm in the z-axis direction (the direction toward the compression flange is positive) (unit: mm) j: Any distance from the center of the diaphragm in the y-axis direction (absolute value) (unit: mm) y-axis: direction perpendicular to the maximum wind direction of the lighting pole Z axis: Maximum wind direction of the lighting pole F: Allowable tensile stress of the diaphragm (unit: N / mm ２ )

3. 2. The support for installing a lighting fixture according to claim 1, wherein the steel pipe column at the top is a circular steel pipe column having a top plate at its upper end for installing a lighting fixture, and the other steel pipe columns are square steel pipe columns.

4. 2. The support for installing a lighting fixture according to claim 1, wherein the cross section of each of the steel pipe columns changes depending on the distance from the top so that the effective slenderness ratio is 200 or less.

5. A method for designing a support for installing lighting fixtures, which is manufactured by vertically welding together a plurality of steel pipe columns of different diameters via a through diaphragm so that the diameter of the lower columns is larger, A method for designing a support for installing a lighting fixture, characterized in that the thickness of the through diaphragm is set so that the out-of-plane stress generated therein is equal to or less than the short-term allowable stress level.

6. A method for designing a support for installing a lighting fixture as described in claim 5, wherein it is confirmed by formula (1) described in claim 2 that the out-of-plane stress generated in the through diaphragm is equal to or less than the short-term allowable stress.

Images