EARTHQUAKE-RESISTANT LIGHT TOWER WITH THE TUNED MASS DAMPER

Abstract

The present invention relates to an earthquake-resistant light tower with a tuned mass damper, in which a tuned mass damper is installed in a head part of a light apparatus installed on the top of a tower to absorb an earthquake or other vibration, thereby protecting a tower from vibration.

Claims

1. An earthquake-resistant light tower with a tuned mass damper, in which an earthquake-resistant means (10) is installed in the light tower including a light device frame (200) in which a light device (201) is installed and/or a tower head (300) on the top of a tower body (100), wherein the earthquake-resistant means (10) includes a guide (11) fixedly installed in the tower body; a slider (12) fixedly installed below the light device frame or tower head (300) so as to allow the light device frame or tower head (300) to serve as the tuned mass body and including the light device frame or tower head (300) to serve as the tuned mass body and supported by the guide to be horizontally movable; and multiple tuned damper (13) radially installed between the guide and the slider and absorbing vibration of the slider by vibration of the tower body, a mass of the slider (12) is controlled so that a total mass acquiring by adding the mass of the light device frame (200), and the mass of the tower head (300) and the mass of the slider (12) is 1% or more or 20% or less of the total mass of the light tower including the tower body, the light device frame (200), the owe head (300), and the slider (12).

2. The earthquake-resistant light tower with a tuned mass damper of claim 1, wherein the tuned damper (13) is any one or both of a spring and an oil damper.

3. The earthquake-resistant light tower with a tuned mass damper of claim 1, wherein the friction reducing means (14) is further installed between an upper surface of the guide and the bottom of the slider so that the slider smoothly moves.

Description

DESCRIPTION OF DRAWINGS

[0019] FIG. 1 is a side view of one example of an earthquake-resistant light tower with a tuned mass damper according to the present invention.

[0020] FIG. 2 is a side view of a light device head part having an earthquake-resistant means in the light tower according to the present invention.

[0021] FIG. 3 is a side view of one example of the earthquake-resistant means in the light tower according to the present invention.

[0022] FIG. 4 is a side view of another example of the earthquake-resistant means in the light tower according to the present invention.

[0023] FIG. 5 is a perspective view of the earthquake-resistant means installed in the light tower according to the present invention.

MODE FOR INVENTION

[0024] The present invention may have various modifications and various embodiments and specific embodiments will be illustrated in the drawings and described in detail in the detailed description. However, this does not limit the present invention to specific embodiments, and it should be understood that the present invention covers all the modifications, equivalents and replacements included within the idea and technical scope of the present invention.

[0025] In describing each drawing, reference numerals refer to like elements. In describing the present invention, a detailed description of related known technologies will be omitted if it is determined that they make the gist of the present invention unclear.

[0026] Hereinafter, a preferred embodiment of the present invention will be described in detail with reference to the accompanying drawings.

[0027] In the present invention, a light device frame or a tower head serves as a tuned mass body to effectively absorb vibration of a tower body.

[0028] In an earthquake-resistant light tower with a tuned mass damper according to the present invention, an earthquake-resistant means 10 is installed in a light tower including a light device frame 200 in which a light device 201 is installed and/or a tower head 300 on the top of a tower body 100.

[0029] That is, according to the present invention, a tuned mass damper technologies is applied to the light tower and a separate tuned mass body is not installed in the tower body 100 and the light device frame 200 or the tower head may be used as the tuned mass body.

[0030] The earthquake-resistant means 10 includes: a guide 11 fixedly installed in the tower body 100; a slider 12 fixedly installed below the light device frame or tower head 300 so as to allow the light device frame or tower head 300 to serve as the tuned mass body and including the light device frame or tower head 300 to serve as the tuned mass body and supported by the guide to be horizontally movable; and multiple tuned damper 13 radially installed between the guide and the slider and absorbing vibration of the slider by vibration of the tower body.

[0031] A normal light tower includes a fixation type light tower in which the light device is fixedly installed and an elevation type light tower capable of elevating the light device, and in the case of the fixation type light tower, the light device frame 200 in which the light device 201 is installed on a platform of the tower body is integrally fixedly installed and in the case of the elevation type light tower, the light device frame 200 is elevatably installed and the tower head 300 is provided on the top of the tower body in order to elevate the light device frame.

[0032] As a result, in the case of the fixation type light tower, the earthquake-resistance means 10 is installed in the light device frame 200 and in the case of the elevation type light tower, the light device frame is elevated, and as a result, the earthquake-resistance means 10 is installed in the tower head 300.

[0033] Therefore, the light device frame 200 or the tower head 300 serves as the tuned mass body.

[0034] In FIGS. 1 to 5, one example of the elevation type light tower is illustrated and hereinafter, the earthquake-resistant tower with the tuned mass damper according to the present invention will be described based on the elevation type light tower.

[0035] The guide 11 is fixedly installed in the tower body 100 below the light device frame 200 or the tower head 300 as illustrated in FIGS. 2 to 5.

[0036] In the guide 11 as a means that supports the slider 12 to horizontally move, a support projection 11d is formed on an upper surface so as to restrict a movement range of the slider 12 or a sliding hole 11h is formed so as to move while a sliding rod 12r formed in the slider 12 engages in the sliding hole 11h as illustrated in FIG. 5.

[0037] Of course, as illustrated in FIGS. 2 to 4, the guide 11 may be formed in a circular plate shape and the sliding groove may be formed by bending an edge of a circular plate.

[0038] The slider 12 is fixedly installed on the bottom of the light device frame 200 or the tower head 300 and installed to be horizontally moved by the guide 11.

[0039] That is, when the tower body 100 vibrates, the guide 11 horizontally moves, but the slider 12 may not move and as a means that buffers the vibration of the guide so as to prevent the vibration of the guide from being transferred to the slider, the tuned damper 13 is provided.

[0040] The tuned damper 13 as a means for absorbing the vibration of the guide 11 so as to prevent the guide 11 which vibrates by the vibration of the tower body 100 from being just transferred to the slider 12 may adopt any one or both of a guide spring and an oil damper.

[0041] The tuned damper 13 may be installed between the support projection 11d formed on the edge of the guide 11 and an outer peripheral end of the slider 12 as illustrated in FIG. 2 or installed between a part on the top of the guide, which is bent inward and an outer wall of a body of the slider 12 as illustrated in FIG. 4.

[0042] Further, a friction reducing means 14 may be further installed between the upper surface of the guide 11 and the bottom of the slider 12 so that the slider smoothly moves.

[0043] The friction reducing means 14 may be achieved by installing a bearing between the guide 11 and the slider 12 or manufacturing the guide 11 and the slider 12 with bearing metal.

[0044] Further, the slider 12 preferably controls a mass so as to serve as the tuned mass damper.

[0045] That is, in the normally used tuned mass damper, the mass of the tuned mass body varies in proportion to the mass of the entirety of a structure which requires earthquake resistance.

[0046] As a result, only when a mass acquiring by adding the mass of the light device frame 200 or the tower head 300 and the mass of the slider 12 needs to be controlled in proportions to the mass of the entirety of the light tower including the tower body, the light device frame, the tower head, and the slider, optimal earthquake-resistant performance may be exhibited.

[0047] As a result, the mass of the slider 12 is preferably controlled so that the mass acquired by adding the mass of the light device frame 200 or the tower head 300 and the mass of the slider 12 is 1% or more or 20% or less of the total mass of the light tower including the tower body, the light device frame, the tower head, and the slider.

[0048] A result of structurally analyzing the earthquake-resistant light tower with the tuned mass damper according to the present invention, which is configured as above is shown in a comparison table given below.

TABLE-US-00001 Maximum displacement Maximum bottom Input of uppermost part (mm) shear force (kN) Earthquake Normal Tower TMD effect Normal Tower TMD effect Earthquake Wave Tower with TMD (%) Tower with TMD (%) Kobe KB-KBU-E 338.7 50.3 85.16 14.9 8.7 41.66 KB-KBU-N 180.3 49.0 72.85 8.1 6.4 21.26 KB-PRI-E 469.6 71.4 84.81 18.6 10.0 46.22 KB-PRI-N 437.0 62.0 85.81 16.1 9.1 43.41 Loma Prieta LP-CAP-E 242.8 64.2 73.54 15.8 9.8 38.13 LP-CAP-N 138.3 60.6 56.17 10.5 10.6 1.30 LP-CLS-E 221.3 105.2 52.45 14.6 12.2 16.59 LP-CLS-N 194.4 54.7 71.85 11.4 11.4 0.19 Northridge NO-ARL-E 235.6 47.9 79.68 13.8 7.8 43.45 NO-ARL-N 142.9 44.3 69.02 11.5 6.9 39.46 NO-SCS-E 791.8 89.2 88.73 30.0 12.9 57.05 NO-SCS-N 876.5 165.4 81.13 29.2 21.0 28.13 Average 75.10 Average 31.16

[0049] As the result of analyzing a structure in which the earthquake-resistant means is not installed and the earthquake-resistant light tower with the tuned mass damper according to the present invention by using 12 earthquake waves, it can be seen that a maximum displacement of an uppermost part is reduced by an average of 75.1% and maximum bottom shear force is reduced by an average of 31.2% and it can be seen that in the case of the earthquake-resistant light tower with the tuned mass damper according to the present invention, the mass of the light device is relatively large, and as a result, a significant effect is achieved.

[0050] Further, it is preferable to control a width of a displacement T of the slider according to the mass of the mass body, which is acquired by adding the mass of the light device frame 200 or the tower head 300 and the mass of the slider 12.

[0051] That is, as illustrated in FIGS. 3 and 4, it is very important to select and apply an optimal mass displacement limit as the displacement T which is a distance between an edge end of the slider 12 and an end support projection of the guide 11.

[0052] That is, when the displacement is excessively narrow, a movement width of the slider is small, and s a result, elastic force of the tuned damper 13 is still applied to the slider to serve to accelerate the vibration of the slider, and as a result, more effective earthquake resistance may be preferably achieved by controlling the displacement T and this may vary depending on a scale of the light tower.

SEQUENCE LIST TEXT

[0053] 10: Earthquake-resistance means [0054] 11: Guide [0055] 11d: Support projection [0056] 11h: Sliding hole [0057] 12: Slider [0058] 12b: Slider body [0059] 12r: Sliding rod [0060] 13: Tuned damper [0061] 14: Friction reducing means [0062] 100: Tower body [0063] 200: Light device frame [0064] 201: Light device [0065] 300: Tower head