Spring, handrail, and lattice structure

Abstract

To provide a spring easily installed on a handrail of a lattice structure and capable of reducing wind noise, a handrail to which the spring is attached, and a lattice structure provided with a handrail.SOLUTION: A spring 14 comprises a plate part 23 that has a pair of plate materials 22 arranged opposite each other inside the handrail 12 and extending in the elongation direction of the handrail 12, and elastic parts 24, 25 attached at both ends of the plate materials 22 in the elongation direction of the handrail 12 and forming an annular shape together with the plate materials 22. The elastic parts 24, 25 cause the plate materials 22 to always bring the entire surface of each contact surface 22a of the plate materials 22 into contact with an inner wall surface 12a, and the plate material 22 and the inner wall surface 12e exert relatively movable pressing force when the handrail 12 is deformed.SELECTED DRAWING: Figure 2

Description

[Technical field]

[0001] The present invention is directed to reducing the volume of structure-borne sound (hereinafter referred to as wind noise) emitted by lattice structures consisting of handrails installed on windows, verandas, balconies, rooftops, emergency stairs, etc. of buildings, or fences installed on the boundaries of land, houses, etc., when they are hit by wind. [Background technology]

[0002] The above-mentioned lattice structure has a number of balusters that are arranged at intervals and extend linearly vertically, horizontally or diagonally. Wind noise is generated by a resonance phenomenon (vortex induced vibration) that occurs when the predominant frequency of Karman vortices that are generated when wind blows through between the balusters of the lattice structure matches the natural frequency of the balusters, or when the predominant frequency of the Karman vortices is close to the natural frequency of the balusters.

[0003] As a technique for reducing the magnitude of wind noise in vertical lattice handrails, which are one type of lattice structure, Patent Document 1 discloses a wind noise reduction structure that includes a plate material fixed to the surface or inside of the balusters. With this wind noise reduction structure, the energy that causes the balusters to vibrate due to wind pressure is reduced compared to a case where no plate material is installed, making it possible to suppress vibration. This reduces the magnitude of wind noise caused by the vibration of the balusters. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] JP 2022-154394 A Summary of the Invention [Problem to be solved by the invention]

[0005] In the technology of Patent Document 1 described above, the plate material is fixed to the balusters by fasteners such as tapping screws and rivets, adhesives, welding, etc. For this reason, particularly when fixing the plate material inside the balusters, work must be done in a narrow space, making it difficult to install the plate material on the balusters.

[0006] The present invention has been made in consideration of the above, and has an object to provide a spring that can be easily installed on a balusters of a lattice structure and can reduce wind noise, a balusters with a spring attached, and a lattice structure equipped with a balusters. [Means for solving the problem]

[0007] In order to achieve the above-mentioned object, the spring of the present invention comprises a plate portion having a pair of plate materials arranged relative to each other inside a hollow member having a rectangular cross-sectional shape and extending in the extension direction of the hollow member, and a pair of elastic portions arranged at both ends of the plate portion in the extension direction and forming a ring shape integrally with the plate portion, the pair of elastic portions causing the entire surfaces of both plate materials that contact the inner wall surface of the hollow member to always be in contact with the inner wall surface, and exerting a pressing force that allows the plate materials and the inner wall surface to move relatively when the hollow member is deformed.

[0008] The handrail of the present invention is a handrail used in the manufacture of a lattice structure consisting of a handrail or fence, and comprises a tubular member having a rectangular cross-sectional shape and the above-mentioned spring of the present invention arranged inside the tubular member.

[0009] The lattice structure of the present invention is a lattice structure consisting of a handrail or fence having a plurality of balusters, each of which is made of the above-mentioned balusters of the present invention. Effect of the Invention

[0010] According to the present invention, it is possible to provide a spring that can be easily installed on a balusters of a lattice structure and can reduce wind noise, a balusters to which the spring is attached, and a lattice structure equipped with a balusters. [Brief description of the drawings]

[0011] [Figure 1] FIG. 1 is a perspective view of a vertical lattice handrail, which is one example of a lattice structure according to the present invention. [Diagram 2] FIG. 2 is a schematic vertical cross-sectional view showing a spring according to the first embodiment and a handrail to which the spring is attached. [Diagram 3] FIG. 3 is a cross-sectional view taken along line AA in FIG. 2. [Figure 4] (a) is a schematic vertical cross-sectional view of the balusters and the springs inside them when not vibrating. (b) is a schematic vertical cross-sectional view of the balusters and the springs inside them when vibrating in the first vibration mode. (c) is a schematic vertical cross-sectional view of the balusters and the springs inside them when vibrating in the second vibration mode. (d) is a schematic vertical cross-sectional view of the balusters and the springs inside them when vibrating in the third vibration mode. [Diagram 5] FIG. 11 is a schematic vertical cross-sectional view showing a spring according to a second embodiment and a handrail to which the spring is attached. [Figure 6] FIG. 11 is a schematic vertical cross-sectional view showing a spring according to a third embodiment and a handrail to which the spring is attached. [Figure 7] FIG. 11 is a schematic vertical cross-sectional view showing a spring according to a fourth embodiment and a handrail to which the spring is attached. [Figure 8] FIG. 11 is a schematic vertical cross-sectional view showing a spring according to a fifth embodiment and a handrail to which the spring is attached. [Figure 9] FIG. 13 is a schematic vertical cross-sectional view showing a spring according to a sixth embodiment and a handrail to which the spring is attached. [Figure 10] FIG. 13 is a schematic vertical cross-sectional view showing a spring according to a seventh embodiment and a handrail to which the spring is attached. [Figure 11] FIG. 13 is a diagram showing the results of a hammering test. [Figure 12] FIG. 13 is a diagram showing the results of a hammering test. [Figure 13] FIG. 13 is a diagram showing the results of a hammering test. [Figure 14] FIG. 13 is a diagram showing the results of a hammering test. [Figure 15] FIG. 13 is a diagram showing the results of a wind tunnel experiment. [Figure 16] FIG. 13 is a diagram showing the results of a wind tunnel experiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0012] Hereinafter, an embodiment of the present invention will be described with reference to the drawings. In the drawings, the same or equivalent parts and components are denoted by the same or equivalent reference numerals, and the description thereof will be omitted or simplified.

[0013] (First embodiment) The present invention is directed to reducing wind noise from lattice structures consisting of handrails (vertical lattice handrails, horizontal lattice handrails, diagonal lattice handrails, etc.) installed on windows, verandas, balconies, rooftops, emergency stairs, etc. of buildings, or fences installed on the boundaries of land, houses, etc.

[0014] As shown in Fig. 1, a vertical lattice handrail 10, which is an example of the above-mentioned lattice structure, includes a plurality of balusters 12. A spring 14 (see Figs. 2 and 3) according to the first embodiment is attached to each baluster 12.

[0015] The illustrated vertical lattice handrail 10 comprises a pair of posts 16 extending vertically (up and down) and two upper and lower chord members 18 fixed to both posts 16 and extending horizontally. A number of balusters 12 extend vertically and are disposed at intervals between both chord members 18. Each baluster 12, each post 16, and each chord member 18 is made of, for example, an extruded aluminum material.

[0016] As shown in FIGS. 2 and 3, the handrail 12 is a hollow member having a rectangular cross-sectional shape, that is, a pipe member. The handrail 12 has upper ends 12a and lower ends 12b that face each other, and is fixed to the upper and lower chord members 18 at the upper and lower ends 12a and 12b. Further, the handrail 12 has two pairs of outer wall surfaces (outer surfaces) 12c and 12d that face each other, and two pairs of inner wall surfaces (inner surfaces) 12e and 12f that face each other (see FIGS. 2 and 3). One pair of outer wall surfaces 12c of the handrail 12 faces the adjacent handrail 12 or the column 16. The other pair of outer wall surfaces 12d face the front side and the back side of the vertical lattice handrail 10, respectively.

[0017] The spring 14 includes a plate portion 23 having a pair of plate members 22 disposed opposite to each other inside the handrail 12, and elastic portions 24 and 25 disposed at the upper end and the lower end of the plate portion 23, respectively. As shown in FIG. 2, the plate portion 23 (both plate members 22) and the elastic portions 24 and 25 integrally form an annular shape. The elastic portions 24 and 25 constitute a pair of elastic portions disposed at both ends of the plate portion 23 in the extending direction of the handrail 12.

[0018] The spring 14 is formed by bending a single elongated flat plate made of metal such as aluminum or steel, and fixing the fixing portion 26, which is one end portion in the longitudinal direction of the flat plate, and the fixing portion 27, which is the other end portion, so as to overlap each other. The fixing portions 26 and 27 can be fixed to each other by, for example, riveting or welding. The flat plate forming the spring 14 preferably has a thickness dimension in the range of 0.8 to 1.0 mm in consideration of workability such as bending and elastic deformability (bendability) of the plate member 22.

[0019] Both plate members 22 extend in the extending direction of the handrail 12 inside the handrail 12 and abut against both inner wall surfaces 12e of the handrail 12 under the elastic force of the elastic portions 24 and 25. The plate member 22 has a length dimension L2 (L2 < L1) shorter than the length dimension L1 of the handrail 12 (see FIG. 3). Further, both plate members 22 have a width dimension smaller than the width dimension of the inner wall surface 12e of the handrail 12 (see FIG. 3). Instead of the illustrated example in which the contact targets of both plate members 22 are a pair of inner wall surfaces 12e, it can be a pair of other inner wall surfaces 12d.

[0020] The length dimension L2 of the plate material 22 is not particularly limited, but may be a length dimension which enables the plate material 22 to abut against the inner wall surface 12e of the balusters 12 at amplitude peak locations, which are the tops of mountains or the bottoms of valleys in the generated vibrations (the location of one peak P1 in the primary vibration mode, the locations of two peaks P2 and P3 in the secondary vibration mode, and the locations of three peaks P4 to P6 in the tertiary vibration mode), when the vertical lattice handrail 10 receives wind and the wind blows through between the balusters 12 of the vertical lattice handrail 10, causing the balusters 12 to vibrate in one or more of the primary vibration mode (Figure 4(b)), secondary vibration mode (Figure 4(c)), and tertiary vibration mode (Figure 4(d)). The reason why this is defined as when the vertical lattice handrail 10 is subjected to wind and each balusters 12 vibrates in one or more of the primary, secondary, and tertiary vibration modes is based on the knowledge that the wind speed (wind speed) that normally acts on the vertical lattice handrail 10 is within the range of 5 to 15 m / s, and that within this wind speed range, the vibration of each balusters 12 is one or more of the primary to tertiary vibration modes.

[0021] In addition, even if the spring 14 slides down inside the handrail 12 to the lower end 12b of the handrail 12 due to its own weight when the handrail 12 vibrates, both plate materials 22 may be formed in a shape that maintains a state in which they can abut against the inner wall surface 12e of the handrail 12 at the point P1 of one peak of the primary vibration mode, at the points P2 and P3 of two peaks of the secondary vibration mode, and at the points P4, P5, and P6 of three peaks of the tertiary vibration mode.

[0022] In the illustrated example, point P1 of one peak of the amplitude of the vibration in the primary vibration mode is located at a position away from the upper end 12a and lower end 12b of the balusters 12 by a distance equivalent to 1 / 2 of the length dimension L1 of the balusters 12 (see FIG. 4(b)), i.e., at the center in the longitudinal direction of the balusters 12. Also, points P2 and P3 of two peaks of the amplitude of the vibration in the secondary vibration mode are located at positions away from the upper end 12a and lower end 12b of the balusters 12 by a distance equivalent to 1 / 4 of the length dimension L1 of the balusters 12 (see FIG. 4(c)), respectively. Furthermore, of the three amplitude peaks in the third vibration mode, two peaks P4 and P6 are located at a distance equivalent to 1 / 6 of the length dimension L1 of the balusters 12 (see Figure 4(d)) from the upper end 12a and lower end 12b of the balusters 12, respectively, and the remaining peak P5 is located at a distance equivalent to 1 / 2 of the length dimension L1 of the balusters 12, i.e., at the center position in the longitudinal direction of the balusters 12.

[0023] The elastic portion 24 is connected to the upper ends of both plate members 22 and is formed in a valley fold shape that fits inside the ring shape of the spring 14 between both plate members 22.

[0024] The elastic portion 25 is connected to the lower ends of both plate materials 22, and is formed in a mountain fold shape between both plate materials 22, protruding outward from the ring shape of the spring 14. Here, as described above, the elastic portion 25 is formed in a shape similar to a flat plate folded in a mountain shape between the lower ends of both plate materials 22 by overlapping and fixing the fixing portions 26, 27 to each other. For this reason, it can be said that the elastic portion 25 is formed in a mountain fold shape.

[0025] The spring 14 presses the pair of plate materials 22 toward each other, putting the elastic portions 24, 25 in a compressed state, and can be inserted from one to the other of the upper and lower ends 12a, 12b of the balusters 12 used in the manufacture of the vertical lattice handrail 10 into the interior of the balusters 12. This allows the spring 14 to be easily positioned inside the balusters 12.

[0026] Both plate materials 22 are subjected to the elastic force of elastic portions 24, 25 inside the balusters 12 and come into contact with both inner wall surfaces 12e of the balusters 12, with the contact surfaces 22a being in intimate contact with both inner wall surfaces 12e of the balusters 12, respectively.

[0027] Here, the contact surface 22a of the plate 22 is the surface of the plate 22 that comes into contact with the inner wall surface 12e of the balusters 12. In addition, in the spring 14, a state in which the contact surface 22a of the plate 22 is in close contact with the inner wall surface 12e of the balusters 12 means a state in which the entire surface of the contact surface 22a is in contact with the inner wall surface 12e.

[0028] The spring 14 is formed so that the elastic portions 24, 25 constantly keep the contact surfaces 22a of both plate materials 22 in close contact with the inner wall surface 12e of both plate materials 22, and exert a pressing force that allows the plate materials 22 and the inner wall surface 12e to move relative to one another when the handrail 12 is deformed.

[0029] As a result, even if the balusters 12 are elastically deformed when the vertical lattice handrail 10 is exposed to wind as described below, the springs 14 maintain a state in which the contact surfaces 22a are in close contact with the inner wall surface 12e. Also, when the balusters 12 are elastically deformed, minute slippage occurs between the contact surfaces 22a and the inner wall surface 12e, generating friction.

[0030] Next, the function of the spring 14 will be described.

[0031] When the vertical lattice handrail 10, which is equipped with multiple balusters 12 to which springs 14 are attached, receives wind, vibrations occur in the balusters 12 in one or more of the primary, secondary, and tertiary vibration modes, and the balusters 12 undergo elastic deformation (curved deformation) corresponding to the vibrations thus generated. The two plate materials 22, whose contact surfaces 22a are in close contact with the two inner wall surfaces 12e of the balusters 12, undergo elastic deformation along the curved inner wall surfaces 12e of the balusters 12 due to external forces from the balusters 12 caused by the elastic deformation. At this time, the two plate materials 22 slide slightly on the two inner wall surfaces 12e of the balusters 12 while maintaining a state in which the contact surfaces 22a are in close contact with the two inner wall surfaces 12e of the balusters 12. As a result, friction occurs between the inner wall surfaces 12e of the balusters 12 and the contact surfaces 22a of the two plate materials 22.

[0032] This friction acts as a force that tries to stop the vibration through frictional damping (energy loss due to friction when considered in terms of energy balance), and increases the damping capacity of the balusters 12. Therefore, friction occurring between the inner wall surface 12e of the balusters 12 and the contact surfaces 22a of both plate materials 22 reduces the vibration of the balusters 12 and the associated wind noise.

[0033] As described above, the spring 14 includes a plate portion 23 having a pair of plate materials 22, and elastic portions 24, 25 that are respectively disposed at the upper and lower ends of the plate portion 23 and integrally form a ring shape with the plate portion 23. The elastic portions 24, 25 constantly bring the contact surfaces 22a of both plate materials 22 into close contact with the inner wall surface 12e (the entire surfaces of the contact surfaces 22a constantly contact the inner wall surface 12e), and exert a pressing force on both plate materials 22 that allows the plate materials 22 and the inner wall surface 12e to move relatively when the handrail 12 is deformed.

[0034] This causes vibrations in the balusters 12, and when the balusters 12 undergo elastic deformation corresponding to the vibrations generated therein, both plate materials 22 undergo elastic deformation along the inner wall surfaces 12e of the balusters 12. At this time, both plate materials 22 slide slightly on both inner wall surfaces 12e of the balusters 12 while maintaining a state in which their contact surfaces 22a are in close contact with both inner wall surfaces 12e of the balusters 12. As a result, friction is generated between the inner wall surfaces 12e of the balusters 12 and the contact surfaces 22a of both plate materials 22, and the vibrations of the balusters 12 and the associated wind noise are reduced by frictional damping.

[0035] Here, the spring 14 is not fixed to the balusters 12 by fasteners, welding, or the like, so the plate material 22 can slide on the inner wall surface 12e of the balusters 12, as described above. Therefore, as described above, the vibration of the balusters 12 and the associated wind noise can be reduced by friction damping between the inner wall surface 12e of the balusters 12 and the contact surface 22a of the plate material 22.

[0036] In addition, the spring 14 can be inserted into the inside of the handrail 12 with the elastic portions 24, 25 between the two plate materials 22 in a compressed state, and since there is no need to fix the spring 14 to the handrail 12 with fasteners, welding, etc., it can be easily installed on the handrail 12.

[0037] Therefore, the spring 14 can be easily installed on the handrail 12 and can reduce wind noise from the vertical lattice handrail 10.

[0038] Note that multiple springs 14 may be installed inside the balusters 12. In this case, the springs 14 are arranged at intervals so that adjacent springs 14 do not come into contact with each other even if the springs 14 slide down when the balusters 12 vibrate.

[0039] Second embodiment Next, a second embodiment, which is a partial modification of the first embodiment described above, will be described.

[0040] As shown in FIG. 5, a spring 14A according to the second embodiment has a configuration in which the elastic portions 24 and 25 of the spring 14 of the first embodiment are replaced with elastic portions 31 and 32, respectively.

[0041] The elastic portions 31 and 32 are formed in a planar shape inclined at the same angle with respect to the plate material 22 .

[0042] One end of the elastic portion 31 is connected to the upper end of one of the plate materials 22 (the plate material 22 on the left side in FIG. 5), and the other end is connected to a fixed portion 33. The fixed portion 33 is overlapped and fixed to a fixed portion 34 connected to the upper end of the other plate material 22 (the plate material 22 on the right side in FIG. 5). One end of the elastic portion 32 is connected to the lower end of the other plate material 22, and the other end is connected to a fixed portion 35. The fixed portion 35 is overlapped and fixed to a fixed portion 36 connected to the lower end of one of the plate materials 22.

[0043] As a result, the elastic portions 31, 32 are disposed at the upper and lower ends, respectively, of the plate portion 23, and form a ring shape integrally with the plate portion 23. Here, the fixing portions 33, 34 and the fixing portions 35, 36 can be fixed to each other by, for example, riveting or welding, similarly to the fixing portions 26, 27 of the spring 14 in the first embodiment.

[0044] The spring 14A is formed by combining two bent flat plates. The two flat plates are similar to the flat plates used to form the spring 14 of the first embodiment. One of the two flat plates includes the one plate material 22, the elastic portion 31, and the fixed portions 33 and 36 described above. The other flat plate includes the other plate material 22, the elastic portion 32, and the fixed portions 34 and 35 described above.

[0045] In the spring 14A, as in the spring 14 of the first embodiment, the length dimension L2 of the plate material 22 may be a length dimension that enables the plate material 22 to abut against the inner wall surface 12e of the handrail 12 at the peak point of the amplitude of the vibration generated when vibration of one or more of the primary vibration mode, secondary vibration mode, and tertiary vibration mode occurs in the handrail 12.

[0046] Furthermore, like the spring 14 of the first embodiment, the spring 14A may be formed in a shape that maintains a state in which both plate materials 22 can abut against the inner wall surface 12e of the handrail 12 at the point P1 of one peak of the primary vibration mode, at the points P2 and P3 of two peaks of the secondary vibration mode, and at the points P4, P5, and P6 of three peaks of the tertiary vibration mode, even if the spring 14A slides down inside the handrail 12 to the lower end 12b of the handrail 12 due to its own weight when the handrail 12 vibrates.

[0047] In the spring 14A, as in the spring 14 of the first embodiment, the elastic portions 31, 32 are formed so as to always bring the contact surfaces 22a of both plate materials 22 into close contact with the inner wall surface 12e of both plate materials 22, and to exert a pressing force that allows the plate materials 22 and the inner wall surface 12e to move relative to one another when the handrail 12 is deformed.

[0048] The above-described spring 14A, like the spring 14 of the first embodiment, is easy to install on the handrail 12 and can reduce wind noise from the vertical lattice handrail 10.

[0049] Third embodiment Next, a third embodiment, which is a partial modification of the first embodiment described above, will be described.

[0050] As shown in FIG. 6, a spring 14B according to the third embodiment has a configuration in which the elastic portion 25 of the spring 14 of the first embodiment is replaced with an elastic portion 41.

[0051] The elastic portion 41 is connected to the lower ends of both plate members 22, and is formed between both plate members 22 in a valley fold shape that fits inside the ring shape of the spring 14B.

[0052] That is, in spring 14B, both of elastic portions 24 and 41 disposed at the upper and lower ends of plate portion 23 are formed into a valley fold shape that goes inside the ring shape of spring 14B.

[0053] The spring 14B is formed by bending a single flat plate similar to that used to form the spring 14 of the first embodiment, and then fixing the fixing portions 26 and 27 to each other by overlapping them on the inside of the ring shape.

[0054] As described above, the elastic portion 41 is formed by overlapping and fixing the fixing portions 26 and 27 on each other inside the ring shape, so that the elastic portion 41 has a shape similar to that of a flat plate that is folded in a valley between the lower ends of both plate members 22. For this reason, it can be said that the elastic portion 41 is formed in a valley fold shape.

[0055] In the spring 14B, as in the spring 14 of the first embodiment, the length dimension L2 of the plate material 22 may be a length dimension that enables the plate material 22 to abut against the inner wall surface 12e of the handrail 12 at the peak point of the amplitude of the vibration generated when vibration of one or more of the primary vibration mode, secondary vibration mode, and tertiary vibration mode occurs in the handrail 12.

[0056] Furthermore, like the spring 14 of the first embodiment, the spring 14B may be formed in a shape that maintains a state in which both plate materials 22 can abut against the inner wall surface 12e of the handrail 12 at the point P1 of one peak of the primary vibration mode, at the points P2 and P3 of two peaks of the secondary vibration mode, and at the points P4, P5 and P6 of three peaks of the tertiary vibration mode, even if the spring 14B slides down inside the handrail 12 to the lower end 12b of the handrail 12 due to its own weight when the handrail 12 vibrates.

[0057] Specifically, the spring 14B may be formed so that the length dimension L2 of the plate material 22 is 10 / 12=5 / 6 of the length dimension L1 of each balusters. In this case, the upper and lower ends of the plate material 22 may be arranged at intervals of 1 / 12 of the length dimension L1 of the balusters 12 from the upper and lower ends 12a, 12b of the balusters 12, respectively.

[0058] In the spring 14B, as in the spring 14 of the first embodiment, the elastic portions 24, 41 are formed so as to always bring the contact surfaces 22a of both plate materials 22 into close contact with the inner wall surface 12e of both plate materials 22, and to exert a pressing force that allows the plate materials 22 and the inner wall surface 12e to move relative to one another when the handrail 12 is deformed.

[0059] The above-described spring 14B is also easy to install on the balusters 12 and can reduce wind noise from the vertical lattice handrail 10, similar to the spring 14 of the first embodiment.

[0060] (Fourth embodiment) Next, a fourth embodiment, which is a partial modification of the first embodiment described above, will be described.

[0061] As shown in FIG. 7, a spring 14C according to the fourth embodiment has a configuration in which an elastic portion 46 (corresponding to the other elastic portion) is added to the spring 14 of the first embodiment.

[0062] The spring 14C is formed by bending a single flat plate similar to that used to form the spring 14 of the first embodiment. Therefore, the plate portion 23 and the elastic portions 24 and 25 integrally form a ring shape. In the spring 14C, the flat plates are not fixed to each other by riveting or welding at any point.

[0063] In the spring 14C, one end of the elastic portion 24 is connected to the upper end of one plate material 22 (the plate material 22 on the left side in FIG. 7), and the other end is connected to the upper end of the abutment plate portion 47. The abutment plate portion 47 extends downward from the upper end of the other plate material 22 (the plate material 22 on the right side in FIG. 7) and abuts against the upper end portion of the other plate material 22 inside the ring shape.

[0064] In addition, in the spring 14C, the elastic portion 25 is formed by bending the flat plate forming the spring 14C between the lower ends of both plate members 22 so as to protrude outwardly of the ring shape.

[0065] The elastic portion 46 is disposed between the elastic portions 24 and 25, and presses both the plate members 22. The elastic portion 46 is formed in a shape curved downward. The elastic portion 46 is connected to the lower end of the abutment plate portion 47. The elastic portion 46 is formed by curving one end of a flat plate forming the spring 14C.

[0066] The above-described spring 14C can also be easily installed on the balusters 12 and can reduce wind noise from the vertical lattice handrail 10, similar to the spring 14 of the first embodiment.

[0067] Furthermore, since the spring 14C includes the elastic portion 46 that presses the plate material 22 between the elastic portions 24, 25, it is possible to prevent the inner wall surface 12e and the contact surface 22a from being unable to maintain a state of close contact with each other.

[0068] Fifth embodiment Next, a fifth embodiment, which is a partial modification of the fourth embodiment described above, will be described.

[0069] 8, the spring 14D according to the fifth embodiment has a configuration in which the elastic portion 25 of the spring 14C according to the fourth embodiment is replaced with an elastic portion 41. In other words, the spring 14D has a configuration in which an elastic portion 46 is added to the spring 14B according to the third embodiment.

[0070] In the spring 14D, the elastic portion 41 is formed by folding the flat plate forming the spring 14D between the lower ends of both plate members 22 in a valley shape so as to enter inside the ring shape.

[0071] The above-described spring 14D is also easy to install on the balusters 12 and can reduce wind noise from the vertical lattice handrail 10, similar to the spring 14 of the first embodiment.

[0072] Furthermore, since the spring 14D also includes the elastic portion 46, like the spring 14C of the fourth embodiment, it is possible to prevent the inner wall surface 12e and the contact surface 22a from being unable to maintain their tight contact state.

[0073] Sixth embodiment Next, a sixth embodiment, which is a partial modification of the fourth embodiment described above, will be described.

[0074] As shown in FIG. 9, a spring 14E according to the sixth embodiment has a configuration in which the elastic portions 24 and 25 of the spring 14C according to the fourth embodiment are replaced with elastic portions 51 and 52, respectively.

[0075] The elastic portions 51 and 52 are formed in a shape that is curved outwardly of the ring shape.

[0076] Like the spring 14 of the first embodiment, this spring 14E can also be easily installed on the handrail 12 and can reduce wind noise from the vertical lattice handrail 10.

[0077] Furthermore, since the spring 14E also includes the elastic portion 46, like the spring 14C of the fourth embodiment, it is possible to prevent the inner wall surface 12e and the contact surface 22a from being unable to maintain their tight contact state.

[0078] Seventh embodiment Next, a seventh embodiment, which is a partial modification of the above-described fourth embodiment, will be described.

[0079] 10, the spring 14F according to the seventh embodiment has a configuration in which the elastic portions 24 and 25 of the spring 14C according to the fourth embodiment are replaced with elastic portions 31 and 32, respectively. In other words, the spring 14F has a configuration in which an elastic portion 46 is added to the spring 14A according to the second embodiment.

[0080] Like the spring 14 of the first embodiment, this spring 14F can be easily installed on the handrail 12 and can reduce wind noise from the vertical lattice handrail 10.

[0081] Furthermore, since the spring 14F also includes the elastic portion 46, like the spring 14C of the fourth embodiment, it is possible to prevent the inner wall surface 12e and the contact surface 22a from being unable to maintain their tight contact state.

[0082] (Hammering test) Next, a hammering test that was carried out to verify the effect of reducing vibration of the handrail 12 by the springs 14, 14A to 14F of the above-mentioned first to seventh embodiments will be described.

[0083] In this hammering test, a balusters 12 was used, which was an aluminum tubular member having a rectangular cross-sectional shape of 20 mm wide x 30 mm long and a length of 1000 mm. The measurement point for this hammering test was a point 250 mm above the lower end 12b of the balusters 12.

[0084] Then, for each of the springs 14, 14A to 14F of the first to seventh embodiments, hammering tests were performed in the following cases: when one plate material 22 with a length dimension L2 of 950 mm was installed on the balusters 12, when one plate material 22 with a length dimension L2 of 475 mm was installed on the balusters 12, when one plate material 22 with a length dimension L2 of 315 mm was installed on the balusters 12, and when two plate material 22 with a length dimension L2 of 475 mm were installed on the balusters 12. For comparison, hammering tests were also performed on a balusters 12 on which none of the springs 14, 14A to 14F was installed (balusters 12 without measures).

[0085] Here, when one plate material 22 having a length dimension L2 of 475 mm is installed on the handrail 12, and when one plate material 22 having a length dimension L2 of 315 mm is installed on the handrail 12, springs 14, 14A to 14F are installed on the upper part of the handrail 12.

[0086] The springs 14, 14A to 14F used in this hammering test were formed from aluminum flat plates having a thickness of 0.5 mm and a width of 20 mm.

[0087] In this hammering test, based on the knowledge that within the wind speed range of 5 to 15 m / s that normally acts on the vertical lattice handrail 10, the vibration of the handrail 12 is one or more of the first to third vibration modes, the first, second and third vibration modes were evaluated.

[0088] By carrying out this hammering test, the damping constant of the balusters 12 was estimated. The damping constant can be used as an index of the level of ability to dampen vibrations occurring in the balusters 12 (damping capacity), that is, the level of ability to suppress vibrations of the balusters 12. The larger the damping constant value, the higher the damping capacity. The damping constant can be estimated from the excitation force and acceleration applied to the balusters 12 in the hammering test.

[0089] The results of the hammering test are shown in Figs. 11 to 14. Fig. 11 shows the results of the hammering test when each of the springs 14, 14A to 14F, whose plate material 22 has a length dimension L2 of 950 mm, is attached to the balusters 12. Fig. 12 shows the results of the hammering test when each of the springs 14, 14A to 14F, whose plate material 22 has a length dimension L2 of 475 mm, is attached to the balusters 12. Fig. 13 shows the results of the hammering test when each of the springs 14, 14A to 14F, whose plate material 22 has a length dimension L2 of 315 mm, is attached to the balusters 12. Fig. 14 shows the results of the hammering test when each of the springs 14, 14A to 14F, whose plate material 22 has a length dimension L2 of 475 mm, is attached to the balusters 12, two of which are respectively. 11 to 14 also show the results of a hammering test on the handrail 12 without any countermeasures.

[0090] 11 to 14, the balusters 12 on which the springs 14, 14A to 14F of the first to seventh embodiments are installed have a higher damping constant than the balusters 12 on which no countermeasures are taken. This shows that the balusters 12 on which the springs 14, 14A to 14F are installed contribute to reducing noise (wind noise) generated by winds with speeds of 5 to 15 m / s that are said to regularly act on the vertical lattice handrail 10.

[0091] (Wind tunnel experiment) Next, a wind tunnel experiment conducted on the springs 14, 14A of the first and second embodiments described above will be described.

[0092] In this wind tunnel experiment, a vertical lattice handrail 10 with 20 handrails 12 measuring 20 mm wide x 30 mm long was used.

[0093] The spring 14 of the first embodiment was installed on one of the two central balusters 12 of this vertical lattice handrail 10, and the spring 14A of the second embodiment was installed on the remaining one. A flat plate was fixed to the nine balusters 12 to the left of the two central balusters 12 to suppress vibration. The same measure was taken for the nine balusters 12 on the right side.

[0094] The springs 14, 14A were made of aluminum and had a thickness of 0.5 mm and a width of 20 mm, and the length L2 of the plate material 22 was 950 mm.

[0095] For comparison, a case was also included in which the two central balusters 12 of the vertical lattice handrail 10 were balusters 12 without any of the springs 14, 14A to 14F (balusters 12 without measures).

[0096] In this wind tunnel experiment, wind at a speed of 3 to 20 m / s was blown from the front to the back of the vertical lattice handrail 10. Then, the A-weighted sound pressure level and the vibration acceleration level were measured. For the vibration acceleration level of the vertical lattice handrail 10 in which springs 14, 14A were installed on the two central balusters 12, the vibration acceleration level of the balusters 12 in which the spring 14 was installed, out of the two central balusters 12, was measured.

[0097] The measurement results of the A-weighted sound pressure level and the vibration acceleration level in the wind tunnel experiment are shown in Fig. 15 and Fig. 16. In Fig. 15 and Fig. 16, the cases where the springs 14 and 14A are installed are shown as the cases where measures are taken.

[0098] As shown in Figures 15 and 16, when springs 14, 14A were installed (measures taken), the A-weighted sound pressure level and vibration acceleration level were lower than when no measures were taken, confirming the effect of reducing wind noise.

[0099] (Other embodiments) As described above, the present invention has been described by the first to seventh embodiments, but the descriptions and drawings forming part of this disclosure should not be understood as limiting this invention. Various alternative embodiments, examples, and operating techniques will become apparent to those skilled in the art from this disclosure.

[0100] In the above-described first and fourth embodiments, the elastic portion 24 arranged at the upper end of the plate portion 23 has a valley fold shape that fits inside the ring shape of the spring 14, 14C, and the elastic portion 25 arranged at the lower end of the plate portion 23 has a mountain fold shape that protrudes outside the ring shape. However, a mountain fold-shaped elastic portion may be arranged at the upper end of the plate portion 23, and a valley fold-shaped elastic portion may be arranged at the lower end of the plate portion 23. Also, both of the pair of elastic portions may be formed in a mountain fold shape.

[0101] In the second and seventh embodiments described above, the planar elastic portions 31, 32 are inclined at the same angle relative to the plate material 22. However, the pair of elastic portions may be formed in a planar shape inclined at different angles relative to the plate material 22. Furthermore, at least one of the pair of planar elastic portions may be formed perpendicular to the plate material 22.

[0102] In the sixth embodiment described above, the elastic parts 51 and 52 are curved outward from the ring shape of the spring 14E. However, at least one of the pair of curved elastic parts may be curved inward from the ring shape.

[0103] In addition, one of the pair of elastic parts may be a mountain fold or a valley fold, and the other elastic part may be a flat shape or a shape curved outward or inward of a ring shape. In addition, one of the pair of elastic parts may be a shape curved outward or inward of a ring shape, and the other elastic part may be flat. In addition, the elastic parts may have a shape other than the shapes shown in the first to seventh embodiments.

[0104] Thus, the present invention naturally includes various embodiments not described herein. Therefore, the technical scope of the present invention is defined only by the invention-specifying matters related to the scope of the claims appropriate from the above description. [Explanation of symbols]

[0105] 10 Vertical lattice handrail 12 Baluster 12e, 12f Inner wall surface 14,14A~14F Spring 22 Board material 22a Contact surface 23 Board part 24, 25, 31, 32, 41, 46, 51, 52 Elastic part

Claims

1. a plate portion having a pair of plate members disposed opposite each other inside a hollow member having a rectangular cross-sectional shape and extending in an elongation direction of the hollow member; a pair of elastic portions disposed on both ends of the plate portion in the extension direction and integrally forming a ring shape with the plate portion; The pair of elastic portions are springs that constantly keep the entire surfaces of both plate materials that contact the inner wall surface of the hollow member in contact with the inner wall surface, and exert a pressing force that allows the plate materials and the inner wall surface to move relative to each other when the hollow member is deformed.

2. The spring according to claim 1 , wherein the elastic portion is formed in a mountain fold shape protruding outward from the ring shape or a valley fold shape recessed into the ring shape.

3. The spring according to claim 1 , wherein the elastic portion is formed in a shape curved outwardly of the ring shape or inwardly of the ring shape.

4. The spring according to claim 1 , wherein the elastic portion is formed in a planar shape.

5. The spring according to any one of claims 1 to 4, further comprising another elastic portion disposed between the pair of elastic portions in the extension direction and pressing both plate materials.

6. A balusters for use in the manufacture of a lattice structure consisting of a handrail or fence, A tube member having a rectangular cross-sectional shape; A balustrade comprising the spring according to any one of claims 1 to 4, disposed inside the tubular member.

7. A lattice-like structure consisting of a handrail or fence having a plurality of balusters, 7. A lattice structure, each of which is made of a balustrade according to claim 6.

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