Vibration absorption method for vibration-damping racks and cable racks

Abstract

This invention provides a vibration-damping rack that absorbs seismic vibration energy using vibration-damping components in the cable rack, allowing for horizontal use without being limited by installation space. [Solution] Multiple child girders 20 are erected between a pair of long main girders 10. Vibration-damping connection parts 30 are provided at both ends of the child girders 20 to connect the main girders 10 and the child girders 20. The vibration-damping connection part 30 consists of a connector 31 and a vibration-absorbing member 32. The connector 31 connects the main girders 10 and the child girders 20. An insertion hole 32A is formed in the vibration-absorbing member 32 through which the connector 31 is inserted. The vibration-absorbing member 32 absorbs vibrations transmitted from the main girders 10 to the child girders 20.

Description

Technical Field

[0001] The present invention relates to a vibration damping rack used as a seismic countermeasure for a cable rack, and to a vibration damping rack capable of absorbing vibration energy during an earthquake with vibration damping members attached inside the cable rack and a method for absorbing vibration of the cable rack.

Background Art

[0002] Conventionally, as a vibration damping device used as a seismic countermeasure for a cable rack, for example, there is a seismic cable tray hanger device of the device described in Patent Document 1.

[0003] This hanger device includes a support frame 2 that supports the lower surface of the cable tray 1, a first support rod 3 connected to the ceiling, and a second support rod 4 connected to both ends of the support frame 2.

[0004] And, by providing a seismic section 30 that absorbs vibration between the first support rod 3 and the second support rod 4, it absorbs vibration in the vertical and horizontal directions and prevents damage to the cable rack.

Prior Art Documents

Patent Documents

[0005]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0006] However, all of the conventional vibration damping devices have a structure that is separately installed around the cable rack, so an installation space is required and the structure of the vibration damping device becomes complicated.

[0007] In other words, the hanger device described in Patent Document 1 has a structure in which a first support rod 3 and a second support rod 4 are arranged vertically at both longitudinal ends of the support frame 2, and a vibration-absorbing section 30 is provided between these upper and lower rods. Therefore, it is necessary to attach many vibration-damping members around the cable rack.

[0008] Therefore, this hanger device presents challenges in terms of its use in limited installation spaces, such as being difficult to use in confined spaces like above ceilings.

[0009] Furthermore, in many conventional cable racks, the main beam and secondary beam are fixed together by welding. If the main beam of the cable rack is repeatedly deformed horizontally due to an earthquake, there is a risk that the weld will break and the secondary beam will separate. As a result, even if the cable rack itself does not fall, the secondary beam may fall, which poses a problem.

[0010] Furthermore, with conventional cable racks, an earthquake could cause the entire rack to sway, potentially leading to the breakage of the suspension bolts used to install the rack. This presented a problem where the entire cable rack could fall.

[0011] Therefore, the present invention was created to solve the above-mentioned problems, and aims to provide a vibration-damping rack and a method for absorbing vibrations in a cable rack that can absorb vibration energy during earthquakes with vibration-damping members of the cable rack, can be installed without being limited by construction space, can prevent the fall of the secondary girders by preventing the fracture of the main girders and secondary girders, and can prevent the fall of the entire cable rack by preventing the fracture of the suspension bolts. [Means for solving the problem]

[0012] To achieve the above objective, the first means of the present invention comprises a pair of elongated main girders 10, a plurality of sub-girders 20 erected between the main girders 10, and vibration-damping connection parts 30 provided at the longitudinal ends of the sub-girders 20, which connect the main girders 10 and the sub-girders 20 and absorb vibrations transmitted from the main girders 10 to the sub-girders 20.

[0013] The vibration-damping connection portion 30 of the second means comprises a connector 31 that connects the main girder 10 and the sub-girder 20, and a vibration-absorbing member 32 which is an elastic member that has an insertion hole 32A through which the connector 31 is inserted and absorbs vibrations transmitted from the main girder 10 to the sub-girder 20.

[0014] The third means of the connector 31 comprises a male screw 31A and a female screw 31B provided on the sub-girder 20, wherein the male screw 31A is inserted through an insertion hole 10A provided on the side surface of the main girder 10.

[0015] In the fourth means, the main girder 10 and the sub-girder 20 are connected by at least one of the connectors 31, and the vibration absorbing member 32 is attached by at least one of the connectors 31.

[0016] The elastic member of the fifth means is viscoelastic rubber or a spring.

[0017] The sixth means of the vibration-damping connection section 30 comprises a connector 31 that connects the main girder 10 and the sub-girder 20, and a damper provided between the main girder side connection portion of the connector 31 and the sub-girder side connection portion of the connector 31.

[0018] The seventh means is a vibration absorption method for a cable rack P comprising a pair of elongated main girders 10 and a plurality of sub-girders 20 erected between the main girders 10, wherein vibrations transmitted from the main girders 10 to the sub-girders 20 are absorbed by vibration-damping connection parts 30 provided at the longitudinal ends of each sub-girder 20 and connecting the main girders 10 and the sub-girders 20. [Effects of the Invention]

[0019] According to the present invention, by absorbing the vibration energy during an earthquake with a vibration damping member installed inside the cable rack, it becomes unnecessary to separately install an earthquake-resistant device or an earthquake-resistant pedestal. As a result, it is expected to reduce the size of the earthquake-resistant device and improve the support interval, and it becomes possible to use it horizontally without being restricted by the construction space. Also, since breakage between the main girder and the sub-girder can be prevented, dropping of the sub-girder can be prevented. Further, since breakage of the suspension bolt can be prevented, dropping of the entire cable rack can be prevented.

Brief Description of the Drawings

[0020] [Figure 1] It is a perspective view of a main part showing the rack of the present invention. [Figure 2] It is a longitudinal sectional view of a main part showing the rack of the present invention. [Figure 3] It is a front view of a main part obtained by disassembling the rack of the present invention. [Figure 4] It is a side view showing an end portion of a sub-girder used in the rack of the present invention. [Figure 5] It is a plan view of a main part with a part of the rack of the present invention cut out. [Figure 6] It is a front view of a main part showing another embodiment obtained by disassembling the rack of the present invention. [Figure 7] It is a side view showing another embodiment of an end portion of a sub-girder used in the rack of the present invention. [Figure 8] (a) to (c) are schematic plan views showing the vibration damping principle of the rack of the present invention. [Figure 9] It is an enlarged plan view showing the inside of the enclosed line A shown in FIG. 8.

Mode for Carrying Out the Invention

[0021] The rack of the present invention is a vibration damping rack used as a countermeasure against earthquakes for a cable rack, and its main configuration is such that an anti-vibration connection part 30 is interposed between the main girder 10 and the sub-girder 20 of the cable rack P (see FIG. 1). The cable rack P to be used is a ladder-type cable rack P in which a plurality of sub-girders 20 are connected between a pair of main girders 10 (see FIG. 8).

[0022] The vibration-damping connection section 30 comprises a connector 31 and a vibration-absorbing member 32 (see Figure 1). The connector 31 is a threaded member that connects the main girder 10 and the sub-girder 20.

[0023] The illustrated connector 31 consists of a male screw 31A and a female screw 31B (see Figure 2). When fastening the male screw 31A, which is inserted from the outside into the insertion hole 10A of the main girder 10, to the female screw 31B located on the inside of the sub-girder 20, a vibration absorbing member 32 is installed between the main girder 10 and the sub-girder 20 (see Figure 3).

[0024] This vibration-absorbing member 32 is an elastic member that absorbs vibrations transmitted from the main girder 10 to the sub-girder 20. In the illustrated example, a through hole 32A is formed in this vibration-absorbing member 32 through which a male screw 31A is inserted (see Figure 3). This through hole 32A is continuous with the through hole 21A formed at the end of the sub-girder 20 (see Figure 4).

[0025] Then, by placing vibration-absorbing members 32 at both ends of the sub-girder 20, the main girder 10 and the sub-girder 20 of the cable rack P are connected via the two vibration-absorbing members 32 (see Figure 2).

[0026] The elastic material constituting the vibration absorbing member 32 can be, for example, rubber, silicone, elastomer, or other viscoelastic rubber, as well as springs or steel dampers.

[0027] Furthermore, when using viscoelastic rubber such as rubber, silicone, or elastomer as the vibration absorbing member 32, one male screw 31A is used (see Figure 1). In this case, the insertion hole 21A formed in the bent piece 21 at the end of the sub-girder 20 is utilized (see Figure 4). By using only one male screw 31A when viscoelastic rubber is used as the vibration absorbing member 32, the viscoelastic rubber becomes more flexible in following the horizontal deformation of the main girder 10. Specifically, the surface of the viscoelastic rubber in contact with the main girder 10 expands and contracts in accordance with the horizontal deformation of the girder 10. At this time, a resistance force is generated against the deformation of the viscoelastic rubber, and the vibration gradually attenuates. In other words, the viscoelastic rubber suppresses the deformation of the main girder 10. By suppressing the deformation of the main girder 10, it is possible to prevent the main girder 10 from breaking and thus prevent the sub-girder 20 from falling. In addition, as the vibration is attenuated, the sway of the entire cable rack P also decreases, which prevents the suspension bolts from breaking. This prevents the entire cable rack P from falling.

[0028] This through-hole 21A is formed when a bent piece 21 is bent at the end of the sub-girder 20 (a segment extending from the bottom surface of the sub-girder 20 is bent upward to form the bent piece 21), and one through-hole 21A is drilled in this bent piece 21 (see Figure 4). Therefore, when using a vibration-absorbing member 32 such as viscoelastic rubber, this through-hole 21A can be utilized. Note that the through-hole 21A is not limited to the one shown in the figure, and may be drilled in an extended portion that extends across two sides of the sub-girder 20, for example.

[0029] On the other hand, when using a spring such as a coil spring as the vibration absorbing member 32, the main girder 10 and the sub-girder 20 are connected via the vibration absorbing member 32 using a male screw 31A (see Figure 6). In this case, two male screws 31A are used, and a vibration absorbing member 32 is attached to each male screw 31A (see Figure 5). By using two male screws 31A when using a spring as the vibration absorbing member 32, the spring can easily expand and contract in accordance with the horizontal deformation of the main girder 10. Specifically, one spring remains extended while the other spring contracts. At this time, a resistance force is generated against the expansion and contraction of the spring, so the vibration gradually decreases. In other words, the spring suppresses the deformation of the main girder 10. By suppressing the deformation of the main girder 10, it is possible to prevent the main girder 10 and the sub-girder 20 from breaking, thus preventing the sub-girder 20 from falling. In addition, as the vibration decreases, the sway of the entire cable rack P also decreases, so it is possible to prevent the suspension bolts from breaking. This prevents the entire cable rack P from falling.

[0030] In the illustrated example, a U-shaped fitting 22 with a U-shaped cross-section is fitted into the end of the sub-girder 20, and the U-shaped fitting 22 is secured with fixing screws 23 that are screwed in from the side of the sub-girder 20 (see Figure 5). Two through holes 22A are drilled in the end of this U-shaped fitting 22 (see Figure 7).

[0031] Then, the male screw 31A, which is inserted from the outside into the insertion hole 10A of the main girder 10, is passed through the coil spring of the vibration absorbing member 32, inserted into the insertion hole 22A, and then fixed with the female screw 31B, thereby mounting two vibration absorbing members 32 between the main girder 10 and the sub-girder 20 (see Figure 5).

[0032] In this case, by drilling two through holes 21A in the bent piece 21 at the end of the sub-girder 20 shown in Figure 4, it becomes possible to use two coil springs as vibration absorbing members 32. Similarly, by drilling one through hole 21A in the center of the U-shaped fitting 22 of the sub-girder 20 shown in Figure 7, it becomes possible to use a vibration absorbing member 32 such as viscoelastic rubber.

[0033] Furthermore, if a damper is used as the vibration absorbing member 32, for example, the damper can be installed between the main girder side connection portion of the connector 31 and the sub-girder side connection portion of the connector 31.

[0034] Thus, the vibration absorption method in the rack of the present invention absorbs vibrations transmitted from the main beam 10 to the sub-beam 20 by a vibration-damping connection part 30 that connects the main beam 10 and the sub-beam 20.

[0035] The vibration damping principle is as follows (see Figure 8). When an earthquake occurs in the cable rack P under normal conditions (see Figure 8(a)), the main girder 10 first deforms horizontally (see Figure 8(b)). Then, a rebound occurs and it deforms in the opposite direction (see Figure 8(c)). As the main girder 10 undergoes repeated such deformations, the elastic force of the vibration-damping connection part 30 suppresses the deformation of the main girder 10 (see Figure 9).

[0036] Furthermore, the elastic force of the vibration-isolating connection section 30 expands the range of motion of the child girder 20 relative to the main girder 10, thus preventing the child girder 20 from falling without the weld breaking, as would occur if the main girder 10 and the child girder 20 were fixed by welding. Also, as the vibration is dampened, the sway of the entire cable rack P decreases, preventing the suspension bolts from breaking. This prevents the entire cable rack P from falling. In addition, by adjusting the performance of the vibration-absorbing member 32 used in the vibration-isolating connection section 30 (for example, parameters related to the elastic member such as the modulus of elasticity and Young's modulus), the amplitude of the sway of the cable rack P during an earthquake can be controlled, allowing for the setting of the separation distance from surrounding equipment and walls. For example, assuming an earthquake of magnitude 6, by adjusting the performance of the vibration-absorbing member 32, the separation distance can be set to ±200 mm of the sway of the cable rack P.

[0037] In the above embodiment, when using viscoelastic rubber such as rubber, silicone, or elastomer as the elastic member constituting the vibration absorbing member 32, an example was shown in which one vibration absorbing member 32 is attached between the main girder 10 and the sub-girder 20 by one connector 31. However, one vibration absorbing member 32 may be attached between the main girder 10 and the sub-girder 20 by multiple connectors 31. Alternatively, multiple vibration absorbing members 32 may be attached between the main girder 10 and the sub-girder 20 by one connector 31. Furthermore, one vibration absorbing member 32 may be attached between the main girder 10 and the sub-girder 20 by multiple connectors 31.

[0038] In the above embodiment, when a spring such as a coil spring is used as the elastic member constituting the vibration absorbing member 32, an example was shown in which multiple vibration absorbing members 32 are attached between the main girder 10 and the sub-girder 20 using multiple connectors 31. However, one vibration absorbing member 32 may be attached between the main girder 10 and the sub-girder 20 using one connector 31. Alternatively, multiple vibration absorbing members 32 may be attached between the main girder 10 and the sub-girder 20 using one connector 31. Furthermore, one vibration absorbing member 32 may be attached between the main girder 10 and the sub-girder 20 using multiple connectors 31.

[0039] In the above embodiment, an example was shown in which a male screw 31A inserted from the outside into an insertion hole 10A of the main beam 10 is inserted into an insertion hole 21A formed at the end of the sub-beam 20 and then screwed into a female screw 31B located on the inside of the sub-beam 20. However, a female screw may be formed instead of an insertion hole 21A, and the male screw 31A may be screwed into this female screw. Also, when a U-shaped fitting 22 with a U-shaped cross-section is fitted to the end of the sub-beam 20, an example was shown in which a male screw 31A inserted from the outside into an insertion hole 10A of the main beam 10 is inserted into an insertion hole 22A and then fixed with a female screw 31B. However, a female screw may be formed instead of an insertion hole 22A, and the male screw 31A may be screwed into this female screw.

[0040] In the above embodiment, a bent piece 21 is formed by bending at the end of the sub-girder 20, and an insertion hole 21A is drilled in this bent piece 21. However, the insertion hole 21A may be drilled in an extended portion that extends across two sides of the sub-girder 20.

[0041] Furthermore, the support structure of the present invention is not limited to the illustrated example, and for example, each component such as the main girder 10, the sub-girder 20, and the vibration-damping connection part 30 can be arbitrarily changed. In addition, the material and configuration of the connector 31 and vibration-absorbing member 32 can also be freely designed and changed without altering the essence of the present invention. [Explanation of symbols]

[0042] P Cable Rack 10 main digits 10A Through hole 20 sub-digits 21 Bent piece 21A Through hole 22 U-shaped metal fittings 23 Fixing screws 30 Vibration-isolating connection section 31 Connectors 31A Male thread 31B Female thread 32 Vibration absorbing member 32A Through hole

Claims

1. A pair of long main beams, Multiple subgirders erected between the aforementioned main girders, A vibration-damping rack characterized by comprising vibration-damping connection parts provided at the longitudinal ends of the sub-girders, which connect the main girder and the sub-girders and absorb vibrations transmitted from the main girder to the sub-girders.

2. The vibration-damping connection part is, A connector for connecting the main beam and the sub-beam, The vibration-damping rack according to claim 1, further comprising a vibration-absorbing member which is an elastic member having an insertion hole through which the connector is inserted, and which absorbs vibrations transmitted from the main girder to the sub-girder.

3. The aforementioned connector is It comprises a male screw and a female screw provided on the sub-girder, The vibration-damping rack according to claim 2, wherein the male screw is inserted into an insertion hole provided on the side surface of the main beam.

4. The main beam and the child beam are connected by at least one of the connecting devices. The vibration-absorbing member is attached by at least one of the connectors, as described in claim 3.

5. The vibration-damping rack according to any one of claims 2 to 4, wherein the elastic member is viscoelastic rubber or a spring.

6. The vibration-damping connection part is, A connector for connecting the main beam and the sub-beam, The vibration-damping rack according to claim 1, further comprising a damper provided between the main girder side connection portion of the connector and the sub-girder side connection portion of the connector.

7. A method for absorbing vibrations in a cable rack comprising a pair of long main girders and a plurality of sub-girders erected between the main girders, A method for absorbing vibrations in a cable rack, characterized in that vibrations transmitted from the main girder to the sub-girder are absorbed by vibration-damping connection parts provided at the longitudinal ends of the sub-girders and connecting the main girder and the sub-girder.

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