JP2024056245A - Cable Tray - Google Patents

Abstract

[Problem] To provide a cable tray that is excellent in arrangement and has high earthquake resistance. [Solution] The cable tray according to the present invention comprises a plurality of trays 2 capable of storing cables 1, a support member 4 that supports the plurality of trays 2 and is fixed to an installation location 5, and an elastic bearing member 3 that is an elastic member having rigidity. Of the plurality of trays 2, at least one tray 2A is fixed to the support member 4 via the elastic bearing member 3, and all other trays 2B, 2B are fixed directly to the support member 4. [Selected Figure] Figure 1

Description

The present invention relates to a cable tray in which cables for transmitting power, signals, etc. are laid.

A cable tray is a piece of equipment in which cables (such as power cables, control cables, and communication cables) are laid to transmit power, control signals, or communication signals to electrical equipment and instrumentation. Cable trays are installed on the ceiling, floor, or wall of facilities such as plants, stations, and buildings, including factories and power plants, and are equipped with cables, a tray for storing the cables, and support members that are fixed to the installation location and support the tray.

A tray is a steel container that has a shape that extends in the extension direction (axial direction) of the stored cable, and its cross section perpendicular to the axial direction has a U-shape with an open top. The tray is supported at regular intervals in the axial direction by support members and fixed to the ceiling, floor, or wall of the facility. In particular, plant facilities such as factories and power plants where many types of equipment are in operation require many cables to send power and control signals to these devices. For this reason, in such facilities, cable trays may be equipped with multi-stage support members that support multiple trays.

If a strong earthquake motion acts on plant equipment such as factories or power plants and the cable trays are damaged, it may become difficult for such equipment to maintain proper operation. Furthermore, if a cable tray is damaged by an earthquake, it will take time to repair it after the earthquake, and the plant equipment may not be able to operate until repairs are made. For this reason, there is a demand for improved earthquake resistance for cable trays.

Conventional technology for improving the earthquake resistance of cable trays is described, for example, in Patent Document 1. The cable support device described in Patent Document 1 includes a cable housing structure that houses multiple cables and includes a support member, and two support mechanisms that connect the side walls of the support member to a structure and apply elastic force to the side walls. When the cable housing structure shakes due to an earthquake, these support mechanisms apply elastic force alternately from both sides of the support member, reducing the shaking of the cable housing structure and improving the earthquake resistance of the cable housing structure.

JP 2017-139908 A

Conventional cable trays have the problem that when a mechanism for improving earthquake resistance is installed, the space required for installing the cable tray increases and the ease of placement decreases. For example, in the cable support device described in Patent Document 1, the support mechanism is located outside the support member in order to connect the side wall of the support member to the structure. That is, one support mechanism is located outside one side of the support member, and the other support mechanism is located outside the other side of the support member. This requires space to connect the support mechanism to the structure, which can decrease the ease of placement. When the ease of placement of the cable tray decreases, the installation locations for the cable tray are limited, and it can be difficult to install the necessary cable tray in a facility that requires a highly earthquake-resistant cable tray.

The object of the present invention is to provide a cable tray that is easy to place and has high earthquake resistance.

The cable tray according to the present invention comprises a plurality of trays capable of storing cables, a support member that supports the plurality of trays and is fixed to the installation location, and an elastic bearing member that is an elastic member having rigidity. At least one of the plurality of trays is fixed to the support member via the elastic bearing member, and all the other trays are fixed directly to the support member.

The present invention provides a cable tray that is easy to place and has high earthquake resistance.

1 is a cross-sectional view (elevation cross-sectional view) of a cable tray according to an embodiment of the present invention, taken along a plane perpendicular to the extension direction of the stored cables. FIG. 2 is a perspective view of the cable tray according to the present embodiment. FIG. 2 is a diagram showing a vibration model of the cable tray according to the present embodiment. 1 is a cross-sectional view (elevation cross-sectional view) of a cable tray according to this embodiment taken along a plane parallel to the extension direction of a stored cable. 2 is a cross-sectional view of the cable tray according to the present embodiment taken along a plane perpendicular to the extension direction of the stored cables, and shows an enlarged view of the vicinity of the elastic support member. FIG. 2 is a cross-sectional view of the cable tray according to the present embodiment taken along a plane parallel to the extension direction of the stored cables, and shows an enlarged view of the vicinity of the elastic support member. FIG. 1 is a cross-sectional view (elevation cross-sectional view) of a cable tray according to this embodiment fixed to a floor, taken along a plane perpendicular to the extension direction of the stored cables. FIG. 1 is a cross-sectional view (elevation cross-sectional view) of a cable tray according to this embodiment fixed to a wall, taken along a plane perpendicular to the extension direction of the stored cables. FIG. 1 is a cross-sectional view (elevation cross-sectional view) of a cable tray according to this embodiment having multiple trays in a horizontal direction, taken along a plane perpendicular to the extension direction of the stored cables. FIG. 1 is a cross-sectional view (elevation cross-sectional view) of a cable tray according to this embodiment in which elastic support members are installed on multiple trays in the height direction, taken along a plane perpendicular to the extension direction of the stored cables.

The cable tray according to the present invention comprises a number of trays capable of storing cables, a support member that supports the number of trays, and an elastic support member, and of the number of trays, at least one tray is fixed to the support member via the elastic support member, and all other trays are fixed directly to the support member without the elastic support member. In the cable tray according to the present invention, even if a strong earthquake motion acts on it, the tray fixed to the support member via the elastic support member acts as a dynamic vibration absorber, thereby suppressing the response (vibration) of the tray fixed directly to the support member and the support member during an earthquake, and improving the earthquake resistance of the cable tray.

The cable tray of the present invention does not require the addition of a support mechanism or new reinforcement material located outside the support member to improve the earthquake resistance of the cable tray, so the space required for the cable tray does not increase. Therefore, the cable tray of the present invention has high earthquake resistance and excellent positioning properties, and can be easily installed, for example, in narrow spaces.

A cable tray according to an embodiment of the present invention will be described below with reference to the drawings. Note that in the drawings used in this specification, identical or corresponding components are given the same reference numerals, and repeated explanations of these components may be omitted.

The cable tray of this embodiment can be fixed to an installation location such as a ceiling, floor, or wall. First, an example of the cable tray of this embodiment fixed to a ceiling will be described.

Figure 1 is a cross-sectional view (elevational cross-sectional view) of a cable tray according to this embodiment, taken along a plane perpendicular to the extension direction of the stored cable. Figure 2 is a perspective view of the cable tray according to this embodiment.

The cable tray of this embodiment comprises a cable 1, a number of trays 2, a support member 4, and an elastic support member 3. The cable tray shown in Figures 1 and 2 is fixed to the ceiling 5, which is the installation location.

Cable 1 is, for example, a cable for transmitting power or signals.

The tray 2 is a container capable of storing the cable 1. The cable tray according to this embodiment can include any number of trays 2. The multiple trays 2 are arranged side by side in the height direction (vertical direction) and supported by the support member 4, and each of them stores one or multiple cables 1. In the example shown in Figures 1 and 2, the cable tray includes three trays 2A, 2B, and 2C. The trays 2A, 2B, and 2C are arranged in this order from bottom to top and supported by the support member 4, and each of them stores four cables 1.

The support member 4 is a member that supports multiple trays 2 and is fixed to the installation location. In the example shown in Figures 1 and 2, since the installation location is the ceiling 5, the upper end of the support member 4 is connected to and fixed to the ceiling 5. The support member 4 has multiple placement sections 41 arranged side by side in the height direction, and supports the trays 2 by placing them on each of the placement sections 41. The placement sections 41 are members that extend horizontally (left and right direction in Figure 1) and can be composed of rod-shaped or plate-shaped members.

Of the three trays 2A, 2B, and 2C, tray 2A is located furthest from the part where the support member 4 is fixed (the ceiling 5, which is the installation location in Figures 1 and 2), and an elastic support member 3 is installed between tray 2A and support member 4. In other words, tray 2A is fixed to support member 4 via elastic support member 3. All other trays 2B and 2C are fixed directly to support member 4 without elastic support member 3. Elastic support member 3 suppresses vibration of tray 2A.

In the cable tray according to this embodiment, at least one of the multiple trays 2 is fixed to the support member 4 via the elastic support member 3, and all other trays 2 are fixed directly to the support member 4 without the elastic support member 3. In a more preferred configuration, at least the tray 2 (2A) located farthest from the part where the support member 4 is fixed is fixed to the support member 4 via the elastic support member 3, and all other trays 2 (trays 2B and 2C) are fixed directly to the support member 4. In an even more preferred configuration, only the tray 2 located farthest from the part where the support member 4 is fixed is fixed to the support member 4 via the elastic support member 3, and all other trays 2 are fixed directly to the support member 4.

The elastic bearing member 3 is an elastic member having rigidity and has the desired rigidity and damping characteristics. The elastic bearing member 3 can be made of any material that can set the desired rigidity and damping characteristics, and can be made of, for example, high-damping rubber, sliding bearings, and coil springs and dampers. The number of elastic bearing members 3 can be determined arbitrarily, but it is preferable to have multiple elastic bearing members for one tray 2. The elastic bearing members 3 are installed on the mounting portion 41 of the support member 4.

As described above, the elastic support member 3 does not necessarily have to be installed for all trays 2A, 2B, and 2C. Among the multiple trays 2A, 2B, and 2C, the tray 2A, which is located at the farthest position from the part where the support member 4 is fixed, has the largest vibration. Therefore, if the elastic support member 3 is installed for tray 2A among the multiple trays 2A, 2B, and 2C, the vibration of the tray 2A can be suppressed to effectively suppress the vibration of the entire cable tray. However, the elastic support member 3 can be installed between the tray 2 and the support member 4 for any one or more trays 2 among the multiple trays 2. For example, the elastic support member 3 may be installed only for tray 2A, or may be installed for all trays 2A, 2B, and 2C.

Figure 3 shows a vibration model of the cable tray according to this embodiment. This vibration model is composed of a primary vibration system 12 and a secondary vibration system 13.

The primary vibration system 12 comprises a spring 9A and a dashpot 10A arranged side by side and fixed to the fixed part 11, and a mass 8A connected to the spring 9A and the dashpot 10A. The secondary vibration system 13 comprises a spring 9B and a dashpot 10B arranged side by side and fixed to the mass 8A of the primary vibration system 12, and a mass 8B connected to the spring 9B and the dashpot 10B, and operates as a dynamic vibration absorber. In the cable tray according to this embodiment shown in Figures 1 and 2, the fixed part 11 is the ceiling 5, which is the installation location.

In the cable tray of this embodiment shown in Figures 1 and 2, the primary vibration system 12 is composed of the support member 4, tray 2B, tray 2C, and cable 1 stored in trays 2B and 2C, while the secondary vibration system 13 is composed of tray 2A, cable 1 stored in tray 2A, and elastic support member 3. In the secondary vibration system 13, the elastic support member 3 is represented by spring 9B and dashpot 10B.

When the secondary vibration system 13 vibrates, it acts as a dynamic vibration absorber and absorbs the vibration of the primary vibration system 12. That is, the vibration of the primary vibration system 12 is suppressed by the vibration of the secondary vibration system 13. In the cable tray of this embodiment, the secondary vibration system 13 vibrates to suppress the vibration of the primary vibration system 12, thereby suppressing the vibration of the entire cable tray and improving earthquake resistance.

In the cable tray according to this embodiment, if the natural frequency of the secondary vibration system 13 is close to the natural frequency of the primary vibration system 12, the secondary vibration system 13, which is a dynamic vibration absorber, can more effectively suppress the vibration of the primary vibration system 12, improving the earthquake resistance of the cable tray. For this reason, it is preferable that the value of the ratio of the natural frequency of the secondary vibration system 13 to the natural frequency of the primary vibration system 12 is within a specific range that is determined in advance so that the natural frequency of the secondary vibration system 13 and the natural frequency of the primary vibration system 12 can be considered to be approximately equal to each other. This range is the range of values of the ratio of natural frequencies that allows the secondary vibration system 13 to effectively absorb and suppress the vibration of the primary vibration system 12.

Therefore, it is preferable that the elastic bearing member 3 has a rigidity such that the ratio of the natural frequency of the secondary vibration system 13 to the natural frequency of the primary vibration system 12 is within a predetermined range. This range is a specific range that is predetermined so that the natural frequency of the secondary vibration system 13 and the natural frequency of the primary vibration system 12 can be considered to be approximately equal to each other.

For example, it is preferable that the ratio of the natural frequency of the secondary vibration system 13 to the natural frequency of the primary vibration system 12 is 0.9 or more and 1.1 or less, that is, the natural frequency of the secondary vibration system 13 is within ±10% of the natural frequency of the primary vibration system 12. Therefore, it is preferable that the elastic support member 3 has a rigidity such that the natural frequency of the secondary vibration system 13 is within ±10% of the natural frequency of the primary vibration system 12.

Here, we will explain the behavior of the cable tray when it vibrates due to an earthquake. When earthquake motion acts on the building in which the cable tray is installed, horizontal earthquake motion, which is vibration acting in the horizontal direction (left and right direction in Figure 1), is input to the cable tray from the ceiling 5.

Conventional cable trays (i.e., cable trays without elastic support members 3) respond by causing horizontal displacement and acceleration when horizontal seismic motion is input from the ceiling 5. In particular, the response is large at the lower end of the support member 4, which is the part away from the ceiling 5 (fixed part 11), and stress increases at the connection part of the support member 4 with the ceiling 5. When a strong seismic motion is applied, stress exceeding the allowable value is generated near the connection part of the support member 4 with the ceiling 5, and there is a possibility that the support member 4 may be damaged.

When horizontal seismic motion is input from the ceiling 5, the cable tray of this embodiment responds in the same way as a conventional cable tray, with the response being particularly large at the lower end of the support member 4. However, in the cable tray of this embodiment, the secondary vibration system 13 (tray 2A, cable 1 stored in tray 2A, and elastic support member 3) acts as a dynamic vibration absorber, so the response of the primary vibration system 12 is suppressed by the interaction between the primary vibration system 12 and the secondary vibration system 13, and the vibration of the entire cable tray can be suppressed.

As described above, in the cable tray of this embodiment, the tray 2A located at the farthest position from the part where the support member 4 is fixed has the elastic bearing member 3 installed thereon and is fixed to the support member 4 via the elastic bearing member 3. Therefore, in the cable tray of this embodiment, the tray 2A, which is the secondary vibration system 13, the cable 1 stored in the tray 2A, and the elastic bearing member 3 act as dynamic vibration absorbers during an earthquake, and can suppress the response of the support member 4, tray 2B, tray 2C, and the cable 1 stored in the trays 2B and 2C, which are the primary vibration system 12, during an earthquake, resulting in high earthquake resistance.

In addition, in the cable tray according to this embodiment, the tray 2A and the cable 1 stored in the tray 2A are treated as the mass 8B of the secondary vibration system 13, so when adding mass to the secondary vibration system 13, which is a dynamic vibration absorber, the mass can be added without changing the support member 4. Therefore, an existing cable tray can be easily changed to the cable tray according to this embodiment. In other words, the cable tray according to this embodiment can be easily applied to an existing cable tray.

In the cable tray of this embodiment, an elastic support member 3 having the desired rigidity and damping characteristics is installed between the tray 2A and the support member 4, forming a secondary vibration system 13 that is a dynamic vibration absorber. As a result, the space required for the cable tray does not increase, and the cable tray has high earthquake resistance and excellent positioning properties.

Figure 4 is a cross-sectional view (vertical cross-sectional view) of the cable tray according to this embodiment, taken along a plane parallel to the extension direction of the stored cable 1. Figure 4 shows the portion of the cable tray where trays 2A, 2B, and 2C are supported by four support members 4A, 4B, 4C, and 4D.

The upper ends of support members 4A to 4D are fixed to the ceiling 5. Elastic bearing members 3A, 3B, 3C, and 3D are installed between tray 2A and support members 4A, 4B, 4C, and 4D, respectively. Tray 2A is the tray 2 located furthest from the portion (ceiling 5) to which support members 4A to 4D are fixed. Tray 2A is fixed to support members 4A to 4D via elastic bearing members 3A to 3D. Trays 2B and 2C are fixed directly to support members 4A to 4D without using elastic bearing members 3.

Figure 5A is a cross-sectional view of the cable tray according to this embodiment taken along a plane perpendicular to the extension direction of the stored cable 1, and shows an enlarged view of the vicinity of the elastic support member 3. Figure 5B is a cross-sectional view of the cable tray according to this embodiment taken along a plane parallel to the extension direction of the stored cable 1, and shows an enlarged view of the vicinity of the elastic support member 3.

The elastic support member 3 is fastened and fixed to the tray 2A and the mounting portion 41 of the support member 4 with bolts 14.

The elastic support member 3 preferably has different rigidity in the direction perpendicular to the extension direction of the cable 1 stored in the tray 2 and in the direction parallel to the extension direction. In the cable tray according to this embodiment, the rigidity of the support member 4 differs in the direction perpendicular to the extension direction of the cable 1 stored in the tray 2 and in the direction parallel to the extension direction, and the natural frequencies of the cable tray also differ. For this reason, if the elastic support member 3 has a rigidity in each of these directions such that the natural frequency of the secondary vibration system 13 is within ±10% of the natural frequency of the primary vibration system 12, the elastic support member 3 has different rigidity in the direction perpendicular to the extension direction of the cable 1 stored in the tray 2 and in the direction parallel to the extension direction.

When the elastic support member 3 has different rigidity in the direction perpendicular to the extension direction of the cable 1 stored in the tray 2 and in the direction parallel to the extension direction, the cross-sectional area in the plane perpendicular to the extension direction and the cross-sectional area in the plane parallel to the extension direction differ from each other. Which cross-sectional area is larger depends on the rigidity of the support member 4. In this embodiment, the cross-sectional area in the perpendicular plane (Figure 5A) is smaller than the cross-sectional area in the parallel plane (Figure 5B).

The elastic bearing member 3 has different rigidity (or cross-sectional area) in the direction perpendicular to the extension direction of the cable 1 stored in the tray 2 and in the direction parallel to it, so that the secondary vibration system 13 can have a natural frequency that has a large effect of reducing the response of the primary vibration system 12 in each of these directions, and the vibration of the primary vibration system 12 can be more effectively suppressed, improving the earthquake resistance of the cable tray.

The stiffness of the elastic bearing member 3 can be set, for example, by measuring the natural frequency of the tray 2 and the support member 4 in an impact test. The impact test is performed, for example, on the portion of the cable tray that spans multiple support members 4 (for example, on the portion of support members 4A to 4C in Figure 4). The elastic bearing member 3 can have a stiffness that is set using, for example, the natural frequency of the tray 2 and the support member 4 measured in the impact test, the mass of the tray 2, and the mass of the cable 1 stored in the tray 2.

Next, we will explain an example in which the cable tray of this embodiment is fixed to the floor.

Figure 6 is a cross-sectional view (elevational cross-sectional view) of the cable tray according to this embodiment taken along a plane perpendicular to the extension direction of the stored cable 1. The cable tray shown in Figure 6 is fixed to the floor 6, which is the installation location.

The lower end of the support member 4 is connected and fixed to the floor 6.

Of the three trays 2A, 2B, and 2C, tray 2C is located furthest from the part where the support member 4 is fixed (floor 6, the installation location in FIG. 6), and an elastic support member 3 is installed between it and the support member 4. In other words, tray 2C is fixed to the support member 4 via the elastic support member 3. All other trays 2A and 2B are fixed directly to the support member 4 without the elastic support member 3. The elastic support member 3 suppresses vibration of tray 2C.

The vibration model of the cable tray according to this embodiment (Fig. 6) fixed to the floor 6 has a configuration that is the upside-down version of the vibration model of the cable tray according to this embodiment (Fig. 3) fixed to the ceiling 5. The primary vibration system 12 is composed of the support member 4, the tray 2A, the tray 2B, and the cable 1 stored in the trays 2A and 2B, and is fixed to the floor 6, which is the fixed part 11. The secondary vibration system 13 is composed of the tray 2C, the cable 1 stored in the tray 2C, and the elastic support member 3.

The principle of suppressing vibration of the cable tray during an earthquake in a cable tray fixed to the floor 6 (Figure 6) is the same as that of a cable tray fixed to the ceiling 5 (Figures 1 to 3). Therefore, even when the cable tray according to this embodiment is fixed to the floor 6, it has excellent positioning properties and high earthquake resistance.

Next, we will explain an example in which the cable tray of this embodiment is fixed to a wall.

Figure 7 is a cross-sectional view (elevational cross-sectional view) of the cable tray of this embodiment taken along a plane perpendicular to the extension direction of the stored cable 1. The cable tray shown in Figure 7 is fixed to a wall 7, which is the installation location.

One end of the support member 4 in the horizontal direction (left and right direction in Figure 7) is connected and fixed to the wall 7.

Of the three trays 2A, 2B, and 2C, tray 2A has an elastic support member 3 installed between it and the support member 4. That is, tray 2A is fixed to the support member 4 via the elastic support member 3. All other trays 2B and 2C are fixed directly to the support member 4 without the elastic support member 3. The elastic support member 3 suppresses vibration of tray 2A.

In a cable tray fixed to a wall 7, trays 2A-2C are arranged in a line in the height direction (the vertical direction in FIG. 7), and it is difficult to determine the tray 2 that is located farthest from the part where the support member 4 is fixed (the wall 7 where it is installed in FIG. 7). In other words, in a cable tray fixed to a wall 7, it is difficult to determine the tray 2 in which the elastic support member 3 is to be installed between the support member 4 and the tray 2.

However, at least one of the trays 2 (tray 2A in FIG. 7) is fixed to the support member 4 via the elastic support member 3, and all other trays 2 (trays 2B and 2C in FIG. 7) are fixed directly to the support member 4 without the elastic support member 3, so that the vibration of the cable tray can be suppressed. In the cable tray shown in FIG. 7, the main vibration system 12 is composed of the support member 4, tray 2B, tray 2C, and the cable 1 stored in trays 2B and 2C, and the secondary vibration system 13 is composed of tray 2A, the cable 1 stored in tray 2A, and the elastic support member 3. During an earthquake, the secondary vibration system 13 operates as a dynamic vibration absorber to suppress the vibration of the main vibration system 12, suppressing the vibration of the entire cable tray and improving earthquake resistance.

When the cable tray is fixed to the wall 7, the elastic support member 3 may be installed on any of the multiple trays 2. In other words, in a cable tray fixed to the wall 7, at least one of the multiple trays 2 may be fixed to the support member 4 via the elastic support member 3, and all other trays 2 may be fixed directly to the support member 4 without using the elastic support member 3.

Next, an example of the cable tray according to this embodiment having multiple trays 2 in the horizontal direction will be described. This cable tray can be fixed to an installation location such as a ceiling 5, floor 6, or wall 7, but below, an example of the cable tray being fixed to a ceiling 5 will be described.

Figure 8 is a cross-sectional view (elevational cross-sectional view) of a cable tray according to this embodiment, which has multiple trays 2 in the horizontal direction, taken on a plane perpendicular to the extension direction of the stored cable 1. The cable tray shown in Figure 8 has six trays 2A, 2B, 2C, 2D, 2E, and 2F. When a cable tray has many trays 2, multiple trays 2 may be installed side-by-side in the horizontal direction (left-right direction in Figure 8) as shown in Figure 8.

Trays 2A, 2B, and 2C are supported by the support member 4 in the order lined up from bottom to top. Trays 2D, 2E, and 2F are supported by the support member 4 in the order lined up from bottom to top. Trays 2A, 2B, and 2C and trays 2D, 2E, and 2F are each installed side by side in the horizontal direction.

The support member 4 supports trays 2A, 2B, 2C and trays 2D, 2E, 2F arranged horizontally, and its upper end is connected and fixed to the ceiling 5.

Of the six trays 2A-2F, the trays 2A and 2D located furthest from the part where the support member 4 is fixed (the ceiling 5, which is the installation location in FIG. 8) have elastic bearing members 3 installed between the trays 2A and 2D and the support member 4. In other words, the trays 2A and 2D are fixed to the support member 4 via the elastic bearing members 3. All other trays 2B, 2C, 2E, and 2F are fixed directly to the support member 4 without the elastic bearing members 3. The elastic bearing members 3 suppress vibrations of the trays 2A and 2D.

In the cable tray shown in FIG. 8, the primary vibration system 12 is composed of the support member 4, tray 2B, tray 2C, tray 2E, tray 2F, and the cable 1 stored in trays 2B, 2C, 2E, and 2F, while the secondary vibration system 13 is composed of the cable 1 stored in tray 2A, tray 2D, tray 2A, and 2D, and the elastic support member 3. During an earthquake, the secondary vibration system 13 acts as a dynamic vibration absorber to suppress the vibration of the primary vibration system 12, suppressing the vibration of the entire cable tray and improving earthquake resistance.

In the above explanation (excluding the explanation of the cable tray shown in FIG. 7), the cable tray has been described in which the elastic bearing member 3 is installed only on the tray 2 among the multiple trays 2 that is located farthest from the portion where the support member 4 is fixed. In the cable tray according to this embodiment, the elastic bearing member 3 can also be installed on trays 2 other than the tray 2 located farthest from the portion where the support member 4 is fixed. In the following, an example of a cable tray according to this embodiment in which the elastic bearing member 3 is installed on the tray 2 located farthest from the portion where the support member 4 is fixed and on trays 2 other than this tray 2 will be described. In the following explanation, a cable tray fixed to a ceiling 5 will be described as an example.

Figure 9 is a cross-sectional view (vertical cross-sectional view) of the cable tray according to this embodiment taken on a plane perpendicular to the extension direction of the stored cable, showing a cable tray in which elastic support members 3 are installed on multiple trays 2 in the height direction (up and down direction in Figure 9). The cable tray shown in Figure 9 has a similar configuration to the cable tray shown in Figure 1, but differs in that elastic support members 3 are installed not only on tray 2A but also on tray 2B.

Of the three trays 2A, 2B, and 2C, tray 2A, which is located furthest from the part where the support member 4 is fixed (ceiling 5, which is the installation location in Figure 9), and tray 2B, which is located above tray 2A, have elastic support members 3 installed between them and the support member 4. In other words, trays 2A and 2B are fixed to the support member 4 via the elastic support members 3. The other tray 2C is fixed directly to the support member 4 without the elastic support member 3. The elastic support members 3 suppress vibrations of trays 2A and 2B.

In the cable tray shown in FIG. 9, the support member 4, the tray 2C, and the cable 1 stored in the tray 2C constitute the main vibration system 12. The tray 2A, the cable 1 stored in the tray 2A, and the elastic support member 3 installed in the tray 2A constitute the first sub-vibration system 13, and the tray 2B, the cable 1 stored in the tray 2B, and the elastic support member 3 installed in the tray 2B constitute the second sub-vibration system 13. The first sub-vibration system 13 and the second sub-vibration system 13 are connected in parallel to the main vibration system 12.

During an earthquake, these two secondary vibration systems 13 act as dynamic vibration absorbers and interact with the primary vibration system 12, thereby suppressing the vibration of the primary vibration system 12. For this reason, the cable tray shown in FIG. 9 has a greater effect of suppressing the vibration of the primary vibration system 12 and has higher earthquake resistance than, for example, a cable tray with one secondary vibration system 13 as shown in FIG. 1, and can effectively suppress the vibration of the cable tray even against stronger earthquake motions.

In the above embodiment, a cable tray having three or six trays 2 has been described, but the cable tray according to this embodiment can have any number of trays 2. In addition, in the above embodiment, an example has been described in which the support member 4 has basic components (e.g., the mounting portion 41), but the support member 4 may also have reinforcing members such as diagonal members or earthquake-resistant support members. If the support member 4 has reinforcing members, the cable tray according to this embodiment can have higher earthquake resistance.

The present invention is not limited to the above-mentioned examples, and various modifications are possible. For example, the above-mentioned examples have been described in detail to clearly explain the present invention, and the present invention is not necessarily limited to an embodiment having all of the configurations described. It is also possible to replace part of the configuration of one example with the configuration of another example. It is also possible to add the configuration of another example to the configuration of one example. It is also possible to delete part of the configuration of each example, or to add or replace other configurations.

1...cable, 2, 2A-2F...tray, 3, 3A-3D...elastic bearing member, 4, 4A-4D...support member, 5...ceiling, 6...floor, 7...wall, 8A, 8B...mass, 9A, 9B...spring, 10A, 10B...dashpot, 11...fixed part, 12...main vibration system, 13...secondary vibration system, 14...bolt, 41...mounting part.

Claims (5)

Multiple trays for storing cables,
A support member that supports a plurality of the trays and is fixed to an installation location;
an elastic support member that is an elastic member having rigidity;
Equipped with
At least one of the plurality of trays is fixed to the support member via the elastic support member, and all the other trays are directly fixed to the support member.
A cable tray comprising: Among the plurality of trays, at least the tray located farthest from the portion to which the support member is fixed is fixed to the support member via the elastic support member, and all the other trays are directly fixed to the support member.
The cable tray of claim 1 . the tray fixed to the support member via the elastic bearing member is a first tray;
the tray directly fixed to the support member is a second tray;
a main vibration system is composed of the support member, the second tray, and the cable housed in the second tray,
a secondary vibration system is composed of the first tray, the cable housed in the first tray, and the elastic support member,
the elastic support member has a rigidity such that a ratio of the natural frequency of the secondary vibration system to the natural frequency of the primary vibration system is within a predetermined range.
The cable tray of claim 1. The elastic support members have different rigidities in a direction perpendicular to the extending direction of the cable stored in the tray and a direction parallel to the extending direction of the cable.
The cable tray of claim 1 . The elastic support member has a stiffness set using a natural frequency of the tray and the support member measured by an impact test.
The cable tray of claim 1 .

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