Vibration damping structure for rack warehouse

Abstract

To provide a damping structure for a rack warehouse that prevents reduction in storage space for stored objects, and is easy to install.SOLUTION: A damping structure for a rack warehouse has: a foundation floor part 12; a rack structure 2 which is installed on the foundation floor part 12, and has a plurality of racks 21 arrayed and connected vertically and horizontally; and damper devices 3 which are provided on both sides of one of the rigidity center and gravity center of the rack structure 2, respectively. The damper device 3 has: a rigid member 4 which is provided at a top part of the rack structure 2 integrally with the rack structure 2; an axial force member 5 which couples the rigid member 4 and the foundation floor part 12 to each other; and a rotational inertia mass damper 6 which is provided between the foundation floor part 12 and the axial force member 5 and generates a rotational inertia mass as a weight rotates when tension generated at the axial force member 5 is transmitted.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present invention relates to a vibration damping structure for a rack warehouse.

Background Art

[0002] In the Great East Japan Earthquake, many damages were observed in logistics facilities such as rack warehouses. A rack warehouse is provided with a rack structure in which racks are arranged in multiple stages. However, it has been found that the damage is more due to the collapse or fall of the stored items in the rack structure than the damage to the rack structure itself. Therefore, a vibration damping structure for a rack warehouse that reduces the acceleration of each pallet storing the stored items when an earthquake occurs has been proposed. For example, Patent Document 1 discloses a vibration damping structure for a rack warehouse in which a TMD (tuned mass damper) or a mass damper is provided in the rack structure. Patent Document 2 discloses a vibration damping structure for a rack warehouse in which an inclined sliding bearing is provided between the support member of the rack supporting the pallet and the pallet.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Patent Document 2

Summary of the Invention

Problems to be Solved by the Invention

[0004] However, in the vibration damping structure of a rack warehouse in which a TMD or a mass damper is provided in the rack structure, there is a problem that the storage space for the stored items is reduced by the TMD or the mass damper. In the vibration damping structure of a rack warehouse in which an inclined sliding bearing is provided between the support member of the rack supporting the pallet and the pallet, since it is necessary to install an inclined sliding bearing for each pallet, there is a problem that the installation of the inclined sliding bearing is troublesome and costly.

[0005] This invention has been made in view of the above-mentioned problems, and aims to provide a vibration-damping structure for a rack warehouse that can minimize the reduction in storage space for stored items due to installation and is easy to install. [Means for solving the problem]

[0006] To achieve the above objective, the vibration damping structure for a rack warehouse according to the present invention comprises a base floor, a rack structure installed on the base floor and having a plurality of racks arranged and connected in the vertical and horizontal directions, and vibration damping devices provided on either side of the rigidity center and the center of gravity of the rack structure, wherein the vibration damping device comprises a rigid member provided integrally with the rack structure at the top of the rack structure, an axial force member connecting the rigid member and the base floor, and a rotational inertia mass damper provided between the base floor and the axial force member, which generates rotational inertia mass by transmitting tension generated in the axial force member, causing a weight to rotate.

[0007] In this invention, when bending deformation occurs in the rack structure due to earthquake vibrations, tension is generated in the axial force member of the vibration damping device that is pulled by the bending deformation, among the vibration damping devices provided on both sides of either the rigidity center or the center of gravity of the rack structure. When tension is generated in the axial force member of a vibration damping device, the rotational inertia mass damper deforms in the axial direction and rotates due to the tension, exhibiting damping performance. The damping performance of the rotational inertia mass damper acts on the top of the rack structure via the axial force member and the rigidity member, thereby reducing the acceleration and displacement of the top of the rack structure. The rotational inertia of the vibration damping device is equivalent to 10 to 500 times the actual mass of the weight, and it has performance comparable to vibration reduction mechanisms with large masses, thus enabling the vibration damping device to be made lighter and smaller. This makes it possible to minimize the reduction in storage space for stored items caused by installing a vibration damping structure in a rack warehouse. Furthermore, because the present invention can be installed on a rack structure in which multiple racks are connected, it is easier to install compared to a vibration damping structure in which vibration damping devices are installed on each pallet installed on the rack structure.

[0008] In the vibration damping structure for a rack warehouse according to the present invention, the rotational mass generated by the rotational inertia mass and the axial stiffness determined by the axial stiffness of the axial force member may be tuned to the natural frequency of the rack structure.

[0009] By adopting this configuration, the response acceleration of the rack structure can be significantly reduced.

[0010] The vibration damping structure for a rack warehouse according to the present invention may include an additional spring provided between the foundation floor and the axial force member to adjust the axial stiffness of the axial force member.

[0011] This configuration allows for easy adjustment of the axial stiffness of the axial force member, significantly reducing the response acceleration of the rack structure.

[0012] In the vibration damping structure for a rack warehouse according to the present invention, the rack structure has a long shape extending in the first horizontal direction, with the plurality of racks arranged in the vertical direction and the first horizontal direction, and the vibration damping device consists of a first vibration damping device provided on one side of the second horizontal direction intersecting the first horizontal direction of the rack structure, and a second vibration damping device provided on the other side of the second horizontal direction of the rack structure, and the first vibration damping device and the second vibration damping device may be provided alternately for each rack arranged in the first horizontal direction.

[0013] This configuration allows for a balanced arrangement of vibration damping devices while leaving space on the sides of the rack structure where no damping devices are installed.

[0014] In the vibration damping structure for a rack warehouse according to the present invention, the rigid member has a cantilevered portion that extends laterally from the top of the rack structure, and the axial force member may be provided on the side of the rack structure and configured to connect the cantilevered portion and the base floor portion.

[0015] Since the vibration damping device is arranged on the side of the rack structure, the vibration damping device does not reduce the accommodation space of the rack structure. Further, when the stacker crane is arranged in the space provided inside the rack structure, the vibration damping device does not affect the operation of the stacker crane or the loading and unloading of the stored items.

[0016] In the vibration damping structure of the rack warehouse according to the present invention, the base floor portion may be a seismic isolation floor provided on the base portion via a seismic isolation bearing.

[0017] By adopting such a configuration, the response acceleration of the rack structure can be significantly reduced.

Effect of the Invention

[0018] According to the present invention, it is possible to suppress a reduction in the storage space of stored items due to the installation of the vibration damping structure of the rack warehouse, and the installation is easy.

Brief Description of the Drawings

[0019] [Figure 1] It is a schematic diagram of the vibration damping structure of the rack warehouse according to the embodiment. [Figure 2] (a) Plan view of the rack structure, (b) Elevation view of the rack structure, (c) Side view of the rack structure. [Figure 3] It is a perspective view of the rack structure. [Figure 4] It is a plan view showing the arrangement of the vibration damping devices arranged in a staggered manner. [Figure 5] It is a schematic diagram showing how the rack structure is bent and deformed in the Y direction. [Figure 6] It is a schematic diagram showing how the rack structure is bent and deformed in the opposite direction of the Y direction. [Figure 7] It is a plan view showing the arrangement of all the installed vibration damping devices. [Figure 8] It is a graph showing the seismic wave used in the analysis. [Figure 9] It is a graph showing the acceleration at the center of the top of the rack structure when all the vibration damping devices are installed. [Figure 10] This graph shows the acceleration at the center of the top of the rack structure when vibration damping devices are installed in an intersecting manner. [Figure 11] This is a schematic diagram of a vibration damping structure for a rack warehouse according to a first modified embodiment. [Figure 12] This is a schematic diagram of a vibration damping structure for a rack warehouse according to a second modified embodiment. [Figure 13] This is a schematic diagram of a vibration damping structure for a rack warehouse according to a third modified embodiment. [Modes for carrying out the invention]

[0020] The vibration damping structure for a rack warehouse according to an embodiment of the present invention will be described below with reference to Figures 1-6. As shown in Figure 1, the vibration damping structure 1 for a rack warehouse according to this embodiment is installed in a rack warehouse 11 such as an automated rack warehouse. The vibration damping structure 1 for a rack warehouse includes a base floor 12, a rack structure 2 installed on the base floor, and vibration damping devices 3 provided on both sides of the rack structure 2. The base floor 12 is the foundation 14 of the rack warehouse 11 and is a fixed floor. The base floor 12 may also be a fixed floor constructed on the foundation 14 of the rack warehouse 11.

[0021] As shown in Figures 2 and 3, the rack structure 2 consists of multiple racks 21 arranged and connected in the vertical and horizontal directions. The rack structure 2 of this embodiment has two rack groups 22, 22 arranged and connected in the vertical and first horizontal directions. The two rack groups are spaced apart in a second direction perpendicular to the first horizontal direction, and their tops are connected to each other. The rack structure 2 has a long shape that extends in the first horizontal direction when viewed from above. Hereinafter, the first horizontal direction in which the rack structure 2 extends in a plan view will be referred to as the X direction, and the second horizontal direction perpendicular to the first horizontal direction will be referred to as the Y direction. Figure 2 shows the dimensions of the model for the analysis described later. The dimensions of the rack structure 2 are not limited to the values ​​shown in Figure 2. As shown in Figure 1, a stacker crane 13 is installed in the space 23 between the two rack groups 22, 22. Rack 21 stores, for example, items contained on pallets.

[0022] The vibration damping devices 3 are provided on both sides of the rack structure 2 in the Y direction. The vibration damping device 3 provided on one side of the rack structure 2 in the Y direction will be referred to as the first vibration damping device 31, and the vibration damping device 3 provided on the other side of the rack structure 2 in the Y direction will be referred to as the second vibration damping device 32. The first vibration damping device 31 and the second vibration damping device 32 have the same configuration except for their installation location. The first vibration damping device 31 and the second vibration damping device 32 are positioned on either side of the center of rigidity and the center of gravity of the rack structure 2. That is, the first vibration damping device 31 and the second vibration damping device 32 are positioned on either side of the center of rigidity and the center of gravity of the rack structure 2. Note that the vibration damping structure 1 of the rack warehouse according to this embodiment also includes a configuration in which the first vibration damping device 31 and the second vibration damping device 32 are positioned on either side of the center of rigidity and the center of gravity of the rack structure 2.

[0023] The vibration damping device 3 includes a rigid member 4 integrally provided with the rack structure 2 at the top of the rack structure 2, an axial force member 5 connecting the rigid member 4 and the base floor 12, and a rotational inertia mass damper 6 provided between the base floor 12 and the axial force member 5.

[0024] The rigid member 4 has approximately the same rigidity as the rack structure 2 and is provided to be structurally integrated with the rack structure 2. The rigid member 4 of the first vibration damping device 31 and the rigid member 4 of the second vibration damping device 32 are provided integrally. The rigid member 4 has a protruding portion 41 that extends outward in the Y direction from the top of the rack structure 2. The protruding portion 41 of the first vibration damping device 31 protrudes from the top of the rack structure 2 to one side in the Y direction. The protruding portion 41 of the second vibration damping device 32 protrudes from the top of the rack structure 2 to the other side in the Y direction.

[0025] The axial force member 5 is a member that extends in the vertical direction, with its upper end joined to the cantilevered portion 41 of the rigid member 4 and its lower end joined to the rotational inertia mass damper 6. The axial force member 5 is joined to the foundation floor portion 12 via the rotational inertia mass damper 6. The axial force member 5 and the rotational inertia mass damper 6 are installed in series between the rigid member 4 and the foundation floor portion 12. The rotational inertia mass damper 6 generates rotational inertia mass when the tension generated in the axial force member 5 is transmitted to the mass, causing the mass to rotate. The rotational inertia mass damper 6 can achieve vibration reduction by utilizing the moment of inertia generated in the mass due to the rotational moment of inertia of the mass and the rotational angular acceleration as a control force.

[0026] As shown in Figure 4, multiple first vibration dampers 31 and multiple second vibration dampers 32 are provided on the rack structure 2. The multiple first vibration dampers 31 and multiple second vibration dampers 32 are arranged alternately one by one in the X direction. That is, the multiple first vibration dampers 31 and multiple second vibration dampers 32 are arranged in an alternating pattern, so that the first vibration dampers 31 and the second vibration dampers 32 do not line up in the Y direction. In this embodiment, one first vibration damper 31 and one second vibration damper 32 are arranged alternately in the X direction for each rack arranged in the X direction.

[0027] As shown in Figures 5 and 6, in the vibration damping structure 1 for a rack warehouse according to this embodiment, when bending deformation in the Y direction occurs in the rack structure 2 due to earthquake vibrations, tension is generated in the axial force member 5 of one of the vibration damping devices 3, the first vibration damping device 31 and the second vibration damping device 32. When tension is generated in the axial force member 5 of the vibration damping device 3, the rotational inertia mass damper 6 deforms axially and rotates due to the tension, and damping performance is exhibited. The damping performance of the rotational inertia mass damper 6 acts on the top of the rack structure 2 via the axial force member 5 and the rigid member 4, thereby reducing the acceleration and displacement of the top of the rack structure 2. The vibration damping device 3 exhibits damping performance when tension is generated in the axial force member 5, but does not exhibit damping performance when axial compressive force is generated in the axial force member 5.

[0028] In this embodiment, the rotational mass generated by the rotational inertia mass damper 6 and the axial stiffness determined by the axial stiffness of the axial force member 5 are synchronized to the natural frequency of the rack structure 2. An additional spring may be provided between the foundation floor 12 and the axial force member 5 to adjust the axial stiffness of the axial force member 5.

[0029] In this embodiment, the mass ratio α between the inertial mass of the rotational inertia mass damper 6 and the total weight of the rack structure 2, and the stiffness ratio β between the axial stiffness of the axial force member 5 and the synchronized axial stiffness of the rotational inertia mass damper 6 were set as follows.

[0030]

number

[0031] Next, the operation and effects of the vibration damping structure for the rack warehouse according to this embodiment will be explained. In the vibration damping structure 1 for a rack warehouse according to this embodiment, when bending deformation occurs in the rack structure 2 due to earthquake vibrations, tension is generated in the axial force member 5 of the vibration damping device 3 on the side that is pulled by the bending deformation, among the vibration damping devices 3 provided on each side of the rack structure 2. When tension is generated in the axial force member 5 of the vibration damping device 3, the rotational inertia mass damper 6 deforms in the axial direction and rotates due to the tension, and damping performance is exhibited. The damping performance of the rotational inertia mass damper 6 acts on the top of the rack structure 2 via the axial force member 5 and the rigid member 4, thereby reducing the acceleration and displacement of the top of the rack structure 2. The rotational inertia of the vibration damping device 3 is equivalent to 10 to 500 times the actual mass of the weight, and it has performance equivalent to that of a vibration reduction mechanism with a large mass, so the vibration damping device 3 can be made lighter and smaller. This makes it possible to minimize the reduction in storage space for stored items caused by installing the vibration damping structure 1 in the rack warehouse. Furthermore, the vibration damping structure 1 for the rack warehouse according to this embodiment can be installed on a rack structure 2 which is made up of multiple connected racks 21, making it easier to install compared to vibration damping structures that install vibration damping devices on each rack 21 or each pallet. Furthermore, since the vibration damping device 3 is positioned to the side of the rack structure 2, it does not reduce the storage space of the rack structure 2. In this embodiment, when the stacker crane 13 is positioned in the space 23 between the two rack groups 22, it does not affect the operation of the stacker crane 13 or the loading and unloading of stored items.

[0032] Furthermore, in the vibration damping structure 1 of the rack warehouse according to this embodiment, the rotational mass that generates rotational inertia mass and the axial stiffness determined by the axial stiffness of the axial force member 5 are tuned to the natural frequency of the rack structure 2. By adopting this configuration, the response acceleration of the rack structure 2 can be significantly reduced.

[0033] Furthermore, in the vibration damping structure 1 of the rack warehouse according to this embodiment, an additional spring may be provided between the foundation floor 12 and the axial force member 5 to adjust the axial stiffness of the axial force member 5. By providing the additional spring, the axial stiffness of the axial force member 5 can be easily adjusted, and the response acceleration of the rack structure 2 can be significantly reduced.

[0034] Furthermore, in the vibration damping structure 1 of the rack warehouse according to this embodiment, the planar shape of the rack structure 2 is a long shape extending in the X direction, and the first vibration damping device 31 and the second vibration damping device 32 are arranged alternately in the X direction. By adopting this configuration, it is possible to secure space on the side of the rack structure 2 where vibration damping devices 3 are not installed, while arranging the vibration damping devices 3 in a balanced manner.

[0035] This section describes the analysis method and results for confirming the effectiveness of the vibration damping structure of the rack warehouse in this embodiment. (Analysis conditions) The target rack structure 2, as shown in Figures 2 and 3, has dimensions of 22.7 m in the X direction, 4.1 m in the Y direction, and a height of 20 m. Sixteen racks, each 1.42 m long, are arranged in the X direction. Two cases were analyzed: one in which the first vibration damping device 31 and the second vibration damping device 32 are alternately arranged in the X direction, as shown in Figure 7, and another in which the first vibration damping device 31 and the second vibration damping device 32 are provided for each rack 21 arranged in the X direction, as shown in Figure 7. The weight of the contents housed in rack structure 2 is 2772 kN. The weight of rack structure 2 itself is 213 kN. The seismic waves were normalized to the 50kine NS component of the EL Centro Imperial Valley earthquake (1940.5.18, M7.1) shown in Figure 8. The analysis direction was set to the Y direction, which is where the shaking is greater and where the contents are moved in and out. The parameters for the mass ratio α and stiffness ratio β are as follows: Mass ratio α (= rotational inertia mass of damper / total rack weight) = 0.1, 0.3, 0.5, 0.7, 0.9 Stiffness ratio β (= axial stiffness of axial force member / synchronous stiffness of rotational inertia mass damper) = 0.5, 1, 2, 3, 4 The rigidity of the axial force member was calculated assuming that the axial force member 5 is a steel rod with a radius of 23 mm.

[0036]

number

[0037] As shown in Figures 9 and 10, it can be confirmed that the vibration damping structure 1 of the rack warehouse in this embodiment can reduce the acceleration at the top of the rack structure compared to a rack structure without a rotational inertia mass damper. In the vibration damping structure 1 of the rack warehouse of this embodiment, it can be confirmed that it is desirable to have a stiffness ratio β ≥ 2 and a mass ratio α ≥ 0.4 in order to achieve the effect of reducing acceleration. In the case where the first vibration damping device 31 and the second vibration damping device 32 are installed in an intersecting manner, it can be confirmed that almost the same acceleration reduction effect as in the case where all devices are installed is achieved.

[0038] Although embodiments of the vibration damping structure for rack warehouses according to the present invention have been described above, the present invention is not limited to the above embodiments and can be modified as appropriate without departing from the spirit of the invention. For example, in the above embodiment, the rack structure 2 consists of two connected rack groups 22, 22, but it may consist of three or more connected rack groups 22, or it may consist of a single rack group 22. A stacker crane 13 is not required to be provided between the connected rack groups 22. Furthermore, in the above embodiment, the first vibration damping device 31 and the second vibration damping device 32 are installed intersectingly with respect to the rack structure 2, but as shown in Figure 7, the first vibration damping device 31 and the second vibration damping device 32 may be provided for each rack in the X direction.

[0039] Furthermore, in the vibration damping structure 1 of the rack warehouse according to the above embodiment, the vibration damping devices 3 are arranged on both sides of the rack structure 2 in the Y direction. In contrast, as shown in the vibration damping structure 1B of the rack warehouse in Figure 11, the vibration damping device 3B may be placed in the space 23 between the rack groups 22, 22 of the rack structure 2. In this case as well, the first vibration damping device 31B and the second vibration damping device 32B are positioned to sandwich either the center of rigidity or the center of gravity of the rack structure 2. In this case, the rigid member 4B does not need to be provided with the cantilevered portion 41 as in the above embodiment. The axial force member 5B extends vertically in the space 23 between the rack groups 22, 22. A rotational inertia mass damper 6 is provided between the axial force member 5B and the base floor 12, similar to the above embodiment.

[0040] Furthermore, as shown in Figure 12, the vibration damping device 3C of the vibration damping structure 1C of the rack warehouse, the axial force member 5C may extend diagonally and be provided to penetrate the rack group 22. In this case as well, the first vibration damping device 31C and the second vibration damping device 32C are arranged to sandwich either the rigidity center or the center of gravity of the rack structure 2. For example, the axial force member 5C may extend diagonally by having its upper end joined to the rigid member 4C in the inner part of the rack structure 2 in plan view (for example, the rack group 22, the space 23 between the rack groups 22), and its lower end joined to the base floor 12 via a rotational inertia mass damper 6 on the side of the rack structure 2. In this case as well, the rigid member 4C does not need to be provided with a cantilevered portion 41. In either case, if a stacker crane 13 is provided between the connected rack groups 22, it is preferable to provide vibration damping devices 3B and 3C so as not to interfere with the stacker crane 13.

[0041] Furthermore, in the above embodiment, the base floor 12 is a fixed floor, but as shown in Figure 13, the base floor 12D of the vibration-damping structure 1D of the rack warehouse, it may be a seismic isolation floor 71 provided on the base 14 via seismic isolation bearings 72, and the rack structure 2 and vibration-damping device 3 may be provided on the seismic isolation floor 71. The seismic isolation bearings 72 are, for example, laminated rubber bearings, spherical sliding bearings, inclined sliding bearings, inclined elastic sliding bearings, etc. This configuration significantly reduces the response acceleration of the rack structure 2. [Explanation of symbols]

[0042] 1,1B-1D Vibration damping structure for rack warehouse 2. Rack structure 3,3B,3C vibration damping device 4,4B,4C Rigid member 5 Axial force member 6. Rotational Inertia Mass Damper 11 Rack Warehouse 12. Foundation floor section 14 Foundation 21 racks 22 racks 31. First vibration control device 32. Second vibration control device 41. Outward-facing section 71 Seismic isolation floor 72 Seismic isolation bearings

Claims

1. The foundation floor and, A rack structure is installed on the aforementioned base floor and consists of multiple racks arranged and connected in the vertical and horizontal directions, The rack structure comprises vibration damping devices provided on both sides of either the center of rigidity or the center of gravity, The vibration damping device, A rigid member is provided integrally with the rack structure at the top of the rack structure, An axial force member connecting the rigid member and the foundation floor, The system includes a rotational inertia mass damper provided between the base floor and the axial force member, which generates a rotational inertia mass by transmitting tension generated in the axial force member, causing a weight to rotate. The rack structure has a long shape extending in the first horizontal direction, with the plurality of racks arranged in the vertical direction and the first horizontal direction. The vibration damping device, A first vibration damping device is provided on one side of the rack structure in the second horizontal direction intersecting the first horizontal direction, It consists of a second vibration damping device provided on the other side of the rack structure in the second horizontal direction, The vibration damping structure for a rack warehouse is such that the first vibration damping device and the second vibration damping device are alternately provided for each of the racks arranged in the first horizontal direction.

2. The vibration damping structure for a rack warehouse according to claim 1, wherein the rotational mass generated by the rotational inertia mass and the axial stiffness determined by the axial stiffness of the axial force member are tuned to the natural frequency of the rack structure.

3. The vibration damping structure for a rack warehouse according to claim 2, further comprising an additional spring provided between the foundation floor and the axial force member to adjust the axial rigidity of the axial force member.

4. The vibration damping device is provided on each side of the rack structure, The rigid member has a projection that extends laterally from the top of the rack structure, The vibration damping structure for a rack warehouse according to claim 1, wherein the axial force member is provided on the side of the rack structure and connects the cantilevered portion and the base floor portion.

5. The vibration control structure for a rack warehouse according to claim 1, wherein the aforementioned base floor is a seismic isolation floor provided on the base via seismic isolation bearings.

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