JP6035528B2 - Cabinet vibration control structure - Google Patents

Description

  The present invention relates to a cabinet damping structure for preventing damage caused by vibration of internal equipment such as a server during an earthquake.

  To protect internal equipment when a cabinet containing electrical and electronic equipment is subjected to earthquake vibration, the cabinet has a double structure consisting of an outer cabinet and an inner cabinet, and the upper and lower parts of the inner cabinet are made of viscoelastic material. A seismic control structure supported by an outer cabinet via a vibration control member is known. (Patent Document 1)

  The vibration control structure of the cabinet of Patent Document 1 is to change the vibration energy to thermal energy and thereby attenuate the vibration by deforming a viscoelastic body. The vibration applied to the inner cabinet is mitigated by the viscoelastic bodies arranged above and below the inner cabinet, and the shaking of the inner cabinet can be converged at an early stage.

  However, in order to attach the damping member to the ceiling portion of the inner cabinet, a heavy plate-like ceiling member of the inner cabinet and a mounting bracket for the damping member are required, so that the center of gravity of the inner cabinet cannot be increased. Absent. As a result, there is a problem that the spring constant of the inner cabinet is reduced and the rigidity of the inner cabinet is lowered.

  In addition, since a plate-like ceiling member is attached to the inner cabinet, there is a problem that it becomes an obstacle when it is desired to draw in the wiring from the ceiling part of the cabinet (ceiling part of the outer cabinet) or when the ventilation fan is arranged on the ceiling part. there were. Further, since many expensive vibration control members are used, there is a problem that the cost becomes high.

JP 2007-2111916 A

  Therefore, the object of the present invention is to solve the above-mentioned conventional problems, and can lower the position of the center of gravity and reduce the cost without deteriorating the vibration control performance, and the degree of freedom in using the ceiling portion of the inner cabinet. It is to provide a vibration control structure of a cabinet that can improve the performance.

The cabinet vibration control structure of the present invention made to solve the above problems comprises an outer cabinet in which a frame member is firmly joined by welding or a corner member, and an inner cabinet housed therein,
The lower part of the inner cabinet is supported by a vibration control member having a viscoelastic body on the outer cabinet, and the upper part of the inner cabinet is supported by a vibration absorbing part that absorbs vibrations by rubbing the joined members. By fixing to the outer cabinet, the ceiling of the cabinet is shared,
By placing the damping member only in the lower part of the cabinet, the center of gravity of the entire cabinet is in a position lower than the center,
The spring constant of the outer cabinet is larger than the spring constant of the inner cabinet,
The attenuation constant of the inner cabinet is characterized by being larger than the attenuation constant of the outer cabinet.

  According to the second aspect of the present invention, the upper end of the mounting rail of the inner cabinet is fixed to the frame member of the outer cabinet, and the frame member of the ceiling portion of the cabinet can be made common.

In the cabinet damping structure of the present invention, the inner cabinet with a small spring constant is housed in the outer cabinet with a large spring constant in which the frame members are firmly joined by welding or corner members, and the lower part of the inner cabinet is placed in the outer cabinet. The upper part of the inner cabinet is fixed to the outer cabinet via a vibration absorbing part that absorbs vibrations by rubbing the joined members together. The parts are shared, and the damping member is disposed only at the lower part of the cabinet so that the center of gravity of the entire cabinet is lower than the center . By adopting such a structure, it is possible to secure a vibration control performance comparable to that of conventional products, as shown in the experimental data to be described later, even though the vibration control member at the ceiling is eliminated. .

  For this reason, the position of the center of gravity of the entire cabinet can be lowered as compared with the conventional product, and since there is no plate-like ceiling member in the ceiling portion, wiring drawing from the ceiling portion and attachment of a ventilation fan are also free. Furthermore, since the number of expensive seismic control members used can be reduced, the cost can be significantly reduced.

It is a whole perspective view of the cabinet using the damping structure of the present invention. It is a front view of the cabinet using the damping structure of this invention. It is a perspective view of a lower part. It is an upper perspective view. It is a perspective view which shows the damping member on a depth frame. It is a perspective view of a damping member. It is sectional drawing of a damping member.

Embodiments of the present invention will be described below.
FIG. 1 is an overall perspective view of a cabinet using the vibration control structure of the present invention, where 1 is an outer cabinet and 2 is an inner cabinet housed therein. The outer cabinet 1 has a skeletal structure in which twelve frame members 3 are assembled in a rectangular parallelepiped shape, and is constructed by attaching a side plate, a back plate, a door, etc. (not shown) in addition to the top plate 4 as in the prior art. Yes.

  Since the outer cabinet 1 is required to have strong strength against an external force such as an earthquake, the outer cabinet 1 has a structure in which the frame members 3 are firmly joined to each other by welding or a corner member. In addition, a polygonal hollow frame having a thick plate thickness is used for the support frame arranged at least in the vertical direction among the frame members 3, and the rigidity is increased by increasing the section modulus. Because of this structure, the spring constant of the outer cabinet 1 is larger than that of the inner cabinet 2, and the damping coefficient when receiving an external force is small.

  The inner cabinet 2 is constituted by four mounting rails 5 serving as support columns, and the lower ends of the four mounting rails 5 are the four corners of the bottom plate 6 of the inner cabinet 2 as shown in FIGS. It is fixed to the fixing part 7 formed by screwing. Further, the upper ends of the four mounting rails 5 are screwed and fixed to the depth frame 8 of the ceiling portion of the outer cabinet 1 via a connection fitting 17 as shown in FIGS. These screwing portions function as a vibration absorbing portion that converts vibration energy into heat energy by rubbing the joined members together in the event of an earthquake to absorb the vibration. Note that the bottom plate of the inner cabinet 2 is not essential, and the frame members may be fixed to each other by a screwed frame structure, and the lower end portion of the mount rail 5 may be fixed to the frame structure by screws. The depth frame 8 of the ceiling part is bent wide and is the depth frame of the outer cabinet 1, and at the same time the upper end of the mount rail 5 is fixed via the connection fitting 17, so the depth frame of the ceiling part of the inner cabinet Also works.

  Further, by fixing the upper end of the mount rail 5 constituting the inner cabinet 2 to the depth frame 8 of the ceiling portion of the outer cabinet 1 in this way, the ceiling portion of the outer cabinet 1 and the inner cabinet 2 are made common, and the weight is reduced. Cost reduction is planned.

  The mount rail 5 constituting the inner cabinet 2 is a frame member that is bent. For this reason, the spring constant of the inner cabinet 2 is smaller than the spring constant of the outer cabinet 1.

  As shown in FIG. 3, the bottom plate 6 of the inner cabinet 2 is fixed to the depth frame 8 at the bottom of the outer cabinet 1, but the bottom surface of the bottom plate 6 of the inner cabinet 2 has viscoelasticity shown in FIGS. 6 and 7. A vibration control member 9 having a body 13 is arranged. FIG. 5 is a perspective view showing the damping member 9 on the depth frame 8, FIG. 6 is a perspective view of one damping member 9, and FIG. 7 is a central longitudinal sectional view thereof. In this embodiment, six damping members 9 are arranged, but all have the same structure.

  As shown in FIGS. 6 and 7, the vibration control member 9 includes a base plate 10, an intermediate plate 11, an upper plate 12, and two upper and lower flat plate-like viscoelastic bodies 13 sandwiched therebetween. It is constituted by. The base plate 10 is fixed to the depth frame 8 of the ceiling portion of the outer cabinet 1 via the mounting bracket 15, and the bottom plate 6 of the inner cabinet 2 is supported on the upper surface of the upper plate 12. When the inner cabinet 2 is displaced (vibrated) with respect to the outer cabinet 1 due to the vibration, the viscoelastic body 13 is deformed and absorbs the vibration energy to attenuate the vibration. Stoppers 14 are attached to the four sides of the intermediate plate 11 to prevent excessive deformation of the lower viscoelastic body 13. In addition, load support members 16 are provided at both ends of the intermediate plate 11 and outside the stopper 14 to prevent the viscoelastic body 13 from being crushed by a load related to the inner cabinet.

  The amount of displacement of the viscoelastic body 13 is determined by its spring constant ke, and the amount of displacement increases as the spring constant decreases. Factors that determine the spring constant of the viscoelastic body 13 include its thickness H, the number N, the area A, and the shear modulus G. When the thickness H increases, the spring constant decreases and the displacement increases, and when the arrangement number N decreases, the spring constant decreases and the displacement increases, and when the area decreases, the spring constant decreases and the displacement increases. Become. When the shear elastic modulus G is small (soft), the spring constant is small and the displacement is large. Between these, the relational expression ke = G · A · N / H holds. Further, since the displacement X of the viscoelastic body 13 with respect to the assumed maximum seismic force F is X = F / ke, the viscoelastic body 13 is selected in consideration of the above characteristics.

  As described above, the outer cabinet 1 has the highest rigidity, the inner cabinet 2 has the lower rigidity, and the viscoelastic body 13 has the lowest rigidity. For this reason, the vibration of the inner cabinet 2 at the time of the occurrence of the earthquake is quickly attenuated by the viscoelastic body 13, and excellent attenuation performance can be obtained for the entire cabinet as shown in the experimental data described later.

Note that a relationship of f = (1 / 2π) (ke / m) ^1/2 is established between the spring constant ke, the natural frequency f, and the mass m, and the natural frequency f changes depending on the spring constant ke. . Therefore, the spring constant ke is set in consideration of the mass of the internal equipment mounted on the inner cabinet 2 in consideration of the assumed earthquake frequency.

In the cabinet vibration damping structure of the present invention configured as described above, the bottom surface of the inner cabinet 2 is supported on the bottom surface of the outer cabinet 1 via the vibration damping member 9 including the viscoelastic body 13. The upper end of the mounting rail 5 of the inner cabinet 2 is fixed to the depth frame 8 of the ceiling portion of the outer cabinet 1 with screws or the like. For this reason, the center of gravity of the inner cabinet is lower than the center of the inner cabinet. Thus, unlike the conventional structure of Patent Document 1, since the vibration control member 9 is not disposed between the outer cabinet and the ceiling of the inner cabinet 2, the plate-like ceiling member of the inner cabinet having a heavy weight for that purpose. In addition, the mounting bracket for the vibration control member 9 is not required, and the mass of the inner cabinet 2 is greatly reduced. For this reason, the load which the inner cabinet 2 receives at the time of the earthquake occurrence calculated as f = ma (a is a response acceleration with respect to a seismic wave, f is the load generated by it) becomes small. Also due to a decrease in the mass m, energy input to the inner cabinet 2 calculated decreases as E = mv ^2/2. For this reason, the center of gravity of the entire cabinet is lower than the center of the cabinet as compared with the conventional structure, and as shown in the experimental data to be described later, the damping member 9 on the ceiling of the inner cabinet 2 is eliminated. The same vibration control effect as that of the conventional structure in which the seismic member 9 is disposed can be obtained.

  Further, in the cabinet vibration control structure of the present invention, since the heavy ceiling member of the inner cabinet 2 and the mounting bracket of the vibration control member 9 are not arranged, the center of gravity of the inner cabinet 2 is lowered. This increases the spring constant of the inner cabinet 2 and makes it difficult to break. Moreover, since the force which acts on the upper end of the mount rail 5 which comprises the inner cabinet 2 reduces, vibration energy can be absorbed also by the vibration absorption part by screwing.

  Furthermore, in the cabinet damping structure of the present invention, since there are no obstacles such as the ceiling member of the inner cabinet 2, wiring from the ceiling of the cabinet is easy, and a ventilation fan may be arranged on the ceiling of the cabinet. It becomes possible. Furthermore, since there is room in the upper space of the cabinet, it is possible to increase the installation space for the equipment in the height direction, and to achieve a significant cost reduction.

  Next, data of the vibration test is shown. In the test, as shown in the embodiment, the damping member 9 is arranged only in the lower part of the inner cabinet 2, the damping member 9 is arranged above and below the inner cabinet 2 as in the prior art, and the damping member 9 is completely. Three types were prepared, and the test acceleration of 1000 gal was applied in the front-rear direction on a vibration tester. Inside each inner cabinet 2, a 500 kg weight corresponding to 100% of the allowable load capacity was mounted. In any case, the natural frequency of the outer cabinet 1 is 6 Hz, the natural frequency of the inner cabinet 2 is 2 Hz, and the outer cabinet 1 has a larger spring constant. The attenuation constant is 2% for the outer cabinet 1 and 8% for the inner cabinet 2. The amount of deformation at the top of the outer cabinet and the acceleration at the top of the inner cabinet were measured and displayed as an index in Table 1 on the basis that no damping member 9 was arranged at all.

  As shown in Table 1, the cabinet damping structure of the present invention has the same acceleration when subjected to vibrations with the internal equipment fully loaded, and the amount of deformation at the top is slightly smaller than that of the conventional structure. It was confirmed that it was only inferior.

DESCRIPTION OF SYMBOLS 1 Outer cabinet 2 Inner cabinet 3 Frame member 4 Top plate 5 Mount rail 6 Bottom plate 7 Fixed part 8 Depth frame 9 Damping member 10 Base plate 11 Intermediate plate 12 Upper plate 13 Viscoelastic body 14 Stopper 15 Mounting bracket 16 Load support member 17 Connecting bracket

Claims (2)

It consists of an outer cabinet in which frame members are firmly joined by welding or corner members, and an inner cabinet housed inside the cabinet.
The lower part of the inner cabinet is supported by a vibration control member having a viscoelastic body on the outer cabinet, and the upper part of the inner cabinet is supported by a vibration absorbing part that absorbs vibrations by rubbing the joined members. By fixing to the outer cabinet, the ceiling of the cabinet is shared,
By placing the damping member only in the lower part of the cabinet, the center of gravity of the entire cabinet is in a position lower than the center,
The spring constant of the outer cabinet is larger than the spring constant of the inner cabinet,
A cabinet damping structure characterized in that the attenuation constant of the inner cabinet is larger than the attenuation constant of the outer cabinet.   2. The cabinet damping structure according to claim 1, wherein the upper end of the mounting rail of the inner cabinet is fixed to the frame member of the outer cabinet, and the frame member of the ceiling of the cabinet is made common.

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