Vertical vibration control device

Abstract: A vertical vibration control device (1) comprises an air spring (4) provided between a foundation (2) and a superstructure (3) separated from each other, an upper support (5) fixed to the superstructure (3) so as to support an upper end of the air spring (4), a lower support (6) fixed to the foundation (2) so as to support a lower end of the air spring (4), and guide means (7) disposed on opposite sides of the air spring (4) so as to guide the vertical motions of both supports (5,6), the guide means (7) restricting the horizontal motion of the air spring (4). The air spring (4) is thus arranged to act only for vertical motion of the superstructure (3) separated from the foundation (2), i.e., only for any vertical vibrations.

Description: This invention relates to a vertical vibration control device, which is disposed between a foundation and a superstructure such as a floor slab, a building frame or a machine provided on the foundation by separating the foundation from the superstructure, and causes to act for any vertical vibrations, in cases where a base-isolation floor slab is provided within the building frame, a base-isolation frame is provided on a building foundation or a machine is base-isolationally mounted on a machine foundation. Taking examples of vibrations which give influences to a superstructure such as a floor slab, a building frame or a machine provided on a foundation, e.g., earthquake, a known base isolation device comprises a member rolling without any frictional resistances, such as a bearing, and a saucer-like member for receiving the rolling member, as for a vibration control device for managing any horizontal vibrations. Since normal earthquake is mainly characterized by horizontal vibrations, the above-mentioned base isolation device can substantially cope with such horizontal vibrations. However, a large-scale structure which induces vertical vibrations due to an earthquake directly above an epicenter or a horizontal earthquake, experiences much more often the vertical vibrations and necessitates a vertical vibration control device against the vertical vibrations. As for such a vertical vibration control device, it has been generally known in the prior art to provide vertically-expanding air springs in the places where vibration control should be done (c.f. EP-A- 0 439 273). Incidentally, the air spring is made of an expansion casing composed of external and internal cylinders movably combined with each other. If a vibration portion to be vibrated by an earthquake or the like is a foundation and a non-vibration portion kept not so as to receive any vibrations due to an earthquake is a superstructure (i.e., a floor slab, a building frame or the like), the expansion casing is provided so as to fix a lower end thereof to the foundation and set so as to support the superstructure on an upper end thereof. Even if the foundation is vertically vibrated by an earthquake or the like, the vertical vibrations can be absorbed by the variations in the relative positions between the external and internal cylinders due to the installation of the air springs between the foundation and the superstructure in this manner. Therefore, the superstructure is hardly vibrated vertically. However, since the air spring has little horizontal stiffness, the air spring moves not only in a vertical direction but also in a horizontal direction when any vertical vibrations are applied to the air spring. Consequently, rocking or like very unstable motion is produced, and no vibration control against any vertical vibrations can be surely done by the air spring. Furthermore, as described above, the air spring is made of the expansion casing composed of the external and internal cylinders movably combined with each other. However, since the air spring is to hinder mutual transverse motions of the external and internal cylinders, the overlap between the external and internal cylinders cannot be made longer. Accordingly, the overlapping portion between the external and internal cylinders cannot regulate the horizontal motion as described above. The present invention Drovides a vertical vibration control device according to the claims for carrying out a vibration control against any vertical vibrations by restricting any horizontal motions so that an air spring may smoothly act only for a vertical motion thereof. EP-A-0 380 304 discloses a vibration control device which is provided between a foundation and a superstructure and which comprises an air spring (in the form of a bellows) and a laminated rubber assembly arranged one above the other and integrally connected together. The air spring has an upper support and a lower support vertically guided relative to each other by vertical rails (guide posts) which are fixed to the upper support and along which the lower support is slidable. The rails are disposed on opposite sides of the air spring. The present invention provides a vertical vibration control device, which is provided between a foundation and a superstructure separated from each other and which acts against any vertical vibrations, comprising: an air spring provided between the foundation and the superstructure; an upper support fixed to the superstructure so as to support an upper end of the air spring; a lower support fixed to the foundation so as to support a lower end of the air spring; and guide means disposed on opposite sides of the air spring so as to guide the vertical motions of both supports, the guide means being arranged so as to restrict the horizontal motion of the air spring, the guide means including vertically extending guide rails on opposite sides of the air spring, the guide rails being mounted on one of the supports; characterised in that: the air spring comprises a telescopic expansion casing consisting of an external cylinder and an internal cylinder, one of which is vertically movable relative to the guide rails; and the guide means include guide blocks slidably engaged with the respective guide rails and connected to the relatively movable one of the cylinders by elastic means. In this manner, according to the present invention, the work of the air spring is arranged to smoothly act only for the vertical motion of the superstructure, that is, only for the vertical vibration. The invention will become apparent from the following description of a preferred embodiment of the invention with reference to the accompanying drawings, in which: Fig. 1 is a sectional view showing a vertical vibration control device as a first embodiment of the present invention; and Fig. 2 is a sectional view taken along the line A-A in Fig. 1. Referring now to Figs. 1 and 2 showing a preferred embodiment of the present invention, a vibration control device 1, which is provided between a foundation 2 and a superstructure 3 separated from each other and which acts against any vertical vibrations, comprises an air spring 4 provided between the foundation 2 and the superstructure 3 and made of an expansion casing composed of an external cylinder 4a and an internal cylinder 4b movably combined with each other, an upper support 5 fixed to the superstructure 3 such as to support an upper end of the air spring 4, a lower support 6 fixed to the foundation 2 such as to support a lower end of the air sprung 4, and guide means 7 for guiding the vertical motions of both supports 5 and 6 for supporting the air spring 4. Additionally, the guide means 7 are arranged so as to be capable of restricting the horizontal motion of the air spring 4. The guide means 7 are disposed on opposite sides of the air spring 4 so as to clamp the air spring 4. The guide means 7 includes a vertically extending guide rail 8 provided at the positions on both sides of the air spring 4 in a state integrally erected from the lower support 6, and a guide block 10 slidably engaged with the guide rail 8 and fixed to a movable part of the air spring 4 through an elastic body 9 in the form of a vertically extending plate-like rubber element sandwiched between respective vertically extending surfaces provided on the guide block 10 and external cylinder 4a. In addition, the guide rail 8 in this embodiment is made of H-section steel or the like and mounted on a couple of columns integrally erected from the lower support 6. It can be seen that the upper end of each guide rail 8 is spaced from the superstructure 3 and the upper support 5. Also, the elastic body 9 inserted between the guide block 10 and the movable part of the air spring 4 absorbs the amount of displacement by deforming when a horizontal force is applied to the elastic body so that the elastic body remains perpendicular with the guide rail 8 and the guide block 10. Therefore, the guide block 10 smoothly slides on the rail even in a case where a horizontal force is applied, similarly to a case where the horizontal force is not so. From these reasons, the air spring 4 of the vibration control device 1 is restricted in horizontal motion against the vertical vibrations and smoothly acts only in a vertical direction. In accordance with the vibration control device 1 of the present invention as described in the embodiment shown in Figs. 1 and 2 including such a construction, the vibration control against any vertical vibrations can be surely performed by setting such that the air spring 4 may smoothly act only for the vertical motion by restricting the horizontal motion of the air spring 4.

Claims: A vertical vibration control device (1), which is provided between a foundation (2) and a superstructure (3) separated from each other and which acts against any vertical vibrations, comprising: an air spring (4) provided between the foundation (2) and the superstructure (3); an upper support (5) fixed to the superstructure (3) so as to support an upper end of the air spring (4); a lower support (6) fixed to the foundation (2) so as to support a lower end of the air spring (4); and guide means (7) disposed on opposite sides of the air spring (4) so as to guide the vertical motions of both supports (5,6), the guide means (7) being arranged so as to restrict the horizontal motion of the air spring (4), the guide means (7) including vertically extending guide rails (8) on opposite sides of the air spring (4), the guide rails (8) being mounted on one of the supports (6,7); characterised in that: the air spring (4) comprises a telescopic expansion casing consisting of an external cylinder (4a) and an internal cylinder (4b), one of which is vertically movable relative to the guide rails (8); and the guide means (7) include guide blocks (10) slidably engaged with the respective guide rails (8) and connected to the relatively movable one of the cylinders (4a,4b) by elastic means (9). A vertical vibration control device (1) according to claim 1, wherein the guide rails (8) are mounted on the lower support (6). A vertical vibration control device (1) according to claim 2, wherein the upper ends of the guide rails (8) are spaced from the superstructure (3) and the upper support (5). A vertical vibration control device (1) according to any preceding claim, wherein the external cylinder (4a) is supported by the upper support (5), and the internal cylinder (4b) is supported by the lower support (6). A vertical vibration control device (1) according to any preceding claim, wherein the guide rails (8) are H-shaped in cross-section. A vertical vibration control device (1) according to any preceding claim, wherein each elastic means (9) comprises a vertically extending plate-like rubber element sandwiched between respective vertically extending surfaces provided on the associated guide block (10) and cylinder (4a).

Inventors: FUNAKI NOBUMITSU, HAYASHI HIDEO, KAMIMURA RYUICHI, KANDA KATSUHISA, KASAI TORU, MATSUSHIMA JUN, MIYAMURA MASAMITSU, YANO KENICHI, FUNAKI, NOBUMITSU, HAYASHI, HIDEO, KAMIMURA, RYUICHI, KANDA, KATSUHISA, KASAI, TORU, MATSUSHIMA, JUN, MIYAMURA, MASAMITSU, YANO, KENICHI, FUNAKI, NOBUMITSU C/O YACMO K.K. (IWATA BLDG.), HAYASHI, HIDEO C/O KAJIMA CORPORATION, Kamimura, Ryuichi c/o Kajima Corp. Tokyo Branch, KANDA, KATSUHISA C/O KAJIMA CORPORATION, KASAI, TORU C/O KAJIMA CORPORATION, MATSUSHIMA, JUN C/O KAJIMA CORP. TOKYO BRANCH, MIYAMURA, MASAMITSU C/O KAJIMA CORPORATION, YANO, KENICHI C/O KAJIMA CORP. GIJUTSU KENKYUSHO
Applicants: KAJIMA CORP, YACMO KABUSHIKI KAISHA, KAJIMA CORPORATION
Application year: 1992
Main classification: E04H9
IPC codes: E04H9