JP2018168868A - Shock absorber - Google Patents

Abstract

To provide a shock absorber capable of preventing force causing nonaxisymmetric deformation of crushable pipes, from affecting the other.SOLUTION: A shock absorber 1 includes an upper plate 2, a lower plate 3, crushable pipes 4 therebetween, and connection plates 5 for connecting joining portions of the crushable pipes 4 of upper and lower stages in an axial orthogonal direction. A central portion of each connection plate 5 and a central portion of the lower plate 3 are respectively provided with guide cylinders 6 raised in a vertical direction. A central portion of the upper plate 2 is provided with a vertical guide recessed portion 2a to which an upper portion of the guide cylinder 6 of an uppermost level is vertically slidably fitted. An upper portion of the guide cylinder 6 of a lower level is telescopically slidably fitted into the guide cylinder 6 of the upper level or the guide recessed portion 2a. The connection plate 5 can be horizontally kept by sliding between the upper and lower guide cylinders 6 or sliding to the guide recessed portion 2a when the crushable pipes 4 are compressed.SELECTED DRAWING: Figure 3

Description

  The present invention relates to a shock absorber for buffering an impact caused by dropping of a heavy object by plastic deformation in the axial direction of a pipe and preventing the heavy object itself and a floor surface receiving the shock.

  2. Description of the Related Art Conventionally, for example, a device described in Patent Document 1 is known as a device for buffering an impact caused by dropping of a heavy object by plastic deformation in the axial direction of a pipe. This consists of a number of cylindrical crushable pipes arranged in parallel between the upper plate that directly receives the impact load and the lower plate that supports the impact load, with the axis line aligned with the direction of the impact load. It is. The crushable pipe is further stacked in a plurality of stages between the upper plate and the lower plate in series in the vertical direction with the upper and lower ends abutting each other. A connecting plate for connecting the upper and lower joints of the crushable pipe in the direction perpendicular to the axis is provided so that the plurality of crushable pipes arranged in parallel in each stage receive an impact load equally. A plurality of through-holes are provided at positions where the crushable pipes are fixed on the upper plate, the connecting plate, and the lower plate so that the axes are aligned vertically. An upper lid is fitted into the through hole of the upper plate. A pair of upper and lower connecting rings that contact the lower and upper ends of the upper and lower crushable pipes are fitted to the connecting plate. A lower lid is fitted into the through hole of the lower plate. A plurality of crushable pipes arranged in series vertically pass through a tightening rod in the axial direction, and the upper end threaded portion is screwed to the upper lid, and the upper end threaded portion is threaded to the lower lid. As a result, the plurality of crushable pipes and the connecting plate between the upper plate and the lower plate are fastened and fixed in the vertical direction. The upper and lower lids are provided with tool hooks in order to be screwed into the upper and lower ends of the tightening rod.

Japanese Patent Laid-Open No. 3-168428

In the shock absorber described in Patent Document 1, the crushable pipe is deformed non-axisymmetrically when the falling posture of the fallen object is inclined with respect to the axis of the crushable pipe. When non-axisymmetric deformation occurs in the crushable pipe, the parallelism between the upper plate and the lower plate is lost, or mutual twisting occurs, and the initial shock absorbing function cannot be obtained.
Therefore, according to the present invention, it is possible to reliably deform a crushable pipe in an axisymmetric manner, and even if a force causing a non-axisymmetric deformation is applied to a specific crushable pipe, An object of the present invention is to provide an impact shock absorber that does not affect deformation.

  In order to solve the above problems, the shock absorber 1 of the present invention includes an upper plate 2 that directly receives a downward impact load, and a space parallel to the lower portion of the upper plate 2 so as to support the impact load. A plurality of lower plates 3 are arranged between the upper plate 2 and the lower plate 3 in parallel so that the direction of the impact load and the axis coincide with each other, and the upper and lower ends are butted against each other in the axial direction. The cylindrical crushable pipes 4 that are arranged in a plurality of stages in series and are capable of plastic deformation in the axial direction upon receiving an impact load, and the plurality of crushable pipes 4 arranged in parallel in the upper and lower stages are evenly distributed. And a connecting plate 5 for connecting the upper and lower joints of the crushable pipe 4 in the direction orthogonal to the axis so as to receive an impact load. A guide cylinder 6 is provided at the center of each connecting plate 5 and the center of the lower plate 3 so as to stand vertically. A vertical guide recess 2a is provided at the center of the upper plate 2 so that the upper portion of the uppermost guide tube 6 can be moved up and down. The upper portion of the lower guide tube 6 is slidably fitted into the upper guide tube 6 or the guide recess 2a in order.

  In the shock absorbing device 1 of the present invention, when the crushable pipe 4 is subjected to an impact load and plastically deforms in the axial direction, even if non-axisymmetric abnormal deformation occurs in the specific crushable pipe 4, Since the up and down guide cylinder 6 slides and maintains the level of each connecting plate 5, the influence of abnormal deformation is not propagated to the other crushable pipes 4.

It is a front view of the shock absorbing device according to the present invention. FIG. 2 is a plan view of the shock absorber shown in FIG. FIG. 2 is a longitudinal front view of the shock absorber shown in FIG. It is a vertical front view at the time of the shock absorption of the shock absorber of FIG. FIG. 2 is an explanatory diagram of a usage state of the shock absorber shown in FIG. It is a vertical front view of the shock absorbing device of another embodiment. It is a longitudinal front view at the time of impact absorption of the shock absorber of FIG.

Embodiments of the present invention will be described with reference to the drawings.
For example, as shown in FIG. 5, a plurality of canisters C that store molten solidified radioactive waste discarded from a nuclear power plant or the like are stacked and stored in a pit P. If the canister C is accidentally dropped into the pit P when it is carried in, the canister C may be destroyed by the impact and the radioactive material may leak out. In order to prevent this, the shock absorbing device 1 of this embodiment is installed at the bottom of the pit P.

  In FIG. 1 to FIG. 4, the shock absorbing device 1 is a circular upper plate 2 that directly receives an impact load and a circular bottom plate that is provided in parallel and spaced below the upper plate 2 and supports the impact load at the bottom of the pit P. The lower plate 3 and a plurality of cylindrical crushable pipes 4 arranged in an annular shape are provided between the upper plate 2 and the lower plate 3 so as to be plastically deformed in the axial direction in response to an impact load. When a heavy object such as the canister C falls on the upper plate 2, as shown in FIG. 4, the crushable pipe 4 is plastically deformed in the axial direction to absorb impact energy, and the canister C or the pit P Prevent floor destruction.

  The crushable pipes 4 are also arranged in a plurality of stages in series in the vertical axis direction with the upper and lower ends abutting each other.

  A circular connecting plate 5 is interposed at the upper and lower joints of the crushable pipe 4. The connecting plate 5 connects the crushable pipes 4 in the direction orthogonal to the axis so that the upper and lower crushable pipes 4 receive an impact load evenly.

  At the center of each connecting plate 5 and lower plate 3, a guide tube 6 is provided that stands vertically. The upper part of the lower guide tube 6 penetrates the upper connection plate 5 and is slidably fitted into the upper guide tube 6 in a slidable manner.

  At the center of the upper plate 2, a vertical guide recess 2a is provided in which the upper part of the uppermost guide tube 6 is slidably fitted.

  Thus, for example, as shown in FIG. 5, the shock absorbing device 1 of this embodiment is installed at the bottom of the pit P for storing the canister C containing the molten solidified material of the radioactive substance. If the canister C is accidentally dropped into the pit P when the canister C is suspended in the pit P, the crushable pipe 4 is plasticized in the axial direction by the impact load as shown in FIG. Deforms and absorbs the energy of impact load.

  At this time, even if a stress that causes non-axisymmetric deformation occurs in the specific crushable pipe 4, the upper and lower guide cylinders 6 standing vertically slide relative to each other or the guide recess 2 a, and each connecting plate 5 Therefore, the influence of abnormal deformation of a specific crushable pipe 4 is not propagated to other crushable pipes 4. For this reason, the parallelism between the upper plate 2 and the lower plate 3 is not lost, and mutual twisting does not occur and the initial shock absorbing function is not affected.

  In other embodiments shown in FIGS. 6 and 7, guide cylinders 7 extending vertically downward are provided at the central portion of the upper plate 2 and the central portions of the connecting plates 5. The lower part of the upper guide cylinder 7 sequentially passes through the lower connecting plate 5 and is slidably fitted into the lower guide cylinder 7 in a nested manner.

  In addition, a vertical guide recess 3a is provided at the center of the lower plate 3 so that the lower portion of the lowermost guide tube 7 can be slid up and down.

  When absorbing the impact, the connecting plate 5 is kept horizontal by sliding between the guide cylinders 7 or between the guide recesses 3a.

DESCRIPTION OF SYMBOLS 1 Shock absorber 2 Upper board 2a Guide recessed part 3 Lower board 3a Guide recessed part 4 Crashable pipe 5 Connection board 6 Guide cylinder 6a Outer flange 6b Opening 7 Guide cylinder C Canister P Pit

Claims (2)

An upper plate that directly receives a downward impact load, and a lower plate that is provided in parallel and spaced below the upper plate so as to support the impact load;
Between the upper plate and the lower plate, a plurality of them are arranged in parallel so that the direction of the impact load and the axial center coincide with each other, and the upper and lower ends are abutted to each other and arranged in a plurality of stages in the axial direction in series. And a cylindrical crushable pipe that is plastically deformable in the axial direction under impact load,
A connecting plate that connects the upper and lower joints of the crushable pipe in the direction perpendicular to the axis so that the plurality of crushable pipes arranged in parallel in the upper and lower stages receive an impact load evenly.
In the central part of each of the connecting plates and the central part of the lower plate, there are provided guide tubes that stand vertically,
In the central part of the upper plate, a vertical guide recess for fitting the upper part of the uppermost guide cylinder so as to be movable up and down is provided,
The upper part of the lower guide cylinder is sequentially slidably fitted into the upper guide cylinder or the guide recess,
The shock absorbing device is configured so that the level of the connecting plate is maintained by sliding of each guide tube when absorbing the shock. An upper plate that directly receives a downward impact load, and a lower plate that is provided in parallel and spaced below the upper plate so as to support the impact load;
Between the upper plate and the lower plate, a plurality of them are arranged in parallel so that the direction of the impact load and the axial center coincide with each other, and the upper and lower ends are abutted to each other and arranged in a plurality of stages in the axial direction in series. And a cylindrical crushable pipe that is plastically deformable in the axial direction under impact load,
A connecting plate that connects the upper and lower joints of the crushable pipe in the direction perpendicular to the axis so that the plurality of crushable pipes arranged in parallel in the upper and lower stages receive an impact load evenly.
A guide tube extending vertically downward is provided at the central portion of the upper plate and the central portion of each connecting plate,
At the center of the lower plate is provided with a vertical guide recess for fitting the lower part of the lowermost guide cylinder so as to be movable up and down,
The lower part of the upper guide cylinder is sequentially slidably fitted into the lower guide cylinder,
The shock absorbing device is configured so that the level of the connecting plate is maintained by sliding of each guide tube when absorbing the shock.

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