JP6283322B2 - Shock absorber - Google Patents

Description

  The present invention relates to a shock absorber for suppressing the movement of a structure subjected to an external force such as an earthquake.

  In the design of a base-isolated structure that moves a specific part of a building, etc., absorbs the force generated by an earthquake and prevents its destruction, the maximum amount of movement (maximum deformation) assumed by the earthquake motion is estimated. Thus, a necessary gap is set around a building or the like.

  However, under the present circumstances, it has not been assumed that even a large earthquake that exceeds the expectation has occurred, such as contact and collision with surrounding objects accompanying the movement of buildings and the like. For this reason, in the case of a huge earthquake that may occur in the future, there is a demand for the addition of a fail-safe function to the seismic isolation structure when a building or the like exhibits a behavior that exceeds expectations.

  Also, in bridges, especially for bridges with low horizontal rigidity between the pier and bridge girder, in order to prevent the bridge girder from dropping off from the support due to the movement of the bridge girder and falling from the pier of the bridge girder, usually a falling bridge prevention device is installed. It is attached. And the buffer device for buffering the impact load which arises at the time of the collision prevention of a bridge girder fall or bridge girder is added to such a fall bridge prevention device.

  As a shock absorber used for such a falling bridge prevention device, a device in which a chain is covered with rubber or the like, and a ring-shaped rubber is attached to the tip of a steel rod has been proposed (for example, Patent Documents). 1).

  In addition, as a shock absorber that achieves a shock absorbing function with only steel members without using rubber or other members, a number of circumferentially extending slits are provided in the steel pipe at intervals in the axial direction to reduce strength and rigidity. Also proposed are those that absorb energy by plastic deformation of a steel pipe (see, for example, Patent Document 2).

JP 2002-97607 A JP 2010-53618 A

  However, in a shock absorber in which a chain is covered with rubber or the like, as described in Patent Document 1, or a ring-shaped rubber is attached to the tip of a steel rod, a member made of rubber or the like is made of ultraviolet light, ozone, or the like. As a result, there is a problem that the initial buffering capacity cannot be exhibited due to deterioration due to aging, or the member such as rubber is burned down due to a fire or the like and the buffering capacity is lost.

  In addition, in the example using a high damping rubber as a shock absorber, there is data that the energy absorption capacity in the hysteresis cycle is reduced to about 60%, and about 40% of the input energy is released from the shock absorber. Secondary vibration may occur. Further, when rubber is used, a special manufacturing technique is required, and since there are limited companies that can supply the rubber, there is a disadvantage that the product price is increased.

  Moreover, in the shock absorber which implement | achieves a shock absorbing function only by steel parts like the patent document 2, the initial gradient at the time of apparatus operation | movement is large, and a certain amount of impact load inputs into a structure in a steel pipe elastic region, and a structure There was a possibility that the burden on things would increase. From these facts, the reality is that it has not yet been possible to develop the same level of buffer performance as a shock absorber using a member such as rubber with only steel parts.

  The present invention has been made in view of the circumstances as described above, and becomes a problem when a structure such as a building or a bridge is moved beyond a design assumption due to an external force such as earthquake motion. It is an object of the present invention to provide a shock absorber having a function of preventing collision between adjacent structures, dropping of a bridge girder in a bridge, and the like to minimize damage to the structure.

  The shock absorber according to the present invention has been made to solve the above technical problem, and is characterized by the following.

First, in the shock absorber according to the present invention, a constraining material is provided in the central space of the coil spring at a specific interval with respect to the circumferential direction of the coil spring, and the constraining member is provided at one end of the coil spring. Attachment members for attaching to the structure are provided at both ends of the coil spring, and external force is applied outward in the axial direction at both ends of the coil spring, and the coil spring receiving the tensile force is throttled. When the inner diameter is deformed to be small , the shock absorber is characterized in that the inner diameter of the coil spring is not deformed to be smaller than a certain level by the restraining material provided therein .

  Second, in the shock absorber according to the first invention, the coil spring is preferably a coil spring in which a steel material having a rectangular cross section is wound in a spiral shape.

  Third, in the shock absorber according to the first invention, the coil spring is preferably a coil spring in which a helical slit is formed in a steel pipe material.

  Fourthly, in the shock absorber according to the first to third aspects of the present invention, it is preferable that a torsion preventing member for preventing the torsion caused by the extension of the coil spring is provided.

  According to the present invention, when a structure such as a building or a bridge is subjected to an external force such as an earthquake motion and moves beyond a design assumption, a collision between adjacent buildings or a bridge becomes a problem. It is possible to provide a shock absorber having a function of preventing a bridge girder from falling and preventing damage to a structure to a minimum.

Fig.1 (a) is a schematic front sectional view which shows the structure of one Embodiment of the buffering device of this invention, FIG.1 (b) is a schematic perspective view of this embodiment. It is a schematic front sectional drawing which shows the structure of one Embodiment of the buffering device of this invention using the divided | segmented restraint material. FIG. 3A is a schematic front cross-sectional view of a shock absorber provided with one embodiment of a twist preventing mechanism, and FIG. 3B is a schematic top view of this embodiment. It is a schematic front sectional view of a shock absorber provided with an embodiment of another twist prevention mechanism. It is a graph which shows the relationship between axial force-axial displacement. It is the schematic which shows the structure which installed the buffering device of this invention between the seismic isolation layer of the building which provided the seismic isolation apparatus, and the building. It is the schematic which shows the structure which installed the buffering device of this invention between the bridge pier and the bridge girder of the bridge.

  In the shock absorber according to the present invention, as described above, a constraining material is provided in the central space of the coil spring at a specific interval with respect to the circumferential direction of the coil spring, and the constraining material is bonded to one end of the coil spring. And the attachment member for attaching to a structure is provided in the both ends of a coil spring.

  In such a shock absorber according to the present invention, when an external force is applied outward in the axial direction at both ends of the coil spring, and the coil spring that receives the tensile force is squeezed to deform the inner diameter to a small extent, it is more than a certain level by the restraining material provided inside. The inner diameter of the coil spring is small and does not deform.

  Hereinafter, embodiments of a shock absorber according to the present invention will be described in detail with reference to the drawings. Fig.1 (a) is a schematic front sectional view which shows a structure of an example of the buffering device of this invention, FIG.1 (b) is the schematic perspective view.

  The coil spring 2 used in the shock absorber 1 has a shape in which a plate-shaped steel material is spirally wound with a constant inner diameter. That is, the cross section of the spring wire of the coil spring 2 has a rectangular shape.

  Further, the type of steel material can be used without limitation as long as it is a steel material that is used for ordinary springs, that is, has an appropriate elasticity, for example, low carbon steel, high carbon steel that is spring steel (hot material). , Silicon manganese steel, manganese chromium steel, chromium vanadium steel, manganese chromium boron steel, silicon chromium steel, chromium molybdenum steel, stainless steel and the like.

  In the production of the coil spring, the desired properties are obtained by forming a plate-shaped steel material into a spiral shape and then subjecting it to cold working or a heat treatment such as low-temperature annealing in the same manner as in the ordinary coil spring manufacturing method. The coil spring 2 can be used.

  The width of the plate-shaped steel material constituting the coil spring 2 and the number of turns can be appropriately set according to the material and characteristics of the steel material to be used, the size of the structure to be attached, and the required buffer capacity, Although not particularly limited, it is preferable to use a rectangular steel material having a wide cross section in order to increase energy absorption capability. Specifically, it is desirable that the width-to-diameter ratio (spring diameter / wire width) of the rectangular cross-section of the steel material is in a range of about 0.5 to 1 as a setting for expressing sufficient buffer performance.

  Here, the dimension of the spring diameter for calculating the width-diameter ratio of the rectangular shape of the steel material cross section corresponds to the diameter of the helically wound coil spring, that is, the diameter of the shock absorber 1 in FIG.

  The coil spring 2 can be manufactured by winding the plate-shaped steel material in a spiral shape, or by forming slit-shaped cuts at regular intervals around the cylindrical steel pipe material in a spiral shape. .

  According to this method of manufacturing a coil spring that forms a spiral cut in a steel pipe, desired spring characteristics can be realized by adjusting the angle and width of the cut formed in the steel pipe. In addition, by changing the angle of the spiral portion partially, the elasticity at a specific position can be changed, and the application range in design can be widened. Moreover, since a coil spring can be formed only in an arbitrary portion of the steel pipe material and can be formed in a cylindrical shape with both ends closed, it is preferable from the viewpoint of expandability of application and workability. In addition, since the processing yield is increased and the production can be automated, mass production becomes possible.

  In the shock absorber 1, the constraining material 3 is provided with a specific interval 5 in the circumferential direction of the coil spring 2. Further, one end of the restraining material 3 inserted in the central space of the coil spring 2 in parallel with the longitudinal direction is fixed to the inner surface of one end of the coil spring 2.

  The material of the restraint material 3 is not particularly limited as long as it has a strength capable of preventing the deformation of the inner diameter of the coil spring 2. For example, steel, non-ferrous metal, engineering plastic, FRP, hard rubber, damper, etc. are used. Can do.

  Moreover, the shape of the restraint material 3 is not particularly limited, and a column, cylinder, polygonal column or the like can be used. In addition, when using the thing of a polygonal column, in order to increase the contact area with the inner side of the coil spring 2, it is preferable to use what chamfered the corner | angular. This is because, when the coil spring 2 is entangled with the restraining material 3, if the sharp corner of the restraining material 3 is contacted, the yield strength of the coil spring 2 may be reduced.

  Further, attachment members 4 for attaching the shock absorber 1 to the structure are provided at both ends of the coil spring 2. The attachment member 4 is not particularly limited as long as it can be joined to the structure. For example, a wire, a chain, a steel plate, a bolt, a pin, or the like is connected to the connection hole 41 provided in the attachment member 4. The thing of the form joined to a building etc. can be illustrated.

  The operation of such a shock absorber will be described as follows.

  When a normal coil spring is extended outward in the axial direction by the external force, the coil spring is squeezed and the inner diameter is reduced. As described above, when an external force continues to be applied to the coil spring, the coil spring continues to extend in the major axis direction in a constricted state, and finally the coil spring breaks.

  On the other hand, in the shock absorber 1 of the present invention, when an external force is applied outward in the both end directions of the coil spring 2 and the coil spring 2 is squeezed and the inner diameter is reduced, the restraining material 3 is prevented from being deformed to be smaller than a certain value. Has been inserted.

  That is, the coil spring 2 is squeezed and the inner diameter is deformed to be small, and the coil spring 2 functions as a tension spring until the inside of the coil spring 2 comes into contact with the restraining material 3. When the deformation of the coil spring 2 is constrained, the rigidity and strength of the entire shock absorber increase.

  The space 5 inside the coil spring 2 and the restraining material 3 provided in the central space of the coil spring 2 influences the external force load applied to the shock absorber 1 and the deformation relationship of the coil spring 2. The interval 5 can be adjusted by changing the inner diameter of the coil spring 2 and by changing the diameter (thickness) of the restraining material 3. Then, by adjusting the space 5 between the restraining member 3 and the coil spring 2, the extension amount of the coil spring 2, that is, the buffer performance of the shock absorber 1 can be determined. In a normal design, it is preferable that the interval 5 is set as narrow as possible and the constraining material 3 is densely provided.

  In addition, as shown in FIG. 2, the restraining members 31 and 32 divided in the longitudinal direction can be used, and the ends of the restraining members 31 and 32 can be held at both ends of the coil spring 2. Thus, it can be set as the buffering device 1 which has the function to bend | bend by dividing | segmenting the restraining materials 31 and 32. FIG.

  On the other hand, the coil spring 2 is twisted in the spring body as the axially outward force is applied to both ends and the axial deformation is increased, and the coil spring 2 and the restraining material 3 are not sufficiently in contact with each other. There is a possibility that the deformation due to plasticization increases without increasing the load of 2 and the buffer function does not work.

  Therefore, the shock absorber of the present invention can be provided with a twist prevention mechanism in order to prevent the coil spring 2 from being twisted more than a predetermined amount.

  FIG. 3A shows a schematic front cross-sectional view of a shock absorber provided with one embodiment of a twist preventing mechanism, and FIG. 3B shows a schematic top view thereof.

  As shown in FIG. 3A, the torsion prevention mechanism has a structure in which a protrusion 61 is provided on a part of the restraint member 3 and the protrusion 61 is inserted into a slit 62 provided in the longitudinal direction of the coil spring. The prevention mechanism 6 can be illustrated.

  According to this torsion prevention mechanism 6, the coil spring 2 is stretched outward in the axial direction at both ends, and the torsion of the coil spring 2 after the restraining material 3 and the inner surface of the coil spring 2 come into contact with each other. Since it is prevented by contact, it is possible to reliably prevent the coil spring 2 from being broken.

  As another twist prevention mechanism, as shown in FIG. 4, each of the restraining materials 31 and 32 divided at the center is held at both ends of the coil spring 2, and at one portion of the restraining material 31. A columnar member 71 is provided, and a hole 72 into which the columnar member 71 is fitted is provided in the divided portion of the other constraint member 32. The columnar member 71 is inserted into the hole 72 so that each of the constraint members 31 and 32 is provided. It is also possible to exemplify the twist preventing mechanism 7 having a structure in which the members are stretched in the longitudinal direction without being twisted.

  According to this torsion prevention mechanism 7, the torsion generated when the coil spring 2 is extended outward in the axial direction at both ends is transmitted to the restraining members 31 and 32 to which the ends are connected as axial twist. The columnar member 71 and the hole 72 provided in each of the divided constraining materials 31 and 32 are fitted to each other, and the columnar member is inserted so as to be stretchable in the longitudinal direction, whereby the twisting of the constraining materials 31 and 32 is suppressed. As a result, twisting of the coil spring 2 can be prevented.

  In addition, in the above-described twist preventing mechanisms 6 and 7, since there is a friction portion in the mechanism, it is desirable to make the operations of the twist preventing mechanisms 6 and 7 smooth. For this purpose, for example, the inner wall of the protrusion 61 and the slit 62 constituting the torsion prevention mechanism 6 and the inner wall of the columnar member 71 and the hole 72 constituting the torsion prevention mechanism 7 are subjected to a postcarding process for reducing friction. It is preferable to apply a lubricating oil or a lubricating paint.

  Furthermore, as another torsion prevention mechanism, it is possible to adopt a configuration in which coil springs with reversed spirals are joined in series. According to this torsion prevention mechanism, it is possible to cancel the torsion generated when the coil spring is extended outward in the axial direction at both ends by reversing the spiral of the coil spring, thereby preventing the torsion.

  FIG. 5 is a graph showing the relationship between the axial force and the axial displacement of the shock absorber 1 provided with the twist preventing mechanism 6 shown in FIG. In the graph of FIG. 5, the solid line indicates the characteristics of the shock absorber 1 of the present invention, and the broken line indicates the characteristics of a normal coil spring.

  According to this graph, the axial force-axial displacement characteristic (solid line) of the shock absorber 1 of the present invention has a small initial rigidity and a moderate increase in rigidity. Has developed strength. Thereby, it turns out that the transmission of the impact load by the displacement of a structure being restrained rapidly is suppressed.

  Thus, in the process in which the load and rigidity increase while the coil spring 2 is wound around the restraint material 3, the steel material having a rectangular cross section of the coil spring 2 yields a shear yield and absorbs energy.

  On the other hand, in the normal coil spring (broken line), the rigidity is small at the initial stage and the rigidity gradually increases, but it breaks at the limit point as the axial force increases.

  In addition, steel materials have a larger energy absorption capacity in a hysteresis cycle than rubber. In the case of the shock absorber 1 of the present invention, it has been confirmed by experiments that about 90% of the input seismic energy can be absorbed.

  In the shock absorber 1 of the present invention, since the steel elastic region found in the prior art is replaced by the deformation of a coil spring having very low rigidity, there is no initial rise in axial force-axial displacement characteristics. This means that the uniaxial displacement relationship is equivalent to that of a shock absorber using a material such as rubber.

  As described above, a buffer mechanism having the advantages of both a conventional steel material and an organic material system can be realized by giving a gentle load increasing function to the high energy absorption capability unique to the steel material.

  In addition, since the shock absorber 1 of the present invention can be composed entirely of steel, for example, the degree of damage received by the shock absorber after the earthquake is determined by observing cracks in the coil spring 2 or peeling of the paint. It can be easily judged. Further, even in normal maintenance, it is possible to easily determine deterioration or damage of the slit-like interval portion of the coil spring 2 by visual observation. This is a feature that cannot be implemented with a rubber-based shock absorber that is covered with a shock absorber and the inside is not visible.

  In FIG. 6, the schematic of the structure which installed the buffering device 1 of this invention between the seismic isolation layer of the building which provided the seismic isolation apparatus, and the building is shown.

  In the building 8 in which the seismic isolation device 81 is installed, the seismic isolation device 81 normally absorbs seismic motion even if shaking occurs due to an earthquake. However, when the magnitude of the earthquake is large and the deformation of the seismic isolation device 81 exceeds the assumed value, the building 8 is shaken. And when the shaking of the building 8 exceeding this seismic isolation allowance is large, there exists a possibility of contacting or colliding with an adjacent building or the like.

  In order to prevent such contact and collision, for example, even when the foundation and the building are connected by a chain or a wire, the buffering effect cannot be obtained, and the chain or the wire has been fully extended. At the stage, an impact is directly applied to the building, causing breakage of chains, wires, etc. and breakage of attachment members.

  On the other hand, the shock absorber 1 of the present invention exhibits a shock absorbing effect as a tension spring up to a certain moving dimension due to shaking in the building 8 generated exceeding the seismic isolation allowable amount of the seismic isolator 81, and the coil After the inside of the spring 2 and the restraining material 3 contact, it functions as a stopper member similar to a chain or a wire.

  In addition, when the shock absorber 1 of the present invention is used in a base-isolated building, it functions as a collision prevention member between the base-isolated building and other structures while being able to withstand multiple impacts, and also ensures the energy of the base isolation layer. It can be set as the buffer device which absorbs.

  FIG. 7 shows a schematic diagram of a configuration in which the shock absorber of the present invention is installed between the bridge pier and the bridge girder.

  When the bridge pier 91 and the bridge girder 9 are connected using the shock absorber 1 of the present invention, it is necessary to set the maximum extension width of the shock absorber 1 in consideration of the allowable movement range of the bridge girder 9 with respect to the movable support 92. As a result, it is possible to reliably prevent the bridge girder 9 from being dropped due to earthquake motion.

  Moreover, when using the shock absorber 1 of this invention as a fall bridge prevention apparatus, the restraint material 3 inserted in the inside of the shock absorber 1 can be used together as a member which supports the dead load at the time of a girder fall.

  Thus, according to the shock absorber 1 of the present invention, it is possible to suppress an excessive displacement of a structure that moves horizontally, such as a base-isolated building or a bridge, and to prevent a collision or a fall.

  Although the shock absorber according to the present invention has been described based on one embodiment, the present invention is not limited to the above-described embodiment, and various modifications and changes can be made without departing from the scope of the present invention. .

  For example, in the said embodiment, although the material to comprise was demonstrated as a steel material, depending on the scales and uses, such as a building, it can comprise with materials other than steel materials.

  Moreover, not only a simple material such as a steel material but also a shock absorber such as a damper can be used as the restraining material, and a composite seismic isolation member can be obtained.

DESCRIPTION OF SYMBOLS 1 Shock absorber 2 Coil spring 3 Restraint material 4 Attachment member 5 Space | interval 6 Torsion prevention member 7 Torsion prevention member

Claims (4)

A constraining material is provided in the central space of the coil spring at a specific interval with respect to the circumferential direction of the coil spring, the constraining material is joined to one end of the coil spring, and the coil spring is connected to both ends of the coil spring. Is provided with an attachment member for attachment to the structure. When an external force is applied outward in the axial direction at both ends of the coil spring, and the coil spring receiving the tensile force is squeezed, the internal diameter is reduced. The shock absorber is characterized in that an inner diameter of the coil spring is not reduced and deformed by a certain amount or more by the restrained material .   The shock absorber according to claim 1, wherein the coil spring is a coil spring in which a wire having a rectangular cross section is wound in a spiral shape.   The shock absorber according to claim 1, wherein the coil spring is a coil spring in which a spiral slit is formed in a steel pipe material.   The shock absorber according to any one of claims 1 to 3, further comprising a torsion preventing member for preventing the occurrence of torsion accompanying the extension of the coil spring.

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