Braking devices and seismic isolation structures for buildings

Abstract

To provide a damping device which has excellent energy absorption performance, which can be used repeatedly, and which can shorten the length in an action direction of an external force.SOLUTION: A damping device 1 is for absorbing energy generated by an external force, and it includes: a movable plate 5 which is formed in a disc-like shape, and in which a peripheral surface 54 becomes an action surface; a first plate 21 and a second plate 22 which are overlapped with the movable plate; a core material part 4 penetrating the overlapped plates, and fitted in restriction holes 211, 221 of the first plate and the second plate; and a spring part 3 which is mounted on an end part of the core material part so that an axial direction becomes an expansion / contraction direction. Then, the plates receive a resilience force from a spring part in a state where irregularity is fitted which is formed so that slide in the axis orthogonal direction occurs with the same magnitude of the force in any direction.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a damping device for absorbing energy generated by an external force, and to a seismic isolation structure for a building in which the damping device is installed. [Background technology]

[0002] Seismic isolation structures are known for buildings in which seismic isolation devices are placed between the building and its foundation to reduce the transmission of earthquake vibrations. In the event of an unexpectedly large earthquake exceeding the level anticipated during structural design, excessive deformation may occur in the isolation layer where the seismic isolation devices are placed, causing the building to collide with the surrounding retaining walls, or excessive deformation of the seismic isolation devices may damage the isolation layer. Furthermore, the impact force of the collision with the retaining wall may also damage the building above.

[0003] Therefore, as disclosed in Patent Document 1, shocks are mitigated by installing rubber blocks as buffer materials in advance at locations where collisions may occur due to excessive deformation during a major earthquake. Here, it is known that rubber blocks absorb energy by plastically deforming when a large force is applied.

[0004] Meanwhile, Patent Document 2 discloses a vibration suppression device equipped with a spring mechanism in which multiple disc springs are arranged in the direction of external force. This vibration suppression device increases the amount of spring movement when a displacement greater than a predetermined value occurs, thereby reducing rigidity as the displacement increases. Such a vibration suppression device can be used as a spring material to generate a restoring force in a seismic isolation device, or as a damper material by adding a damping material.

[0005] Furthermore, Patent Documents 3 and 4 disclose the use of a spring member with multiple coned disc springs arranged as a vibration control mechanism for structures such as buildings. This spring member, which uses coned disc springs as elements, is configured to be able to withstand both compressive and tensile forces. [Prior art documents] [Patent documents]

[0006] [Patent Document 1] Japanese Patent Application Publication No. 2018-71651 [Patent Document 2] Japanese Patent Application Publication No. 2017-78432 [Patent Document 3] Japanese Patent Application Laid-Open No. 2012-163134 [Patent Document 4] Japanese Patent Application Laid-Open No. 2012-102793 Summary of the Invention [Problem to be solved by the invention]

[0007] However, devices that plasticize to absorb energy, such as those disclosed in Patent Document 1, need to be replaced when their performance deteriorates due to plasticization. However, this is difficult to do quickly after a major earthquake, and replacement costs are required.

[0008] Furthermore, in configurations in which multiple disc springs are lined up, such as those disclosed in Patent Documents 2-4, the amount of deformation per disc spring is small, so if a condition requires a certain amount of displacement in the direction of external force, such as in a vibration control mechanism, it is necessary to incorporate many disc springs, which increases the length and size of the device.The seismic isolation pit in which the seismic isolation device is installed is lined with many pipes and other components, and there are restrictions on the available space, so it is desirable for the device to be as small as possible.

[0009] Therefore, the present invention aims to provide a braking device that has excellent energy absorption performance, can be used repeatedly, and can shorten the length in the direction in which external forces act, as well as a seismic isolation structure for a building in which it is installed. [Means for solving the problem]

[0010] In order to achieve the above-mentioned object, the braking device of the present invention is a braking device for absorbing energy generated by an external force, and comprises a movable plate formed in a disk shape with a peripheral surface serving as an acting surface, a first plate overlapping a first surface of the movable plate perpendicular to the peripheral surface, a second plate overlapping a second surface of the movable plate perpendicular to the peripheral surface, a core material portion that penetrates the overlapping first plate, the movable plate, and the second plate and is fitted into a restraining hole in the first plate and the second plate, and a spring portion attached to an end of the core material portion protruding from at least one of the first plate and the second plate so that the axial direction of the core material portion is the expansion / contraction direction, and the movable plate is provided with a through hole of a size that allows relative movement of the core material portion in a direction perpendicular to the axis, and at least one of the first plate and the second plate and the movable plate are fitted with concave and convex portions that are formed so that sliding in the direction perpendicular to the axis occurs with the same force magnitude in either direction, and are subjected to a restoring force by the spring portion.

[0011] Here, the spring portion can be formed by combining disc spring materials or coil spring materials with different rigidities. The concave and convex portions can be configured to be conical with the through hole as their center. Furthermore, it is preferable that the concave and convex portions have a truncated conical recess on the movable plate side and a truncated conical protrusion on the first plate or the second plate side.

[0012] The core portion may be configured to have a plurality of core portions. Furthermore, the recesses and protrusions may be fitted on both the first plate side and the second plate side. The spring portion may be attached to an end of the core portion protruding from one of the first plate or the second plate, and the other end of the core portion may be fixed to the restraining hole of the second plate or the first plate.

[0013] Furthermore, the invention of a seismic isolation structure for a building is a seismic isolation structure for a building in which a seismic isolation device is placed, characterized in that it comprises any of the braking devices described above that are installed in the seismic isolation layer in which the seismic isolation device is placed, and a reaction force section for activating the braking device before a predetermined or greater deformation occurs in the seismic isolation layer.

[0014] Here, the braking device can be installed on the upper or lower side of the seismic isolation layer, and a cylindrical inner surface that serves as the reaction force part can be provided at a position opposite the peripheral surface of the movable plate. [Effects of the Invention]

[0015] The braking device of the present invention configured in this manner includes a spring portion that expands and contracts in a direction substantially perpendicular to the direction in which an external force acts. When an external force acts on the circumferential surface of the movable plate and causes it to move, the spring portion contracts when the recesses and projections between the first plate or second plate and the movable plate are released, and energy is absorbed by the sliding between them.

[0016] This provides excellent energy absorption performance against external forces acting from any direction within the plane. Furthermore, the mechanism for expanding and contracting the spring section provides excellent recovery performance and allows for repeated use. Furthermore, because the direction of expansion and contraction of the spring section is approximately perpendicular to the direction in which the external force acts, the length of the braking device in the direction in which the external force acts can be shortened.

[0017] Furthermore, if the spring portion is formed by combining disc spring materials or coil spring materials with different rigidities, it can be set to have a restoring force characteristic of increasing rigidity, allowing for gentle braking.

[0018] In addition, the invention of the seismic isolation structure for a building includes a damping device installed in the seismic isolation layer where the seismic isolation device is located, and a reaction unit for activating the damping device before the seismic isolation layer experiences a predetermined level of deformation. Therefore, even if a large earthquake occurs that is greater than anticipated at the time of design, it is possible to prevent the building from colliding with the surrounding retaining walls or the seismic isolation layer from being damaged by excessive deformation of the seismic isolation device. [Brief explanation of the drawings]

[0019] [Figure 1] 1A and 1B are diagrams illustrating the internal structure of the braking device of the present embodiment, in which FIG. 1A is a cutaway perspective view showing the state under normal conditions, and FIG. 1B is a cutaway perspective view showing the state under a major earthquake. [Figure 2] 1A and 1B are diagrams illustrating the seismic isolation structure of a building according to the present embodiment, in which (a) is a schematic diagram showing the state under normal circumstances, and (b) is a schematic diagram showing the state under a major earthquake. [Figure 3] FIG. 1 is a perspective view for explaining the configuration of a braking device according to an embodiment of the present invention. [Figure 4] FIG. 2 is an exploded perspective view for explaining the configuration of the braking device according to the present embodiment. [Figure 5] 1 is a cross-sectional view illustrating a configuration of a braking device according to an embodiment of the present invention. [Figure 6] 10A and 10B are explanatory diagrams illustrating the configuration of a spring portion. [Figure 7] 1A and 1B are diagrams illustrating the restoring force characteristics of the spring section, where (a) is a graph illustrating the restoring force characteristics of the spring section with increased rigidity, and (b) is a graph illustrating the restoring force characteristics of the braking device including friction. [Figure 8] 5A and 5B are diagrams illustrating the operation of the braking device, where (a) is a cross-sectional view illustrating the initial state, and (b) is a cross-sectional view illustrating the state during operation. [Figure 9] 1A and 1B are diagrams showing an example of the installation of a braking device in a seismic isolation structure for a building according to this embodiment, in which (a) is an oblique view with a portion of the target broken away, and (b) is a plan view illustrating the positional relationship between the target and the movable plate. [Figure 10] 1 is an explanatory diagram showing the operating range of a braking device in a seismic isolation structure for a building according to the present embodiment. FIG. [Figure 11] 1A and 1B are diagrams illustrating the configuration of the braking device of the first embodiment, in which (a) is a cross-sectional view showing a case where the upper plate is a flat plate, and (b) is a cross-sectional view showing a case where the lower plate is a flat plate. [Figure 12]10A and 10B are diagrams illustrating the configuration of a braking device according to a second embodiment, in which (a) is a plan view and (b) is a cross-sectional view. [Figure 13] 10A and 10B are diagrams illustrating the configuration of another braking device according to the second embodiment, in which (a) is a plan view and (b) is a cross-sectional view. [Figure 14] FIG. 10 is a diagram illustrating the relationship between the number of axles and other specifications of the braking device and stability. DETAILED DESCRIPTION OF THE INVENTION

[0020] Hereinafter, an embodiment of the present invention will be described with reference to the drawings. Fig. 1 and Figs. 3 to 5 are diagrams for explaining the configuration of a braking device 1 according to this embodiment. Fig. 2 is an explanatory diagram that schematically shows a seismic isolation structure for a building according to this embodiment.

[0021] The braking device 1 of this embodiment is a device for absorbing energy generated by an external force. The braking device 1 of this embodiment can be used in combination with a building with a seismic isolation structure. The braking device 1 of this embodiment can also be attached to the bumper of heavy machinery such as a forklift, mobile equipment controlled by artificial intelligence (AI), and the like.

[0022] In the following, in this embodiment, as shown in Fig. 2(a), a case where a braking device 1 is installed in a building M in which a seismic isolation device E is arranged will be mainly described. In a building M in which a seismic isolation device E is arranged between the building M and a foundation B to suppress the transmission of earthquake vibrations, deformation occurs in the seismic isolation layer in which the seismic isolation device E is arranged during an earthquake (see Fig. 2(b)).

[0023] In a building M with a seismic isolation structure, if an unexpected large earthquake occurs that exceeds the level assumed during structural design, excessive deformation will occur in the seismic isolation layer as shown in Figure 2(b), causing the building M to collide with the surrounding retaining wall M4 or causing excessive deformation of the seismic isolation device E, which could damage the seismic isolation layer. Therefore, in order to suppress such excessive deformation of the seismic isolation layer, the braking device 1 of this embodiment is installed.

[0024] 1 and 3, the braking device 1 of this embodiment includes a movable plate 5 formed in a disk shape with a peripheral surface 54 serving as an acting surface, a first plate 21 superimposed on a first surface perpendicular to the peripheral surface 54 of the movable plate 5, a second plate 22 superimposed on a second surface also perpendicular to the peripheral surface 54, a core portion 4 penetrating the superimposed plates (21, 5, 22), and a spring portion 3 attached to an end of the core portion 4. Here, Fig. 1 is a cutaway perspective view of the braking device 1 taken at a position where the core portions 4 are lined up to show the internal structure, and Fig. 3 is a perspective view of the exterior of the braking device 1 viewed from below.

[0025] As shown in Fig. 4, the movable plate 5 is formed in a thick disk shape, and a cylindrical peripheral surface 54 serves as an acting surface that is pressed from the outside. In this figure, the upper surface of the movable plate 5 serves as a first surface that is perpendicular to the peripheral surface 54, and the lower surface of the movable plate 5 serves as a second surface that is perpendicular to the peripheral surface 54. The first plate 21 that is overlaid on the first surface of the movable plate 5 and the second plate 22 that is overlaid on the second surface are each formed in a disk shape with a smaller diameter than the movable plate 5.

[0026] The movable plate 5 is perforated with through holes 53 having an inner diameter larger than the diameter of the core material portion 4 through which the core material portion 4 passes. In FIG. 4, four through holes 53 are provided to match the number of four core material portions 4 that pass through the movable plate 5.

[0027] 5, the inner diameter of the through hole 53 is sufficiently larger than the outer diameter of the core portion 4, and the distance between the outer peripheral surface of the core portion 4 and the inner peripheral surface of the through hole 53 is large enough to allow relative movement of the core portion 4 in the direction perpendicular to the axis. The range over which the movable plate 5 can move horizontally is also determined by the length by which the movable plate 5 protrudes laterally beyond the first plate 21 or the second plate 22.

[0028] 4, a sloping peripheral surface of a truncated cone-shaped recess 51 is formed on the periphery of the passing hole 53. That is, the conical recess 51 centered on the passing hole 53 is truncated by the passing hole 53, and therefore has a truncated cone shape.

[0029] Similar to the upper surface side, a truncated cone-shaped recess 52 is formed on the lower surface side of the movable plate 5. Meanwhile, a truncated cone-shaped protrusion 222 is formed on the upper surface of the second plate 22, facing the recess 52 on the lower surface side of the movable plate 5. The recess 52 on the lower surface side of the movable plate 5 and the protrusion 222 on the upper surface side of the second plate 22 are fitted together.

[0030] Similarly, a truncated cone-shaped protrusion 212 is formed on the lower surface of the first plate 21, and the recess 51 on the upper surface of the movable plate 5 and the protrusion 212 on the lower surface of the first plate 21 are fitted together. Figure 5 shows the fitted-together state of the protrusions and recesses between the opposing first plate 21 and second plate 22 at the top and bottom of the movable plate 5.

[0031] The fitting relationship of the recesses and protrusions may be reversed between the movable plate 5 side and the first plate 21 or second plate 22 side. In other words, the protrusions may be provided on the movable plate, and the recesses may be provided on the first plate or second plate side.

[0032] The fitting of the truncated cone-shaped recesses and protrusions results in the same binding force in any direction (360°) perpendicular to the axis of the core material part 4 (horizontal direction), so regardless of the force applied from any horizontal direction, the same magnitude of force and the same state of sliding will occur.

[0033] The core portion 4 not only passes through the through hole 53 of the movable plate 5, but also passes through the restraining holes 211, 221 of the first plate 21 and the second plate 22. Here, the meaning of "restraining" in the restraining holes 211, 221 is that they restrict the relative movement of the core portion 4 in the direction perpendicular to the axis (horizontal direction).

[0034] In the braking device 1 of this embodiment, the spring portion 3 is attached only to the lower end of the core portion 4, and therefore the upper end of the core portion 4 is fixed to the restraining hole 211 of the first plate 21. For example, by providing a female thread on the inner circumferential surface of the restraining hole 211 and screwing in the male thread at the upper end of the core portion 4, the core portion 4 is fixed to the first plate 21 so that it does not move in the axial direction.

[0035] In contrast, the relationship between the restraining holes 221 of the second plate 22 and the core portion 4 is such that the relative movement of the core portion 4 in the direction perpendicular to the axis is restricted, but the relative movement of the core portion 4 in the axial direction is not restricted. In other words, the second plate 22 moves up and down depending on the amount of expansion and contraction of the spring portion 3, so the up and down movement of the second plate 22 along the core portion 4 is not restricted.

[0036] In the braking device 1 of this embodiment, the spring portion 3 is attached to the end of the core portion 4 protruding from below the second plate 22 so that the axial direction of the core portion 4 is the expansion / contraction direction. In other words, the acting direction of an external force input to the peripheral surface 54 of the movable plate 5 is a direction perpendicular to the axis of the core portion 4, and the cylindrical spring portion 3 is arranged so that the axial direction of the core portion 4, which is approximately perpendicular to the acting direction, is the expansion / contraction direction of the spring portion 3.

[0037] In other words, the cylindrical core part 4 is inserted into the cylindrical hollow part of the spring part 3. The core part 4 also functions as a guide for the spring part 3. A washer 34 and a nut 35 are attached to the underside of the spring part 3, and the position of the lower end of the spring part 3 is fixed to a predetermined position on the core part 4.

[0038] 1(a), the spring portion 3 is in its most extended state under normal conditions when the braking device 1 is not operating. In short, the nuts 35 are tightened to the extent that the recessed and protruding portions are maintained fitted together between the first plate 21 and the second plate 22 above and below the movable plate 5, fixing the position of the washer 34, and the restoring force of the spring portion 3 placed on the washer 34 presses the second plate 22 and the movable plate 5 against the first plate 21.

[0039] On the other hand, as shown in Figure 1(b), during a major earthquake or the like, when an external force acts on the peripheral surface 54 of the movable plate 5 and the movable plate 5 moves in a direction perpendicular to the axis of the core material portion 4 (horizontal direction), sliding occurs that releases the engagement of the recesses and protrusions between the movable plate 5 and the first plate 21 and the second plate 22.

[0040] When the convex portions 212, 222 move up the concave portions 51, 52 and the distance between the first plate 21 and the second plate 22 increases, the spring portion 3 contracts. If the top surface of the first plate 21 is fixed to a structure or the like, the movable plate 5 will move downward at an angle, and the second plate 22 will move downward straight along the core portion 4, and will be pushed by this, causing the spring portion 3 to contract.

[0041] When the movable plate 5 moves in a manner that causes the spring portion 3 to contract, sliding with frictional resistance occurs between the movable plate 5 and the first plate 21, and between the movable plate 5 and the second plate 22, and energy is absorbed.

[0042] Next, the configuration and restoring force characteristics of the spring portion 3 will be described with reference to Figures 6 and 7. The spring portion 3 arranged in the braking device 1 of this embodiment is formed by combining a plurality of disc spring materials with different rigidities.

[0043] 6 shows a configuration in which three types of disc spring materials with different stiffness are stacked. In detail, from the bottom, four first disc spring materials 31, four second disc spring materials 32, and six third disc spring materials 33 are stacked.

[0044] The first disc spring material 31, the second disc spring material 32, and the third disc spring material 33 have different rigidities due to differences in material thickness and material. Here, the first disc spring material 31, the second disc spring material 32, and the third disc spring material 33 are arranged in order of increasing rigidity. The rigidity of the entire spring portion 3 can also be adjusted by changing the number of disc spring materials (31, 32, 33) stacked on top of each other.

[0045] 7(a) is a graph illustrating the restoring force characteristics of the increased rigidity type of the spring section 3. The spring section 3 configured as described above can increase its rigidity as the deformation increases, so that it can gradually apply the brakes as the deformation of the seismic isolation layer increases, for example.

[0046] Point A in Figure 7(a), where the load acting on the spring portion 3 is 0 (kN) and the deformation is 0 (mm), indicates the initial state as shown in Figure 6. When a load that contracts (compresses) the spring portion 3 is applied, the third disc spring material 33, which has the lowest rigidity, is the main deformed up to point B.

[0047] If the load acting on the spring portion 3 increases beyond point B, the second disc spring material 32 will be primarily deformed up to point C, and once point C is exceeded, the first disc spring material 31, which has the highest rigidity, will be primarily deformed. This restoring force characteristic of the spring portion 3, in which the rigidity of the entire system increases stepwise as the deformation increases, is called the rigidity increasing type.

[0048] The braking device 1 of this embodiment performs braking by utilizing the restoring force characteristics of the contracted spring portion 3. Furthermore, in the braking device 1 of this embodiment, energy is also absorbed by sliding between the movable plate 5 and the first plate 21, and between the movable plate 5 and the second plate 22.

[0049] As described above, when the peripheral surface 54, which is the working surface of the movable plate 5, is pushed and begins to move, the engagement of the recesses and protrusions between the movable plate 5 and the first plate 21 and second plate 22 is released, and sliding with frictional resistance occurs.

[0050] The magnitude of the frictional resistance (friction coefficient) at this time can be set as desired by adjusting the gradient of the peripheral surfaces of the convex portions 212, 222 and concave portions 51, 52, the treatment of the contact surfaces, etc. In addition, the restoring force of the compressed spring portion 3 presses the first plate 21, the movable plate 5, and the second plate 22 together, which also increases the frictional force.

[0051] In particular, the magnitude of the frictional force can be adjusted by the gradient (angle θ) of the peripheral surfaces of the convex portions 212, 222 and the concave portions 51, 52. The smaller the angle θ (gentler gradient), the less deformation is required of the spring portion 3 and the greater the frictional force. However, if the angle θ is made too small, the frictional force will exceed the restoring force of the device, making it unable to restore. For this reason, it is necessary to increase the angle θ to an extent that allows stable restoration. This angle θ is set to 45° or less, for example, around 20° to 30°.

[0052] Fig. 7(b) is a graph illustrating the restoring force characteristics of the braking device 1, including friction. The dashed line in the graph shows the restoring force characteristics of only the spring portion 3 described in Fig. 7(a). When the frictional force generated between the sliding surfaces of the first plate 21, the movable plate 5, and the second plate 22 is added to this, the restoring force characteristics can be set as shown by the solid line.

[0053] In terms of the restoring force characteristics of the braking device 1, including friction, when the peripheral surface 54 of the movable plate 5 is pushed and begins to move, the frictional force between the sliding surfaces and the contraction of the third disc spring material 33 cause the braking device 1 to exhibit behavior with higher rigidity than when only the spring portion 3 is used.

[0054] This behavior of greater rigidity than that of the spring portion 3 alone continues as long as the deformation increases. Furthermore, as the deformation increases, the amount of contraction of the spring portion 3 increases and the restoring force also increases, which increases the friction force between the sliding surfaces.

[0055] Then, when the external force decreases and the spring part 3 begins to restore (extend), the restoring force of the braking device 1 decreases by the amount of friction between the sliding surfaces, allowing for an increase in the amount of energy absorption. If the friction is further increased and the braking device 1 restores more slowly than the building M, the entire area enclosed by the dashed line during compression becomes the energy absorption amount, allowing for even greater energy absorption.

[0056] Next, the operation of the braking device 1 of this embodiment will be described with reference to Fig. 8. Fig. 8(a) is a cross-sectional view for explaining the initial state of the braking device 1. As shown in Fig. 2(a), for example, the braking device 1 is attached to a hanging part M2 that hangs down from the underside of a beam member M1 such as a foundation beam or a floor beam to a seismic isolation layer on which the seismic isolation device E is arranged.

[0057] Here, the first plate 21 is a fixed part in terms of relative positional relationship within the braking device 1. Also, to stabilize performance, an initial compression force is applied to the spring part 3, keeping it in a slightly compressed state. This initial compression force is adjusted to a level that does not generate a large impact force when the braking device 1 starts to operate.

[0058] Fig. 8(b) is a cross-sectional view for explaining the operating state of the braking device 1. As shown in Fig. 2(b), when an earthquake occurs and the shaking of the foundation B increases, the braking device 1 comes into contact with the target 6, which serves as a reaction part and is provided so as to protrude from the foundation B into the seismic isolation layer.

[0059] For example, if contact with the target 6 occurs on the left side of Figure 8(b), the circumferential surface 54 of the movable plate 5 will be pushed toward the right. In other words, the arrow shown adjacent to the circumferential surface 54 in Figure 8(b) indicates the direction of action of the external force received from the target 6. The movable plate 5 pushed in by the external force will move in the direction of action of the external force.

[0060] At this time, the core portion 4 remains suspended from the first plate 21 and does not move, the projections 212, 222 are released from engagement, and the projections 212, 222 move up the recesses 51, 52 while sliding, causing the movable plate 5 and the second plate 22 to move downward. In other words, since the core portion 4 is passed through the through hole 53, which is larger than the amount of movement, the movable plate 5 can move without restriction until it hits the inner circumferential surface of the through hole 53. Note that the movement of the movable plate 5 may be restricted by the periphery of the first plate 21 or the second plate 22.

[0061] When the second plate 22 moves downward in accordance with the movement of the movable plate 5, the gap between the lower surface of the second plate 22 and the washer 34 narrows, causing the spring portion 3 to contract. When the core portion 4 hits the inner peripheral surface of the through hole 53 and the movement of the movable plate 5 stops, the spring portion 3 is no longer compressed, and the state shown in Fig. 8(b) becomes the maximum deformation amount (contraction amount) of the spring portion 3.

[0062] On the other hand, when the external force pressing against the peripheral surface 54 of the movable plate 5 is removed, the spring portion 3 expands due to its restoring force, the second plate 22 moves upward, and the gap between the underside of the second plate 22 and the washer 34 widens, and the movable plate 5, second plate 22 and spring portion 3 return to their initial state as shown in Figure 8(a).

[0063] Next, the operation of the braking device 1 and the seismic isolation structure for a building according to this embodiment will be described. The braking device 1 of this embodiment configured as described above includes the spring portion 3 whose expansion and contraction direction is substantially perpendicular to the direction in which the external force acts (see, for example, the arrow in FIG. 8(b)).

[0064] When an external force acts on the peripheral surface 54 of the movable plate 5 and causes it to move, the spring portion 3 contracts as the recesses and protrusions between the first plate 21 and the second plate 22 and the movable plate 5 are released from their mating, and energy is absorbed by sliding between them with frictional resistance.

[0065] This sliding is performed under the action of the restoring force of the spring portion 3, and therefore, the pressing between the convex portions 212, 222 and the concave portions 51, 52 allows energy to be absorbed more efficiently.

[0066] This provides excellent energy absorption performance. In addition, the mechanism for expanding and contracting the spring portion 3 provides excellent recovery performance and allows for repeated use. In particular, the disc spring material (31, 32, 33) is resistant to plastic deformation even after deformation, so even after the braking device 1 is activated by a major earthquake, it can be used repeatedly without any deterioration in performance due to plastic deformation.

[0067] Furthermore, during sliding, the movable plate 5 is always in contact with the upper and lower plates (21, 22) at three or more points, which prevents unstable behavior such as rotation of the movable plate 5 and allows the expected restoring force characteristics to be obtained.

[0068] Furthermore, because the direction of expansion and contraction of the spring portion 3 is approximately perpendicular to the direction in which the external force acts, the length of the braking device 1 in the direction in which the external force acts can be shortened. For example, if disc spring material, which has a small amount of deformation per piece, is used, many disc spring materials (31, 32, 33) would be incorporated to achieve a certain level of displacement, but because they are simply stacked in the vertical direction, approximately perpendicular to the direction in which the external force acts (horizontal direction), it is possible to prevent the braking device 1 from becoming too long in the direction in which the external force acts. For this reason, a compact braking device 1 can be installed in various locations, even in a seismic isolation pit, which serves as a seismic isolation layer and whose installation range is often limited by piping and the like.

[0069] Furthermore, if the spring portion 3 is formed by combining disc spring materials (31, 32, 33) with different rigidities, it can be set to have a restoring force characteristic of increasing rigidity, allowing for gentle damping. In other words, if a spring portion 3 is used in which the rigidity of the entire system increases stepwise as deformation increases, not only can the generation of initial impact force be suppressed, but damping can also be performed against excessive deformation.

[0070] The seismic isolation structure of building M in this embodiment has a braking device 1 installed in the seismic isolation layer where the seismic isolation device E is placed, and is equipped with a reaction force section for activating the braking device 1 before a predetermined amount of deformation occurs in the seismic isolation layer or the seismic isolation device E.

[0071] 9 and 10 are diagrams illustrating an example of installation and operating range of the braking device 1 in the seismic isolation structure of the building M of this embodiment. As shown in Figs. 9(a) and 9(b), the target 6 can be provided by a steel pipe or a cylindrical reinforced concrete member whose lower end is fixed to the foundation B.

[0072] For example, the braking device 1 can be installed at the center in the longitudinal direction of a beam member M1 supported by the seismic isolation device E. As shown in Fig. 9(a), the braking device 1 is attached by joining the upper surface of a first plate 21 to the lower surface of a hanging part M2 that hangs down from the lower surface of the beam member M1. The outermost diameter of the installed braking device 1 (the diameter of the movable plate 5) is, for example, about 1100 mm.

[0073] As shown in the plan view of Figure 9(b), the inner peripheral surface of a cylindrical target 6 is provided to surround the peripheral surface 54 of the movable plate 5, which faces in all directions in the horizontal plane. In order for the seismic isolation device E to fully function, the distance L1 between the peripheral surface 54 of this braking device 1 and the inner peripheral surface of the target 6 must be such that no contact occurs within the range of deformation of the seismic isolation layer due to an earthquake of the scale assumed at the time of design.

[0074] 10 is a diagram for explaining the operating range of the braking device 1 in the seismic isolation structure for a building according to this embodiment. The braking device 1 is activated by being brought into contact with a cylindrical target 6 that is raised upward from the foundation B.

[0075] If the distance between the end face of beam member M1 of building M and retaining wall M4 (see Figure 2) installed around building M is L2, then it is necessary to activate braking device 1 to absorb the energy of a major earthquake before deformation of the seismic isolation layer exceeds L2. Therefore, the distance L1 (see Figure 9(b)) between peripheral surface 54 of braking device 1 and target 6 is set smaller than L2.

[0076] Specifically, distance L1 is set so that the sum of distance L1 and the maximum deformation of braking device 1 is smaller than L2. By setting distance L1 in this way, even if a major earthquake occurs that is greater than anticipated at the time of design, it is possible to prevent building M from colliding with the surrounding retaining walls M4 and to prevent damage such as tensile fracture or buckling caused by excessive deformation of seismic isolation device E or damper material.

[0077] In addition, when the braking device 1 is activated, the rigidity of the seismic isolation layer gradually increases, making it possible to suppress deformation of the seismic isolation layer while suppressing the amplification of the response acceleration of the building M located above.

[0078] The location of the braking device 1, the slope (angle θ) of the peripheral surfaces of the convex portions 212, 222 and concave portions 51, 52 of the braking device 1, the frictional resistance (friction coefficient) between the sliding surfaces, and the restoring force characteristics of the spring portion 3 can be set appropriately based on the restoring force characteristics of the entire seismic isolation layer.

[0079] Furthermore, since the braking device 1 of this embodiment can be activated against external forces from any direction within 360° in a horizontal plane, the number of devices that need to be installed can be significantly reduced compared to devices that can only act against external forces from one or two directions. [Example]

[0080] Brake devices 1A and 1B according to other embodiments different from the brake device 1 according to the embodiment described above will be described below with reference to Fig. 11. Note that parts that are the same as or equivalent to those described in the embodiment will be described using the same terms or symbols.

[0081] In the above embodiment, a case has been described in which both the first plate 21 and the second plate 22 have convex portions 212, 222 that engage with the movable plate 5, but in Example 1, a configuration in which only one of the plates has a convex-concave engagement is described.

[0082] 11(a) shows a configuration in which a first plate 21A above a movable plate 5A is a flat plate that is circular in plan view. That is, the first plate 21A has no protrusions, and the upper surface of the movable plate 5A that faces the first plate 21A is also flat.

[0083] 11(b) shows a configuration in which the second plate 22B below the movable plate 5B is a flat plate that is circular in plan view. In other words, the second plate 22B has no protrusions, and the lower surface of the movable plate 5B facing the second plate 22B is also flat.

[0084] In this way, when a concave-convex fit is to be achieved only between the movable plate 5A (5B) and the second plate 22 (first plate 21) on one side thereof, the slope (angle θ) of the peripheral surface of the convex portion 222 (212) is set to, for example, approximately 20° to 30°.

[0085] 11(a), the braking device 1A in which the upper first plate 21A is a flat plate can improve the stability of operation and performance by limiting the movement direction of the movable plate 5A to the horizontal direction only. Furthermore, because no protrusions are provided, the outer diameter of the first plate 21A can be made small enough to cover the through hole 53.

[0086] The other configurations and effects are substantially the same as those of the above-described embodiment or other examples, and therefore the description thereof will be omitted. [Example]

[0087] Brake devices 1C and 1D of an embodiment different from the brake devices 1, 1A, and 1B of the embodiment and Example 1 described above will be described below with reference to Figures 12 and 13. Note that parts that are the same as or equivalent to those described in the embodiment or Example 1 will be described using the same terms or symbols.

[0088] The braking devices 1, 1A, and 1B described in the above embodiment and Example 1 were configured with multiple (four in the example) core material portions 4, but Example 2 describes braking devices 1C and 1D configured with a single core material portion 4.

[0089] Fig. 12(a) shows a plan view of a braking device 1C in which one core portion 4 is arranged in the center, and Fig. 12(b) shows a cross-sectional view of the braking device 1C taken along the dashed line in Fig. 12(a). As shown in Fig. 12(b), this braking device 1C has one truncated cone-shaped protrusion 212 provided only in the center of the first plate 21C, and the second plate 22C is formed as a flat plate that is circular in plan view.

[0090] For this reason, the movable plate 5C also has a truncated cone-shaped recess 51 formed only on the upper surface around the periphery of the through hole 53, and the lower surface is formed flat. Such a braking device 1C with one shaft and one convex portion 212 can be manufactured with an outermost diameter (diameter of the movable plate 5C) of 600 mm, for example, which is about half the size of the four-shaft braking device 1.

[0091] In contrast, the braking device 1D shown in Fig. 13 has one core portion 4, but the configuration of the convex portion is different from that of the braking device 1C shown in Fig. 12. Here, Fig. 13(a) shows a plan view, and Fig. 13(b) shows a cross-sectional view.

[0092] In the braking device 1D shown in FIG. 13, a convex portion 212D provided on a first plate 21D is provided in an annular shape along the periphery of a passing hole 53. That is, as shown in the cross-sectional view of FIG. 13(b), the cross section of the convex portion 212D consists of two truncated cone-shaped peaks on both sides of the core portion 4. The concave portion 51D of the movable plate 5D that fits into the convex portion 212D is also provided in an annular shape along the periphery of the passing hole 53. On the other hand, the second plate 22D is formed as a flat plate that is circular in plan view.

[0093] In this way, the engagement of the recesses and protrusions does not necessarily have to be centered on the core material portion 4, and even if an annular protrusion 212D is provided to surround the core material portion 4, the movable plate 5D can slide with the same magnitude of force in either direction. Here, the braking device 1D having the protrusion 212D formed into two peaks can be manufactured to have a slightly larger outer diameter (diameter of the movable plate 5D) than the braking device 1C having one peak, for example, about 700 mm.

[0094] As explained above, the number of core portions 4 arranged in the braking device and the shape of the convex portions can be set arbitrarily depending on the desired load capacity, etc. Fig. 14 is a diagram explaining the relationship between the number of axles and other specifications of the braking device and stability.

[0095] As shown in the table in Figure 14, the number of core parts 4 (number of shafts) arranged in the braking device can be set arbitrarily from 1 to 5 or more. Depending on the number of core parts 4 arranged, the length of the spring part 3 (total spring length), the diameter of the spring part 3 (outer spring diameter), and the diameter of the braking device (movable plate) (outer device diameter) will tend to change.

[0096] Each configuration has its own advantages, such as the outer diameter of the device being smaller when the core part 4 has fewer axes, and the spring part 3 being smaller when the core part 4 has more axes. In terms of stability during operation of the braking device, the movable plate can be moved more stably when the core part 4 has three or more axes.

[0097] The other configurations and effects are substantially the same as those of the above-described embodiment or other examples, and therefore the description thereof will be omitted.

[0098] The embodiments of the present invention have been described above in detail with reference to the drawings, but the specific configurations are not limited to these embodiments and examples, and design changes that do not deviate from the gist of the present invention are included in the present invention.

[0099] For example, the above embodiment has mainly described the case where the braking device 1 is installed in a building M with a seismic isolation structure, but this is not limited to this, and the braking devices 1, 1A-1D of this embodiment or example can also be used as damper materials in contact parts of robots, etc.

[0100] In addition, in the above embodiment, the spring portion 3 is formed by combining three types of disc spring material (31, 32, 33) with different rigidities, but this is not limited to this, and the spring portion can also be formed by combining multiple coil spring materials, square spring materials, rubber materials, or similar materials with different rigidities.

[0101] In addition, in the above embodiment, the reaction part was described using a cylindrical target 6 as an example, but this is not limited to this, and the reaction part can also be polygonal, such as a square or hexagonal cylindrical shape.

[0102] Furthermore, in the above embodiment, the case where the braking device 1 is installed on the upper side of the seismic isolation layer and the target 6 is provided on the lower side (foundation B side) has been described, but this is not limiting, and it is also possible to install the braking device 1 on the lower side of the seismic isolation layer and provide a reaction force part on the upper side. Note that in the above embodiment, the lower side is foundation B, which is merely an example, and the braking device 1 can also be installed on a seismic isolation layer provided in the middle layer of a building.

[0103] Furthermore, in the above-described embodiments and examples, a configuration has been described in which the spring portion 3 is attached only to the end of the core material portion 4 protruding from the second plate 22, 22B, 22C, 22D side, but this is not limited to this, and the configuration may also be such that the end of the core material portion protrudes toward the first plate side and the spring portion 3 is attached, or the end of the core material portion protrudes from both plates and the spring portion 3 is attached to each. [Explanation of symbols]

[0104] 1,1A-1D: Braking device 21, 21A, 21C, 21D: First plate 211: Restraint hole 212, 212D: Convex part 22, 22B, 22C, 22D: Second plate 221: Restraint hole 222: Convex part 3: Spring part 31: First disc spring material (disc spring material) 32: Second disc spring material (disc spring material) 33: Third disc spring material (disc spring material) 4: Core part 5, 5A-5D: Movable plate 51, 51D: recess 52: Recess 53: Passing hole 54: Peripheral surface 6: Target (reaction part) M: Building E: Seismic isolation device

Claims

1. A braking device for absorbing energy generated by an external force, a movable plate formed in a disk shape, the peripheral surface of which serves as an operating surface; a first plate superposed on a first surface of the movable plate that is perpendicular to the circumferential surface; a second plate that is superimposed on a second surface of the movable plate that is perpendicular to the circumferential surface; a core portion that penetrates the stacked first plate, the movable plate, and the second plate and is fitted into the restraining holes of the first plate and the second plate; a spring portion attached to an end of the core portion protruding from at least one of the first plate and the second plate such that the axial direction of the core portion is the expansion / contraction direction, The movable plate is provided with a through hole having a size that allows relative movement of the core portion in a direction perpendicular to the axis, A braking device characterized in that at least one of the first plate and the second plate and the movable plate are subjected to a restoring force by the spring portion in a state in which concave and convex portions are fitted together so that sliding in the direction perpendicular to the axis occurs with the same force magnitude in either direction.

2. 2. The braking device according to claim 1, wherein the spring portion is formed by combining disc spring materials or coil spring materials having different rigidities.

3. 3. The braking device according to claim 1, wherein the projections and recesses are formed in a conical shape with the through hole as a center.

4. 4. The braking device according to claim 3, wherein the unevenness is a truncated cone-shaped recess on the movable plate side and a truncated cone-shaped protrusion on the first plate side or the second plate side.

5. 3. The braking device according to claim 1, wherein a plurality of the core portions are arranged.

6. 3. The braking device according to claim 1, wherein the recessed and protruding portions are provided on both the first plate side and the second plate side.

7. A braking device as described in claim 1 or 2, characterized in that the spring portion is attached to an end of the core portion protruding from one of the first plate or the second plate, and the other end of the core portion is fixed to the restraint hole of the second plate or the first plate.

8. A seismic isolation structure for a building in which a seismic isolation device is arranged, The braking device according to claim 1 or 2, which is installed in a seismic isolation layer in which the seismic isolation device is arranged; A seismic isolation structure for a building, characterized in that it is equipped with a reaction force section for activating the braking device before a predetermined level of deformation occurs in the seismic isolation layer.

9. The braking device is installed on the upper or lower side of the seismic isolation layer, The seismic isolation structure for a building according to claim 8, characterized in that a cylindrical inner peripheral surface serving as the reaction portion is provided at a position facing the peripheral surface of the movable plate.

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