JP7442425B2 - energy absorption structure - Google Patents

Description

The present invention relates to an energy absorbing structure that absorbs impact force by collapsing the pipe and undergoing three-point plastic bending deformation when an impact force is applied to a pipe supported at both ends.

When an object carrying high energy impacts a structure having an internal space, the safety of the person inside the structure is threatened. For example, we sometimes hear of cases where people or buildings were directly hit by cinder blocks from a volcanic explosion, or cases where workers or passersby were directly hit by falling objects from above at construction sites such as building construction. In order to avoid direct hits from objects that retain high energy, mountain huts near volcanoes are installing cinder shelters and reinforcing their roofs using aramid fibers (see Patent Document 1). Further, at construction sites such as building construction, measures are taken such as installing a roof above the sidewalk to prevent falling objects from directly hitting passersby (see Patent Document 2).

When taking these measures, most of the members used to reinforce the roof of the structure are large and heavy, and in the case of a volcano, helicopters and heavy machinery are used to transport and install them. It requires the use of heavy machinery at the construction site, which requires high installation costs. If structures that can absorb impact energy without the use of heavy equipment can be installed in locations where there is a risk of falling objects, installation costs can be reduced. For example, if energy absorbing structures that are heavy enough to be carried by people can be lined up in parallel to absorb energy, there will be no need to use heavy machinery for installation, reducing installation costs and allowing installation in locations where heavy machinery cannot be used. installation becomes possible.

Additionally, as a measure against side collisions, a door impact beam made of high-strength material is generally housed inside the door. A door impact beam has a structure in which both ends of a hardened steel pipe are fixed inside the door (see FIG. 11 of Patent Document 3), and absorbs collision energy by utilizing bending and buckling deformation of the pipe. However, since both ends of the pipe are fixed inside the door, in the event of a side collision, the pipe undergoes three-point plastic bending deformation with both ends fixed and supported, and when an impact force is applied to the middle of the pipe with both ends fixed, the pipe A large tensile strain occurs on the outside of the bend. As a result, the rupture stroke (shock absorption stroke due to bending deformation) of the pipe becomes short, and the impact force on the colliding object side or the collided side becomes large. For example, if the collision object is a human being, the smaller the impact force, the lower the probability of injury.

Further, Patent Document 4 discloses a shock absorber that reduces the radial impact load applied to a shock absorber when stopping a swinging member. According to this shock absorbing device, the roller subjected to the collision receives forces in the thrust direction and the radial direction while rotating, and the impact energy can be reduced compared to the case without the roller. However, this impact force does not have enough energy to deform the swing arm, and is extremely weak compared to the impact force when a heavy object falls, so this structure cannot be expected to be sufficiently effective in alleviating high impact forces. The contact between the swing arm and the roller is a line contact, and an increase in stress at the contact portion is unavoidable. Furthermore, since the roller rotates around a pin at its center, impact force (shearing force) is also transmitted to the pin.

Japanese Patent Application Publication No. 2017-186773 Japanese Patent Application Publication No. 2016-211350 Japanese Patent Application Publication No. 2000-108663 Japanese Patent Application Publication No. 7-158677

The purpose of the present invention, which was created in consideration of the above circumstances, is to create an energy absorption structure that absorbs the impact force by crushing the pipe and deforming it by three-point plastic bending when an impact force is applied to a pipe supported at both ends. An object of the present invention is to provide an energy absorbing structure that reduces impact force by making the impact absorption stroke due to bending deformation as long as possible.

According to the present invention, which was created to achieve the above object, when an impact force is applied to a pipe supported at both ends, the pipe bends and deforms and collapses, thereby absorbing the impact force. , a support part provided at each end of the pipe and having a convex or concave arcuate surface; a pedestal part that supports the support part and has a concave or convex arcuate surface that matches the arcuate surface of the support part; A pin arranged to pass through the center of the arcuate surface of the part and the center of the arcuate surface of the pedestal part, and rotatably connects the support part and the pedestal part along the respective arcuate surfaces. An energy absorbing structure is provided.

In the energy absorption structure according to the present invention, the pipe is a square pipe, a plate is arranged along the longitudinal direction of the square pipe on the lower surface of the square pipe, and support parts are provided on the lower surface of both ends of the plate. , both ends of the plate are fixed to both ends of the square pipe so that when an impact force is applied to the square pipe and the square pipe and plate are bent and deformed, the bottom surface of the square pipe and the top surface of the plate can slide. You can leave it there.

In the energy absorbing structure according to the present invention, the bending rigidity of the square pipe may be lower than that of the plate material, or the section modulus of the square pipe may be set smaller than the section modulus of the plate material.

In the energy absorbing structure according to the present invention, a plurality of pipes are arranged side by side at intervals, and the pins connecting the support part and the pedestal part of each pipe may be independent for each pipe.

In the energy absorbing structure according to the present invention, the lengths of the plurality of pipes installed in parallel are different, and in order to make the inclination angles of each pipe the same, the height of the pin connecting the support part and the pedestal part of each pipe is adjusted. , the shorter the pipe, the higher it may be.

According to the energy absorbing structure according to the present invention, when an impact force is applied to a pipe supported at both ends and the pipe is crushed and deformed by three-point plastic bending, both ends of the pipe are not fixed ends that cannot rotate but are rotatable. Since the pipe has a free end, it is possible to reduce the tensile strain that occurs in the outer part of the bending pipe, and it is possible to reduce the impact force by making the impact absorption stroke due to the bending deformation as long as possible.

FIG. 1 is an explanatory diagram of an energy absorption structure according to a first embodiment of the present invention. 2 is a partially enlarged view of FIG. 1. FIG. FIG. 3 is an explanatory view of a bracket that supports the pin in FIG. 2, in which (a) is a front view of the bracket, (b) is a longitudinal sectional view, (c) is a rear view, and (d) is a plan view. FIG. 3 is an explanatory diagram showing how the energy absorption structure according to the first embodiment absorbs energy upon receiving impact force, in which (a) is a front view of the energy absorption structure before receiving impact force, and (b) is a front view of the energy absorption structure before receiving impact force. FIG. FIG. 2 is an explanatory diagram showing the strain distribution of a bending-deformed pipe (square pipe) and a plate material, (a) is an explanatory diagram showing the strain distribution when the square pipe and the plate material are independently deformed (first embodiment), (b) ) is an explanatory diagram showing the strain distribution when the square pipe and the plate material are integrally deformed. FIG. 2 is an explanatory diagram showing an energy absorption structure according to a second embodiment of the present invention in which a plurality of energy absorption structures of FIG. 1 are arranged in parallel. FIG. 7 is an assembly diagram of an energy absorption structure according to a second embodiment. FIG. 6 is an explanatory diagram showing the assembly procedure of the energy absorption structure according to the second embodiment, in which (a) is the first procedure, (b) is the second procedure, (c) is the third procedure, and (d) is the fourth procedure. , (e) is the fifth step, (f) is the sixth step, (g) is the seventh step, (h) is the eighth step, (i) is the ninth step, (j) is the tenth step, ( k) shows the eleventh procedure. FIG. 3 is an explanatory diagram showing an energy absorbing structure according to a third embodiment of the present invention, in which a plurality of the energy absorbing structures of FIG. 1 are arranged in parallel with different lengths of pipes. FIG. 7 is a plan view of an energy absorption structure and an explanatory diagram of a bracket according to a third embodiment. (a) is a partially enlarged view of FIG. 9, and (b) is an assembled view thereof. It is a partially enlarged view of FIG.11(b). FIG. 13 is an explanatory diagram of a bracket that supports the pin shown in FIG. 12, in which (a) is a front view of the bracket, (b) is a side view, and (c) is a plan sectional view. It is explanatory drawing of the energy absorption structure based on 3rd Embodiment, (a) is a front view, (b) is a side view, and (c) is a top view. It is an explanatory view showing an energy absorption structure concerning a 4th embodiment of the present invention.

DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of the present invention will be described in detail below with reference to the accompanying drawings. The dimensions, materials, and other specific numerical values shown in the embodiments are merely illustrative to facilitate understanding of the invention, and do not limit the invention unless otherwise specified. In this specification and the drawings, elements with substantially the same functions and configurations are given the same reference numerals to omit redundant explanation, and elements not directly related to the present invention are omitted from illustration. do.

(First embodiment: Energy absorption structure)
As shown in FIGS. 4(a) and 4(b), in the energy absorbing structure 1 according to the first embodiment of the present invention, when an impact force is applied to the pipe 2 supported at both ends, the pipe 2 It absorbs impact force by bending and deforming while collapsing. As shown in FIGS. 1 and 2, the energy absorption structure 1 according to the present embodiment includes a support portion 4 provided at both ends of a pipe 2 and having a convex arcuate surface 3, and an arcuate surface 3 of the support portion 4. a pedestal part 6 that supports the support part 4 and has a concave arcuate surface 5 coinciding with the pedestal part 6; , a pin 7 rotatably connecting the support portion 4 and the pedestal portion 6 along the respective arcuate surfaces 3 and 5. Note that, contrary to this embodiment, the convex arcuate surface 3 of the support section 4 may be a concave arcuate surface, and the concave arcuate surface 5 of the pedestal section 6 may be a convex arcuate surface.

(Support part 4)
As shown in FIG. 2, the pipe 2 consists of a square pipe 2, and a plate 8 is disposed on the lower surface of the square pipe 2 along the longitudinal direction of the square pipe 2. On the lower surface of both ends of the plate 8, The support section 4 described above is attached. The support part 4 includes a support block 4a attached to the lower surface of both ends of the plate material 8 by welding, bolt fastening, etc., and a support block 4a integrally provided on the lower surface of the support block 4a so as to protrude perpendicularly to the longitudinal direction of the square pipe 2. The support convex portion 4b has a circular arc surface 3. A first hole 9 is formed in the support portion 4 so as to be located at the center 3x of the arcuate surface 3 and perpendicular to the longitudinal direction of the square pipe 2.

(Pedestal part 6)
As shown in FIG. 2, the pedestal part 6 includes a pedestal block 6a having a concave arc surface 5 that matches the arc surface 3 of the support part 4, and a board attached to the lower surface of the pedestal block 6a by welding, bolting, etc. 6b, and a bracket 6c attached to the base plate 6b so as to sandwich the pedestal block 6a. A second hole 11 is formed in the bracket 6c so as to pass through the center 5x of the concave arc surface 5 formed in the pedestal block 6a when the bracket 6c is fastened to the board 6b with the bolt 10. (See Figure 3). Note that the pedestal block 6a and the substrate 6b may have an integral structure. The substrate 6b is attached to a base 12 (see FIG. 4(a)) that receives impact force.

(pin 7)
As shown in FIG. 2, when the convex arcuate surface 3 of the support section 4 is placed on the concave arcuate surface 5 of the pedestal section 6, the second hole 11 of the pedestal section 6 and the first hole of the support section 4 are placed. A pin 7 is inserted through the hole 9 . The pin 7 is arranged to pass through the center 3x of the arcuate surface 3 of the support portion 4 and the center 5x of the arcuate surface 5 of the pedestal portion 6, and connects the support portion 4 and the pedestal portion 6 to the respective arcuate surfaces 3 and 5. It is connected rotatably along the line.

As a result, as shown in FIGS. 4(a) and 4(b), when an impact force is applied to the square pipe 2 whose both ends are supported, the square pipe 2 is crushed and deformed by three-point plastic bending. Since both ends of the square pipe 2 are not fixed ends that cannot be rotated but are rotatable free ends, the tensile strain that occurs on the outside of the bending (lower side in the figure) of the square pipe 2 that undergoes bending deformation is absorbed by the ends of the square pipe 2. can be reduced compared to the case of a fixed end, the shock absorption stroke due to bending deformation can be lengthened, and the impact force can be reduced.

(Independent bending deformation of square pipe 2 and plate material 8)
The plate material 8 shown in FIG. 1 is fixed to the lower surface of the square pipe 2 by welding, bolting, etc. only at both ends (near the openings at both ends, the part where the support part 4 is attached), and other than the both ends. The part is not fixed to the square pipe 2. As a result, as shown in FIGS. 4(a) and 4(b), an impact force is applied to the middle of the square pipe 2 (the part between the supporting parts 4 at both ends), and the square pipe 2 and the plate material 8 are When bent and deformed, the lower surface of the square pipe 2 and the upper surface of the plate 8 are allowed to slide, as shown in FIG. 5(a). That is, when an impact force is applied to the square pipe 2 and the square pipe 2 and the plate 8 are bent and deformed, the lower surface of the square pipe 2 and the upper surface of the plate 8 slide, and the square pipe 2 and the plate 8 become independent. Both ends of the plate material 8 are fixed to both ends of the square pipe 2 so that the plate material 8 is bent and deformed.

As a result, as shown in FIG. 4(b), when an impact force is applied to the square pipe 2 and the square pipe 2 and the plate 8 are bent and deformed, the square pipe 2 and the plate 8 are bent as shown in FIG. 5(a). are each subjected to independent bending deformation, and the length from the neutral axis N shown by the dashed line to the outer surface is shorter than when the square pipe 2 and plate material 8 are bent and deformed as one unit as shown in Fig. 5(b). , the maximum bending strain E also decreases. That is, the length from the neutral axis N1 of the square pipe 2 shown in FIG. Since the length from the neutral axis N3 to the outer surface is shorter than the length from the neutral axis N3 to the outer surface when the plate member 2 and the plate material 8 are bent and deformed integrally, the maximum bending strain E is reduced. Therefore, the bending stroke up to fracture bending strain can be lengthened, and the amount of energy absorption increases.

(Bending rigidity of square pipe 2 and plate 8)
As shown in FIGS. 4(a) and 4(b), in the square pipe 2 and the plate material 8 that are bent and deformed, the bending rigidity of the square pipe 2 is set lower than that of the plate material 8. That is, by making the thickness of the plate 8 thicker than that of the square pipe 2 and using a material (such as high-strength steel) that is stronger than the material of the square pipe 2, the plate 8 can be bent. The rigidity is higher than the bending rigidity of the square pipe 2.

As a result, when the square pipe 2 and the plate material 8 receive an impact force from above, buckling deformation of the square pipe 2 is induced, and the amount of energy absorption increases. Note that the bending rigidity may be adjusted by changing only either the plate thickness or the material. Further, even if the section modulus of the square pipe 2 is set smaller than that of the plate material 8 by adjusting the plate thickness and material, buckling deformation of the square pipe 2 can be similarly induced during bending deformation.

(action/effect)
Considering the three-point bending of a beam from the perspective of material mechanics, the bending stroke until the surface of the beam (rectangular cross-section plate material) reaches a breaking strain is: If both ends of the beam are fixedly supported, both ends of the beam are supported by the free end. It is 1/2 of the case of . On the other hand, the static load until the surface of the beam reaches the breaking strain is twice as much when the beam is supported at both ends as when it is supported at both ends. Therefore, the amount of energy absorption in the elastic range does not change whether both ends are fixedly supported or both ends are supported with free ends. However, if we assume that an object collides with a beam at a certain speed and the speed becomes zero due to constant acceleration motion, the impact force is inversely proportional to the stroke required for damping, so the stroke can be doubled. The impact force can be halved. When a beam receives an impact force, it is necessary to consider the impact on the colliding object, and if the beam absorbs the same energy rather than receiving the impact energy with a rigid body, a longer stroke is preferable for the structure.

According to the energy absorption structure 1 according to the present embodiment, as shown in FIGS. 4(a) and 4(b), an impact force is applied to the square pipe 2 whose both ends are supported, and the square pipe 2 is moved at three points. When undergoing plastic bending deformation, both ends of the square pipe 2 become rotatable free ends instead of non-rotatable fixed ends, so compared to the case where both ends of the square pipe 2 are fixed ends, the shock absorption stroke ( The bending stroke required to reach breaking strain can be doubled, and the impact force can be reduced by half. Further, the square pipe 2 undergoes buckling (crumbling) deformation at the same time as it bends, and the impact is also absorbed by this buckling deformation, so that the impact absorption stroke can be further lengthened.

The bending strain that affects the rupture timing is expressed as "plate thickness/(2 x radius of curvature of neutral axis)". In this embodiment, as shown in FIG. 5(a), the square pipe 2 and the plate material 8 undergo independent bending deformation, so the square pipe 2 and the plate material 8 in FIG. 5(b) are bent integrally. Compared to the case of deformation, the length from the neutral axis N to the outer surface becomes shorter, and the maximum bending strain E also decreases. That is, the length from the neutral axis N1 of the square pipe 2 shown in FIG. Since the length from the neutral axis N3 to the outer surface is shorter than the length from the neutral axis N3 to the outer surface when the plate member 2 and the plate material 8 are bent and deformed integrally, the maximum bending strain E is reduced. Therefore, the bending stroke until breaking bending strain can be made longer than when the square pipe 2 and the plate material 8 are bent and deformed as one body, and the amount of energy absorption increases.

In this embodiment, as shown in FIGS. 4(a) and 4(b), the square pipe 2 and the plate material 8 that are bent are adjusted to have the bending rigidity of the square pipe 2 by adjusting the wall thickness and material. is set lower than the bending rigidity of the plate material 8, or the section modulus of the square pipe 2 is set smaller than that of the plate material 8. As a result, when the square pipe 2 and the plate material 8 receive an impact force from above, the deformation mode is controlled so that the plate material 8 undergoes a bending deformation and the square pipe 2 undergoes a combination of bending and buckling deformation. As a result, buckling deformation of the square pipe 2 is induced, and the amount of energy absorption increases.

As shown in FIG. 4(b), when an impact force is applied to the square pipe 2, the impact force is absorbed by the surface support by the convex arc surface 3 of the support section 4 and the concave arc surface 5 of the pedestal section 6. (see FIG. 2), the surface pressure can be reduced compared to the case of line support by rollers as shown in FIG. 1 of Patent Document 4.

Further, a pin 7 that connects the support part 4 and the pedestal part 6 shown in FIG. Therefore, as shown in FIG. 4(b), when an impact force is applied to the square pipe 2, the shearing force applied to the pin 7 can be made as small as possible while allowing both ends of the square pipe 2 to rotate. , damage to the pin 7 can be prevented.

Here, in FIG. 2, the hole diameter of the first hole 9 of the support part 4 is made larger than the hole diameter of the second hole 11 of the pedestal part 6, and the convex arcuate surface 3 of the support part 4 is formed in the concave shape of the pedestal part 6. When the pin 7 is inserted from the second hole 11 on the front side through the first hole 9 to the second hole 11 on the back side while seated on the circular arc surface 5, the relationship between the pin 7 and the first hole 9 is A predetermined gap (about 1 to 2 mm) may be formed between them. As a result, the convex arcuate surface 3 of the support part 4 is always seated on the concave arcuate surface 5 of the pedestal part 6, and as shown in FIG. 4(b), when an impact force is applied to the square pipe 2, All of the impact force can be received by the arcuate surface 3 of the support portion 4 and the arcuate surface 5 of the pedestal portion 6 for surface support, and the shearing force applied to the pin 7 can be reduced to zero.

In addition, since the support part 4 and the pedestal part 6 are connected by the pin 7, when an impact force is applied to the square pipe 2, the square pipe 2 jumps up due to the impact force, and the support part 4 of the square pipe 2 is placed on the pedestal. It is possible to prevent the situation in which the person leaves the section 6.

As a result of the above, it is possible to safely absorb a high amount of energy. For example, the impact force can be absorbed by making the stroke of three-point plastic bending deformation as long as possible for objects falling from the upper floors of buildings, volcanic blocks, etc., and the ability to absorb impact energy can be improved. Furthermore, there is no need for molding or processing of die-quenched materials, etc., which are often used for shock absorption, and the product can be manufactured at low cost even without special equipment.

Further, as shown in FIGS. 1 and 2, this energy absorption structure 1 includes a first subassembly product (square pipe 2, plate material 8, support part 4) and a second subassembly product (pedestal block 6a, substrate 6b). , a bracket 6c, a pedestal 6), and a pin 7 that connects them, each component is not heavy and can be easily assembled by hand without heavy machinery. Therefore, the installation cost can be reduced, and it can be installed in places where heavy machinery cannot enter, such as volcano shelters and sidewalk shelters for building construction.

(Second embodiment: pipe parallel type)
By the way, volcanic cinders and falling objects from upper floors of buildings are generally larger than the width (diameter) of the pipe 2, and it is difficult for one pipe 2 to absorb the collision energy. Therefore, in the energy absorption structure 1b according to the second embodiment, by arranging a plurality of energy absorption structures 1 of the first embodiment in parallel, it is possible to cope with a larger impact force and cope with a larger impact force acting area. I made it.

6 and 7 show an energy absorption structure 1b according to the second embodiment. In this energy absorption structure 1b, a plurality of pipes 2 of the first embodiment are arranged in parallel at intervals. Each pipe 2 undergoes bending deformation as well as crushing and buckling deformation when subjected to impact force from cinder blocks, etc. Therefore, the interval between adjacent pipes 2 should be set at a distance that will not interfere with each other during buckling (for example, 1/3 of the pipe width). ~2/3). Further, the pins 7 that connect the support portion 4 and the pedestal portion 6 of each pipe 2 are independent for each pipe 2.

Each component constituting the energy absorbing structure 1b of the second embodiment has the same shape, structure, and name as each component constituting the energy absorbing structure 1 of the first embodiment. Therefore, a detailed explanation of each component will be omitted, and only the assembly procedure for arranging a plurality of pipes 2 in parallel will be explained.

(Assembly procedure)
First, as shown in FIG. 8A, a pedestal section 6 is prepared in which a plurality of pedestal blocks 6a are provided at equal intervals in the longitudinal direction on an elongated rectangular substrate 6c. The pedestal block 6a may be bolted to the substrate 6b from below, or may be formed integrally with the substrate 6b. A groove 6d for attaching a bracket 6c is formed between adjacent pedestal blocks 6a.

As shown in FIG. 8(b), the bracket 6e is fastened with bolts 10 to the groove at the rear end of the base 6b. A second hole 11e is formed in the bracket 6e so as to pass through the center 5x of the concave arc surface 5 of the pedestal block 6a when the bracket 6e is fastened to the base 6b with a bolt 10. As shown in FIG. 7, this second hole 11e is not a through hole but a recessed hole (spotted hole), and prevents the pin 7 from falling off.

As shown in FIG. 8(c), the convex arcuate surface 3 of the support portion 4 attached to the plate material 8 of the square pipe 2 is placed on the concave arcuate surface 5 of the pedestal block 6. A first hole 9 is formed in the support portion 4 so as to be located at the center 3x of the convex arcuate surface 3 and perpendicular to the longitudinal direction of the square pipe 2. The square pipe 2 and the plate material 8 are fixed only at both ends by bolting, welding, etc., as in the first embodiment, and when an impact is received in the middle as shown in FIG. As shown in 5(a), the bending deformation occurs independently.

As shown in FIG. 8(d), the bracket 6c is fastened to the groove 6d of the base 6b with bolts 10. A second hole 9 is formed in the bracket 6c so as to pass through the center 5x of the concave arc surface 5 of the pedestal block 6a when the bracket 6c is fastened to the base 6b with a bolt 10. This second hole 9 is a through hole, as shown in FIG. Insert the pin 7 into the second hole 11. Insert the pin 7 from the second hole 11 (through hole) of the bracket 6c on the front side, through the first hole 9 of the support part 4, until it hits the bottom of the second hole 11e (recessed hole) of the bracket 6e on the back side. It will be done. The pin 9 inserted in this way is in a state where the pin end face is inserted into the second hole of the bracket on the near side to a position half the plate thickness of the bracket 6c, as shown in FIG. 8(e). Become.

As shown in FIG. 8(f), the convex arcuate surface 3 of the support part 4 attached to the plate material 8 of the square pipe 2 is placed on the concave arcuate surface 5 of the pedestal block 6a next to it. 8(g), the bracket 6c is fastened to the groove 6c of the base 6b with bolts 10. As shown in FIG. 7, a second hole 11 is formed through the bracket 6c. Insert the pin 7 into the second hole 11. The pin 7 passes from the second hole 11 (through hole) of the front bracket 6c to the first hole 9 of the support part 4, and connects to the rear pin located in the middle of the second hole 11 of the rear bracket 6c. It can be inserted until it hits the end face of 7. The pin 7 inserted in this way is inserted into the second hole 11 of the bracket 6c on the near side until the end of the pin is half the thickness of the bracket 6c, as shown in FIG. 8(h). state.

The same operation is repeated, and as shown in FIG. 8(i), the pin 7 is inserted into the first hole 9 formed in the support portion 4 attached to the plate 8 of the last square pipe 2 at the right end. The pin 7 is inserted through the first hole 9 until it hits the end surface of the back pin 7 (see FIG. 8(h)) located in the middle of the second hole 11 of the back bracket 6c. The pin 7 inserted in this manner has its end surface protruding from the first hole 9, as shown in FIG. 8(j). The bracket 6f is placed in the groove 6d at the end of the base 6b. As shown in FIG. 7, the bracket 6f has a second hole 11f into which the pin 7 protruding from the first hole 9 is inserted. The second hole 11f is not a through hole but a recessed hole, and prevents the pin 7 from falling off. Finally, as shown in FIG. 8(k), the bracket 6f is fastened to the board 6b with bolts 10, completing the assembly.

By the above procedure, the first sub-assembly consisting of the square pipe 2, the plate material 8, and the support part 4 can be assembled one by one onto the pedestal part 6, making it possible to assemble it on-site without heavy machinery and improving the ease of assembly. improves. Furthermore, since the square pipes 2 are arranged in parallel at intervals, the impact force can be received over a wide area by the square pipes 2. Moreover, since the square pipes 2 are arranged in parallel at intervals, it is possible to avoid a situation in which adjacent square pipes 2 buckled and deformed by impact force interfere with each other. Here, in addition to supporting the pin 7, the bracket 6c also functions as a spacer that maintains the interval between the square pipes 2. Note that a single long pin may be used as the pin 7. Other than that, the basic functions and effects of the second embodiment are the same as those of the first embodiment.

(Third embodiment: Type with different pipe lengths)
9 and 10 show an energy absorption structure 1c according to a third embodiment. This energy absorbing structure 1c is obtained by changing the length of the pipe 2 of the energy absorbing structure 1b of the second embodiment. Specifically, one end (the right end in FIG. 9, the upper end in FIG. 10) of the plurality of pipes 2 arranged in parallel is aligned, and the other ends (the left end in FIG. 9, the lower end in FIG. 10) are arranged in a stepped manner. In this configuration, when each pipe 2 is arranged to be inclined from one end side to the other end side, if the height of the pins 7 on the other end side of the stepped pipe 2 is all the same, the short pipe 2, the inclination angle becomes steeper.

Therefore, in the energy absorption structure 1c according to the third embodiment, in order to make the inclination angles of each pipe 2 the same, the support part 4 and the pedestal part 6 of each pipe 2 are connected at the other end side of the stepped pipe 2. The height of the pin 7 that connects the pipes increases as the pipe 2 becomes shorter, depending on the length of the pipe 2 (see FIGS. 14(a), 14(b), and 14(c)). Thereby, even if the lengths of the plurality of pipes 2 arranged in parallel are different, the inclination angles of the pipes 2 can be made the same, and the functionality and design of the roof material are improved.

In FIGS. 9 and 10, the energy absorption structure 1c according to the third embodiment has a configuration similar to that of the second embodiment on the side where the ends of the pipes 2 are aligned (the right side in FIG. 9, the upper end in FIG. 10). Since they are similar, the explanation will be omitted, and only the structure of the side where the end of the pipe 2 is stepped (the left end in FIG. 9, the lower end in FIG. 10) will be described. FIG. 11(a) shows a partial perspective view of an energy absorption structure 1c according to the third embodiment, FIG. 11(b) shows an exploded view thereof, and FIG. 12 shows a partially enlarged view of FIG. 11(b).

As shown in FIG. 10, FIG. 11(a), and FIG. 11(b), the pedestal portion 6 is formed diagonally when viewed from above on the stepped side of the plurality of pipes 2 arranged in parallel. A substrate 6b, a plurality of pedestal blocks 6a disposed diagonally at intervals on the substrate 6b, an intermediate bracket 6g disposed between each pedestal block 6a, and an end disposed at an end of the substrate 6b. and a bracket 6h. The pedestal block 6a may be bolted to the substrate 6b from below, or may be formed integrally with the substrate 6b. The intermediate bracket 6g is fastened to the board 6b with bolts 10.

As shown in FIG. 12, the upper surface of the substrate 6b has a stepped surface 6x that increases from the front side (the longer side of the pipe 2) to the back side (the shorter side of the pipe 2) as shown in FIG. 11(b). (see FIG. 14), and a pedestal block 6a and an intermediate bracket 6g are attached to each stepped surface 6x. Due to the stepped surface 6x, the height of the pin 7a attached to the intermediate bracket 6g increases as the pipe 2 becomes shorter. The stepped vertical walls 6y between the stepped surfaces 6x also serve as positioning members for the intermediate bracket 6g in the depth direction.

As shown in FIG. 12, a concave arcuate surface 5 similar to the first embodiment is formed on the pedestal block 6a provided on the substrate 6b. A straight hole 13 is formed in the intermediate bracket 6g, which is attached to the board 6b with bolts 10, in alignment with the position of the arcuate surface 5 of the pedestal block 6a on the front side, and a straight hole 13 is formed in alignment with the position of the arcuate surface 5 of the pedestal block 6a on the back side. A stepped hole 14 is formed (see FIG. 13).

As shown in FIG. 12, the straight hole 13 is formed to pass through the center of the circular arc surface 5 of the pedestal block 6a on the near side when the intermediate bracket 6g is fastened to the board 6b with the bolt 10. The stepped hole 14 is formed at a higher position than the straight hole 13, and is formed so as to pass through the center of the arcuate surface 5 of the pedestal block 6a on the back side when the intermediate bracket 6g is fastened to the board with the bolt 10. ing. The height difference between the straight hole 13 and the step hole 14 shown in FIG. 13 matches the height difference between the adjacent step surfaces 6x shown in FIG. 14(a). Thereby, it is possible to use the same shape for all intermediate brackets 6g.

As shown in FIG. 12, the flanged pin 7a inserted into the step hole 14 of the intermediate bracket 6g on the front side is inserted through the first hole 9 of the support part 4, as shown in FIG. It is inserted into the straight hole 13 of the bracket 6g. A screw hole (not shown) is formed in the end surface of the flanged pin 7a inserted into the straight hole 13, and a bolt 16 is screwed into the screw hole through a washer 15. This prevents the flanged pin 7a from coming off.

Further, as shown in FIG. 10, a straight hole 11g is independently formed in the end bracket 6h at the lower left end, and a bolt 16 is attached to the end surface of the flanged pin 7a inserted into the straight hole 11g. The attached washer 15 prevents the flanged pin 7a from coming off. Further, a step hole 11h is independently formed in the end bracket 6h at the lower right end, and the flanged pin 7a is prevented from coming off by the flange of the flanged pin 7a inserted through the step hole 11h.

According to the energy absorption structure 1c according to the third embodiment, as shown in FIG. 9, even if the lengths of the plurality of pipes 2 arranged in parallel are different, the inclination angles of the pipes 2 can be made the same, It improves functionality and design as a roof material for volcano shelters, sidewalk shelters for building construction, apartment entrances, etc. Other than that, the basic functions and effects of the third embodiment are the same as those of the second embodiment and the first embodiment.

(Fourth embodiment: roof material)
FIG. 15 shows a roof to which the energy absorption structure 1d according to the fourth embodiment is applied. This roof is used, for example, as a volcano shelter, a sidewalk shelter for building construction, an apartment entrance, and the like. The energy absorbing structure 1d according to the fourth embodiment has the energy absorbing structure 1b according to the second embodiment and the energy absorbing structure 1c according to the third embodiment arranged next to each other, and the energy absorbing structure 1d according to the second embodiment A rectangular roof plate 17 is attached on top of the square pipes 2 of 1b in accordance with the second group of square pipes, and a stand is attached on top of the square pipes 2 of the energy absorption structure 1c of the third embodiment in accordance with the second group of square pipes. A shaped roof plate 18 is attached.

Fastening means such as bolts and nuts are used to attach the roof plates 17 and 18 to the square pipe 2. The roof plates 17 and 18 are made of a building material used as a roof or a metal plate, and the thickness and size of the plates are set so that the weight can be held by an assembly worker. The roof plates 17 and 18 and the square pipe 2 may be made of different materials. In that case, take measures such as interposing an insulating material between them to avoid electrical contact.

According to the energy absorbing structure 1d according to the fourth embodiment, when used as a volcano shelter, a sidewalk shelter for building construction work, or a roof for an apartment entrance, it has excellent design, and the roof plates 17 and 18 allow the square pipes 2 to be connected to each other. It can prevent rain and foreign objects from entering through the gaps. Other basic operations and effects of the fourth embodiment are the same as those of the third embodiment, the second embodiment, and the first embodiment.

Although preferred embodiments of the present invention have been described above with reference to the accompanying drawings, it goes without saying that the present invention is not limited to the embodiments described above, and various modifications within the scope of the claims are possible. It goes without saying that modifications and modifications also fall within the technical scope of the present invention.

For example, the square pipe 2 and the plate material 8 shown in FIG. 1 do not have to have the same width, and the width of the square pipe 2 may be narrower or wider than the plate material 8. The square pipe 2 may be made of extruded aluminum material with ribs in the hollow part, and the cross-sectional shape is selected from a cross-sectional shape, a cross-sectional shape, etc. depending on the set impact force.

The present invention relates to an energy absorbing structure that absorbs impact force by crushing the pipe and performing three-point plastic bending deformation when an impact force is applied to a pipe supported at both ends, such as a volcano shelter or a sidewalk shelter for building construction. It can be used as an energy-absorbing structure to safely protect people in the interior space below when a heavy object, such as a building or the roof of an apartment entrance, hits it with impact.

1 Energy absorption structure (first embodiment)
1b Energy absorption structure (second embodiment)
1c Energy absorption structure (third embodiment)
1d Energy absorption structure (4th embodiment)
2 pipe (square pipe)
3 Convex arc surface 3x Center of arc surface 3 4 Support part 5 Concave arc surface 5x Center of arc surface 5 6 Pedestal section 7 Pin 8 Plate material

Claims (5)

When an impact force is applied to a pipe supported at both ends, the pipe bends and deforms and collapses, thereby absorbing the impact force, comprising:
Support parts each provided at both ends of the pipe and having a convex or concave arc surface;
a pedestal portion that supports the support portion and has a concave or convex arcuate surface that matches the arcuate surface of the support portion;
a pin arranged to pass through the center of the circular arc surface of the support section and the center of the circular arc surface of the pedestal section, and rotatably connects the support section and the pedestal section along their respective arc surfaces; An energy absorbing structure characterized by: The pipe is a square pipe, a plate is arranged along the longitudinal direction of the square pipe on the lower surface of the square pipe, and the support portion is provided on the lower surface of both ends of the plate,
When an impact force is applied to the square pipe and the square pipe and the plate material are bent and deformed, both ends of the plate material are connected to the square pipe so that the lower surface of the square pipe and the upper surface of the plate material are allowed to slide. The energy absorbing structure according to claim 1, wherein the energy absorbing structure is fixed to both ends of the energy absorbing structure. The energy absorbing structure according to claim 2, wherein the bending rigidity of the square pipe is lower than that of the plate material, or the section modulus of the square pipe is smaller than the section modulus of the plate material. Claims 1 to 3, characterized in that a plurality of the pipes are arranged in parallel at intervals, and the pins connecting the support part and the pedestal part of each pipe are independent for each pipe. The energy absorption structure according to any one of the above. The plurality of pipes arranged in parallel have different lengths, and in order to make the inclination angles of each pipe the same, the height of the pin connecting the support part and the pedestal part of each pipe is such that the pipes are shortened. 5. The energy absorbing structure according to claim 4, wherein the energy absorbing structure is relatively high.

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