JP7032909B2 - Manufacturing method of shock absorbing member, shock absorber, cask and shock absorber - Google Patents

Description

The present invention relates to a shock absorbing member, a shock absorber, a cask, and a method for manufacturing the shock absorber.

As a shock absorbing member that absorbs shock energy, a shock absorbing member composed of a composite material containing reinforcing fibers and a resin is known.
For example, Patent Document 1 discloses a sheet-shaped composite material as a shock absorbing member.

Japanese Patent No. 4118264A

The composite material disclosed in Patent Document 1 absorbs impact by converting impact energy into fracture energy.
However, depending on the load, the composite material may break or buckle, making it impossible to convert impact energy into fracture energy. Therefore, the composite material disclosed in Patent Document 1 may be difficult to absorb impact.

An object of the present invention is to provide a shock absorbing member, a shock absorber, a cask, and a method for manufacturing a shock absorber that easily absorbs shock energy.

The shock absorbing member of the first aspect is composed of a composite material containing continuous reinforcing fibers and a resin, includes a composite material pipe having a pipe shape extending in the pipe axis direction, and the end face of the composite material pipe is the said. It has a plurality of valleys that are lined up in the circumferential direction of the composite material pipe and are concave in the pipe axial direction.

The shock absorbing members of the present embodiment are arranged in the circumferential direction of the composite material pipe and have a plurality of valleys recessed in the pipe axial direction. Therefore, when an impact is applied to the composite material pipe from the extending direction of the composite material pipe, the composite material pipe is torn in the pipe axial direction and becomes a plurality of crushed debris spreading outward in the pipe radial direction. (Spraying Mode) is expressed.
When the Spraying Mode is expressed, the load applied to the composite pipe is distributed in the circumferential direction of the pipe so as to generate a plurality of cracks.
Therefore, since the composite material pipe can suppress breakage and buckling, it is easy to absorb the impact.

Further, in the shock absorbing member of the second aspect, the composite material pipe is formed by laminating the reinforcing fibers in the pipe radial direction, and the orientation direction of the reinforcing fibers is the axial contribution rate and the circumferential contribution rate. When the sum of the above is 100%, the axial contribution ratio is configured to be 20% to 90%, and the pore ratio of the composite material pipe in the cross section perpendicular to the pipe axial direction is 40% to 87%. The composite material pipe has 20% to 90% of the first reinforcing fibers having an orientation direction of −20 ° to + 20 ° with respect to the pipe axial direction as the reinforcing fibers, and the orientation direction with respect to the pipe axial direction. Is the shock absorbing member of the first aspect, which has 10% to 80% of the second reinforcing fibers of + 70 ° to + 110 °.

Further, in the shock absorbing member of the third aspect, the composite material pipe includes an outer layer, an intermediate layer and an inner layer, which are the same laminated layer, respectively, in order from the outside in the pipe radial direction, and the outer layer and the inner layer are the first. (Ii) The shock absorbing member of the second aspect, which is a layer having reinforcing fibers.

Further, the impact absorbing member of the fourth aspect has an axial contribution ratio of 20% to 90% when the alignment direction of the reinforcing fibers in the previous period is 100% when the sum of the axial contribution ratio and the circumferential contribution ratio is 100%. The shock absorbing member of the first aspect is configured to have a porosity of 40% to 87% in the cross section perpendicular to the pipe axis direction.

Further, the shock absorbing member of the fifth aspect is the shock absorbing member of any of the second to fourth aspects having the axial contribution ratio of 50% to 70%.

Further, the shock absorbing member of the sixth aspect is the shock absorbing member of any one of the first to fifth aspects, wherein the composite material tube further includes a cap covering the end face.

Further, the shock absorbing member of the seventh aspect is the shock absorbing member of the sixth aspect in which the cap has a partial shape of a spherical surface.

Further, the shock absorbing member of the eighth aspect is the shock absorbing member of any one of the first to seventh aspects, further comprising a shock absorbing assisting member around the composite material pipe.

Further, the shock absorbing member of the ninth aspect is the shock absorbing member of the eighth aspect in which the shock absorbing auxiliary member is a porous body having a porosity of 40% to 95%.

Further, the shock absorbing member according to the tenth aspect further includes a base to which the root of the composite material pipe is fixed, and the root is fixed to the base so that the pipe can hang down in the axial direction. It is a shock absorbing member according to any one of the first to ninth aspects.

Further, the shock absorber of the eleventh aspect is a shock absorber in which the impact absorbing members of any one of the first to tenth aspects are arranged in a plurality of composite material tubes in the same direction. Is.

Further, in the shock absorber of the twelfth aspect, the composite material pipe is arranged in the circumferential direction of the central axis in a posture in which the shock absorbing member forms an annular shape and extends in the radial direction of the central axis of the shock absorbing member. 11th aspect of the buffer.

Further, in the shock absorber of the thirteenth aspect, the shock absorbing member is composed of a plurality of block bodies, and the block body is configured to include a plurality of the composite material tubes bundled in parallel. It is a buffer of the twelfth aspect.

Further, the buffer of the 14th aspect is the buffer of the 13th aspect in which the plurality of blocks are arranged in the circumferential direction of the central axis.

Further, the shock absorber of the fifteenth aspect is configured by the shock absorbing member in which a plurality of blocks arranged in the circumferential direction of the central axis are laminated with a plurality of layers along the central axis. The block bodies laminated to each other are the buffer bodies of the twelfth aspect in which the postures of the composite material pipes are different from each other.

Further, the shock absorber of the sixteenth aspect is the buffer body of the fifteenth aspect in which the peripheral ends of the central axis are displaced from each other among the block bodies laminated to each other.

Further, in the shock absorber of the seventeenth aspect, the shock absorbing member is composed of a plurality of block bodies arranged in the circumferential direction of the central axis, and the block body includes the plurality of the composite material tubes. It is configured to include a layered structure that is bundled in a plane shape orthogonal to the central axis and a plurality of layers are laminated along the central axis. It is a buffer body of the twelfth aspect in which the postures of the composite material pipes are different from each other.

Further, the buffer of the eighteenth aspect is the buffer of the seventeenth aspect in which the peripheral ends of the central axis are displaced from each other in the layered structures laminated to each other.

Further, in the buffer body of the nineteenth aspect, the block body has a shape in which both ends in the circumferential direction of the central axis are cut out along the radial direction of the central axis. It is a shock absorber of any one of the above embodiments.

Further, the buffer of the twentieth aspect is the buffer of any one of the thirteenth to nineteenth aspects in which a plurality of the composite material tubes constituting the block body are bonded to each other.

Further, the buffer body of the 21st aspect further includes an embedded member in which a plurality of the composite material pipes constituting the block body are embedded so as to be bundled so as to be parallel to the composite material pipes. 20th aspect of the buffer.

Further, the shock absorber of the 22nd aspect is the buffer body of any of the 13th to 21st aspects, which is configured by laminating the block bodies in the direction in which the load is applied.

Further, the buffer of the 23rd aspect is the buffer of any of the 13th to 22nd aspects, which is configured by shifting and stacking the block bodies.

Further, the cask of the 24th aspect includes the buffer according to any one of the twelfth to the twenty-third, and a cylindrical transport container extending along the central axis for accommodating the radioactive substance inside, and the transport thereof. The transport container is attached to the outer periphery of the end of the container.

Further, the method for producing a shock absorber according to the 25th aspect is a composite material pipe composed of a composite material containing continuous reinforcing fibers and a resin and having a pipe shape extending in the pipe axis direction, wherein the composite material pipe is used. A plurality of pipe manufacturing steps for producing the composite material pipe having a plurality of valleys in which the end faces of the composite material pipes are lined up in the pipe circumferential direction and recessed in the pipe axis direction, and after the pipe manufacturing process. After the block body manufacturing step of manufacturing the block body by bundling the composite material pipes in parallel and the block body manufacturing step, the ends of the plurality of the composite material pipes in the block body in the arrangement direction are separated from each other. The assembly process of connecting and assembling to each other and carrying out.

According to one aspect of the present invention, there is provided a shock absorbing member, a shock absorber, a cask, and a method for manufacturing a shock absorber that easily absorbs shock energy.

It is a side view of the cask which concerns on 1st Embodiment. It is a figure which looked at the buffer body which concerns on 1st Embodiment from the direction of the central axis of the buffer body. It is a perspective view of the block body which comprises the shock absorbing member which concerns on 1st Embodiment. It is a perspective view of the composite material pipe which constitutes the shock absorbing member which concerns on 1st Embodiment. It is a partial fracture view of the composite material pipe which constitutes the shock absorbing member which concerns on 1st Embodiment. It is an enlarged view of the VI part of FIG. It is an enlarged view of the VII part of FIG. It is a flowchart explaining the manufacturing method of the shock absorbing member which concerns on 1st Embodiment. It is a figure explaining the fracture state of the composite material pipe which constitutes the shock absorbing member which concerns on 1st Embodiment. It is a perspective view of the block body which comprises the shock absorbing member which concerns on 2nd Embodiment. It is a side view of the cask which concerns on 3rd Embodiment. It is a perspective view of the composite material pipe which constitutes the shock absorbing member which concerns on 3rd Embodiment. The collision mode of the composite material pipe constituting the shock absorbing member according to the third embodiment will be described. It is a flowchart explaining the manufacturing method of the shock absorbing member which concerns on 3rd Embodiment. The collision mode of the composite material pipe constituting the shock absorbing member according to the fourth embodiment will be described. The collision mode of the composite material pipe constituting the shock absorbing member according to the fifth embodiment will be described. It is a figure which shows the layered structure which constitutes the block body of a modification. It is a figure which shows the layered structure which constitutes the block body of a modification. It is a figure which shows the layered structure which constitutes the block body of a modification.

Hereinafter, various embodiments according to the present invention will be described with reference to the drawings.

<First Embodiment>
Hereinafter, the cask provided with the shock absorber according to the first embodiment of the present invention will be described with reference to FIGS. 1 to 9.
As shown in FIG. 1, the cask 100 is composed of a transport container 10 and a pair of buffers 20.

The transport container 10 has a container body 10a having a cylindrical shape. The container body 10a has a cylindrical shape extending along the central axis O1, and both ends in the direction of the central axis O1 are closed. One end of the container body 10a in the central axis O1 direction is openable and closable. The spent nuclear fuel 11 containing radioactive substances is housed inside the container body 10a. The spent nuclear fuel 11 is housed by opening one end of the container body 10a, and the one end is closed during transportation. As a result, the inside of the container body 10a is sealed during transportation.

The shock absorber 20 includes a casing 30 and a shock absorbing means 40.
The casing 30 is a disk-shaped member centered on the central axis O1, and the inside is formed in a hollow shape. A pair of casings 30 are provided at both ends of the central axis O1 of the transport container 10. On the surface of the casing 30 facing the transport container 10, recesses 31 into which both ends of the transport container 10 are fitted are formed. By fitting the end portions of the transport container 10 into the recess 31 of the casing 30, both ends of the transport container 10 are protected against loads from the central axis O1 direction and the radial direction of the central axis O1.

The internal space of the casing 30 is an annular space 32 in which the portion of the recess 31 formed in the central axis O1 direction forms an annular shape, and the outer portion of the casing 30 further in the central axis O1 direction is a disk-shaped space 33. It is said that.

The shock absorbing means 40 includes a first shock absorbing member 40A and a second shock absorbing member 40B. The first shock absorbing member 40A is filled in the disk-shaped space 33 in the casing 30. Any configuration can be adopted as the first shock absorbing member 40A. The second impact absorbing member 40B is housed in the annular space 32 in the casing 30. Hereinafter, the second impact absorbing member 40B to which the present invention is applied is simply referred to as a shock absorbing member 40B.

Hereinafter, the shock absorbing member 40B will be described with reference to FIGS. 2 to 4.
As shown in FIG. 2, the shock absorbing member 40B is an annular member centered on the central axis O1 and is attached to the outer periphery at both ends of the transport container 10 via the casing 30. The shock absorbing member 40B is composed of a plurality of block bodies 50.

As shown in FIG. 3, the block body 50 is configured by densely bundling a plurality of composite material pipes 60. The block body 50 has a trapezoidal shape when viewed from the central axis O1 direction, and has a thickness in the central axis O1 direction while maintaining the shape.

The overall configuration of the composite material pipe 60 will be described.
As shown in FIG. 4, the composite material pipe 60 is a hollow tubular member that extends with a constant diameter and has a hollow portion 60h (vacancy).
In the present embodiment, the composite material pipe 60 has a circular shape in a cross section perpendicular to the pipe axis O2 direction.

The composite material pipe 60 is formed of a reinforced plastic containing fibers 62 as reinforcing fibers with a resin 61.

Specifically, the composite material tube 60 is formed of an FRP sheet in which continuous fibers are impregnated with a plastic resin. The FRP sheet is made of, for example, CFRP, GFRP, or the like.

Here, the continuous fiber includes not only a completely continuous fiber but also a fiber having a length of 100 mm or more, one circumference or more in the tube circumferential direction, or a length similar to the length between both ends in the tube axial direction.

The fiber 62 is CF (carbon fiber), GF (glass fiber), aramid, other organic fibers and the like. CF and GF are preferable, and CF is more preferable.

The resin 61 is a curable resin or a plastic resin.
Examples of the curable resin include phenol resin, epoxy resin, unsaturated polyester resin, polyimide resin, melamine resin and the like.
Examples of the thermoplastic resin include polyphenylene sulfide (PPS), polyethersulfone (PES), polyetherimide (PEI), polyetheretherketone (PEEK), polyetherketone (PEK), polyetherketoneketone (PEKK), and polyketone. Examples thereof include sulphide (PKS), polyetheretherketone (PAEK), aromatic polyamide (PA), polyamideimide (PAI), and polyimide (PI).
From the viewpoint of energy absorption, a resin having excellent toughness is preferable. Epoxy resin is preferable in terms of heat resistance and cost.

The composite material tube 60 is configured so that the fiber volume content in the composite material is 40% or more, preferably 50% or more, and more preferably 55% or more.

The composite material pipe 60 is formed by laminating such FRP sheets while winding them in a tubular shape.

In the composite material tube 60, the sum of the axial contribution rate (contribution rate in the tube axis O2 direction) and the circumferential contribution rate (contribution rate in the tube circumferential direction) is 100% with respect to the orientation direction of the reinforcing fibers. When this is done, the axial contribution ratio is configured to be 20% to 90%. In other words, the composite material pipe 60 is configured so that the circumferential contribution ratio is 10% to 80%.
Here, the axial contribution ratio refers to the axial component of the tube in all the fibers when the orientation direction of each fiber is divided into a tube axial component and a tube circumferential component according to a triangular function and the orientation of all the fibers is considered. It is the ratio of the total amount.
Similarly, the circumferential contribution ratio is the tube circumferential direction in all fibers when the orientation direction of each fiber is divided into a tube axial component and a tube circumferential component according to a triangular function and the orientation of all fibers is considered. It is the ratio of the total amount of ingredients.

In the composite material pipe 60, the axial contribution ratio is 20% to 90%, preferably 25% to 80%, more preferably 37.5% to 75%, still more preferably 50% to 70%. Most preferably, it is 55% to 65%.
In other words, in the composite material pipe 60, the circumferential contribution ratio is 10% to 80%, preferably 20% to 75%, more preferably 25% to 62.5%, still more preferably 30% to 30%. It is 50%, most preferably 35% to 45%.

In the case of the present embodiment, the orientation direction of the reinforcing fibers of the composite material pipe 60 is configured so that the axial contribution ratio is 60%.

The composite material pipe 60 is configured to have a porosity of 40% to 87%.
Here, the porosity is the cross-sectional area of the inner circumference of the composite material pipe 60 (cross-sectional area of the hollow portion) in the cross section perpendicular to the pipe axis of the composite material pipe 60 divided by the cross-sectional area of the outer circumference of the composite material pipe 60. It is the value that was set.

The porosity of the composite material pipe 60 is 40% to 87%, preferably 40% to 81%, more preferably 44% to 77%, and most preferably 49% to 59%.

The wall thickness t of the composite material pipe 60 is preferably 1 mm or more, more preferably 2 mm or more, further preferably 3 mm or more, and most preferably 4 mm or more.

In the case of the present embodiment, the composite material pipe 60 has an outer diameter of φ = 30 mm and a wall thickness of t = 4 mm. As a result, the porosity of the composite material pipe 60 is configured to be 54%. However, it is not limited to this dimension and porosity.

Each layer of the composite material pipe 60 will be described in detail.
As shown in FIG. 5, the composite material pipe 60 has an outer layer 63, an intermediate layer 64, and three identical laminated layers in order from the outside in the radial direction of the pipe shaft O2 (hereinafter, also referred to as “pipe radial direction”). The inner layer 65 is provided.

Here, the same laminated layer refers to a laminated portion in which one or more layers of the same material are laminated in the same fiber orientation direction, and for example, one or more layers in which a certain unidirectional material is oriented at 90 ° are laminated. In the case, it is counted as one regardless of the number of layers.
Further, as a method of counting the layers, the number of layers overlapping in the wall thickness direction may be considered, and even if the layers are continuously connected in the circumferential direction (in a spiral shape), the overlapping in the wall thickness cross section may be considered.
The number of layers in the same laminated layer is preferably one or more, preferably two or more, more preferably three or more, and most preferably four or more.

Each of the outer layer 63, the intermediate layer 64, and the inner layer 65 has the shape of a hollow tube extending with a constant diameter in the extending direction (tube axis O2 direction) of the composite material tube 60, respectively.
Each of the outer layer 63, the intermediate layer 64, and the inner layer 65 is composed of laminated FRP sheets.

The intermediate layer 64 is laminated so as to cover the outer periphery of the inner layer 65. The outer layer 63 is laminated so as to cover the outer periphery of the intermediate layer 64. By being laminated in this way, the outer layer 63, the intermediate layer 64, and the inner layer 65 are integrally formed as a composite material pipe 60.

In the case of the present embodiment, as shown in FIG. 6, the fiber 62 of the intermediate layer 64 is composed of only the first reinforcing fiber 62a whose orientation direction with respect to the tube axis O2 direction is −20 ° to + 20 °. Specifically, the intermediate layer 64 is formed by laminating a plurality of FRP sheets in which the fibers 62 are only the first reinforcing fibers 62a.

In the intermediate layer 64, the orientation direction of the first reinforcing fiber 62a is −20 ° to + 20 ° in the above, but is preferably −10 ° to + 10 °, more preferably −5 ° to + 5 °, and even more preferably. Is -2 ° to + 2 °, most preferably 0 °.

As shown in FIG. 7, the fiber 62 of the outer layer 63 is composed of only the second reinforcing fiber 62b whose orientation direction with respect to the tube axis O2 direction is + 70 ° to + 110 °. Specifically, the outer layer 63 is formed by laminating a plurality of FRP sheets in which the fibers 62 are only the second reinforcing fibers 62b.
Similarly, in the inner layer 65, the fiber 62 is composed of only the second reinforcing fiber 62b whose orientation direction with respect to the tube axis O2 direction is + 70 ° to + 110 °. Specifically, the inner layer 65 is formed by laminating a plurality of FRP sheets in which the fibers 62 are only the second reinforcing fibers 62b.
It is preferable that the number of layers of the outer layer 63 and the number of layers of the inner layer 65 are the same.

In the outer layer 63 and the inner layer 65, the orientation direction of the second reinforcing fiber 62b is + 70 ° to + 110 ° in the above, but is preferably + 80 ° to + 100 °, more preferably + 85 ° to + 95 °, still more preferably. It is set to + 88 ° to + 92 °, most preferably 90 °.

The wall thickness of each of the same laminated layers may be different, but it is preferable that the layers are arranged line-symmetrically in the direction of the surface layer of the wall thickness when viewed from the center line of the wall thickness.

The layer of the reinforcing fibers having an orientation direction of −20 ° to + 20 ° may be any of the outer layer 63, the intermediate layer 64, and the inner layer 65, but the intermediate layer 64 is preferable.
The layer made of reinforcing fibers having an orientation direction of + 70 ° to + 110 ° may be any of the outer layer 63, the intermediate layer 64, and the inner layer 65, but the outer layer 63 and the inner layer 65 are preferable.

The number of the same laminated layers is not particularly limited because the number can be increased as the wall thickness becomes thicker, but it is preferable that the number is three or more and the number is small. For example, about 3 to 11, preferably about 3 to 7, is preferable.

When a prepreg material is used as the laminated material for forming each layer, the thickness of the prepreg material is preferably thin, for example, 0.25 mm or less, more preferably 0.125 mm or less. Further, a multi-layer prepreg in which a thinner prepreg is pre-laminated may be used, and in this case, a multi-layer prepreg in which a thin prepreg such as 0.05 mm is pre-laminated is preferable.

The block body 50 is composed of such a composite material pipe 60. At least one of the composite material pipes 60 constituting the block body 50 is arranged parallel to the radial direction of the central axis O1. In the present embodiment, in each block body 50, the composite material pipe 60 arranged at the center in the width direction (the center in the circumferential direction of the central axis O1) which is the arrangement direction of the composite material pipe 60 is in the radial direction of the central axis O1. They are arranged in parallel, and the other composite material pipes 60 are arranged so as to be parallel to the composite material pipe 60. In the process of manufacturing the block body 50, a plurality of composite material pipes 60 are simply arranged so as to be parallel to each other, and in the process of forming the annular shock absorbing member 40B by assembling the block body 50, among them. One of the composite material pipes 60 is arranged parallel to the central axis O1.

The block body 50 has a shape in which both ends in the width direction are diagonally cut out when viewed from the central axis O1 direction. That is, both ends of the block body 50 are cut off diagonally toward the center of the block body 50 from the radial outside to the inside of the central axis O1.
In the present embodiment, the block body 50 is formed by adhering a plurality of composite material pipes 60 to each other with an adhesive. If the composite material pipes 60 are bonded to each other without a gap, the composite material pipes 60 may be bonded by means other than the adhesive.

By arranging such block bodies 50 so as to face each other at both ends in the width direction, the shock absorbing member 40B forming an annular shape is configured. That is, by sequentially arranging the block bodies 50 having a trapezoidal shape in the axial direction in the width direction of the block bodies 50, an annular shock absorbing member 40B having a shape close to a circle as a whole is configured. ..

The block body 50 may be accommodated and held by the casing 30 to form an annular shock absorbing member 40B formed by the plurality of block bodies 50, or the widthwise ends of the block bodies 50 may be adhered to each other. An annular shock absorbing member 40B may be configured by being joined with an agent or the like.

Next, the manufacturing method of the shock absorbing member 40B of the present embodiment will be described with reference to the flowchart shown in FIG. The manufacturing method includes a tube manufacturing process S1, a block body manufacturing process S2, and an assembly step S3.

In the pipe manufacturing step S1, the composite material pipe 60 described above is manufactured. The composite material tube 60 is manufactured by winding an FRP sheet in multiple layers to form a tube shape. At this time, the FRP sheet A in which the fiber 62 is only the first reinforcing fiber 62a and the FRP sheet B in which the fiber 62 is only the second reinforcing fiber 62b are wound in multiple layers.
For example, the FRP sheet B is wound on a plurality of layers (or one layer) to form an inner layer 65, then the FRP sheet A is wound on a plurality of layers (or one layer) to form an intermediate layer 64, and the FRP sheet B is further wound on a plurality of layers. It is wound around (or one layer) to form the outer layer 63.

After the tube manufacturing step S1, the block body manufacturing step S2 is executed. More specifically, the block body manufacturing step S2 includes two steps, a step of integrating the composite material pipe 60 and a step of partially cutting.
First, a large number of composite pipes 60 are densely packed with an adhesive so as to be parallel to each other, and bundled together. At this time, the plurality of composite material pipes 60 are overlapped not only in the circumferential direction of the shock absorbing member 40B but also in the central axis O1 direction. Next, both ends of the bundled composite material pipes 60 in the arrangement direction (both ends in the circumferential direction of the shock absorbing member 40B) are cut off diagonally in a plane. As a result, the block body 50 is manufactured.

After the block body manufacturing step S2, the assembly step S3 is performed. This assembly step S3 is a step of assembling the annular shock absorbing member 40B as a whole by facing the end faces of the manufactured plurality of block bodies 50 in the width direction. As described above, the annular shock absorbing member 40B may be formed by accommodating each block body 50 in the casing 30, or the shock absorbing member 40B may be formed by joining the block bodies 50 to each other. May be good.

Next, the action and effect of the shock absorbing member 40B, the shock absorber 20 and the cask 100 having the above configuration will be described.

It is assumed that an external force is applied to the shock absorber 20 from the radial outside of the central axis O1 during transportation of the cask 100. In the present embodiment, the composite material pipe 60 constituting the shock absorbing member 40B inside the shock absorber 20 extends in the radial direction of the central axis O1. Therefore, the composite material pipe 60 can exhibit high impact absorption performance. That is, since the composite material pipe 60 has the fiber 62 composed of the first reinforcing fiber 62a and the second reinforcing fiber 62b, the impact on the load from the extending direction (pipe axis O2 direction) of the composite material pipe 60 is effective. Can be absorbed.
In addition, "extending in the radial direction of the central axis O1" includes not only a state of extending in parallel with the radial direction but also a case of extending with a slight inclination.

Here, if the fiber 62 of the composite material pipe 60 is only the second reinforcing fiber 62b, when a large load is applied from the radial outside of the central axis O1 in the direction of the pipe axis O2, the impact is sufficiently absorbed. The composite material pipe 60 itself buckles and breaks in some cases. That is, since there is no fiber 62 that opposes the load in the pipe axis O2 direction of the composite material pipe 60, the strength is inevitably insufficient.
Further, the load that cannot be completely absorbed acts on the surrounding composite material pipes 60, so that the surrounding composite material pipes 60 are also damaged. In this case, since the load is applied to the surrounding composite material pipe 60 from an unexpected direction, the impact absorption performance cannot be exhibited.

On the other hand, if the fiber 62 of the composite material pipe 60 is only the first reinforcing fiber 62a, the composite material pipe 60 is easily torn in the pipe axis O2 direction according to the orientation direction of the first reinforcing fiber 62a, which is also sufficient. Cannot absorb the impact. In this case as well, a load acts on the surrounding composite material pipes 60 as described above, and the surrounding composite material pipes 60 are damaged without exhibiting the impact absorption performance.

On the other hand, in the present embodiment, the fiber 62 of the composite material pipe 60 has the first reinforcing fiber 62a and the second reinforcing fiber 62b. Therefore, when a large load is applied in the direction of the pipe shaft O2, the split portions are restrained by the second reinforcing fiber 62b while being split in the direction of the pipe shaft O2, so that the impact is absorbed based on the binding force. The destruction mode such as separation is shown. Therefore, in the process of tearing according to the first reinforcing fiber 62a, the binding force generated by the second reinforcing fiber 62b is generated, so that the load in the pipe axis O2 direction is effectively absorbed in the process of breaking the composite material pipe 60. From the above, according to the present embodiment, the load from the radial outside of the central axis O1 can be effectively absorbed.

In the present embodiment, the composite material pipe 60 includes an intermediate layer 64, and an outer layer 63 and an inner layer 65 that cover the outer and inner sides of the intermediate layer 64 in the axial direction, respectively.
Therefore, when a large load is applied in the direction of the pipe axis O2, the intermediate layer 64 including the first reinforcing fiber 62a first opposes the load. Even if a load is further applied and the composite material pipe 60 is destroyed, the split portions of the outer layer 63 and the inner layer 65 are restrained while being split, so that the separation and peeling of each layer is suppressed.
Further, as shown in FIG. 9, in the present embodiment, when the composite material pipe 60 is broken, the inner layer 65 becomes crushed waste separated in the pipe radial direction while being torn in the pipe axis O2 direction. At this time, since the composite material pipe 60 has a hole (hollow portion 60h), the crushed waste is contained in the hole of the composite material pipe 60 while being curled. In particular, in the present embodiment, since the composite material pipe 60 has pores having a porosity of 40% to 87%, curled crushed debris can be accommodated in the pores.
Therefore, it is possible to suppress the component force of the load applied to the composite material pipe 60 from the direction of the pipe shaft O2 from acting in an unexpected direction. Therefore, it is possible to avoid breakage and buckling of the composite material pipe 60. That is, it is possible to avoid a fracture mode in which the impact due to the load cannot be completely absorbed.

Further, the composite material pipe 60 has a circular shape in a cross section perpendicular to the pipe axis O2 direction. Therefore, even if a large number of the plurality of composite material pipes 60 are closely arranged, a gap is formed between the composite material pipe 60 and the surrounding composite material pipe 60. Therefore, when the composite material pipe 60 is destroyed, the outer layer 63 also becomes crushed waste curled outward in the pipe radial direction, the composite material pipe 60 is accommodated in a gap in the periphery, and the composite material pipe 60 is broken or buckled. You can avoid bending.

In the present embodiment, the shock absorbing member 40B is composed of a plurality of block bodies 50, and each block body 50 is configured such that a plurality of composite material pipes 60 are densely packed in parallel. As a result, high impact absorption performance can be realized while suppressing the manufacturing cost.

For example, if all the composite material pipes 60 are arranged radially so as to be parallel to the radial direction of the central axis O1 of the buffer body 20, the composite material pipes 60 are arranged radially outward of the central axis O1. A gap that spreads to the extent is formed.
If the gap is formed in this way, a component force acts in the direction of widening the gap between the composite material pipes 60 due to the load from the radial outside of the central axis O1. As described above, each composite pipe 60 exhibits the most impact absorbing capacity with respect to the load in the extending direction. However, if the load is dispersed in the other direction, the composite material pipe 60 will buckle or break, and the impact absorbing capacity cannot be exhibited. Therefore, the shock absorbing capacity of the shock absorber 20 as a whole is lowered.

On the other hand, in the present embodiment, the composite material pipes 60 are densely arranged in parallel with each other in each block body 50. Therefore, the gap between the composite material pipes 60 does not become large only in the portion outside the radial direction of the central axis O1. Therefore, it is possible to avoid inadvertent expansion of the gap between the composite material pipes 60. Further, by avoiding the expansion of the gap, it is possible to suppress the component force of the load from the radial outside of the central axis O1 from acting in an unexpected direction. Therefore, it is possible to avoid breakage and buckling of the surrounding composite material pipe 60. That is, it is possible to avoid a fracture mode in which the impact due to the load cannot be completely absorbed.

Further, for example, when the composite material pipes 60 are arranged radially, a special jig for adjusting the position is required. In addition, labor such as forming the composite material pipe 60 in a tapered shape is required, which increases the cost. On the other hand, in the present embodiment, since the composite material pipes 60 may be simply bundled in parallel, the manufacturing cost can be reduced.

Further, in the present embodiment, both ends of the block body 50 in the circumferential direction are diagonally cut out along the radial direction of the central axis O1, so that the block bodies 50 are sequentially arranged in the circumferential direction. By doing so, the shock absorbing member 40B forming an annular shape can be easily configured.
Further, since the block body 50 is configured by joining the composite material pipes 60 to each other with an adhesive, the block body 50 can be easily manufactured.

<Second embodiment>
Next, the second embodiment of the present invention will be described with reference to FIG. In the second embodiment, the same components as those in the first embodiment are designated by the same reference numerals, and detailed description thereof will be omitted.
In the block body 50 of the first embodiment, a plurality of composite material pipes 60 are joined with an adhesive to be densely packed and integrated. On the other hand, in the block body 150 of the second embodiment, a plurality of composite material pipes 60 are densely packed and integrated by the embedded member 160.

The embedded member 160 is made of, for example, foamed resin, wood, a porous material, or the like, and by embedding a plurality of composite material pipes 60, these composite material pipes 60 are densely packed and integrated with each other in parallel. .. The embedded member 160 may be made of a material other than the above.
When the embedded member 160 is a foaming resin, a storage space may be formed in the foaming resin while embedding the composite material pipe 60 in the foaming resin, or after the composite material pipes 60 are assembled in parallel with each other, between them. It may be formed by supplying a foaming resin and solidifying it. Further, when the embedded member 160 is made of wood, a hole for accommodating the composite material pipe 60 may be formed in advance, and the composite material pipe 60 may be installed by fitting the composite material pipe 60 into the hole.

Even when the block body 150 of the second embodiment is used, the shock absorbing member 40B forming an annular shape as a whole is configured by arranging a plurality of the block bodies 150 as in the first embodiment. Therefore, it has the same effect as that of the first embodiment.

<Third embodiment>
Next, the third embodiment of the present invention will be described with reference to FIGS. 11 to 14. In the third embodiment, the same components as those in the first embodiment are designated by the same reference numerals, and detailed description thereof will be omitted.
In the plurality of composite material pipes 60 of the first embodiment, in order to avoid breakage and buckling of the composite material pipe, at least holes having a pore ratio of 40% to 87% are provided in the composite material pipe, and the composite material pipe is provided with holes. It suppresses the component force of the applied load from the pipe axis direction from acting in an unexpected direction.
On the other hand, the composite material pipe 560 of the third embodiment has a point that the end faces of the composite material pipe 560 have a plurality of valleys lined up in the circumferential direction in order to avoid breakage and buckling of the composite material pipe. It's different.

An example in which the composite material pipe 560 is applied to the transport container 10 is shown.
As shown in FIG. 11, the cask 500 includes a transport container 10 and a pair of shock absorbers 520.
The shock absorber 520 includes shock absorbing means 540.
The shock absorbing means 540 includes a first shock absorbing member 540A and a second shock absorbing member 540B.

The first shock absorbing member 540A is provided at each end of both the central axis O1 of the container body 10a. In the present embodiment, the first shock absorbing member 540A is mounted on the bottom surface of the container body 10a having a cylindrical shape. Any configuration can be adopted as the first shock absorbing member 540A.

The second impact absorbing member 540B is provided at each end of both the central axis O1 of the container body 10a. Hereinafter, the second impact absorbing member 540B to which the present invention is applied is simply referred to as a shock absorbing member 540B.

Hereinafter, the shock absorbing member 540B will be described.
The shock absorbing member 540B is an annular member centered on the central axis O1 and is attached to the outer periphery at both ends of the container body 10a.
The shock absorbing member 540B includes a plurality of composite material pipes 560. The plurality of composite material pipes 560 have end faces 560e at both ends in the pipe axial direction.
A plurality of composite material pipes 560 are arranged to form an annular shock absorbing member 540B as a whole. In that case, each composite material pipe 560 is attached to the container body 10a so that its end face 560e faces the collision target. Specifically, each composite material pipe 560 is attached to the container body 10a so that its end surface 560e faces the radial outer side of the container body 10a.

The overall configuration of the composite material pipe 560 will be described.
The composite material tube 560 is composed of a composite material containing continuous reinforcing fibers and a resin.
The composite material pipe 560 is formed of a reinforcing fiber plastic containing the fiber 562 as a reinforcing fiber by the resin 561. Specifically, the composite material tube 560 is formed of an FRP sheet in which continuous fibers are impregnated with a plastic resin. The FRP sheet is made of, for example, CFRP, GFRP, or the like.

The fiber 562 is a material similar to the fiber 62 of the first embodiment, that is, CF (carbon fiber), GF (glass fiber), aramid, other organic fibers and the like. CF and GF are preferable, and CF is more preferable.

The resin 561 is the same material as the resin 61 of the first embodiment.

The composite material pipe 560 is configured so that the fiber volume content in the composite material is 40% or more, preferably 50% or more, and more preferably 55% or more.

As shown in FIG. 12, the end face 560e of the composite material pipe 560 has a plurality of valleys 560v arranged in the pipe circumferential direction of the composite material pipe 560. As shown in FIG. 12, each valley 560v is concave in the pipe axis O2 direction.
In the present embodiment, the end face 560e of the composite material pipe 560 has a mountain 560 m between the valleys 560v and the valleys 560v which are arranged adjacent to each other in the pipe circumferential direction. As shown in FIG. 12, each mountain 560 m is convex in the pipe axis O2 direction.
Further, as shown in FIG. 12, both the valley 560v and the peak 560m have a V-shape.

Next, the action and effect of the composite material pipe 560 will be described.
The composite material pipe 560 of the present embodiment has a plurality of valleys 560v arranged in the pipe circumferential direction. Therefore, not only when the load is applied along the pipe axis O2 direction, but also when the load is applied diagonally with respect to the pipe shaft O2 direction, the composite material pipe 560 has the pipe shaft O2 as a starting point from the plurality of valleys 560v. Multiple cracks that extend occur. The plurality of cracks occur along the dotted line shown in FIG.
Therefore, the composite material pipe 560 expresses a fracture mode (Spraying Mode) that absorbs an impact while being split in the pipe axis O2 direction and becoming a plurality of crushed debris spreading outward in the pipe radial direction.
In this case, the load applied to the composite pipe 560 is divided in the circumferential direction of the pipe so as to generate a plurality of cracks. Therefore, it is possible to avoid the breakage and buckling of the composite material pipe 560. That is, it is possible to avoid a fracture mode in which the impact due to the load cannot be completely absorbed.

The number of valleys 560v in the composite material pipe 560 of the present embodiment may be any number, but it is preferable that the number is large to some extent.
As shown in FIG. 13, consider the case where the composite material pipe 560 collides with the collision target OBJ (for example, the floor) in an oblique posture with respect to the pipe axis O2 direction. In this case, any one of the composite pipes 560, 560 m (circle ○ shown in FIG. 13), first collides with the collision target OBJ.
As the number of valleys 560v increases, the size of one mountain 560m becomes smaller and the load capacity also becomes smaller. Therefore, as the number of valleys 560v increases, the initial load of the composite material pipe 560 decreases, and the Spraying Mode is more likely to be expressed.
Therefore, the larger the number of valleys 560v, the more the breakage and buckling of the composite material pipe 560 can be avoided.
The amount of energy absorbed by the composite material pipe 560 is constant regardless of the number of valleys 560v.

In the present embodiment, the composite material pipe 560 is composed of a composite material containing continuous reinforcing fibers and a resin.
As a modification, the composite material pipe 560 may be configured by laminating FRP sheets while winding them in a tubular shape.
As another modification, the composite tube 560 has an axial contribution rate (which is the contribution rate in the tube axis O2 direction) and a contribution rate in the tube circumferential direction (contribution rate in the tube axis O2 direction) with respect to the orientation direction of the reinforcing fibers as in the first embodiment. It may be configured so that the axial contribution ratio is 20% to 90% when the sum with the circumferential contribution ratio is 100%. Further, in the composite material pipe 60, the axial contribution ratio is preferably 25% to 80%, more preferably 37.5% to 75%, further preferably 50% to 70%, and most preferably 55% to 65%. May be.
As yet another modification, the composite material pipe 560 may be configured to have a porosity of 40% to 87% as in the first embodiment.

In the present embodiment, the end face 560e of the composite material pipe 560 has a V-shaped (inverted V-shaped) mountain 560 m. As a modification, the end face 560e of the composite material pipe 560 does not have to have a mountain 560 m. As another modification, the mountain 560 m may have a U-shape (inverted U-shape) or a trapezoidal shape.

In the present embodiment, the composite material pipe 560 has end faces 560e at both ends in the pipe axial direction.
As a modification, if the composite pipe 560 can be loaded from either end in the pipe axial direction, the composite pipe 560 is directed toward the pipe circumferential direction on both end faces of both ends in the pipe axial direction. It may have a plurality of valleys lined up. Even in that case, there may be mountains between the valleys.

In the present embodiment, the composite material pipe 560 is individually attached to the container body 10a.
As a modification, as in the first and second embodiments, a plurality of blocks may be configured by the composite material pipe 560. For example, a plurality of blocks made of a composite material pipe 560 may be assembled to form an annular shock absorbing member 540B. Further, the annular shock absorbing member 540B may be formed by accommodating each block body in the casing, or the shock absorbing member 540B may be formed by joining the block bodies to each other.
As another modification, a plurality of composite material pipes 560 may be fixed to a ring member forming an annular shape centered on the central axis O1. In that case, a ring member to which a plurality of composite material pipes 560 are fixed is attached to the outer periphery at both ends of the container body 10a and acts as a shock absorbing member.

For example, as shown in FIG. 14, the method for manufacturing the shock absorbing member 540B using a plurality of blocks made of the composite material pipe 560 is the same as in the first embodiment, in the pipe manufacturing step S1', the block body. It includes the manufacturing process S2'and the assembly process S3'.

In the pipe manufacturing step S1', the composite material pipe 560 described above is manufactured. After forming the composite material into a pipe shape, the composite material pipe 560 is manufactured by forming a plurality of valleys 560v lined up in the pipe circumferential direction of the composite material pipe 560 on the end face 560e of the composite material pipe 560. .. At this time, the composite material pipe 560 may have a mountain 560 m between the valleys 560v and the valleys 560v that are lined up next to each other in the pipe circumferential direction.

After the tube manufacturing step S1', the block body manufacturing step S2'is executed. More specifically, the block body manufacturing step S2'includes two steps, a step of integrating the composite material pipe 560 and a step of partially cutting.
First, a large number of composite pipes 560 are densely packed with an adhesive so that the end faces 560e of the large number of composite pipes 560 are aligned on one side and the large number of composite pipes 560 are parallel to each other, and are bundled together. At this time, the plurality of composite material pipes 560 are overlapped not only in the circumferential direction of the shock absorbing member 540B but also in the central axis O1 direction. Next, both ends of the bundled composite material pipes 560 in the arrangement direction (both ends in the circumferential direction of the shock absorbing member 540B) are cut off diagonally in a plane. As a result, a block body similar to the block body 50 of the first embodiment is manufactured.

After the block body manufacturing step S2', the assembly step S3'is performed. This assembly step S3'is a step of assembling the annular shock absorbing member 540B as a whole by facing the end faces in the width direction of the manufactured plurality of blocks. In that case, the annular shock absorbing member 540B is assembled so that the end surface 560e of each composite material pipe 560 faces the radial outer side of the annular shock absorbing member 540B. Further, the annular shock absorbing member 540B may be formed by accommodating each block body in the casing, or the shock absorbing member 540B may be formed by joining the block bodies to each other.

<Fourth Embodiment>
Next, a fourth embodiment of the present invention will be described with reference to FIG. In the fourth embodiment, the same components as those in the third embodiment are designated by the same reference numerals, and detailed description thereof will be omitted.
In the fourth embodiment, the composite pipe 560 differs in that it has a cap.
As shown in FIG. 15, in this embodiment, the composite pipe 560 includes a cap 560c. The cap 560c covers the end face 560e of the composite material pipe 560. The bottom of the cap 560c is a recess. The cap 560c is fixed by covering the outside of the outer periphery of the end surface 560e of the composite material pipe 560. The cap 560c may be fixed to the end face 560e of the composite material pipe 560 by fitting, or may be fixed to the end face 560e of the composite material pipe 560 by adhesion, joining or the like.
In this embodiment, the cap 560c has the shape of a part of a spherical surface. Therefore, the plurality of ridges 560 m lined up in the circumferential direction of the pipe are all in contact with the inner surface of the cap 560c.

As shown in FIG. 15, consider a case where the composite material pipe 560 collides with the collision target OBJ (for example, the floor) in an oblique posture with respect to the pipe axis O2 direction. In this case, since the composite material pipe 560 has the cap 560c, when colliding with the collision target OBJ, the load is applied not only to one mountain 560 m but to a plurality of mountains 560 m. Further, when the cap 560c is present, the composite material pipe 560 and the collision target OBJ collide with each other at a position closer to the pipe axis O2 than when the cap 560c is not present.
Therefore, the load is distributed over the entire mountain and the pressure point approaches the center of the end face 560e of the composite material pipe 560.
Therefore, it is possible to further avoid the breakage and buckling of the composite material pipe 560.

The cap 560c is not limited to a partial spherical shape, but may have a dome shape such as a hemispherical shape or a bowl shape, or may have a cone shape or an umbrella shape. Further, it may have an intermediate shape between them. By having the cap 560c, the robustness against at least the impact load is improved in the composite material pipe 560.

<Fifth Embodiment>
Next, the fifth embodiment of the present invention will be described with reference to FIG. In the fifth embodiment, the same components as those in the third embodiment are designated by the same reference numerals, and detailed description thereof will be omitted.
The shock absorbing member of the fifth embodiment is different in that the roots of a plurality of composite material pipes 560 are attached to the container body 10a so that the pipes can hang down in the axial direction.

As shown in FIG. 16, in the present embodiment, each composite material pipe 560 is attached to the container body 10a at the root 560b of the composite material pipe 560 via the base 590, respectively. The root 560b of each composite pipe 560 is rotatably fixed to the base 590 by a pin 591.
The pin 591 penetrates the composite material pipe 560 together with the base 590 in the pipe radial direction of the composite material pipe 560. As a result, the composite material pipe 560 can rotate around the axis of the pin 591.

Since the composite material pipe 560 is rotatable around the axis of the pin 591, the composite material pipe 560 can be rotated so as to hang down in the pipe axis direction.
Therefore, at the time of falling, each composite material pipe 560 can have the end face 560e directed to the falling surface as much as possible.

A ball joint is provided between the base 560b and the base 590 of each composite material pipe 560 so that each composite material pipe 560 can rotate so as to hang down in the pipe axial direction in any direction. May be done. Compared with the case where the pin 591 is provided, the end surface 560e of each composite material pipe 560 can face the falling surface more freely at the time of dropping.

<Modification example>
In the above embodiment, the block body is formed into a trapezoidal shape when viewed from the central axis O1. However, the present invention is not limited to this, and for example, the block body may be configured to form a fan shape. In this case, the composite material pipes 60 and 560 may be densely packed and integrated in parallel with each other, and then cut to form a fan shape. Further, in the process of arranging the composite materials, the radial inner end portion and the radial outer end portion of the central axis O1 in the block body may form an arc shape.

In the above embodiment, the shock absorbing member having the composite material pipes 60 and 560 is applied to the second shock absorbing members 40B and 540B, but as a modification, the shock absorbing member having the composite material pipes 60 and 560 is the first. (1) It may be applied to the shock absorbing member 40A and 540A.

In the above embodiment, the casks 100 and 500 in which the shock absorbers 20 and 520 using the shock absorbing member are applied to the transport container 10 for transporting the spent nuclear fuel 11 have been described as an example. However, the present invention is not limited to this, and may be applied to anything that needs to avoid impact during transportation or installation, for example.
As a modification, the impact absorbing member or the shock absorber of the above embodiment may be provided on an object that collides with an object that needs to avoid being impacted during transportation or installation. For example, the shock absorbing member or the shock absorber of the above embodiment may be provided on the wall or floor around which the cask is transported, or on the floor or wall on which the cask is installed.

In the above embodiment, an example in which the second impact absorbing member 40B and 540B as the impact absorbing member are configured in an annular shape has been described, but the impact absorbing member does not necessarily have to be annular.

The shock absorbing member may be configured by laminating blocks in the direction of the central axis O1. At this time, the postures of the composite material pipes 60 and 560 in the blocks laminated to each other may be different from each other. Further, in the block bodies stacked on each other, the peripheral ends of the central axis O1 may be displaced from each other.
When a plurality of layers having a shape notched along the radial direction of the central axis O1 are laminated, the notched surfaces are not concentrated in one place by shifting the ends of each layer. Therefore, stress concentration can be avoided.

In the above embodiment, the block body has a shape in which both ends in the circumferential direction of the central axis O1 are cut out along the radial direction of the central axis O1.
As a modification, in a single layer or each layer having a shape cut out along the radial direction of the central axis O1, among the tubes constituting the layer, the long tube and the shorter short tube have different characteristics. A tube may be used. At that time, it is preferable to use a pipe having high shock absorption performance as the long pipe.

When the composite material tube 60 is used, the block bodies arranged in the circumferential direction are arranged and bundled in parallel with each other in a plane orthogonal to the central axis O1 as shown in FIGS. 17 to 19, for example. A plurality of layered structures 70 may be laminated in the direction of the central axis O1. At this time, as shown in FIGS. 17 to 19, the posture of the composite material pipe 60 may be different between the layer structures. Further, the peripheral end portions (left-right end portions of FIGS. 17 to 19) of each layered structure 70 may be offset from each other. By shifting the ends, the notch surface is not concentrated in one place, so that stress concentration can be avoided.
The same applies to the case of the composite material pipe 560.

Further, the block bodies may be laminated in the radial direction of the central axis O1 in which the load is applied. Further, the block bodies stacked in the radial direction of the central axis O1 may have different positions of the end portions in the circumferential direction of the central axis O1.

As a modification, the composite material pipes 60 and 560 may contain a plurality of materials having different characteristics.
As another modification, the composite material pipes 60 and 560 may be in the form of being stacked in a plurality of directions in the direction of absorbing impact energy.

As a modification, a porous body may be arranged in the hollow portions 60h and 560h of the composite material pipes 60 and 560.
As another modification, the composite pipes 60 and 560 may be configured to be double pipes or multiple pipes. Specifically, the composite material pipes 60 and 560 may further have a pipe-shaped member in the hollow portions 60h and 560h of the composite material pipes 60 and 560, and further pipes outside the outer shell of the composite material pipes 60 and 560. It may have a member having a shape. Further, when arranging a plurality of tube shapes in the above-mentioned shape, another material may be arranged between each tube shape (for example, between the outer tube and the inner tube).

In the above embodiment, the composite material pipe 60 has a layer of the first reinforcing fiber 62a and a layer of the second reinforcing fiber 62b as layers different in the pipe radial direction.
As a modification, the composite pipe 60 may further have different layers from all viewpoints such as grade, fiber type, orientation direction and the like.
For example, the composite material pipe 60 may have layers having different resin types from each other in the pipe radial direction.
Further, the composite material pipe 60 may have layers having different fiber grades from each other in the pipe radial direction.
Further, the composite material pipe 60 may have layers having different fiber types (CF, GF, etc.) from each other in the pipe radial direction.
Further, the composite material pipe 60 may have layers having different prepreg types (unidirectional material prepreg, woven prepreg, etc.) from each other in the pipe radial direction.
Further, the composite material tube 60 may be a hybrid of CFRP and GFRP.
The same applies when the layer of the first reinforcing fiber and the layer of the second reinforcing fiber are applied to the composite material pipe 560.

The shock absorbing member may further include a shock absorbing assisting member around the composite material pipes 60 and 560.
The shock absorbing auxiliary member arranged around the composite material pipes 60 and 560 includes, but is not limited to, metal, ceramic, resin, rubber, wood and the like as materials. The resin material includes, but is not limited to, acrylic, polypropylene, polystyrene, urethane, polyester, phenol, polyphenylsulfone, polyimide, polymethacrylicimide, and the like. For example, acrylic, special polyester, polymethacrylicimide, polyphenylsulfone and the like are preferable.
As the structure of the shock absorbing auxiliary member arranged around the composite material pipes 60 and 560, a porous structure (porous structure) or a perforated structure is preferable, and a porous structure is preferable.

The material of the porous body having a porous structure includes, but is not limited to, metal, ceramic, resin, rubber, wood and the like. The resin material includes, but is not limited to, acrylic, polypropylene, polystyrene, urethane, polyester, phenol, polyphenylsulfone, polyimide, polymethacrylicimide, and the like. Acrylics, special polyesters, polymethacrylicimides and polyphenylsulfone are preferred. As the wood, balsa wood, rice sugi wood and the like are preferable.
The porosity of the porous body is 40% to 95%, preferably 40% to 87%, more preferably 40% to 81%, still more preferably 44% to 70%, and most preferably 49% to 59. %.
The specific gravity of the porous body is preferably 0.05 to 0.6, and more preferably 0.1 to 0.2 or 0.2 to 0.4 depending on the necessity thereof.

In the above embodiment, the shock absorbing member forms an annular shape, and the composite material pipes 60 and 560 are arranged in the circumferential direction of the central axis O1 in a posture extending in the radial direction of the central axis O1 of the shock absorbing member.
In this way, when a plurality of composite material pipes 60 and 560 are collectively arranged in the same direction, the directions of the composite material pipes 60 and 560 may not be the same among the shock absorbing members.

For example, a case where the shock absorbing member is configured by laminating a plurality of blocks arranged in the circumferential direction of the central axis along the central axis will be illustrated.
In this case, the postures of the composite material pipes 60 and 560 may be different from each other among the block bodies laminated to each other.
By integrating single layers in different orientations, the directionality to the load becomes robust. The directional deviation width is preferably ± 10 °, more preferably ± 5 °, and most preferably ± 2 ° when the load direction is 0 °.
Further, the peripheral ends of the central axis O1 may be displaced from each other among the blocks stacked on each other.
By shifting the ends of each layer, it is possible to prevent the concentration of high-performance parts and low-strength parts periodically, and not only can uniform performance be obtained, but also when arranging adjacent blocks during assembly, they fit together. It becomes a shape and can prevent the assembly from shifting.

Similarly, the shock absorbing member is composed of a plurality of blocks arranged in the circumferential direction of the central axis O1, and the block bodies bundle the plurality of composite pipes 60 and 560 in a plane orthogonal to the central axis. An example will be given of a case where the layered structure is configured to include a layered structure in which a plurality of layers are laminated along the central axis O1.
In this case, the postures of the composite material pipes 60 and 560 may be different from each other among the layered structures laminated to each other.
By integrating single layers in different orientations, the directionality to the load becomes robust. The directional deviation width is preferably ± 10 °, more preferably ± 5 °, and most preferably ± 2 ° when the load direction is 0 °.
Further, the layered structures laminated to each other may have their peripheral ends of the central axis deviated from each other.
In this case as well, by shifting the ends of each layer, it is possible to suppress the concentration of high-performance parts and low-strength parts periodically, and not only can uniform performance be obtained, but also when arranging adjacent blocks during assembly. , It becomes a shape that fits each other, and it is possible to prevent the assembly from shifting.

The block bodies may be configured by stacking in the load direction.
By stacking the blocks, the size of each block can be reduced, the formability of the blocks can be improved, and the quality can be stabilized.
Further, by changing the characteristics of each block body, it is possible to control the destruction form and the order of destruction.
The size and shape of each block may be different, and the degree of freedom in design can be improved by changing the size and shape of the block for each layer in which the blocks are stacked.
Further, by shifting and stacking the block bodies, it is possible to suppress the concentration of high-performance parts and low-strength parts periodically, and obtain uniform performance.

In the above embodiment, the single-layer FRP sheet A is wound a plurality of times to form the inner layer 65, then the single-layer FRP sheet B is wound a plurality of times to form the intermediate layer 64, and the single-layer FRP sheet A is further wound. The composite material pipe 60 is formed by winding the outer layer 63 a plurality of times to form the outer layer 63.
As a modification, a single-layer FRP sheet A and a single-layer FRP sheet B may be stacked and wound a plurality of times (or once) to form a composite material tube, or a plurality of layers of the FRP sheet A and a plurality of layers. The composite material tube may be formed by stacking the FRP sheet B of the layer and winding it a plurality of times (or once). In this case, the composite material pipe 60 is a composite material pipe in which a single layer (or a plurality of layers) of the FRP sheet A and a single layer (or a plurality of layers) of the FRP sheet B are alternately laminated in the pipe radial direction.
As another modification, a composite material tube may be formed by simply winding the FRP sheet A having a plurality of layers a plurality of times (or once) and then winding the FRP sheet B having a plurality of layers. On the contrary, after winding the FRP sheet B having a plurality of layers, the FRP sheet A having a plurality of layers may be wound a plurality of times (or once) to form a composite material tube.
The same applies when the composite material pipe 560 is provided with an inner layer, an intermediate layer, and an outer layer.

In the above embodiment, the cross-sectional shape of the composite material pipes 60 and 560 is circular, but as a modification, it may be an elliptical shape, a polygonal shape (square, hexagon, etc.), and in addition, a hexagonal shape. The aggregate cross section of the composite material pipes 60 and 560 may be a honeycomb cross section, and is not limited thereto. From the viewpoint of shock absorption characteristics and moldability, a circular shape is preferable.

Although some embodiments of the present invention have been described above, these embodiments are presented as examples and are not intended to limit the scope of the invention. These embodiments can be implemented in various other embodiments, and various omissions, replacements, and changes can be made without departing from the gist of the invention. These embodiments and variations thereof shall be included in the scope of the invention described in the claims and the equivalent scope thereof, as well as in the scope and gist of the invention.

10 Transport container 11 Spent nuclear fuel 20 Cushioning body 30 Casing 31 Recessed 32 Circular space 33 Disc-shaped space 40 Impact absorbing means 40A First impact absorbing member 40B Second impact absorbing member (impact absorbing member)
50 Block body 60 Composite material pipe 60h Hollow part 61 Resin 62 Fiber 62a First reinforcing fiber 62b Second reinforcing fiber 63 Outer layer 64 Intermediate layer 65 Inner layer 70 Layered structure 100 Cask 150 Block body 160 Embedded member 500 Cask 520 Buffer 540 Shock absorbing means 540A First shock absorbing member 540B Second shock absorbing member (shock absorbing member)
560 Composite material pipe 560b Root 560c Cap 560e End face 560h Hollow part 560m Mountain 560v Valley 561 Resin 562 Fiber 590 Base 591 Pin S1 Pipe manufacturing process S2 Block manufacturing process S3 Assembly process S1'Pipe manufacturing process S2'Block manufacturing process S3' Assembly process OBJ Collision target O1 Central axis O2 Pipe axis

Claims (25)

It is composed of a composite material containing continuous reinforcing fibers and a resin, and has a composite material pipe having a pipe shape extending in the pipe axial direction.
The end faces of the composite material pipe are arranged in the pipe circumferential direction of the composite material pipe, and have a plurality of valleys concave in the pipe axis direction.
The end face of the composite material pipe has a plurality of peaks convex in the pipe axis direction between the plurality of valleys arranged adjacent to each other in the pipe circumferential direction.
The plurality of valleys and the plurality of peaks are all shock absorbing members having a V shape . The composite material pipe is configured by laminating the reinforcing fibers in the pipe radial direction.
The orientation direction of the reinforcing fibers is configured so that the axial contribution ratio is 20% to 90% when the sum of the axial contribution ratio and the circumferential contribution ratio is 100%.
The porosity of the composite material pipe in the cross section perpendicular to the pipe axis direction is 40% to 87%.
The composite material tube has 20% to 90% of the first reinforcing fibers having an orientation direction of −20 ° to + 20 ° with respect to the tube axis direction as the reinforcing fibers, and the orientation direction with respect to the tube axis direction is + 70 °. The shock absorbing member according to claim 1, which has 10% to 80% of the second reinforcing fiber of ~ + 110 °. The composite material pipe includes an outer layer, an intermediate layer, and an inner layer, which are the same laminated layer, in order from the outside in the pipe radial direction.
The shock absorbing member according to claim 2, wherein the outer layer and the inner layer are layers having the second reinforcing fiber, respectively. The orientation direction of the reinforcing fibers is configured so that the axial contribution ratio is 20% to 90% when the sum of the axial contribution ratio and the circumferential contribution ratio is 100%.
The shock absorbing member according to claim 1, wherein the composite material pipe has a porosity of 40% to 87% in a cross section perpendicular to the pipe axis direction. The shock absorbing member according to any one of claims 2 to 4, wherein the axial contribution ratio is 50% to 70%. The shock absorbing member according to any one of claims 1 to 5, wherein the composite material tube further includes a cap covering the end face. It is composed of a composite material containing continuous reinforcing fibers and a resin, and has a composite material pipe having a pipe shape extending in the pipe axial direction.
The end faces of the composite material pipe are arranged in the pipe circumferential direction of the composite material pipe, and have a plurality of valleys concave in the pipe axis direction.
The composite tube further comprises a cap covering the end face.
A shock absorbing member in which the cap has a partial shape of a spherical surface. The shock absorbing member according to any one of claims 1 to 7, further comprising a shock absorbing assisting member around the composite material pipe. The shock absorbing member according to claim 8, wherein the shock absorbing assisting member is a porous body having a porosity of 40% to 95%. Further provided with a base to which the root of the composite pipe is fixed,
The shock absorbing member according to any one of claims 1 to 9, wherein the root is fixed so that the tube axis can hang down from the base. The shock absorbing member according to any one of claims 1 to 10.
A buffer body in which a plurality of the composite material pipes are arranged together in the same direction. The shock absorbing member forms an annular shape,
The shock absorber according to claim 11, wherein the composite material pipes are arranged in the circumferential direction of the central axis in a posture extending in the radial direction of the central axis of the shock absorbing member. Equipped with a shock absorbing member,
The shock absorbing member is composed of a composite material containing continuous reinforcing fibers and a resin, and includes a composite material pipe having a pipe shape extending in the pipe axis direction.
The end faces of the composite material pipe are arranged in the pipe circumferential direction of the composite material pipe, and have a plurality of valleys concave in the pipe axis direction.
The shock absorbing member is configured by forming a plurality of the composite material pipes together and arranging them in the same direction.
The shock absorbing member forms an annular shape,
The composite material pipes are arranged in the circumferential direction of the central axis in a posture extending in the radial direction of the central axis of the shock absorbing member.
The shock absorbing member is composed of a plurality of blocks.
The block body is a buffer body including a plurality of the composite material tubes bundled in parallel. The buffer according to claim 13, wherein the plurality of blocks are arranged in the circumferential direction of the central axis. Equipped with a shock absorbing member,
The shock absorbing member is composed of a composite material containing continuous reinforcing fibers and a resin, and includes a composite material pipe having a pipe shape extending in the pipe axis direction.
The end faces of the composite material pipe are arranged in the pipe circumferential direction of the composite material pipe, and have a plurality of valleys concave in the pipe axis direction.
The shock absorbing member is configured by forming a plurality of the composite material pipes together and arranging them in the same direction.
The shock absorbing member forms an annular shape,
The composite material pipes are arranged in the circumferential direction of the central axis in a posture extending in the radial direction of the central axis of the shock absorbing member.
The shock absorbing member is configured by laminating a plurality of blocks arranged in the circumferential direction of the central axis along the central axis.
The block bodies laminated to each other are buffer bodies having different postures of the composite material pipes. The buffer body according to claim 15, wherein the end portions in the circumferential direction of the central axis are displaced from each other among the block bodies laminated to each other. Equipped with a shock absorbing member,
The shock absorbing member is composed of a composite material containing continuous reinforcing fibers and a resin, and includes a composite material pipe having a pipe shape extending in the pipe axis direction.
The end faces of the composite material pipe are arranged in the pipe circumferential direction of the composite material pipe, and have a plurality of valleys concave in the pipe axis direction.
The shock absorbing member is configured by forming a plurality of the composite material pipes together and arranging them in the same direction.
The shock absorbing member forms an annular shape,
The composite material pipes are arranged in the circumferential direction of the central axis in a posture extending in the radial direction of the central axis of the shock absorbing member.
The shock absorbing member is composed of a plurality of blocks arranged in the circumferential direction of the central axis.
The block body is configured to include a layered structure in which a plurality of the composite material pipes are bundled in a plane shape orthogonal to the central axis, and a plurality of layers are laminated along the central axis.
A buffer body in which the postures of the composite material pipes are different from each other among the layered structures laminated to each other. The buffer according to claim 17, wherein the peripheral ends of the central axes of the layered structures laminated to each other are displaced from each other. The buffer according to any one of claims 14 to 18, wherein the block body has a shape in which both ends in the circumferential direction of the central axis are cut out along the radial direction of the central axis. body. The buffer according to any one of claims 13 to 19, wherein a plurality of the composite material tubes constituting the block body are bonded to each other. The invention according to any one of claims 13 to 20, further comprising an embedded member that bundles the composite material pipes constituting the block body so as to be parallel to each other by embedding the composite material pipes. Buffer. The buffer body according to any one of claims 13 to 21, which is configured by laminating the block bodies in a direction in which a load is applied. The buffer according to any one of claims 13 to 22, which is configured by shifting and laminating the block bodies. The buffer according to any one of claims 12 to 23,
A cylindrical transport container extending along the central axis for accommodating radioactive substances inside is provided.
A cask in which the cushioning body is mounted on the outer periphery of the end of the transport container. It is a composite material pipe composed of a composite material containing continuous reinforcing fibers and a resin and having a pipe shape extending in the pipe axis direction, and the end face of the composite material pipe faces the pipe circumferential direction of the composite material pipe. A pipe manufacturing process for producing the composite material pipe having a plurality of valleys recessed in the pipe axis direction.
After the pipe manufacturing step, a block body manufacturing step of manufacturing a plurality of block bodies by bundling a plurality of the composite material pipes in parallel,
After the block body manufacturing step, an assembly step of connecting and assembling the ends of the plurality of composite material pipes in the block body in the arrangement direction to each other,
A method for manufacturing a buffer body.

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