JP2006166524A

JP2006166524A - Floater

Info

Publication number: JP2006166524A
Application number: JP2004351282A
Authority: JP
Inventors: Takayuki Kameshita; 孝之亀下; Masatoshi Nishida; 正敏西田
Original assignee: Furukawa Electric Co Ltd
Current assignee: Furukawa Electric Co Ltd
Priority date: 2004-12-03
Filing date: 2004-12-03
Publication date: 2006-06-22

Abstract

<P>PROBLEM TO BE SOLVED: To provide a floater for fixing a tubular section having buoyancy to the circumference of a pipe or a cable in which a floater of one size can be fixed to pipes or cables of broad size to some extent, and the kinds of size of the floater can be reduced. <P>SOLUTION: The tubular section 4 is formed in multilayer structure of a plurality of foamed synthetic resin layers wherein the innermost foamed synthetic resin layer is a low density foamed synthetic resin layer. For example, the tubular section has a three-layer structure where the innermost layer 6 is a low density foamed synthetic resin layer, the outermost layer 10 is a high density foamed synthetic resin layer, and the intermediate layer 8 is an intermediate density foamed synthetic resin layer having the middle density between those of the innermost layer and the outermost layer. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

本発明は、例えば浚渫用排砂管、浚渫用海上管等のパイプや、電力用ケーブル、通信用ケーブル等のケーブルを水面あるいは水中で浮遊させるために使用されるフロータに関する。 The present invention relates to a floater used for floating pipes such as dredged sand pipes and dredged marine pipes, and cables such as power cables and communication cables in the surface of water or in water.

浚渫工事時に排砂管や海上管を設置する場合、砂利、泥水等を効率よく排出移動させるために、鋼管、合成樹脂管等のパイプを用いて長尺のパイプラインを形成する。その際、パイプラインを浮遊させるために、一連式または二連式のパイプフロータをパイプに装着する（例えば、特許文献１参照）。 When dredging pipes and marine pipes are installed during dredging work, a long pipeline is formed using pipes such as steel pipes and synthetic resin pipes in order to efficiently discharge and move gravel and muddy water. At that time, in order to float the pipeline, a series or double pipe floater is attached to the pipe (for example, see Patent Document 1).

上述した二連式のフロータは、フロータで筏を形成し、その上にパイプラインを敷設するものであるため、フロータ自体は小径であるが、その使用数量が多くなったり、筏形成のための付属部材が必要となったりするため、汎用的に使用することは難しい。 The above-described double type floater forms a ridge with the floater and lays the pipeline on the float, so the floater itself has a small diameter, but its use quantity increases, Since attachment members are required, it is difficult to use them for general purposes.

一方、一連式のフロータは、パイプラインを形成する鋼管や合成樹脂管に直接装着するため、水没率によって外径は変動するものの、数量は比較的少量で済むほか、装着に要する部材も結束バンドだけで済むことから、二連式に比べると汎用的であると言える。 On the other hand, a series of floaters are directly attached to steel pipes and synthetic resin pipes forming the pipeline, so the outer diameter varies depending on the submergence rate, but the quantity is relatively small, and the members required for attachment are binding bands. Therefore, it can be said that it is more versatile than the double type.

上記一連式のフロータとしては、従来例えば図５に示すように、合成樹脂発泡体からなる内層５０の内周面および外周面に非発泡材料からなる表層５２を積層した半円筒形フロータ５４を、パイプの周囲に２個装着してパイプを水面あるいは水中で浮遊させるものがある。この場合、上記内層５０としては、回転成型製法により一体に成型されたものが多く使用されている。 As the series of floaters, as shown in FIG. 5, for example, a semi-cylindrical floater 54 in which a surface layer 52 made of a non-foamed material is laminated on the inner and outer peripheral surfaces of an inner layer 50 made of a synthetic resin foam, Some pipes are mounted around the pipe and float on the water surface or in water. In this case, as the inner layer 50, many are integrally formed by a rotational molding method.

実開平６−６１０６４号公報Japanese Utility Model Publication No. 6-61064

浚渫工事に使用する鋼管や合成樹脂管の径のサイズは、ＪＩＳ規格品だけでも数十種類あり、規格外の鋼管や合成樹脂管も含めると、そのサイズは百種類近くにまで及ぶ。また、それぞれの工事物件で使用する鋼管や合成樹脂管のサイズに合わせてパイプフロータも設計、製造するが、同一パイプライン内で異径管を接続する場合もある。 There are dozens of JIS standard products for the diameters of steel pipes and synthetic resin pipes used for dredging work. When non-standard steel pipes and synthetic resin pipes are included, the size reaches nearly 100 types. In addition, pipe floaters are designed and manufactured according to the size of steel pipes and synthetic resin pipes used in each construction property, but different diameter pipes may be connected in the same pipeline.

しかし、図５に示した従来のパイプフロータは、浮力を有する内層は全体が同一密度の一体成型品であり、最も内側の部分の柔軟性に乏しいので、１つのサイズのフロータを装着できるパイプのサイズの幅が小さい。そのため、従来のパイプフロータを使用する場合は、工事規模、浚渫船規模などにより様々となる鋼管や合成樹脂管のサイズに合わせて、数多くのサイズのパイプフロータが必要となるものであった。 However, in the conventional pipe floater shown in FIG. 5, the inner layer having buoyancy is an integrally molded product having the same density as a whole, and the innermost part is poor in flexibility. The size width is small. Therefore, when a conventional pipe floater is used, a large number of pipe floaters are required in accordance with the sizes of steel pipes and synthetic resin pipes, which vary depending on the construction scale and dredger scale.

本発明は、前述した事情に鑑みてなされたもので、１つのサイズのフロータをある程度幅広いサイズのパイプやケーブルに装着することでき、フロータのサイズ種の低減を図ることが可能なフロータを提供することを目的とする。 The present invention has been made in view of the above-described circumstances, and provides a floater that can attach a single size floater to pipes and cables of a wide range of sizes and can reduce the size of the floater. For the purpose.

本発明は、前記目的を達成するため、浮力を有する筒状部を備え、該筒状部をパイプまたはケーブルの周囲に装着してパイプまたはケーブルを水面もしくは水中で浮遊させるフロータであって、前記筒状部は複数の合成樹脂発泡体層が積層された多層構造を有し、かつ、前記複数の合成樹脂発泡体層のうちの最も内側の合成樹脂発泡体層は低密度の合成樹脂発泡体層であり、その外側の合成樹脂発泡体層のいずれもが前記低密度の合成樹脂発泡体層より密度の高い合成樹脂発泡体層であることを特徴とするフロータを提供する。 In order to achieve the above object, the present invention is a floater comprising a cylindrical portion having buoyancy, and mounting the cylindrical portion around a pipe or cable to float the pipe or cable in the water surface or in water, The cylindrical portion has a multilayer structure in which a plurality of synthetic resin foam layers are laminated, and the innermost synthetic resin foam layer among the plurality of synthetic resin foam layers is a low-density synthetic resin foam. The float is characterized in that any of the synthetic resin foam layers outside the layer is a synthetic resin foam layer having a higher density than the low density synthetic resin foam layer.

本発明のフロータは、筒状部の最も内側の部分に柔軟性に富んだ低密度の合成樹脂発泡体層を有するので、この低密度の合成樹脂発泡体層が幅広い径のサイズのパイプまたはケーブルの外周面によく追随する。そのため、本発明のフロータは、１つのサイズのものを幅広いサイズのパイプやケーブルに装着することできる。 Since the floater of the present invention has a low-density synthetic resin foam layer rich in flexibility at the innermost portion of the cylindrical portion, the low-density synthetic resin foam layer is a pipe or cable having a wide range of sizes. Follows the outer peripheral surface well. Therefore, the floater of the present invention can be attached to a wide range of pipes and cables of one size.

この場合、前述した低密度の合成樹脂発泡体層の見掛け密度は１８〜３０ｋｇ／ｍ^３、特に２０〜３０ｋｇ／ｍ^３であることが適当であり、これにより本発明の効果を確実に得ることができる。 In this case, the apparent density of the synthetic resin foam layer of low density mentioned above is 18~30kg / ^{m 3,} is suitably to be particularly 20-30 kg / ^{m 3,} to obtain thereby to secure the effect of the present invention Can do.

本発明に係るフロータの好ましい構造の一例としては、筒状部が３層の合成樹脂発泡体層が積層された構造を有し、かつ、最内層は低密度の合成樹脂発泡体層、最外層は高密度の合成樹脂発泡体層、中間層は最内層と最外層の中間の密度を有する中密度の合成樹脂発泡体層である構成が挙げられる。この構成のフロータによれば、幅広いサイズのパイプやケーブルへの追随性、良好な浮力、および優れた耐衝撃性を得ることができる。 As an example of a preferable structure of the floater according to the present invention, the cylindrical portion has a structure in which three synthetic resin foam layers are laminated, and the innermost layer is a low-density synthetic resin foam layer, the outermost layer. Is a high-density synthetic resin foam layer, and the intermediate layer is a medium-density synthetic resin foam layer having an intermediate density between the innermost layer and the outermost layer. According to the floater of this structure, followability to a wide range of pipes and cables, good buoyancy, and excellent impact resistance can be obtained.

上記３層構造のフロータにおいて、低密度の合成樹脂発泡体層（最内層）の見掛け密度は１８〜３０ｋｇ／ｍ^３、特に２０〜３０ｋｇ／ｍ^３、中密度の合成樹脂発泡体層（中間層）の見掛け密度は３０〜５０ｋｇ／ｍ^３、特に４５〜５０ｋｇ／ｍ^３、高密度の合成樹脂発泡体層（最外層）の見掛け密度は５０〜２００ｋｇ／ｍ^３、特に１１０〜１８０ｋｇ／ｍ^３であることが適当である（後述）。 In the above three-layer floater, the apparent density of the low-density synthetic resin foam layer (innermost layer) is 18 to ³⁰ kg / m ³ , particularly 20 to ³⁰ kg / m ³ , and the medium-density synthetic resin foam layer (intermediate layer) ) Has an apparent density of 30 to 50 kg / m ³ , particularly 45 to 50 kg / m ³ , and a high-density synthetic resin foam layer (outermost layer) has an apparent density of 50 to 200 kg / m ³ , particularly 110 to 180 kg / m ^3. (It will be described later).

本発明において、複数の合成樹脂発泡体層はそれぞれ独立気泡構造を有する合成樹脂発泡体からなることが好ましい。具体的には、架橋ポリエチレン発泡体、無架橋ポリエチレン発泡体、架橋ポリプロピレン発泡体、無架橋ポリプロピレン発泡体、架橋酢酸ビニル発泡体、無架橋酢酸ビニル発泡体またはこれらの複合構成体のような独立気泡構造を有する発泡体であることが好ましい。 In the present invention, each of the plurality of synthetic resin foam layers is preferably composed of a synthetic resin foam having a closed cell structure. Specifically, closed cells such as crosslinked polyethylene foam, uncrosslinked polyethylene foam, crosslinked polypropylene foam, uncrosslinked polypropylene foam, crosslinked vinyl acetate foam, uncrosslinked vinyl acetate foam, or composite structures thereof. A foam having a structure is preferable.

また、本発明のケーブル用フロータの好適な態様としては、後述する実施形態に示すように、例えば下記の態様が挙げられる。
（１）筒状部は、合成樹脂発泡体からなる四角形のシートをその側縁部を当接させて円筒状に巻き、さらにその周囲に１枚または複数枚の合成樹脂発泡体からなる四角形のシートをその側縁部を当接させて円筒状に巻いた構造を有する態様（図１参照、本明細書ではこのシートの巻き方を積巻きと称する）。
（２）筒状部は、合成樹脂発泡体からなる長尺のシートをらせん状に巻いて円筒状に形成し、さらにその周囲に１枚または複数枚の合成樹脂発泡体からなる長尺のシートをらせん状に巻いて円筒状に形成した構造を有する態様（図４参照）。 Moreover, as a suitable aspect of the cable floater of this invention, as shown in embodiment mentioned later, the following aspect is mentioned, for example.
(1) The cylindrical part is a rectangular sheet made of a synthetic resin foam and is wound into a cylindrical shape with its side edges abutting on each other, and a rectangular sheet made of one or more synthetic resin foams around it. A mode in which a sheet is wound into a cylindrical shape with its side edges abutted (see FIG. 1, in this specification, the method of winding the sheet is referred to as stacked winding).
(2) The cylindrical part is formed in a cylindrical shape by spirally winding a long sheet made of a synthetic resin foam, and a long sheet made of one or more synthetic resin foams around it. The aspect which has the structure formed by spirally winding the shape into a cylindrical shape (see FIG. 4).

ただし、筒状部は、最も内側の合成樹脂発泡体層が低密度の合成樹脂発泡体層、その外側の合成樹脂発泡体層のいずれもが上記低密度の合成樹脂発泡体層より密度の高い合成樹脂発泡体層となるように全体をブロック状に一体成型し、その結果として複数の合成樹脂発泡体層が積層された多層構造を持つようにしてもよい。 However, in the cylindrical portion, the innermost synthetic resin foam layer has a low density synthetic resin foam layer and the outer synthetic resin foam layer has a higher density than the low density synthetic resin foam layer. The whole may be integrally formed in a block shape so as to be a synthetic resin foam layer, and as a result, a multilayer structure in which a plurality of synthetic resin foam layers are laminated may be provided.

なお、本発明のフロータにおいて、合成樹脂発泡体層の厚さや層数に特に限定はなく、使用目的等に応じて適宜設定することができる。また、本発明のフロータのサイズに限定はないが、例えばパイプフロータとして使用する場合、内径を１６０ｍｍ〜９００ｍｍ、外径を３００ｍｍ〜１６００ｍｍ、長さを１３００ｍｍ以下とすることができる。 In addition, in the floater of this invention, there is no limitation in particular in the thickness and the number of layers of a synthetic resin foam layer, According to the intended purpose etc., it can set suitably. The size of the floater of the present invention is not limited. For example, when used as a pipe floater, the inner diameter may be 160 mm to 900 mm, the outer diameter may be 300 mm to 1600 mm, and the length may be 1300 mm or less.

以上のように、本発明のフロータは、１つのサイズのフロータによってある程度の幅のサイズのパイプやケーブルに対応することでき、フロータのサイズ種の低減を図ることが可能である。 As described above, the floater of the present invention can cope with pipes and cables having a certain width by using a single floater, and the size of the floater can be reduced.

次に、添付図面を参照して本発明の実施の形態を説明するが、本発明は下記例に限定されるものではない。図１は本発明に係るフロータの一例を示す斜視図、図２は同フロータの断面図、図３は同フロータをパイプに取り付けた状態を示す斜視図である。本例のフロータ２はパイプ用フロータとして使用されるものである。 Next, embodiments of the present invention will be described with reference to the accompanying drawings, but the present invention is not limited to the following examples. FIG. 1 is a perspective view showing an example of a floater according to the present invention, FIG. 2 is a sectional view of the floater, and FIG. 3 is a perspective view showing a state where the floater is attached to a pipe. The floater 2 of this example is used as a pipe floater.

本例のフロータ２の筒状部４は、見掛け密度の異なる合成樹脂発泡体シートを３種類使用し、これらを積巻きにより熱融着（接着でもよい、以下同じ）させて一体化させたもので、この筒状部４は具体的には次のようにして作製した。まず、低密度（高発泡倍率）の合成樹脂発泡体からなる四角形の最内層シート６をその側縁部（図示せず）を当接させて円筒状に巻き、次に円筒状に巻いた最内層シート６の周囲に中密度（中発泡倍率）の合成樹脂発泡体からなる四角形の中間層シート８をその側縁部（図示せず）を当接させて円筒状に巻き、熱融着により最内層シート６と一体化し、さらに円筒状に巻いた中間層シート８の周囲に高密度（低発泡倍率）の合成樹脂発泡体からなる四角形の最外層シート１０をその側縁部（図示せず）を当接させて円筒状に巻き、熱融着により中間層シート８と一体化することにより、筒状部４を作製した。その後、筒状部４に軸方向に沿って分割スリット１２を形成し、筒状部４を半円筒形に２分割してフロータ２を完成させた。本例のフロータ２は、図３に示すようにその１個または複数個を鋼管等のパイプ２０（図中２２はフランジを示す）の周囲に装着し、結束バンド３０で固定するものである。なお、最内層シート６の内周面あるいは最外層シート１０の外周面に合成樹脂シート等からなるカバー層を設けてもよい。 The cylindrical portion 4 of the floater 2 of this example uses three types of synthetic resin foam sheets having different apparent densities, and these are fused and integrated by stacking (may be bonded, the same applies hereinafter). The cylindrical portion 4 was specifically manufactured as follows. First, a rectangular innermost layer sheet 6 made of a synthetic resin foam having a low density (high expansion ratio) is wound into a cylindrical shape with its side edges (not shown) in contact with each other, and then rolled into a cylindrical shape. A rectangular intermediate layer sheet 8 made of a synthetic resin foam of medium density (medium expansion ratio) is wound around the inner layer sheet 6 in a cylindrical shape with its side edges (not shown) in contact with each other, and heat-sealed. A rectangular outermost layer sheet 10 made of a synthetic resin foam having a high density (low expansion ratio) is formed around the intermediate layer sheet 8 which is integrated with the innermost layer sheet 6 and wound in a cylindrical shape. ) Are brought into contact with each other, wound into a cylindrical shape, and integrated with the intermediate layer sheet 8 by thermal fusion to produce a cylindrical portion 4. Thereafter, the slits 12 were formed in the cylindrical part 4 along the axial direction, and the cylindrical part 4 was divided into two semicylindrical shapes to complete the floater 2. As shown in FIG. 3, one or more floaters 2 of this example are mounted around a pipe 20 such as a steel pipe (22 in the figure indicates a flange) and fixed with a binding band 30. A cover layer made of a synthetic resin sheet or the like may be provided on the inner peripheral surface of the innermost layer sheet 6 or the outer peripheral surface of the outermost layer sheet 10.

本例のフロータ２において、最内層シート６は、見掛け密度が１８〜３０ｋｇ／ｍ^３であるものが好ましい。見掛け密度が３０ｋｇ／ｍ^３より大きい発泡体の場合は、発泡体自体が硬くパイプへの追随性が劣る。中間層シート８は、見掛け密度が３０〜５０ｋｇ／ｍ^３であるものが好ましい。見掛け密度が５０ｋｇ／ｍ^３より大きいと浮力が小さく、結果的にフロータの外径が大きくなったり、装着数量が多くなったりして、パイプへの装着作業性が悪くなるばかりか、保管場所、運搬効率等の点で不利になる。最外層シート１０は、見掛け密度が５０〜２００ｋｇ／ｍ^３であるものが好ましい。見掛け密度が５０ｋｇ／ｍ^３より小さいと耐衝撃性が悪くなり、外力による衝撃でフロータ自体が破損したり、部分的に変形したりする恐れが生じる。各シートの見掛け密度のより好ましい値は前述した通りである。 In the floater 2 of this example, the innermost layer sheet 6 preferably has an apparent density of 18 to 30 kg / m ³ . In the case of a foam having an apparent density greater than 30 kg / m ³ , the foam itself is hard and the followability to the pipe is poor. The intermediate layer sheet 8 preferably has an apparent density of 30 to 50 kg / m ³ . When the apparent density is larger than 50 kg / m ³ , the buoyancy is small, and as a result, the outside diameter of the floater becomes large and the number of fittings increases, so that the workability of fitting to the pipe is deteriorated. This is disadvantageous in terms of transportation efficiency. The outermost layer sheet 10 preferably has an apparent density of 50 to 200 kg / m ³ . When the apparent density is less than 50 kg / m ³ , the impact resistance is deteriorated, and the floater itself may be damaged or partially deformed by an external force. The more preferable value of the apparent density of each sheet is as described above.

なお、本例のフロータ２は、フランジを有する鋼管や合成樹脂管への装着を考慮して、分割スリット１２によって筒状部４を半円筒形に２分割したが、鋼管や合成樹脂管としてフランジのないものを使用する場合は、分割せずに筒状のまま中空部に鋼管や合成樹脂管を挿入するようにしてもよい。要は、鋼管や合成樹脂管にフロータを浮力が保てるように装着することが重要であり、フロータ２の形状は鋼管や合成樹脂管に装着したときに円筒形、角筒形等の筒状であればよい。 In the floater 2 of this example, the cylindrical portion 4 is divided into two semi-cylindrical parts by the dividing slit 12 in consideration of mounting to a steel pipe or synthetic resin pipe having a flange. In the case of using the one without a steel tube, a steel tube or a synthetic resin tube may be inserted into the hollow portion without being divided. In short, it is important to attach the floater to the steel pipe or the synthetic resin pipe so that the buoyancy can be maintained, and the shape of the floater 2 is a cylindrical shape such as a cylindrical shape or a square cylindrical shape when the floater 2 is attached to the steel pipe or the synthetic resin pipe. I just need it.

本例のフロータ２の筒状部４は、前記積巻き以外に、例えば図４に示す方法でも作製することができる。すなわち、合成樹脂等からなる芯材４０の周囲に低密度の合成樹脂発泡体からなる長尺の最内層シート６をらせん状に巻いて円筒状に形成し、次いで円筒状に形成した最内層シート６の周囲に中密度の合成樹脂発泡体からなる長尺の中間層シート８をらせん状に巻き、次いで中間層シート８の周囲に高密度の合成樹脂発泡体からなる長尺の最外層シート１０をらせん状に巻くことにより作製することができる。 The cylindrical portion 4 of the floater 2 of this example can be manufactured by the method shown in FIG. That is, a long innermost layer sheet 6 made of a low-density synthetic resin foam is spirally wound around a core material 40 made of synthetic resin or the like to form a cylindrical shape, and then formed into a cylindrical shape. A long intermediate sheet 8 made of a medium density synthetic resin foam is spirally wound around 6, and then a long outermost sheet 10 made of a high density synthetic resin foam is wound around the intermediate layer sheet 8. Can be produced by winding the wire in a spiral.

（実施例１）
図１に示したフロータ２を作製した。具体的には、前述のように筒状部４を積巻きにより作製した後、分割スリット１２を形成して筒状部４を半円筒形に２分割した。この場合、本例では外径２２０ｍｍの鋼管に装着するために、内径２００ｍｍ、外径９００ｍｍのフロータを作製した。また、最内層シート６は見掛け密度２３ｋｇ／ｍ^３、厚さ２０ｍｍ、中間層シート８は見掛け密度４５ｋｇ／ｍ^３、厚さ３１０ｍｍ、最外層シート１０は見掛け密度１１０ｋｇ／ｍ^３、厚さ２０ｍｍとした。
（実施例２）
実施例１と同様にして図１に示したフロータ２を作製した。この場合、本例では外径２２０ｍｍの鋼管に装着するために、内径２００ｍｍ、外径９００ｍｍのフロータを作製した。また、最内層シート６は見掛け密度３０ｋｇ／ｍ^３、厚さ２０ｍｍ、中間層シート８は見掛け密度４５ｋｇ／ｍ^３、厚さ３１０ｍｍ、最外層シート１０は見掛け密度１１０ｋｇ／ｍ^３、厚さ２０ｍｍとした。
（実施例３）
実施例１と同様にして図１に示したフロータ２を作製した。この場合、本例では外径２２０ｍｍの鋼管に装着するために、内径２１０ｍｍ、外径９００ｍｍのフロータを作製した。また、最内層シート６は見掛け密度３０ｋｇ／ｍ^３、厚さ２０ｍｍ、中間層シート８は見掛け密度４５ｋｇ／ｍ^３、厚さ３０５ｍｍ、最外層シート１０は見掛け密度１１０ｋｇ／ｍ^３、厚さ２０ｍｍとした。
（実施例４）
実施例１と同様にして図１に示したフロータ２を作製した。この場合、本例では外径２２０ｍｍの鋼管に装着するために、内径２００ｍｍ、外径９００ｍｍのフロータを作製した。また、最内層シート６は見掛け密度２０ｋｇ／ｍ^３、厚さ２０ｍｍ、中間層シート８は見掛け密度５０ｋｇ／ｍ^３、厚さ３１０ｍｍ、最外層シート１０は見掛け密度１１０ｋｇ／ｍ^３、厚さ２０ｍｍとした。
（実施例５）
実施例１と同様にして図１に示したフロータ２を作製した。この場合、本例では外径２２０ｍｍの鋼管に装着するために、内径２２０ｍｍ、外径９００ｍｍのフロータを作製した。また、最内層シート６は見掛け密度３０ｋｇ／ｍ^３、厚さ２０ｍｍ、中間層シート８は見掛け密度４５ｋｇ／ｍ^３、厚さ３００ｍｍ、最外層シート１０は見掛け密度１１０ｋｇ／ｍ^３、厚さ２０ｍｍとした。
（比較例１）
実施例１と同様にして図１に示したフロータ２を作製した。この場合、本例では外径２２０ｍｍの鋼管に装着するために、内径２００ｍｍ、外径９００ｍｍのフロータを作製した。また、最内層シート６は見掛け密度４５ｋｇ／ｍ^３、厚さ２０ｍｍ、中間層シート８は見掛け密度６０ｋｇ／ｍ^３、厚さ３１０ｍｍ、最外層シート１０は見掛け密度１８０ｋｇ／ｍ^３、厚さ２０ｍｍとした。 Example 1
The floater 2 shown in FIG. 1 was produced. Specifically, after the cylindrical portion 4 was produced by stacking as described above, the split slit 12 was formed to divide the cylindrical portion 4 into two semicylindrical shapes. In this case, in this example, a floater having an inner diameter of 200 mm and an outer diameter of 900 mm was prepared for mounting on a steel pipe having an outer diameter of 220 mm. The innermost layer sheet 6 has an apparent density of 23 kg / m ³ and a thickness of 20 mm, the intermediate layer sheet 8 has an apparent density of 45 kg / m ³ and a thickness of 310 mm, and the outermost layer sheet 10 has an apparent density of 110 kg / m ³ and a thickness of 20 mm. did.
(Example 2)
The floater 2 shown in FIG. 1 was produced in the same manner as in Example 1. In this case, in this example, a floater having an inner diameter of 200 mm and an outer diameter of 900 mm was prepared for mounting on a steel pipe having an outer diameter of 220 mm. Further, the innermost layer sheet 6 has an apparent density of 30 kg / m ³ and a thickness of 20 mm, the intermediate layer sheet 8 has an apparent density of 45 kg / m ³ and a thickness of 310 mm, and the outermost layer sheet 10 has an apparent density of 110 kg / m ³ and a thickness of 20 mm. did.
(Example 3)
The floater 2 shown in FIG. 1 was produced in the same manner as in Example 1. In this case, in this example, a floater having an inner diameter of 210 mm and an outer diameter of 900 mm was prepared for mounting on a steel pipe having an outer diameter of 220 mm. Further, the innermost layer sheet 6 has an apparent density of 30 kg / m ³ and a thickness of 20 mm, the intermediate layer sheet 8 has an apparent density of 45 kg / m ³ and a thickness of 305 mm, and the outermost layer sheet 10 has an apparent density of 110 kg / m ³ and a thickness of 20 mm. did.
Example 4
The floater 2 shown in FIG. 1 was produced in the same manner as in Example 1. In this case, in this example, a floater having an inner diameter of 200 mm and an outer diameter of 900 mm was prepared for mounting on a steel pipe having an outer diameter of 220 mm. The innermost layer sheet 6 has an apparent density of 20 kg / m ³ and a thickness of 20 mm, the intermediate layer sheet 8 has an apparent density of 50 kg / m ³ and a thickness of 310 mm, and the outermost layer sheet 10 has an apparent density of 110 kg / m ³ and a thickness of 20 mm. did.
(Example 5)
The floater 2 shown in FIG. 1 was produced in the same manner as in Example 1. In this case, in this example, a floater having an inner diameter of 220 mm and an outer diameter of 900 mm was prepared for mounting on a steel pipe having an outer diameter of 220 mm. The innermost layer sheet 6 has an apparent density of 30 kg / m ³ and a thickness of 20 mm, the intermediate layer sheet 8 has an apparent density of 45 kg / m ³ and a thickness of 300 mm, and the outermost layer sheet 10 has an apparent density of 110 kg / m ³ and a thickness of 20 mm. did.
(Comparative Example 1)
The floater 2 shown in FIG. 1 was produced in the same manner as in Example 1. In this case, in this example, a floater having an inner diameter of 200 mm and an outer diameter of 900 mm was prepared for mounting on a steel pipe having an outer diameter of 220 mm. The innermost layer sheet 6 has an apparent density of 45 kg / m ³ and a thickness of 20 mm, the intermediate layer sheet 8 has an apparent density of 60 kg / m ³ and a thickness of 310 mm, and the outermost layer sheet 10 has an apparent density of 180 kg / m ³ and a thickness of 20 mm. did.

実施例、比較例のフロータをそれぞれ図３に示したように結束バンド３０を用いて鋼管２０に装着した。その後、各フロータの鋼管外周面に対する追随性を調べ、下記基準により評価した。結果を表１に示す。
○：フロータ最内層と鋼管外周面との間に隙間が生じず、フロータ最内層の鋼管外周面に対する追随性がよい。
△：フロータ最内層と鋼管外周面との間に部分的な隙間が生じた。
×：フロータ最内層が鋼管外周面に全く追随せず、フロータが装着できない。 The floaters of Examples and Comparative Examples were each attached to the steel pipe 20 using a binding band 30 as shown in FIG. Then, the followability with respect to the steel pipe outer peripheral surface of each floater was investigated, and the following reference | standard evaluated. The results are shown in Table 1.
○: No gap is formed between the innermost layer of the floater and the outer peripheral surface of the steel pipe, and the followability of the innermost layer of the floater to the outer peripheral surface of the steel pipe is good.
(Triangle | delta): The partial clearance gap produced between the floater innermost layer and the steel pipe outer peripheral surface.
X: The floater innermost layer does not follow the outer peripheral surface of the steel pipe at all, and the floater cannot be mounted.

表１の結果より、本発明のパイプフロータは、フロータ最内層のパイプ外周面に対する追随性がよく、１つのサイズのフロータを幅広いサイズのパイプに装着できることがわかる。 From the results in Table 1, it can be seen that the pipe floater of the present invention has good followability with respect to the pipe outer peripheral surface of the innermost layer of the floater, and one size of floater can be mounted on a wide range of pipe sizes.

本発明に係るフロータの一例を示す斜視図である。It is a perspective view which shows an example of the floater which concerns on this invention. 図１のフロータの断面図である。It is sectional drawing of the floater of FIG. 図１のフロータをパイプに取り付けた状態を示す斜視図である。It is a perspective view which shows the state which attached the floater of FIG. 1 to the pipe. 図１のフロータの別の製法を示す斜視図である。It is a perspective view which shows another manufacturing method of the floater of FIG. 従来のパイプフロータの一例を示す断面図である。It is sectional drawing which shows an example of the conventional pipe floater.

Explanation of symbols

２フロータ
４筒状部
６最内層シート
８中間層シート
１０最外層シート
１２分割スリット
２０パイプ
２２フランジ
３０結束バンド
2 Floater 4 Cylindrical part 6 Innermost layer sheet 8 Intermediate layer sheet 10 Outermost layer sheet 12 Split slit 20 Pipe 22 Flange 30 Binding band

Claims

A floater comprising a cylindrical portion having buoyancy, and the cylindrical portion is mounted around a pipe or cable to float the pipe or cable in the water surface or in water, wherein the cylindrical portion has a plurality of synthetic resin foam layers And the innermost synthetic resin foam layer of the plurality of synthetic resin foam layers is a low-density synthetic resin foam layer, and the outer synthetic resin foam All of the layers are synthetic resin foam layers having a higher density than the low density synthetic resin foam layer.

The floater according to claim 1, wherein the apparent density of the low density synthetic resin foam layer is 18 to ³⁰ kg / m ³ .

The cylindrical portion has a structure in which three synthetic resin foam layers are laminated, and the innermost synthetic resin foam layer of the three synthetic resin foam layers is a low-density synthetic resin. The outermost synthetic resin foam layer is a high-density synthetic resin foam layer, and the intermediate synthetic resin foam layer is the low-density synthetic resin foam layer and the high-density synthetic resin. The floater according to claim 1 or 2, wherein the floater is a medium density synthetic resin foam layer having an intermediate density of the foam layer.

The low density synthetic resin foam layer has an apparent density of 18 to ³⁰ kg / m ³ , the medium density synthetic resin foam layer has an apparent density of 30 to 50 kg / m ³ , and the high density synthetic resin 4. The floater according to claim ³ , wherein the apparent density of the foam layer is 50 to 200 kg / m < ³ >.

5. The floater according to claim 1, wherein each of the plurality of synthetic resin foam layers is made of a synthetic resin foam having a closed cell structure.

The cylindrical portion is formed by winding a rectangular sheet made of a synthetic resin foam into a cylindrical shape with its side edges abutting, and a rectangular sheet made of one or more synthetic resin foams around the cylindrical sheet. The floater according to any one of claims 1 to 5, wherein the floater has a structure in which the side edge is brought into contact with each other and wound into a cylindrical shape.

The cylindrical portion is formed by spirally winding a long sheet made of a synthetic resin foam into a cylindrical shape, and spiraling a long sheet made of one or more synthetic resin foams around it. The floater according to any one of claims 1 to 5, wherein the floater has a structure formed into a cylindrical shape by being wound into a cylindrical shape.