JPH11280815A - Energy absorber - Google Patents

Abstract

PROBLEM TO BE SOLVED: To stabilize and reduce the fluctuation of the collapsing load and to improve the impact energy absorption factor by determining a value obtained by dividing the total layer thickness by a number of layers within a specific range in a hollow cylindrical body where plural layers of fiber reinforced composite material body are cylindrically wound. SOLUTION: An energy absorber 1 comprises a hollow cylindrical body having a diameter D and a proper axial length L, and its thick part 2 is formed by winding plural layers of fiber reinfoced composite material body 3. The glass cloth is generally used as this fiber reinfoced composite material body 3. The energy absorber 1 is formed by the hollow cylindrical body of the simple shape in this case, but the shape is not limited to this, and that having a taper face on an upper face side or the like can be also applied. On this occasion, a value of t/n is determined within a range of 0.118 through 0.161 when the thickness of the thick part 2 of the energy absorber 1 is (t), and a number of layers of fiber reinforced composite material body 3 forming the thick part 2 is (n), whereby the stability of the thick collapsing load and the energy absorption factor can be improved.

Description

【発明の詳細な説明】DETAILED DESCRIPTION OF THE INVENTION

【０００１】[0001]

【発明の属する技術分野】本発明は、複数層の繊維強化
複合材料体からなる中空円筒体状のエネルギー吸収体に
係り、特に、荷重変動が少なく、エネルギー吸収率の高
いエネルギー吸収体に関する。BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a hollow cylindrical energy absorber comprising a plurality of layers of a fiber-reinforced composite material, and more particularly to an energy absorber having a small load variation and a high energy absorption rate.

【０００２】[0002]

【従来の技術】例えば、自動車のバンパ周りや座席周り
には、衝撃エネルギーを有効に吸収するエネルギー吸収
体が配置される。このエネルギー吸収体としては従来よ
り各種形状，形態のものが広く使用されている。一般に
使用されているこの種のエネルギー吸収体としては繊維
強化複合材料体を複数層巻回して形成される中空円筒体
状のものが多い。このエネルギー吸収体としては複数層
の繊維強化複合材料体の肉厚や、エネルギー吸収軸の角
度やその材質等に関して色々と工夫されたものが多い
が、中空円筒体の全層厚（中空円筒体の肉厚）と層数と
の関係に関する公知技術は見当らない。例えば、特開平
６−３０７４７５号公報のエネルギー吸収部材は、３層
の補強繊維層を構成する各層の厚みを中心から外周側に
向けて次第に薄くし、これにより、各層がほぼ同時に圧
潰するように工夫したものである。2. Description of the Related Art For example, an energy absorber that effectively absorbs impact energy is disposed around a bumper or a seat of an automobile. As this energy absorber, those having various shapes and forms have been widely used. As this kind of energy absorber generally used, there is often a hollow cylindrical body formed by winding a plurality of layers of a fiber-reinforced composite material. Many energy absorbers have been devised with respect to the thickness of the fiber-reinforced composite material body having a plurality of layers, the angle of the energy absorption axis, the material thereof, and the like. There is no known technique relating to the relationship between the thickness of the layer and the number of layers. For example, in the energy absorbing member disclosed in JP-A-6-307475, the thickness of each layer constituting the three reinforcing fiber layers is gradually reduced from the center toward the outer peripheral side, so that each layer is crushed almost simultaneously. It is something devised.

【０００３】[0003]

【発明が解決しようとする課題】エネルギー吸収体とし
ては、圧潰特における荷重の変動がほぼ一定であり、か
つ衝撃エネルギーの吸収率が高いことが望ましい。この
要件を満足する要因としては各種のものが考えられる
が、本発明の出願人の研究及び実験によれば、複数層の
繊維強化複合材料体からなる中空円筒体の全体の層厚と
層数との関係がこれ等の要因に大きな影響を及ぼすこと
がわかった。また、繊維強化複合材料体としては従来よ
り各種のものが採用されているが、ガラスクロスが衝撃
エネルギーの吸収率や品質の安定性及び製作のし易さ等
の観点が採用されることが望ましい。It is desirable for the energy absorber to have a substantially constant load variation in the crushing characteristic and a high impact energy absorption rate. Although various factors can be considered as factors that satisfy this requirement, according to the research and experiments of the applicant of the present invention, the total layer thickness and the number of layers of a hollow cylindrical body composed of a multi-layer fiber-reinforced composite material are It has been found that the relationship with has a significant effect on these factors. In addition, various types of fiber-reinforced composite materials have been conventionally used, but it is desirable that the glass cloth be used from the viewpoints of absorptivity of impact energy, stability of quality, ease of manufacture, and the like. .

【０００４】本発明は、以上の事情に鑑みて創案された
ものであり、圧潰時における荷重が安定し、所望の性能
を有するエネルギー吸収体を製作することが比較的容易
となると共にエネルギー吸収率が高いエネルギー吸収体
を提供することを目的とする。[0004] The present invention has been made in view of the above circumstances, and it is relatively easy to manufacture an energy absorber having a desired performance in which the load during crushing is stable and has a desired performance. It is an object to provide an energy absorber having a high energy absorption.

【０００５】[0005]

【課題を解決するための手段】本発明は、以上の目的を
達成するために、繊維強化複合材料体の複数層を円筒状
に巻回してなる中空円筒体であって、その全層厚を層数
で除した値が０．１１８ｍｍ乃至０．１６１ｍｍの範囲
にあるエネルギー吸収体を構成するものである。更に具
体的に、前記繊維強化複合材料体が、ガラスクロスであ
ることを特徴とするものである。In order to achieve the above object, the present invention provides a hollow cylindrical body formed by winding a plurality of layers of a fiber-reinforced composite material into a cylindrical shape, and having a total thickness of the hollow cylindrical body. This constitutes an energy absorber whose value divided by the number of layers is in the range of 0.118 mm to 0.161 mm. More specifically, the fiber-reinforced composite material is a glass cloth.

【０００６】複数層の繊維強化複合材料体からなる中空
円筒体に衝撃力が加わると圧潰荷重に到るまでは各層は
分離しない状態で荷重を受け衝撃エネルギーを吸収す
る。その間には中空円筒体の全体としての変位量も少な
い。衝撃力が圧潰に近づくと各層間の分離が生じ、圧潰
が開始される。この場合、層間の分離がばらばらに行わ
れたり、分離形態が相異すると圧潰が安定して行われ
ず、圧潰荷重にばらつきが生ずる。そのため、エネルギ
ー吸収体としての当初の設計仕様の決定が正確に行われ
ないと共に、圧潰荷重にバラツキと変動が生ずると衝撃
エネルギーの吸収率も低下する。圧潰荷重の安定化と衝
撃エネルギー吸収率に影響を与える要因としては各種の
ものがあるが、本発明では、エネルギー吸収体の層数と
その全層厚との関係がこれ等の特性に大きな影響がある
ことがわかり、その関係値を特定し、圧潰荷重の安定化
とエネルギー吸収率の向上とを図るようにしたものであ
る。When an impact force is applied to a hollow cylindrical body composed of a plurality of layers of a fiber reinforced composite material, each layer receives a load without being separated and absorbs impact energy until a crushing load is reached. In the meantime, the displacement of the hollow cylinder as a whole is also small. When the impact force approaches crushing, separation between the layers occurs, and crushing starts. In this case, if the layers are separated from each other or the separation forms are different, the crushing is not performed stably, and the crushing load varies. For this reason, the initial design specification of the energy absorber is not accurately determined, and if the crushing load varies and fluctuates, the impact energy absorption rate also decreases. There are various factors that affect the stabilization of the crushing load and the impact energy absorption rate. In the present invention, however, the relationship between the number of layers of the energy absorber and the total thickness thereof has a great effect on these characteristics. It is understood that there is, and the relational value is specified to stabilize the crushing load and improve the energy absorption rate.

【０００７】[0007]

【発明の実施の形態】以下、本発明のエネルギー吸収体
の実施の形態を図面を参照して詳述する。図１は本発明
のエネルギー吸収体１の軸断面を示す。エネルギー吸収
体１は直径Ｄで適宜の軸長Ｌを有する中空円筒体からな
り、その肉厚部２は、複数の繊維強化複合材料体３を多
層に巻回したものからなる。繊維強化複合材料体は、い
わゆるＦＲＰ（Ｆｉｂｅｒ−ｇｌａｓｓ Ｒｅｉｎｆｏ
ｒｃｅｄ Ｐｌａｓｔｉｃｓ）であり、主として、ガラ
ス繊維にマトリックスとしてポリエステル樹脂を混合し
たガラスクロスが一般に広く仕様されている。勿論、本
発明の場合、ガラスクロスに限定するものではない。ま
た、図１に示したエネルギー吸収体１は単純形状の中空
円筒体からなるが、勿論、これに限定するものではな
く、上面側に圧潰時のトリガーとなるテーパ面を形成し
たもの等も適用される。DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the energy absorber according to the present invention will be described below in detail with reference to the drawings. FIG. 1 shows an axial section of the energy absorber 1 of the present invention. The energy absorber 1 is formed of a hollow cylinder having a diameter D and an appropriate axial length L, and the thick portion 2 is formed by winding a plurality of fiber-reinforced composite materials 3 in multiple layers. The fiber-reinforced composite material body is a so-called FRP (Fiber-glass Reinfo).
rced Plastics), and a glass cloth obtained by mixing a polyester resin as a matrix with glass fibers is generally widely used. Of course, the present invention is not limited to glass cloth. The energy absorber 1 shown in FIG. 1 is formed of a hollow cylindrical body having a simple shape, but is not limited to this. Of course, an energy absorber having a tapered surface on the upper surface serving as a trigger at the time of crushing is also applicable. Is done.

【０００８】図２は図１の肉厚部２の圧潰時の状態を示
すものであり、圧潰時には各層間に割れ４が発生し、こ
こから圧潰が始まる。前記したように、圧潰はエネルギ
ー吸収体１の肉厚部２の層厚（以下、ｔとする）と、肉
厚部２を形成する繊維強化複合材料体３の層数（以下、
ｎとする）に関係する。このｔ／ｎの値をある範囲に決
めることにより、安定した圧潰荷重とエネルギー吸収率
の増大を図ることができる。本発明では、ｔ／ｎの値を
０．１１８乃至０．１６１の範囲に定めている。以下、
その根拠を説明する。FIG. 2 shows a state in which the thick portion 2 of FIG. 1 is crushed. When crushed, cracks 4 are generated between the layers, and crushing starts from here. As described above, the crushing depends on the layer thickness (hereinafter, referred to as t) of the thick portion 2 of the energy absorber 1 and the number of layers (hereinafter, referred to as “t”) of the fiber-reinforced composite material 3 forming the thick portion 2.
n). By setting the value of t / n within a certain range, a stable crushing load and an increase in energy absorption can be achieved. In the present invention, the value of t / n is set in the range of 0.118 to 0.161. Less than,
The grounds will be explained.

【０００９】図３は図１に示したＤ寸法が６３．７３ｍ
ｍで肉厚部２の層厚ｔが６．６１ｍｍでｔ／ｎの値が
０．１６１ｍｍの場合の荷重−変位曲線を示す。曲線の
頂部が圧潰荷重を示し、その凹凸形状が圧潰進行時にお
ける圧潰荷重の変動を示す。また、曲線と横軸との間の
面積がエネルギー吸収量に相当する。図示のように、圧
潰荷重は極めて安定し凹凸も少ない。すなわち、ｔ／ｎ
の値が０．１６１ｍｍの場合は、前記した条件を満足す
るものになる。勿論、Ｄ寸法やｔ寸法の値の相違により
荷重−変位曲線の全体の大きさは異なるが、圧潰荷重が
安定することはＤ寸法及びｔ寸法の値に無関係であるこ
とが実証されている。FIG. 3 shows that the D dimension shown in FIG. 1 is 63.73 m.
7 shows a load-displacement curve when the thickness t of the thick portion 2 is 6.61 mm and the value of t / n is 0.161 mm. The top of the curve indicates the crushing load, and the uneven shape indicates the fluctuation of the crushing load during the crushing progress. The area between the curve and the horizontal axis corresponds to the energy absorption. As shown in the figure, the crushing load is extremely stable, and there are few irregularities. That is, t / n
Is 0.161 mm, the above condition is satisfied. Of course, the overall size of the load-displacement curve differs depending on the value of the D dimension and the t dimension, but it has been proved that the stability of the crushing load is independent of the values of the D dimension and the t dimension.

【００１０】図４は、Ｄ寸法７２．５８ｍｍ、ｔ寸法が
６．０８ｍｍでｔ／ｎの値が０．１９６ｍｍの場合の荷
重−変位線図を示す。この場合、圧潰が始まってからの
圧潰荷重の変動が極めて大きく、大きな谷間も数箇所発
生する。従って、圧潰荷重を特定することが難しい。ま
た、エネルギー吸収量も図３に較べて大幅に小さなもの
となる。なお、この荷重−変位線図の場合のＤ寸法やｔ
寸法が図３のものと相違するが、図示しない他の実験に
よれば、Ｄ寸法やｔ寸法の如何に拘らず、図４に示した
と同様な曲線形態が得られることが実証されている。ま
た、図に示していないが、Ｄ寸法８２．５８ｍｍ、ｔ寸
法６．０３ｍｍでｔ／ｎが０．１８８ｍｍの場合におい
ても図４とほぼ同様な荷重−変位線図が得られることが
実証された。FIG. 4 shows a load-displacement diagram when the D dimension is 72.58 mm, the t dimension is 6.08 mm, and the value of t / n is 0.196 mm. In this case, the fluctuation of the crushing load after the start of the crushing is extremely large, and several large valleys occur. Therefore, it is difficult to specify the crush load. Further, the amount of energy absorption is significantly smaller than that in FIG. In addition, the D dimension and t in the case of this load-displacement diagram
Although the dimensions are different from those of FIG. 3, other experiments not shown demonstrate that a curved form similar to that shown in FIG. 4 can be obtained regardless of the D dimension and the t dimension. Although not shown in the figure, it was demonstrated that a load-displacement diagram substantially similar to that in FIG. 4 was obtained even when the D dimension was 82.58 mm, the t dimension was 6.03 mm, and t / n was 0.188 mm. Was.

【００１１】図５はｔ／ｎの値が０．１０８乃至０．１
１７ｍｍの場合の荷重−変位線図を示す。図示のように
ｔ／ｎの値がこの範囲のものではｔ寸法に対してｎの
値、すなわち、層数が多すぎて全体が低剛性のものにな
り圧潰が急激に生じて衝撃エネルギーを吸収することが
できなくなる。FIG. 5 shows that the value of t / n is 0.108 to 0.1.
The load-displacement diagram in the case of 17 mm is shown. As shown in the figure, when the value of t / n is in this range, the value of n with respect to the t dimension, that is, the number of layers is too large and the whole becomes low rigidity, crushing occurs rapidly, and the impact energy is absorbed. You can't do that.

【００１２】図６は縦軸に平均圧潰荷重をとり横軸にエ
ネルギー吸収体１の横断面積又は肉厚部２の層厚（ｔ寸
法）を表示したものである。Ａ線は前記したｔ／ｎが
０．１６１ｍｍの場合であり、Ｂ線はｔ／ｎが０．１９
６ｍｍの場合である。図から明らかなように、平均圧潰
荷重は段面積又は層厚（ｔ寸法）に関係なくｔ／ｎが
０．１６１ｍｍの方が上廻り、エネルギー吸収率が高い
ことがわかる。FIG. 6 shows the average crush load on the vertical axis and the cross-sectional area of the energy absorber 1 or the layer thickness (t dimension) of the thick portion 2 on the horizontal axis. Line A is for the case where t / n is 0.161 mm, and line B is for t / n of 0.19 mm.
6 mm. As is clear from the figure, the average crushing load is higher when the t / n is 0.161 mm regardless of the step area or the layer thickness (t dimension), and the energy absorption rate is higher.

【００１３】以上の荷重−変位線図から、ｔ／ｎが０．
１１８ｍｍ以下では圧潰が極端に早くなり、エネルギー
吸収体１としては不適当であり、ｔ／ｎの値が例えば、
０．１８８ｍｍや０．１９６ｍｍでは変動が多すぎるた
めｔ／ｎの値は少なくとも０．１８８ｍｍ以下が望まし
く、実験の結果から上限を０．１６１ｍｍと設定した。
すなわち、ｔ／ｎを０．１１８ｍｍから０．１６１ｍｍ
の範囲にすることにより、圧潰荷重の安定化とエネルギ
ー吸収率の増大を図ることができる。From the above load-displacement diagram, t / n is set to 0.
When it is 118 mm or less, the crushing becomes extremely fast, which is inappropriate for the energy absorber 1.
Since 0.188 mm or 0.196 mm has too much variation, the value of t / n is desirably at least 0.188 mm or less.
That is, t / n is changed from 0.118 mm to 0.161 mm.
Within this range, it is possible to stabilize the crushing load and increase the energy absorption rate.

【００１４】[0014]

【発明の効果】１）本発明の請求項１に記載のエネルギ
ー吸収体によれば、複数層の繊維強化複合材料体からな
るエネルギー吸収体の層厚と層数との比を０．１１８ｍ
ｍ乃至０．１６１ｍｍの範囲にすることにより、圧潰荷
重の安定化と変動を低下させることができると共に、衝
撃エネルギー吸収率の向上が図れる。 ２）本発明の請求項２に記載のエネルギー吸収体によれ
ば、本発明は最も広く使用されているガラスクロスに適
用され、広範囲に使用される。1) According to the energy absorber according to the first aspect of the present invention, the ratio between the layer thickness and the number of layers of the energy absorber composed of a plurality of layers of the fiber-reinforced composite material is 0.118 m.
By setting the range of m to 0.161 mm, the crushing load can be stabilized and the fluctuation can be reduced, and the impact energy absorption rate can be improved. 2) According to the energy absorber according to claim 2 of the present invention, the present invention is applied to the most widely used glass cloth and is widely used.

【図面の簡単な説明】[Brief description of the drawings]

【図１】本発明のエネルギー吸収体の軸断面図。FIG. 1 is an axial sectional view of an energy absorber of the present invention.

【図２】エネルギー吸収体の圧潰初期状態を示す模式
図。FIG. 2 is a schematic view showing an initial state of crushing of the energy absorber.

【図３】ｔ／ｎ＝０．１６１ｍｍの場合のエネルギー吸
収体の荷重−変位線図。FIG. 3 is a load-displacement diagram of the energy absorber when t / n = 0.161 mm.

【図４】ｔ／ｎ＝０．１９６ｍｍの場合のエネルギー吸
収体の荷重−変位線図。FIG. 4 is a load-displacement diagram of the energy absorber when t / n = 0.196 mm.

【図５】ｔ／ｎ＝０．１０８乃至０．１１７ｍｍの場合
のエネルギー吸収体の荷重−変位線図。FIG. 5 is a load-displacement diagram of the energy absorber when t / n = 0.108 to 0.117 mm.

【図６】ｔ／ｎ＝０．１６１ｍｍとｔ／ｎ＝０．１９６
ｍｍのエネルギー吸収体の平均圧潰荷重−断面積（層厚
ｔ）線図。FIG. 6: t / n = 0.161 mm and t / n = 0.196
FIG. 2 is a diagram showing an average crushing load-cross-sectional area (layer thickness t) of an energy absorber of mm.

【符号の説明】[Explanation of symbols]

１ エネルギー吸収体 ２ 肉厚部 ３ 繊維強化複合材料体 ４ 割れ DESCRIPTION OF SYMBOLS 1 Energy absorber 2 Thick part 3 Fiber reinforced composite material 4 Crack

Claims (2)

【特許請求の範囲】[Claims] 【請求項１】 繊維強化複合材料体の複数層を円筒状に
巻回してなる中空円筒体であって、その全層厚を層数で
除した値が０．１１８ｍｍ乃至０．１６１ｍｍの範囲に
あることを特徴とするエネルギー吸収体。1. A hollow cylindrical body formed by winding a plurality of layers of a fiber-reinforced composite material into a cylindrical shape, wherein the total layer thickness divided by the number of layers is in the range of 0.118 mm to 0.161 mm. An energy absorber characterized by the following. 【請求項２】 前記繊維強化複合材料体が、ガラスクロ
スである請求項１に記載のエネルギー吸収体。2. The energy absorber according to claim 1, wherein the fiber-reinforced composite material is a glass cloth.