JPS5818538B2 - Automotive leaf spring - Google Patents

Description

【発明の詳細な説明】 ガラス繊維、化学繊維等の織布を補強材とし、該補強材
に熱可塑性または熱硬化性の合成樹脂を含浸せしめて、
これを加圧成形し、合成樹脂を硬化せしめて所望の製品
を得る技術、いわゆるＦＲｒ技術は、多くの産業分野に
おいて、ＦＲＰの強度弾性、振動減衰性、耐蝕性、軽量
性、加工性等の特性を利用して実用化されているが、従
来使用されていた金属材料に比して強度、特に耐久性が
低いとされ、一般汎用機械への利用もあまり強度、耐久
性を必要としない準強度部材的な用途に使用されている
。[Detailed description of the invention] A woven fabric such as glass fiber or chemical fiber is used as a reinforcing material, and the reinforcing material is impregnated with a thermoplastic or thermosetting synthetic resin,
The so-called FRr technology, which is a technology to pressure mold this material and harden the synthetic resin to obtain the desired product, is used in many industrial fields to improve the strength and elasticity, vibration damping properties, corrosion resistance, lightness, processability, etc. of FRP. Although it has been put into practical use by taking advantage of its properties, it is said to have lower strength and especially durability than conventionally used metal materials, and it cannot be used in general-purpose machinery because it does not require much strength or durability. It is used as a strength member.

近年、自動車産業の分野においては自動車の低燃費、軽
量化の傾向の高まり、自動車部品の軽量化が各部品分野
で検討され、従来の金属製部品に代え、合成樹脂成形品
、ＦＲＰ製品が広く採用されるようになった。In recent years, in the automobile industry, there has been an increasing trend towards low fuel consumption and weight reduction of automobiles, and the weight reduction of automobile parts has been considered in various parts fields, and synthetic resin molded products and FRP products are widely used instead of conventional metal parts. started to be adopted.

しかしながら前記した強度、耐久性の低さから苛酷な使
用条件にさらされる部品にまでは適用されていない。However, due to the aforementioned low strength and durability, it has not been applied to parts that are exposed to severe usage conditions.

自動車の車軸懸架ばねは、自動車の円滑な走行のために
欠くことのできない機能部品であるが、その使用条件は
極めて苛酷であり、かつ長期間にわたり耐久性が要求さ
れるものである。Automobile axle suspension springs are functional parts indispensable for the smooth running of automobiles, but they are used under extremely harsh conditions and are required to have long-term durability.

従来ＦＲＰの特異な弾性、振動減衰性等の性質に着目し
てＦＲＰ製板ばねの開発が試みられたが、自動車の車軸
懸架の苛酷な使用条件に合わせた煉労耐久試験を行うと
、板ばねの高応力部における補強材の繊維織布の経糸と
緯糸の交叉部におし・て白化現象ト呼ばれるミクロ剥離
や亀裂が生じ、自動軍用としての使用に耐えないものが
殆んどであった。Attempts have been made to develop FRP leaf springs by focusing on FRP's unique properties such as elasticity and vibration damping properties, but when a fatigue test was conducted under the harsh operating conditions of automobile axle suspensions, it was found that the At the intersection of the warp and weft of the reinforcing fiber fabric in the high-stress areas of the spring, micro-peeling and cracking, known as whitening, occurs, and most of the fabrics cannot withstand use in automatic military applications. Ta.

この原因について本発明者が研究したところ、通常ＦＲ
Ｐの補強材として用いられるガラス繊維の引張り強さは
２５０〜３５０ｋｙ／ ｍｉであって、これに含浸し硬
化せしめられる熱硬化性合成樹脂（例えば不飽和ポリエ
ステル樹脂）の引張り強さの５〜１０ ｋｇ／ｍｍ２に
比して桁違いに大きく、そのためガラス繊維強化合成樹
脂成形板の強度はその殆んどについてガラス繊維の織布
が寄与していることが明らかであるが、ＦＲＰの内部に
おいて織布の経糸と緯糸とが共にその全長にわたって波
状を呈しており、経糸と緯糸の交叉部にて重ね合わされ
た繊維布間に合成樹脂が塊状に存在しており、板ばねの
高応力部における合成樹脂塊において前記白化現象を牛
じ、塊状の合成樹脂部分に発生した剥離または電熱が起
点となって合成樹脂部分の破壊が進行し、短期間に表層
剥離や破壊を生ずるものであることを発見した。The inventor researched this cause and found that normally FR
The tensile strength of the glass fiber used as a reinforcing material for P is 250 to 350 ky/mi, which is 5 to 10 times higher than the tensile strength of the thermosetting synthetic resin (for example, unsaturated polyester resin) that is impregnated into it and cured. kg/mm2, so it is clear that most of the strength of the glass fiber-reinforced synthetic resin molded plate is contributed by the glass fiber woven fabric, but the woven fabric inside the FRP The warp and weft of the cloth are both wavy over their entire length, and a lump of synthetic resin exists between the overlapped fibers at the intersection of the warp and weft. After observing the whitening phenomenon in resin lumps, it was discovered that destruction of the synthetic resin part progresses due to peeling or electric heating that occurs in the lumpy synthetic resin part, resulting in surface layer peeling and destruction in a short period of time. did.

このことは、繊維強化合成樹脂成形品の母材マ） ＩＪ
ラックスある合成樹脂は補強材の繊維および繊維布間を
接着し、繊維および繊維布間の摩耗や損傷を防ぐ役割は
極めて高いが、合成樹脂自体の疲労強度、耐久性の向上
への寄与は極めて僅かであると考えられる。This is true for the base material of fiber-reinforced synthetic resin molded products.
Lux synthetic resin bonds between the fibers and fiber cloth of the reinforcing material and plays an extremely important role in preventing wear and damage between the fibers and fiber cloth, but it does not significantly contribute to improving the fatigue strength and durability of the synthetic resin itself. It is thought that the amount is small.

以上の知見から、本発明者は、繰返し荷重が頻繁に作用
する弾性板、特に自動車用板ばねのように繰返し荷重の
ほかに長手方向の強度、剛性、耐久性を必要とし、横応
力、ねじり応力をも問題とする部品においては、弾性板
の強度を主に負担する繊維布補強材の強度を高め、かつ
前記白化現象を生じて疲労による剥離や破壊の起点とな
るミクロ剥離や電熱を生じ易い繊維布補強材中の合成樹
脂の塊をなくシ、合成樹脂は繊維布補強材の経糸または
緯糸等の繊維束の接着の役割を主に果すべき構造を探求
し、本発明を案出したものである。Based on the above findings, the present inventor discovered that elastic plates that are frequently subjected to repeated loads, especially automobile leaf springs, require strength, rigidity, and durability in the longitudinal direction in addition to repeated loads, and are capable of resisting lateral stress and torsion. For parts where stress is a problem, it is necessary to increase the strength of the fiber cloth reinforcing material, which mainly bears the strength of the elastic plate, and to cause the whitening phenomenon described above, which causes micro-delamination and electric heating that become the starting point for peeling and fracture due to fatigue. The present invention was devised by exploring a structure in which the synthetic resin mainly plays the role of adhering the fiber bundles such as the warp or weft of the fiber cloth reinforcement, in order to eliminate the easy-to-understand lumps of synthetic resin in the fiber cloth reinforcement. It is something.

即ち本発明は、常法、により、繊維束を織成した複数枚
の繊維布を重ねた繊維基材に合成樹脂を含浸させ、加圧
成形して合成樹脂を硬化せしめた自動車用板ばねにおい
て、前記繊維布はすべて同一の幅を有し、かつ長さの異
るものを包含しており、その長さの短いものを中央部に
配して、長さ方向中央部の板厚を厚く両端部を薄くする
よう積層され、前記繊維布の一部または全部は、長繊維
よりなる連続せしめた繊維束を経糸とし、これを長さ方
向が相互に平行するように弛みなく平滑な線状に並列せ
しめ、緯糸は、長繊維によりなる連続せしめた繊維束で
あってその断面積または単位重量において前記経糸の１
／３以下のものを用い、該緯糸を前記経糸の繊維束の幅
の４倍以上の間隔を保たせ、かつ前記経糸の上面または
下面に巻回されるように前記経糸に織り込まれた一方向
性繊維布とし、これら一方向性繊維布の経糸はすべて平
行するように積層せしめられ、１かつ加圧成形の際厚さ
方向に圧潰されて広い面積で相互に接触し、前記繊維基
材に含浸の合成樹脂の硬化マ） ＩＪラックスより平滑
な線状で広い面積で接着されていることを特徴とするも
のである。That is, the present invention provides a leaf spring for an automobile in which a fiber base material made by stacking a plurality of fiber cloths woven with fiber bundles is impregnated with a synthetic resin, and the synthetic resin is cured by pressure molding. All of the fiber cloths have the same width and include those of different lengths, with the shorter length placed in the center, and the thickness at the center in the longitudinal direction thicker at both ends. Part or all of the fiber cloth is laminated to make the fiber cloth thinner, and the warp is a continuous fiber bundle made of long fibers, and the fiber cloth is made into a smooth linear shape without slack so that the length directions are parallel to each other. The weft is a continuous fiber bundle made of long fibers, and its cross-sectional area or unit weight is equal to 1 of the warp.
/3 or less, the weft yarns are woven in one direction into the warp yarns so as to maintain an interval of four times or more the width of the fiber bundle of the warp yarns, and to be wound around the upper or lower surface of the warp yarns. The warps of these unidirectional fiber cloths are all laminated in parallel, and are crushed in the thickness direction during pressure molding so that they contact each other over a wide area, and the Cured resin impregnated synthetic resin) This product is characterized by being bonded in a smoother linear shape over a wider area than IJ Lux.

本発明における繊維布の繊維束は、ガラス繊維、化学繊
維（ポリプロピンン、ポリエステル、ビニロン、ポリア
ミド等）または炭素繊維が用い得られ、また合成樹脂と
しては熱可塑性樹脂、熱硬化性樹脂の何れのタイプも用
い得られるが、一般には不飽和ポリエステル樹脂、エポ
キシ樹脂、ビニルエステル樹脂等の熱硬化性樹脂が用い
られる。The fiber bundle of the fiber cloth in the present invention can be obtained using glass fiber, chemical fiber (polypropylene, polyester, vinylon, polyamide, etc.) or carbon fiber, and the synthetic resin can be either a thermoplastic resin or a thermosetting resin. Generally, thermosetting resins such as unsaturated polyester resins, epoxy resins, and vinyl ester resins are used.

また本発明においては端部にブツシュを配し、前記繊維
基材を該ブツシュの外周に巻回して前記繊維基材の端部
をブツシュ内側の繊維基材上面に接着した目玉付の板ば
ねとすることができる。Further, in the present invention, a leaf spring with an eyelet is provided, in which a bush is arranged at the end, the fiber base material is wound around the outer periphery of the bush, and the end of the fiber base material is adhered to the upper surface of the fiber base material inside the bush. can do.

図面に基いて本発明を説明すれば、第１図は本発明の自
動車用板ばねの一実施例の側面図であって、一般的に言
えば繊維束を織成した複数枚の繊維布を重ね合成樹脂を
含浸せしめた繊維基材を加圧成形して合成樹脂を硬化せ
しめたものであって、その繊維基材１０は例えば第２図
に示すように、所定の幅のテープ状をなす繊維布１１，
１２゜１３を長さを異らせて切断し、その最も短い繊維
布１３を長さ方向のほぼ中央部に、次に長い繊維布１２
を前記繊維布１３を包み込むように、さらに最も長い繊
維布１１を最外層にかつ前記繊維布１２を包み込むよう
に、すべての繊維布の幅を揃えて重ね合わせて構成され
る。To explain the present invention based on the drawings, Fig. 1 is a side view of one embodiment of the leaf spring for an automobile of the present invention, and generally speaking, it is made by overlapping a plurality of fiber cloths woven with fiber bundles. A fiber base material impregnated with a synthetic resin is pressure-molded and the synthetic resin is cured.The fiber base material 10 is, for example, a tape-shaped fiber of a predetermined width, as shown in FIG. cloth 11,
12 and 13 are cut into different lengths, and the shortest fiber cloth 13 is placed approximately in the center in the length direction, and the next longest fiber cloth 12 is cut into different lengths.
It is constructed by stacking all the fiber cloths with the same width so as to wrap around the fiber cloth 13, and further, with the longest fiber cloth 11 as the outermost layer and so as to wrap around the fiber cloth 12.

該繊維布１１゜１２．１３には合成樹脂が含浸せしめら
れ脱泡されており、繊維基材１０は常法に従って第１図
に示す板ばねの形状のほぼ中央部力肉厚ｔ１が両端部の
肉厚ｔ２ よりも犬であるような型面を形成した上下金
型閘に挿入され、加圧成形され、金型とともに合成樹脂
のキュア温度に加熱され硬化せしめられる。The fiber cloths 11, 12, and 13 are impregnated with a synthetic resin and degassed, and the fiber base material 10 is formed in the shape of a leaf spring shown in FIG. The material is inserted into upper and lower molds having mold surfaces that are more dog-shaped than the wall thickness t2, is press-molded, and is heated and cured together with the mold to the curing temperature of the synthetic resin.

本発明の板ばねの上記各繊維布１は、第４図に示すよう
に経糸２を複数本平行せしめて弛みなく平滑な線状に並
行させ、該経糸２の断面積または単位重量の１／３以下
の断面積または単位重量を有する緯糸３を打ち込んで織
成されているものであって、かつ前記緯糸３は第５図に
示すように経糸２の弛みのない平滑な線状を保持させる
ように、交互に経糸２の上面または下面に巻回されるよ
うに緩く配設され、かつ第４図に示すように、緯糸３間
の間隔を経糸２０幅の４倍以上（経糸２として従来慣用
のガラス繊維のロービングを使用する場合は８間以上に
相当する）の間隔を隔てて経糸２間にほぼ直角方向に挿
入さ風雨側端部に配列された経糸２の・側面に沿って曲
げられその上面から下面へ、または下面から上面へと再
び挿入されて耳部４を形成している一方向性の繊維布で
ある。As shown in FIG. 4, each fiber cloth 1 of the leaf spring of the present invention has a plurality of warp threads 2 arranged in parallel to form a smooth linear shape without slack, and 1/1/2 of the cross-sectional area or unit weight of the warp threads 2. It is woven by inserting weft yarns 3 having a cross-sectional area or unit weight of 3 or less, and the weft yarns 3 maintain the smooth linear shape of the warp yarns 2 without slack, as shown in FIG. As shown in FIG. If conventional glass fiber roving is used, the warp threads 2 are inserted approximately perpendicularly between the warp threads at intervals of 8 or more rovings) and bent along the sides of the warp threads 2 arranged on the wind and rain side ends. It is a unidirectional fiber cloth which is inserted again from the upper surface to the lower surface or from the lower surface to the upper surface to form the ears 4.

この緯糸２の挿入の間隔は、繊維布の幅を以って上限と
するっ 上記緯糸３の挿入は第５図に示すように、緯糸３が経糸
２と交叉することによって経糸２に小径の屈曲部を形成
することのないよう、経糸２をその滑らかな線状を維持
するように、緯糸３に張力をかけることなく行われなけ
ればならず、緯糸３は単に経糸２が第６図に示すように
個々に滑らかな線状を維持しかつ第４図に示すように相
互に平行を維持するように維持布をまとめているにすぎ
ないものである。The insertion interval of the weft threads 2 is set at the upper limit by the width of the textile fabric.As shown in Fig. 5, the insertion of the weft threads 3 causes the warp threads 2 to have a small diameter by crossing the weft threads 3 with the warp threads 2. It must be done without applying tension to the weft threads 3, in order to maintain the warp threads 2 in their smooth line shape, without forming any bends, and the weft threads 3 should be simply warp threads 2 as shown in Figure 6. As shown in FIG. 4, the maintenance cloths are simply grouped together so that each maintains a smooth linear shape and is mutually parallel to each other as shown in FIG.

仮に緯糸３に張力を作用させて打ち込めば、第５図に示
す関係位置において緯糸は隣接する経糸２を上下にずら
し、第６図に示す関係位置において経糸２を波うたせて
、繊維布を重ねて繊維基材を構成した場合に波状の経糸
の重ね合わせ部に大きな空隙を形成させ、加圧成形によ
っても該空隙を押し潰すことができずに、繊維布（（含
浸せしめた合成樹脂の塊を該空隙に形成させ、疲労破壊
の起点となる亀裂を該塊から発生することになる。If tension is applied to the weft threads 3 when driving, the weft threads will shift the adjacent warp threads 2 up and down at the relative positions shown in FIG. 5, cause the warp threads 2 to wave at the relative positions shown in FIG. When stacking fibers to form a fiber base material, large voids are formed at the overlapping portions of the wavy warps, and the voids cannot be crushed even by pressure molding. A lump is formed in the void, and a crack that becomes a starting point for fatigue failure is generated from the lump.

上記のように構成された合成樹脂含浸の繊維基材を常法
により加圧成形し、加熱して得られた板ばねは、繊維基
材を構成する一方向性繊維布に含浸せしめられた合成樹
脂が硬化して経糸２緯糸３の繊維間を接着するとともに
、長さ方向に滑らかな線状に維持されている経糸２を押
し潰して経糸２周面の広い面積で接触させ相互に経糸２
を接着して全経糸を一体化するとともに、繊維束間を充
填する。The leaf spring obtained by pressure-molding the synthetic resin-impregnated fiber base material constructed as described above by a conventional method and heating it is a synthetic resin impregnated fiber base material impregnated with the unidirectional fiber cloth constituting the fiber base material. The resin hardens and bonds the fibers of the warp 2 and weft 3, and also crushes the warp 2, which is maintained in a smooth linear shape in the length direction, so that it comes into contact with a wide area of the circumference of the warp 2, so that the warp 2
are glued together to integrate all the warp yarns and fill in the spaces between the fiber bundles.

緯糸３の太さは前記のように経糸２の太さの１７３以下
とされているから、繊維基材内部において上下の経糸２
間に挿入されている緯糸３は経糸２を大きく屈曲させる
ことなく、かつ緯糸３０間隔は経糸２０幅の４倍以上の
間隔とされているから、第７図において緯糸３を接着す
る上下の経糸２，２間の空隙５は極めて小さく形成され
、緯糸の太さが経糸の太さにほぼ等しい従来の繊維基材
に比して該空隙５によって形成される合成樹脂の塊は極
めて小さいもの゛となり、該塊状合成樹脂が繰返し荷重
等に基く疲労によって剥離や亀裂を生ずる危険を著るし
く減少し、耐久性を向上する。Since the thickness of the weft yarn 3 is set to be 173 or less than the thickness of the warp yarn 2 as described above, the upper and lower warp yarns 2 are
The weft threads 3 inserted between the weft threads 2 do not bend the warp threads 2 significantly, and the weft thread spacing is set to be more than four times the width of the warp threads 20. Therefore, in Fig. 7, the upper and lower warp threads that bond the weft threads 3 The gap 5 between 2 and 2 is formed extremely small, and the mass of synthetic resin formed by the gap 5 is extremely small compared to conventional fiber base materials where the thickness of the weft is almost equal to the thickness of the warp. This significantly reduces the risk of the bulk synthetic resin peeling or cracking due to fatigue due to repeated loads, and improves durability.

逆に前記空隙５が極めて小さく形成されることから、す
べての経糸２は含浸合成樹脂によって繊維間が接着され
、繊維基材内のすべての経糸２は相互に平行を保たせし
められて広い接着面積で接着された一体構造を有する細
長横断面を谷部において呈することから、本発明板ばね
め第８図の横断面内に垂直方向に作用する荷重につ（ζ
では極めて優れた弾性と減衰性を示し、また板ばねの長
手方向に作用する荷重に対しても経糸が長手方向に揃え
て通されていることから強い強度と剛性を示すものであ
る。On the contrary, since the void 5 is formed extremely small, all the warps 2 are bonded between fibers by the impregnated synthetic resin, and all the warps 2 in the fiber base material are kept parallel to each other, resulting in wide bonding. Since the flat spring of the present invention exhibits an elongated cross-section with a monolithic structure in the valley part, the load acting vertically within the cross-section of FIG.
It exhibits extremely excellent elasticity and damping properties, and also exhibits strong strength and rigidity against loads that act in the longitudinal direction of the leaf spring because the warp threads are aligned in the longitudinal direction.

本発明における緯糸３は、前述したように経糸２の滑ら
かな線状と平行配列を損わない程度に緩くかつ間隔を置
いて挿入したもので、重量比にしても経糸と比較すれば
僅かなものではあるが、緯糸３が経糸２の上面および下
面を巻回するように挿入されて硬化合成樹脂により経糸
２に接着されていることにより、繰返し荷重の負荷によ
っても経糸の広い接着面積による接着とともに板ばねの
長さ方向（経糸の長さ方向）に沿う亀裂を防止し、ねじ
り応力に対しても十分な強度を発揮する。As mentioned above, the weft yarns 3 in the present invention are inserted loosely and at intervals to the extent that they do not impair the smooth linear shape and parallel arrangement of the warp yarns 2, and their weight ratio is small compared to the warp yarns. However, since the weft threads 3 are inserted so as to wrap around the upper and lower surfaces of the warp threads 2 and are bonded to the warp threads 2 using a hardened synthetic resin, the large adhesion area of the warp threads allows the warp threads to be bonded even under repeated loads. It also prevents cracks along the length of the leaf spring (the warp length direction) and provides sufficient strength against torsional stress.

前記一方向性繊維布の緯糸は経糸の整列を主なる役割り
とするものであるから、経糸間に挿入して経糸を波状に
屈曲せしめないため、その断面積または重量比を経糸の
それの１／３以下可及的に小なるものが好ましいが、経
糸間の分離に抗するために１／１００以上とするととが
好ましく、また緯糸間の間隔は経糸の幅の４倍以上繊維
布の幅（板ばねの幅）以下の間隔で経糸に挿入されるこ
とが好ましい。The weft yarns of the unidirectional fiber cloth have the main role of aligning the warp yarns, so in order to prevent the warp yarns from being inserted between the warp yarns and causing the warp yarns to bend in a wavy manner, the weft yarns of the unidirectional fiber cloth have a cross-sectional area or weight ratio that is smaller than that of the warp yarns. It is preferable that the spacing be as small as possible, 1/3 or less, but preferably 1/100 or more to prevent separation between the warp yarns, and the spacing between the weft yarns should be at least 4 times the width of the warp yarns of the fiber cloth. It is preferable that they be inserted into the warp threads at intervals equal to or less than the width (width of the leaf spring).

繊維布の幅以上の間隔とすると、経糸の配列を乱す原因
となり、板ばねの強度、剛性、耐久性の低下や品質のバ
ラツキを生ずるばかりでなく、成形にあたり合成樹脂含
浸の繊維布の取り扱いが困難となる。If the spacing is larger than the width of the fiber cloth, it will cause the warp yarns to be disarranged, resulting in a decrease in the strength, rigidity, and durability of the leaf spring, and variations in quality. It becomes difficult.

第３図に示す目玉部を有する本発明の自動車用板ばねは
、前記のように構成した合成樹脂含浸の繊維基材の長さ
方向の両端部はその一面に載置されたブツシュ６の外周
を巻回して内側に折り返され、ブツシュ内側の繊維基材
上面に重ねられて目玉部７を構成し、板ばねのリーフ部
の端部８と目玉部７との間に厚肉部９を形成するように
加圧成形されて合成樹脂を硬化せしめたものであって、
前記ばねと同様に板ばねのリープ部のほぼ中央部の厚さ
ｔｌはリーブ部の端部８の厚さｔ２ より大に形成され
、前記ブツシュ６に巻回された目主部７の厚さはｔ２に
等しく、厚肉部９の厚さｔ３は前記ｔ２のほぼ２倍に形
成されている。In the automobile leaf spring of the present invention having the center portion shown in FIG. is wound and folded back inward, and is overlapped on the upper surface of the fiber base material inside the bushing to form the centerpiece 7, and a thick wall portion 9 is formed between the end 8 of the leaf portion of the leaf spring and the centerpiece 7. It is made of hardened synthetic resin that is pressure molded to
Similar to the above-mentioned spring, the thickness tl of the approximately central portion of the leaf spring's leaf spring is larger than the thickness t2 of the end portion 8 of the leaf spring, and the thickness of the eye main portion 7 wound around the bushing 6 is greater than the thickness t2 of the end portion 8 of the leaf spring. is equal to t2, and the thickness t3 of the thick portion 9 is approximately twice the thickness t2.

このような目玉付板ばねを成形するには、ブツシュ６を
巻回して内側に折り曲げられ厚肉部９を形成すべき繊維
基材をその厚さ方向に押圧しながら加圧成形されるので
、繊維基材内部の経糸にその長さ方向の張力が加えられ
た状態で成形され合成樹脂によって接着されるので、一
層板ばわの強度を増し、目玉部によって自動車の車体に
取付けられるべき板ばねとして極めて有利である。In order to form such a leaf spring with eyelets, the bushing 6 is wound and bent inward, and the fiber base material to form the thick part 9 is press-formed while pressing in the thickness direction of the fiber base material. The warp inside the fiber base material is molded with longitudinal tension applied to it and bonded with synthetic resin, which further increases the strength of the leaf spring, making it ideal for use as a leaf spring to be attached to the body of an automobile using the centerpiece. This is extremely advantageous.

ここに本発明の一実施例を示す。An embodiment of the present invention is shown here.

繊維布の繊維束としてガラス繊維を使用し、合成樹脂と
してビニルエステル樹脂を用いた。Glass fiber was used as the fiber bundle of the fiber cloth, and vinyl ester resin was used as the synthetic resin.

繊度１３μのガラス・ファイバーよりなる太さ約１．８
關、単位重量２．４０ｇ／ｍのロービングを経糸とし、
該経糸を２３本平行に密に並列させ、一方繊度９μのガ
ラス・ファイバーよりなる太さ約０．４朋、単位重量０
．１５ｇ／ｍのヤーンを緯糸（経糸の断面積の１／１６
）とし、前記並列する経糸ＶＣ１５ｍｍ隔隔緩く挿入し
て繊維布を織成した。Approximately 1.8 in thickness made of glass fiber with a fineness of 13μ
The warp is made of roving with a unit weight of 2.40g/m.
23 of the warp yarns are closely arranged in parallel, and each one is made of glass fiber with a fineness of 9μ and has a thickness of about 0.4 mm and a unit weight of 0.
．． 15g/m yarn is used as weft (1/16 of warp cross-sectional area)
), and the parallel warp yarns VC were inserted loosely at intervals of 15 mm to weave a fiber cloth.

緯糸たけ張力をかけず、緩く経糸に交“〃に上面または
下面に巻回さ騒、耳部４は第４図に示すように最外側の
経糸に緩く巻回せしめて一方向性繊維布を形成したつ ビニル・エステル樹脂に硬化剤を加え、前記繊維布を経
糸の長手方向の長さを短かくしたものを含め２３枚用意
し、前記合成樹脂溶液に浸漬、脱泡せしめた後第２図に
示すように幅を揃えて重ね合わせ、第３図に示す目玉付
板ばねを成形した。The unidirectional fiber cloth is made by winding the weft threads loosely across the warp threads on the top or bottom surface without applying any tension.The selvage 4 is wound loosely around the outermost warp threads as shown in Figure 4 to make a unidirectional fiber cloth. A curing agent was added to the formed vinyl ester resin, and 23 pieces of the fiber cloth, including one whose warp length was shortened, were immersed in the synthetic resin solution and degassed. As shown in the figure, they were overlapped with the same width to form a leaf spring with eyelets as shown in Figure 3.

前記合成樹脂含浸の一方向性繊維布のガラス繊維含有率
は重量比にして７０％になるようにし、その成形条件は
金型による加圧をプレス圧２．０に９／ｃＩＲ２とする
。The glass fiber content of the synthetic resin-impregnated unidirectional fiber cloth is set to 70% by weight, and the molding conditions are such that the press pressure by the mold is 2.0 and 9/cIR2.

合成樹脂の硬化条件は１００℃において１時間加熱、さ
ら妃１２０℃で２時間アフタキュア処理を施した。The curing conditions for the synthetic resin were heating at 100°C for 1 hour and after-cure treatment at 120°C for 2 hours.

成形された目玉付板ばねは、ブツシュ６の中心間板長が
１２００＋ｔＡ幅５０１１！Ｗで、板ばね中央部の最も
厚い部分の板厚ｔ１は１８龍、該部分における繊維布の
積層数は２３層、リーフ部の端部８における板厚ｔ２は
１１朋、該部における繊維布の積層数は１４層、目玉部
７の肉厚は前記ｔ２ と同じであり、厚肉部の板厚ｔ３
は２２龍であった。The molded leaf spring with eyelets has a center-to-center plate length of the bushing 6 of 1200 + tA width 5011! W, the plate thickness t1 of the thickest part at the center of the leaf spring is 18 mm, the number of layers of fiber cloth in this part is 23 layers, the plate thickness t2 at the end 8 of the leaf part is 11 mm, the fiber cloth in this part The number of laminated layers is 14, the wall thickness of the eyeball part 7 is the same as t2 above, and the plate thickness of the thick part is t3.
There were 22 dragons.

上記板ばねのばね定数を測定したところ１．７ゆ／朋が
得られた（以下本発明板ばねと称する斥次に上記板ばね
のばね定数と同一の１．７に９／ｕｒｎのばね定数を有
し、目玉部の中心間板長が１２００ｍｍ、各リーフの板
幅が５０朋である鋼板（ＳＵＰ６車の重ね板ばねを構成
したところ、４枚構成の重ね板ばねであって、各構成板
ばねの板厚が６朋（前記本発明板ばねのｔ２に相当）、
中央部のセンタボルトにより締着けられた最も厚さの大
なる部分の厚さが２４ｍｍ（前記本発明板ばねのｔｌに
相当）が得られた（以下公知板ばねと称する）。When the spring constant of the above leaf spring was measured, a spring constant of 1.7/urn was obtained (hereinafter referred to as the leaf spring of the present invention). The steel plate has a center-to-center plate length of 1200 mm at the center of the eye, and a plate width of each leaf of 50 mm. The plate thickness of the plate spring is 6 mm (corresponding to t2 of the plate spring of the present invention),
A thickness of 24 mm (corresponding to tl of the leaf spring of the present invention) at the thickest portion tightened by the center bolt at the center was obtained (hereinafter referred to as a known leaf spring).

そこで、本発明板ばねと公知板ばねとを同一の荷重条件
（２３４ｋｇ±１３６に９）で繰返し荷重試験を行った
ところ、公知板ばねの繰返し寿命回数がｌ０ＸＩＯ’回
であったの洗対し、本発明板ばねの繰返し寿命回数は２
０ Ｘ １０’回以上であり、公知板ばねに対し２倍以
上Ω耐久性を示した。Therefore, when the leaf spring of the present invention and the known leaf spring were subjected to a cyclic load test under the same load conditions (234 kg ± 136 to 9), the cycle life of the known leaf spring was 10XIO' times, in contrast to that of the known leaf spring. The number of cycles of the leaf spring of the present invention is 2.
0 x 10' times or more, showing ohm durability more than twice that of known leaf springs.

以上詳説した本発明の実施例は、繊維基材を構成する繊
維布のすべてを一方向性繊維布としたものであって、こ
れにより同一板長でばね定数の等しい従来の鋼製重ね板
ばねの２倍早上の耐久性を示したものであるが、耐久性
をこれほど必要とせず、従来の鋼製重ね板ばねと同等で
差し支えない用途の板ばねにおいては、繊維基材を構成
する繊維布の一部を一方向性繊維布の積層とすることが
できる。In the embodiment of the present invention described in detail above, all of the fiber cloth constituting the fiber base material is made of unidirectional fiber cloth. However, in leaf springs for applications that do not require this much durability and can be equivalent to conventional steel laminated leaf springs, the fibers that make up the fiber base material A portion of the fabric may be a laminate of unidirectional fiber fabrics.

即ち、軽量で走行頻度の高℃第動単に用いる板ばねとし
ては、繊維基材の最外層部の何れか一面または両面に数
枚づつ積層せしめることにより、板ばわの高応力部とな
る引張り側または圧縮側表面もしくはその両面に、経糸
を平行せしめて弛みなく平滑な線状に平行させ、かつ広
い表面積で接着した高耐久性層が形成され、苛酷な使用
条件に耐える軽量の板ばねな構成することができる。In other words, for leaf springs that are lightweight and used in high-temperature, high-temperature motions that run frequently, they can be made by laminating several sheets on either or both sides of the outermost layer of the fiber base material to reduce tension, which is the high-stress area of the leaf. A highly durable layer is formed on the side or compressed side surface or both sides, with the warp yarns parallel to each other in a smooth linear shape without slack, and bonded over a wide surface area, making it a lightweight leaf spring that can withstand harsh usage conditions. Can be configured.

また構内用重量運搬車のように、積載重量は大きいが走
行距離が短かく平坦路のみ走行する車輛に用いる板ばね
としては、繊維基材の中央部の板厚を増加せしめる部分
の内部に前詰一方向性繊維布の積層を用いることができ
る。In addition, for leaf springs used in vehicles that can carry a large load but have a short mileage and travel only on flat roads, such as heavy-duty transport vehicles for premises, it is recommended that a leaf spring be installed inside the central part of the fiber base material to increase the plate thickness. Laminations of packed unidirectional fiber fabrics can be used.

特に目玉付きの板ばねにおいては、ブツシュを巻回する
目玉部の繊維基材に前記一方向性繊維布を積層すること
により目玉部の強度、耐久性を向上せしめる効果は顕著
であり、この積層が図示した厚肉部にも及ぶことによっ
て、板ばねの長手方向応力やねじり応力によって目玉部
近傍に破壊を生ずる危険をなくし、目玉部近傍を補強す
る効果は顕著である。Particularly in the case of leaf springs with eyelets, the strength and durability of the eyelet portion is significantly improved by laminating the unidirectional fiber cloth on the fiber base material of the eyelet portion around which the bushing is wound. By extending this to the thick portion shown in the figure, there is a remarkable effect of eliminating the risk of breakage in the vicinity of the eyepiece due to longitudinal stress or torsional stress of the leaf spring, and reinforcing the vicinity of the eyepiece.

以上詳細に説明したように本発明の板ばねは繊維基材に
合成樹脂を含浸させ、加圧成形して合成樹脂を硬化せし
めた自動車用板ばねにおいて、繊維基材を構成する積層
された繊維布の長さ方向中央部の板厚を最も厚く、端部
に至るに従い次第に板厚を薄くするように積層して成形
され、かつ前記繊維布の積層の一部または全部を、長繊
維よりなる連続せしめた繊維束を経糸とし、長繊維によ
って連続せしめられかつその断面積または単位重量が経
糸のそれの１／３以下の繊維束を緯糸とし、前記経糸を
その長さ方向が相互に平行するように弛みなく平滑な線
をなして並列せしめ、前記緯糸を前記経糸の幅の４倍以
上の間隔を保たせて緩く前記経糸の上下面に巻回される
ように織り込んだ一方向性繊維布とし、この一方向繊維
布はその経糸が相互に平行するように積層されて加圧変
形されており、繊維布に含浸せしめられた合成樹脂は一
方向繊維布の経糸を広い表面積で隣接させて接着し一体
化しているものであるから、前記一方向性繊維布の経糸
の一体接着構造は板ばねの強度、剛性および耐久性の大
部分を負担し、かつ該一体接着構造の内部には白化現象
を生ずる危険の大なる合成樹脂塊は含まれないので、繰
返し荷重に対し、その重量に比して大なる耐久性を示す
ものであって、自動車の板ばねとして゛要求される横応
力、ねじり応力にも強く、かつ軽量であって、独特の弾
性と振動減衰性を示すものということができる。As explained in detail above, the leaf spring of the present invention is an automotive leaf spring in which a fiber base material is impregnated with a synthetic resin, and the synthetic resin is cured by pressure molding. The fabric is formed by laminating the fabric so that the thickness is greatest at the center in the longitudinal direction and gradually becomes thinner toward the ends, and part or all of the laminated fiber cloth is made of long fibers. A continuous fiber bundle is used as a warp, and a fiber bundle that is continuous by long fibers and whose cross-sectional area or unit weight is 1/3 or less of that of the warp is used as a weft, and the longitudinal directions of the warp are parallel to each other. A unidirectional fiber cloth woven in such a way that the weft threads are arranged in parallel in smooth lines without slack, and the weft threads are wound loosely around the upper and lower surfaces of the warp threads with an interval of at least four times the width of the warp threads. This unidirectional fiber cloth is laminated and deformed under pressure so that its warp threads are parallel to each other, and the synthetic resin impregnated into the fiber cloth causes the warp threads of the unidirectional fiber cloth to be adjacent to each other over a wide surface area. Since the warp yarns of the unidirectional fiber cloth are bonded and integrated, the integral bonding structure of the warp yarns of the unidirectional fiber cloth provides most of the strength, rigidity, and durability of the leaf spring, and there is no whitening inside the integral bonding structure. Since it does not contain synthetic resin lumps that pose a risk of causing damage, it exhibits high durability relative to its weight against repeated loads, and has the ability to withstand the lateral stress required for automobile leaf springs. It can be said to be strong against torsional stress, lightweight, and exhibit unique elasticity and vibration damping properties.

特に繊維基材を前記一方向性繊維布で構成し、その経糸
をすべて長さ方向に平行させて一体に接着したものにお
いては同一板長、同一ばね定数の従来の鋼製４枚構成の
重ね板ばねの２倍以上の耐久性を、単板の板ばねで達成
し得る優れた自動車用板ばねな得ることができる大なる
特長を有する。In particular, in the case where the fiber base material is made of the above-mentioned unidirectional fiber cloth, and the warp threads are all parallel to each other in the length direction and are bonded together, the conventional four-sheet structure made of steel with the same length and the same spring constant can be stacked. It has the great advantage of being an excellent automotive leaf spring that can achieve durability more than twice that of a leaf spring with a single leaf spring.

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

第１図は本発明の−の実施の態様を示す側面図、第２図
は本発明を構成する繊維基材における繊維布の配列の→
りを示す概念図、第３図は本発明の他の実施の態様を示
す側面図、第４図は本発明の一方向性繊維布の上面図、
第５図は第４図ｖ−ｖ線に沿う断面図、第６図は第４図
ＶＩ−Ｖｌ線に沿う断面図、第７図は本発明板ばねの縦
断面図の一部を示す概念図、第８図は同じく横断面の一
部を示す概念図である。 なお図中、１は繊維布、２は経糸、３は緯糸、４はその
耳部、５は空隙、６はブツシュ、１は目玉部、８はリー
フ部端部、９は厚肉部、１０は繊維基材、ＩＬ １２，
１３は繊維布をそれぞれ示す。Fig. 1 is a side view showing an embodiment of the present invention, and Fig. 2 is a side view showing the arrangement of the fiber cloth in the fiber base material constituting the present invention.
FIG. 3 is a side view showing another embodiment of the present invention, FIG. 4 is a top view of the unidirectional fiber cloth of the present invention,
5 is a sectional view taken along the line v-v in FIG. 4, FIG. 6 is a sectional view taken along the line VI-Vl in FIG. FIG. 8 is a conceptual diagram showing a part of the cross section. In the figure, 1 is the fiber cloth, 2 is the warp, 3 is the weft, 4 is the edge, 5 is the gap, 6 is the bush, 1 is the eye, 8 is the end of the leaf, 9 is the thick part, 10 is a fiber base material, IL 12,
13 each indicates a fiber cloth.

Claims (1)

【特許請求の範囲】 １ 繊維束を織成した複数枚の繊維布を重ねた繊維基材
に合成樹脂を含浸させ、加圧成形して合成樹脂を硬化せ
しめた自動車用板ばねにおいて、前記繊維布はすべて同
一の福を有し、かつ長さの異るものを包含しており、そ
の長さの短い繊維布を長さ方向の中央部付近に配設して
、その長さ方向の中央部付近の板厚を最も厚く長さ方向
の端部に向うに従い板厚を薄くするように積層されて加
圧成形されており、 前記繊維布の一部または全部が、長繊維よりなる連続せ
しめた繊維束を経糸とし、これを長さ方向が相互に平行
するように弛みなく平滑な線状に並列せしめられ、長繊
維によって連続せしめられかつその断面積または単位重
量において前記経糸の１／３以下の繊維束を緯糸として
、前記経糸の繊維束の幅の４倍以上の間隔を保たせて緩
く前記経糸の上面または下面に巻回きれるように前記経
糸に織り込まれている一方向性繊維布よりなり、前記一
方向性繊維布は、すべての経糸がその長さ方向に平行す
るように積層されて加圧変形されており、 前記繊維基材に含浸の合成樹脂の硬化マトリックスによ
りすべての繊維束間は充填され、前記一方向性繊維布の
経糸は広い表面積により相互に隣接されて接着されてい
ることを特徴とする自動車用板ばね。 ２ 前記一方向性繊維布は、板ばねの最高応力部である
表層部を構成していることを特徴とする特許請求の範囲
第１項に記載の自動車用板ばね。 ３ 前記一方向性繊維布は、板ばねの厚さ方向中央部の
積層部を構成していることを特徴とする特許請求の範囲
第１項に記載の自動車用板ばね。 ４ 前記繊維基材を構成する積層された繊維布はすべて
前記一方向性繊維布であり、該繊維布の経糸はすべて相
互に平行するように弛みなく平滑な線状に並列せしめら
れて加圧変形されており、これら経糸が相互に広い表面
積で硬化合成樹脂により一体に接着されていることを特
徴とする特許請求の範囲第１項に記載の自動車用板ばね
。 ５ 繊維束を織成した複数枚の繊維布を積層した繊維基
材に合成樹脂を含浸させ、加圧成形して合成樹脂を硬化
せしめた自動車用板ばねにおいて、前記繊維布はすべて
同一の幅を有し、かつその長さの異るものを包含してお
り、その長さの短い繊維布を長さ方向の中央部付近に配
設して、その長手方向の中央部付近の板厚を最も厚く、
その長さ方向の端部に向うに従い板厚を薄くするように
積層されて加圧成形されており、 前記繊維布の少くと□も最外層部または全部が、長繊維
よりなる連続せしめた繊維束を経糸とし、これを長さ方
向が相互に平行するように弛みなく平滑な線状に並列せ
しめられ、長繊維によって連続せしめられかつその断面
積または単位重量において前記経糸の１／３以下の繊維
束を緯糸として、前記経糸の幅の４倍以上′の間隔を保
たせて緩く前記経糸の上面または下面に巻回されるよう
に前記経糸に織り込まれている一方向性繊維布よりなり
、前記一方向性繊維布は、すべての経糸がその長さ方向
に平行するように積層されて加圧変形されており、 該繊維基材の両端部はその一面に載置されたブツシュの
外周を巻回して内側に折り返され、ブツシュ内側の繊維
基材上に重ねられて目玉部を構成され、 前記繊維基材に含浸の合成樹脂の硬化マトリックスは、
すべての繊維束間に充填され、前記一方向性繊維布の経
糸は相互に隣接する経糸と広い表面積により接着されて
いることを特徴とする自動車用板ばね。 ６ 前記繊維束を構成する積層された繊維布はすべて前
記一方向性繊維布よ、りなり、該繊維布の経糸はすべて
相互に平行するように弛みなく平滑な線状に並列せしめ
られて加圧変形されており、これら経糸がその全長に沿
って広い表面積で硬化合成樹脂のマトリックスにより相
互に隣接されて一体に接着されていることを特徴とする
特許請求の範囲第５項に記載９自動車用板ばね。[Scope of Claims] 1. A leaf spring for an automobile in which a fiber base material made of a plurality of stacked fiber cloths woven from fiber bundles is impregnated with a synthetic resin, and the synthetic resin is cured by pressure molding, wherein the fiber cloth is All have the same fortune and include those of different lengths, and by placing the short fiber cloth near the center in the length direction, The fiber cloth is laminated and pressure-molded so that the thickness of the cloth is thickest near the end and becomes thinner toward the end in the length direction, and part or all of the fiber cloth is made of continuous fibers made of long fibers. Fiber bundles are used as warp threads, which are lined up in a smooth line without slack so that their longitudinal directions are parallel to each other, and are continuous with long fibers, and whose cross-sectional area or unit weight is 1/3 or less of the warp threads. From a unidirectional fiber cloth that is woven into the warp so that it can be loosely wound around the upper or lower surface of the warp at intervals of at least four times the width of the fiber bundle of the warp, using the fiber bundle as the weft. The unidirectional fiber cloth is laminated and deformed under pressure so that all the warps are parallel to the length direction, and all the fiber bundles are formed by a hardening matrix of synthetic resin impregnated in the fiber base material. A leaf spring for an automobile, characterized in that the spaces between the fibers are filled, and the warp threads of the unidirectional fiber cloth are adjacent to each other and bonded together over a large surface area. 2. The automobile leaf spring according to claim 1, wherein the unidirectional fiber cloth constitutes a surface layer portion which is the highest stress portion of the leaf spring. 3. The leaf spring for an automobile according to claim 1, wherein the unidirectional fiber cloth constitutes a laminated portion at a central portion in the thickness direction of the leaf spring. 4 All of the laminated fiber cloths constituting the fiber base material are the unidirectional fiber cloths, and the warp threads of the fiber cloths are all parallel to each other in a smooth line without slack and are pressed. 2. A leaf spring for an automobile according to claim 1, wherein the warp threads are bonded together with a hardened synthetic resin over a large surface area. 5. In a leaf spring for an automobile in which a fiber base material is made by laminating a plurality of fiber cloths made of woven fiber bundles, impregnated with a synthetic resin, and pressure-molded to harden the synthetic resin, all the fiber cloths have the same width. The fiber cloth with the shortest length is placed near the center in the longitudinal direction, and the thickness of the fabric near the center in the longitudinal direction is maximized. thick,
The fiber cloth is laminated and pressure-molded so that the thickness becomes thinner toward the ends in the length direction, and at least the outermost layer or all of the fiber cloth is made of continuous fibers made of long fibers. The bundles are used as warp threads, which are lined up in a smooth line without slack so that their longitudinal directions are parallel to each other, are continuous with long fibers, and have a cross-sectional area or unit weight of 1/3 or less of the warp threads. It is made of a unidirectional fiber cloth that is woven around the warp so that the fiber bundle is used as the weft and is loosely wound around the upper or lower surface of the warp at an interval of at least 4 times the width of the warp, The unidirectional fiber cloth is laminated and deformed under pressure so that all the warp yarns are parallel to the length direction, and both ends of the fiber base material extend around the outer periphery of a bushing placed on one surface of the unidirectional fiber cloth. It is wound and folded inward, and is layered on the fiber base material inside the bushing to form the centerpiece, and the hardened matrix of synthetic resin impregnated in the fiber base material is
A leaf spring for an automobile, characterized in that all the fiber bundles are filled between the fiber bundles, and the warp threads of the unidirectional fiber cloth are bonded to mutually adjacent warp threads by a large surface area. 6. All of the laminated fiber cloths constituting the fiber bundle are made of the unidirectional fiber cloth, and the warp threads of the fiber cloths are all parallel to each other in a smooth line without slack. 9. An automobile according to claim 5, characterized in that the warp threads are bonded together and adjacent to each other by a matrix of hardened synthetic resin over a large surface area along their entire length. Leaf spring for use.