JP3596380B2

JP3596380B2 - Resin gear

Info

Publication number: JP3596380B2
Application number: JP30842999A
Authority: JP
Inventors: 昭治沢井; 伸一田原
Original assignee: Shin Kobe Electric Machinery Co Ltd
Current assignee: Resonac Corp
Priority date: 1999-10-29
Filing date: 1999-10-29
Publication date: 2004-12-02
Anticipated expiration: 2019-10-29
Also published as: JP2001124179A

Description

【０００１】
【発明の属する技術分野】
本発明は、自動車部品等として適した樹脂製歯車に関する。
【０００２】
【従来の技術】
上記樹脂製歯車は、歯の噛み合い時の騒音発生を抑えるために、金属製歯車と噛み合う相手歯車として用いられ、耐摩耗性に優れ、高い強度が要求される。従来、樹脂製歯車として、樹脂を含浸した補強繊維基材のリング状成形体に歯を加工したものが提案されている。例えば、次のような技術である。
（１）補強繊維をフェノール樹脂粉末と共に水中に分散して抄造したシート状繊維基材を重ね巻きし、中心には空間を残したリング状の補強繊維基材とする。このリング状の補強繊維基材を厚さ方向に加熱加圧成形してリング状成形体とし、このリング状成形体の周囲に切削加工により歯を形成する（特開平１０−２８６８８８号公報）。
（２）補強繊維を束ねた糸を織って又は編んで筒状体を構成し、この筒状体を端部から軸方向に巻き上げてリング状の補強繊維基材とする。そして、リング状の補強繊維基材に樹脂を含浸して、厚さ方向に加熱加圧成形又は加圧成形してリング状成形体とし、このリング状成形体の周囲に切削加工により歯を形成する（特開平８−１５６１２４号公報）。
【０００３】
これらの技術においては、リング状の補強繊維基材の周方向のつなぎ目が目立たないか、つなぎ目が全くないので、特定の箇所で強度が低下するという問題が一応回避されている。
【０００４】
【発明が解決しようとする課題】
上記（１）の技術では、補強繊維基材の周方向のつなぎ目が目立たないといっても、不織布の巻き始めと巻き終わりの端縁に軸方向のつなぎ目が線状に現れる。従って、このつなぎ目箇所での強度低下は多少であっても避けられない。
【０００５】
上記（２）の技術は、つなぎ目がないという点では申し分ない。しかし、補強繊維を束ねた糸を織ったり編んだりするため織目や編目ができ、（１）の技術に比べて補強繊維の粗密が大きくなる。また、補強繊維を束ねた糸の内部まで樹脂が浸透しにくい。補強繊維を束ねた糸を織ったり編んだりした基材を使用しているため、歯車の強度は十分に大きいわけであるが、さらに、補強繊維に粗密がなく樹脂が補強繊維間に十分に浸透したものであることが望まれる。
また、補強繊維として芳香族ポリアミド繊維など高強度の繊維を採用した場合には、その繊維を収束した糸が歯の切削加工時に切断されずに切削面に残りやすい。
【０００６】
本発明が解決しようとする課題は、リング状補強繊維基材のつなぎ目を極力目立たないようにして強度を均一にし、また、補強繊維の粗密を作らず補強繊維間に樹脂が十分に浸透した樹製脂歯車とし、長寿命の樹脂製歯車とすることである。
【０００７】
【課題を解決するための手段】
本発明に係る樹脂製歯車は、樹脂を含浸した補強繊維基材のリング状成形体により歯部を構成したものであって、上記課題を解決するために次のような構成を有する。
まず、前記補強繊維基材は、帯状の不織布を重ね巻きして筒状にし、さらにその筒状体を軸方向に蛇腹状に折り畳んだ構成を有する。そして、前記筒状に重ね巻きした不織布の巻き始め端縁と巻き終わり端縁不織布を構成する補強繊維を毛羽立たせたことを特徴とする。
【０００８】
上記筒状体を軸方向に蛇腹状に折り畳んだ構成の補強繊維基材を成形し、そのリング状成形体で歯車の歯部を構成する場合、他の箇所との強度の差ができやすいのは巻き始め端縁と巻き終わり端縁である。そこで、上記のように補強繊維を毛羽立たせることにより、巻き始め端縁と巻き終わり端縁が線状にはっきりと現れないようにすることができる。また、端縁から毛羽立たせた補強繊維は重ね巻きした不織布の表面に絡み付きやすくなる。これらの作用により、巻き始め端縁と巻き終わり端縁箇所に他の箇所との強度の差ができにくくなる。
【０００９】
もう一つの発明では、前記筒状に重ね巻きした不織布の巻き始め端縁と巻き終わり端縁はジグザグに形成したことを特徴とする。この場合にも、巻き始め端縁と巻き終わり端縁が線状にはっきりと現れなくなり、強度の差ができにくくなる。さらに、ジグザグの端縁から補強繊維を毛羽立たせると、さらに端縁が目立たなくなる。
【００１０】
【発明の実施の形態】
不織布を構成する補強繊維には、綿や麻等の天然繊維、ポリエステル、フッ素樹脂、パラ系芳香族ポリアミド、メタ系芳香族ポリアミド等の有機繊維、ガラスやステンレス等の無機繊維を適宜採用することができる。これらの繊維は、歯車の特性を勘案して、単独で採用してもよいし複数種類を組合せて採用してもよい。これら補強繊維を集積して不織布を構成するが、補強繊維の集積には、水中で抄造する湿式と気中で散布して集積する乾式のいずれの手段も採用できる。乾式の方が廃液処理の工程を必要としないので都合がよい。
不織布は、単に補強繊維を集積してシート状にしただけのものでもよいが、これは補強繊維同士の絡み合いが少なく引張り強度が小さい。そこで、厚さ方向に配向させた補強繊維で面方向に配向した補強繊維同士を結合して引張り強度を大きくするとよい。このような不織布は通常フェルトと呼ばれ好ましいものである。フェルトは、補強繊維の集積体にニードリングを施すことにより製造できる。
【００１１】
補強繊維の集積体に施すニードリングは、採用する補強繊維の種類に応じて植針密度を適宜設定する。切断を起こしやすいガラス繊維や金属繊維に対しては植針密度を小さくしなければならないが、切断を起こしにくい芳香族ポリアミド繊維等に対しては植針密度を高くすることができる。植針密度の大小で、フェルトの厚さ方向を向く補強繊維の量を変えることができ、フェルトの密度と引張り強度を適宜調整する。
【００１２】
適度に引張り強度を付与した帯状のフェルトを重ね巻きして筒状にし、さらにその筒状体を軸方向に蛇腹状に折り畳んだリング状の補強繊維基材を形成する。重ね巻きに際して、フェルトの巻き終わり端縁、必要に応じて巻き始め端縁を引っ掻くようにして或いは梳くようにして、補強繊維を端縁から毛羽立たせる。
帯状のフェルトを重ね巻きした上記筒状体は、重ね巻きしたフェルト層間が一体になっていない。しかし、かえってこのことが、筒状体を軸方向に圧縮して蛇腹状にきれいに折り畳む上で好都合となっている。蛇腹状に折り畳む際にフェルト層間に滑りが生じて、きれいに蛇腹状に折り畳め、折り畳み後はフェルト層間を一体化したのと同じ状態にすることができる。帯状のフェルトを構成している補強繊維同士は強固に結合されているので、蛇腹状に折り畳むに際して補強繊維の配向が乱れることはない。また、筒状体を蛇腹状にきれいに折り畳むことができれば折り畳んだ後の補強繊維の配向は乱れない。
【００１３】
リング状成形体の成形は、上記補強繊維基材に適宜の樹脂を含浸して行なう。例えば、補強繊維基材にフェノール樹脂を予め含浸乾燥しておき、これを成形金型に投入し中心には金属製ブッシュを配置して加熱加圧成形をする。別の方法では、補強繊維基材を成形金型に投入し中心には金属製ブッシュを配置して成形金型を閉じ、液状樹脂（架橋ポリアミノアミド、エポキシ樹脂、ポリイミドなど）を注入して加熱成形する。
さらに別の方法では、フェルトを製造するときに樹脂微粒子を混入しておく。、すなわち、湿式法による製造では水中で補強繊維を抄造する段階で、乾式法による製造では気中で補強繊維を散布・集積する段階で、フェノール樹脂等の微粒子を混入する。このような樹脂微粒子含有フェルトを用いて形成したリング状の補強繊維基材は、成形金型に投入してそのまま加熱加圧成形することができる。
【００１４】
リング状の補強繊維基材一つで一つの歯車を成形してもよいし、リング状の補強繊維基材を複数個重ねて一体に成形し、歯幅の大きい歯車の製造に対処することもできる。
【００１５】
【実施例】
実施例１
パラ系アラミド繊維原綿（繊維径５〜２０μｍ，繊維長５０ｍｍ）とメタ系アラミド繊維原綿（繊維径５〜２０μｍ，繊維長５０ｍｍ）を重量比で５０／５０の割合で気中に散布して集積し、これにニードリングを施して、幅２０００ｍｍ，厚さ３ｍｍ，単位重量１５０ｇ／ｍ^２のフェルト１を準備した。図３に示すように、フェルト１は厚さ方向を向いた補強繊維１１が平面方向を向いた補強繊維１２同士を結合した構成を有している。このフェルト１を１００ｍｍの幅に裁断し次に説明するように重ね巻きするわけであるが、重ね巻きに先立ち、フェルトの巻き始め端縁と巻き終わり端縁には引っ掻き処理を施し、補強繊維を毛羽立たせる。針を植設したブラシ３０でフェルト１の端縁に引っ掻き処理を施し、補強繊維を毛羽立たせる様子を示している。図１（ａ）に示すように、巻き始め端縁と巻き終わり端縁に毛羽立たせ処理をしたフェルト１を所定の軸に４回重ね巻きし、外径９０ｍｍ，内径６０ｍｍ，高さ１００ｍｍの筒状体２とする。そして、図１（ｂ）に示すように、筒状体２を予備成形型内で軸方向に圧縮し、蛇腹状に折り畳んで外径９０ｍｍ，内径６０ｍｍ，厚さ２０ｍｍのリング状の補強繊維基材３とする。
次に、図２に示すように、２個積み重ねたリング状の補強繊維基材３を、その中心に配置した金属製のブッシュ４とともに２００℃の成形金型５に投入し、型締めしてから架橋ポリアミノアミドを注入して加熱成形した。歯車の歯は、補強繊維基材３で成形されたリング状成形体の周囲に機械切削により形成し、樹脂製歯車とした。その特性を表１に示す。
【００１６】
実施例２
上記実施例１において、フェルトを重ね巻きしてリング状の補強繊維基材３を構成するに先立ち、フェルト１の巻き始め端縁と巻き終わり端縁を毛羽立たせる代わりにジグザグに裁断処理した。その他は実施例１と同様にして樹脂製歯車を製造した。その特性を表１に示す。図５（ａ）は、フェルト１の巻き始め端縁と巻き終わり端縁をジグザグに形成してから重ね巻きする様子を示している。図５（ｂ）は、重ね巻きした筒状体２を示しており、両端縁は、筒状体２の軸方向に対して斜めになっている。
【００１７】
実施例３
上記実施例２において、ジグザグ裁断処理したフェルトの巻き始め端縁と巻き終わり端縁にさらに引っ掻き処理を施し、補強繊維を毛羽立たせた。その他は実施例２と同様にして樹脂製歯車を製造した。その特性を表１に示す。
【００１８】
比較例１
上記実施例１において、フェルトの巻き始め端縁と巻き終わり端縁に引っ掻き処理もジグザグ裁断処理も施さず、その他は実施例１と同様にして樹脂製歯車を製造した。その特性を表１に示す。
【００１９】
実施例４
パラ系アラミド繊維チョップ（繊維径５〜２０μｍ，繊維長３ｍｍ）及びメタ系アラミド繊維チョップ（繊維径５〜２０μｍ，繊維長３ｍｍ）を、重量比で５０／５０の割合で水に分散し、これを連続抄造して幅９６０ｍｍ，厚さ３ｍｍ，単位重量１５０ｇ／ｍ^２の不織布とした。この不織布を１００ｍｍの幅に裁断し所定の軸に４回重ね巻きして、外径９０ｍｍ，内径６０ｍｍの筒状体とする。この筒状体を予備成形型内で軸方向に圧縮し、外径９０ｍ，内径６０ｍｍ，厚さ２０ｍｍのリング状の補強繊維基材とする。前記重ね巻きに先立ち、フェルトの巻き始め端縁と巻き終わり端縁には引っ掻き処理を施し、補強繊維を毛羽立たせた。尚、この不織布は、補強繊維同士の結合が弱く、重ね巻きした筒状体を軸方向に圧縮したとききれいに蛇腹状に折り畳むことができず、繊維の配向が乱れた。
上記リング状の補強繊維基材を用いて、以下実施例と同様に樹脂製歯車とした。その特性を表１に示す。
【００２０】
従来例１
上記実施例４において、不織布の巻き始め端縁と巻き終わり端縁に引っ掻き処理を施さず、その他は実施例４と同様にして樹脂製歯車を製造した。その特性を表１に示す。
【００２１】
従来例２（図６参照）
パラ系アラミド繊維及びメタ系アラミド繊維を、重量比で５０／５０の割合で混紡した糸をニット編みして筒状体６を構成した。この筒状体６を端部から軸方向に巻き上げて、外径９０ｍｍ，内径６０ｍｍ，厚さ２０ｍｍのリング状の補強繊維基材３とする。
上記リング状の補強繊維基材を用いて、以下実施例１と同様に樹脂製歯車とした。その特性を表１に示す。
【００２２】
表１に示した各特性の測定は次のようにして行なった。尚、各例の樹脂製歯車の樹脂中に占める補強繊維の含有量はいずれも同じである。
曲げ強度は、製造した樹脂製歯車の歯部から切り出した円弧状試料の曲げ強度（初期強度）を測定したものである。試料は、巻き終わり端縁相当箇所から切り出した試料１と他の箇所から切り出した試料２である。
実装耐久時間は、自動車エンジンのギヤ加速テスト（回転数：６０００ｒｐｍ，油温１３０℃，歯元負荷応力２５５ＭＰａ）での耐久時間を測定した。
【００２３】
【表１】

【００２４】
【発明の効果】
本発明に係る樹脂製歯車は、リング状補強繊維基材のつなぎ目が目立たなくなるので、つなぎ目に相当する箇所とそうでない箇所の強度に差がなくなる。
特に、不織布としてフェルトを選択すると（実施例１〜３）、補強繊維の糸を織ったり編んだりしない点で実施例４と同様の補強繊維基材構成であるにもかかわらず、大きな機械強度を保持させることができる。補強繊維同士が強固に結合されたフェルトを重ね巻きした筒状体を蛇腹状に折り畳んだ構成が有効に作用しており、その強度は、補強繊維の糸を編んだ補強繊維基材構成である従来例２に比べると多少劣るものの、それに匹敵するものである。そして、補強繊維の糸を織ったり編んだ場合に見られた補強繊維の粗密がなく、水分や油分が歯車表面から内部に侵入しにくいので、耐久性がさらに向上している。
【図面の簡単な説明】
【図１】本発明に係る実施例においてフェルトからリング状の補強繊維基材を製造する工程を示す説明図である。
【図２】本発明に係る実施例において補強繊維基材を成形する様子を示す断面説明図である。
【図３】フェルトを構成する補強繊維の配向状態を示す概念説明図である。
【図４】フェルトの端縁に引っ掻き処理を施す様子を示す説明図である。
【図５】本発明に係る他の実施例においてフェルトから補強繊維基材を製造する様子を示す説明図である。
【図６】従来例２において、樹脂製歯車を製造する工程の一部を示す説明図である。
【符号の説明】
１：フェルト
１１：厚さ方向を向いた補強繊維
１２：平面方向を向いた補強繊維
２：筒状体
３：リング状の補強繊維基材
４：ブッシュ
５：成型金型
６：筒状体
３０：ブラシ[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a resin gear suitable as an automobile part or the like.
[0002]
[Prior art]
The resin gear is used as a mating gear that meshes with a metal gear in order to suppress the generation of noise when the teeth mesh with each other, and is required to have excellent wear resistance and high strength. BACKGROUND ART Conventionally, as a resin gear, there has been proposed a gear formed by processing teeth into a ring-shaped molded body of a reinforcing fiber base material impregnated with a resin. For example, the following technology is used.
(1) A sheet-like fiber base material formed by dispersing reinforcing fibers in water together with a phenolic resin powder is wound in a stack, and a ring-shaped reinforcing fiber base body is left with a space in the center. This ring-shaped reinforcing fiber base material is heated and pressed in the thickness direction to form a ring-shaped molded body, and teeth are formed around the ring-shaped molded body by cutting (Japanese Patent Laid-Open No. 10-286888).
(2) A tubular body is formed by weaving or knitting a yarn obtained by bundling reinforcing fibers, and the tubular body is rolled up in an axial direction from an end to form a ring-shaped reinforcing fiber base material. Then, a resin is impregnated into the ring-shaped reinforcing fiber base material, and heated and pressed or pressed in the thickness direction to form a ring-shaped body, and teeth are formed around the ring-shaped body by cutting. (JP-A-8-156124).
[0003]
In these techniques, the circumferential joint of the ring-shaped reinforcing fiber base material is inconspicuous or has no joint, so that the problem that the strength is reduced at a specific location is temporarily avoided.
[0004]
[Problems to be solved by the invention]
According to the technique (1), even though the seam in the circumferential direction of the reinforcing fiber base is inconspicuous, the seam in the axial direction appears linearly at the edges at the start and end of winding of the nonwoven fabric. Therefore, a slight decrease in strength at the joint is unavoidable.
[0005]
The technique (2) is satisfactory in that there is no seam. However, weaving or knitting the yarn obtained by bundling the reinforcing fibers results in a weave or stitch, and the density of the reinforcing fibers becomes larger than that of the technique (1). In addition, the resin hardly penetrates into the inside of the yarn in which the reinforcing fibers are bundled. The strength of the gears is large enough because the base material is made of woven or knitted yarn that bundles reinforcing fibers, but the reinforcing fibers are not dense and dense, and the resin penetrates sufficiently between the reinforcing fibers. It is hoped that it is done.
When a high-strength fiber such as an aromatic polyamide fiber is used as the reinforcing fiber, a thread converging the fiber is likely to remain on the cutting surface without being cut at the time of cutting the teeth.
[0006]
The problem to be solved by the present invention is to make the joints of the ring-shaped reinforcing fiber base as inconspicuous as possible to make the strength uniform, and to make the resin sufficiently penetrated between the reinforcing fibers without making the reinforcing fibers dense and dense. That is, a resin gear having a long life is used as an oil-made gear.
[0007]
[Means for Solving the Problems]
The resin gear according to the present invention has a tooth portion formed of a ring-shaped molded body of a reinforcing fiber base material impregnated with a resin, and has the following configuration in order to solve the above problem.
First, the reinforcing fiber substrate has a configuration in which a band-shaped nonwoven fabric is wound in a pile to form a tube, and the tube is folded in a bellows shape in the axial direction. In addition, the reinforcing fibers constituting the winding start edge and the winding end edge nonwoven fabric of the nonwoven fabric layered and wound in a cylindrical shape are fluffed.
[0008]
When forming a reinforcing fiber base having a configuration in which the cylindrical body is folded in a bellows shape in the axial direction, and forming a tooth portion of a gear with the ring-shaped formed body, a difference in strength from other parts is easily generated. Is a winding start edge and a winding end edge. Thus, by making the reinforcing fibers fluff as described above, the winding start edge and the winding end edge can be prevented from appearing linearly. In addition, the reinforcing fibers fluffed from the edge easily become entangled with the surface of the nonwoven fabric wound in a lap. Due to these effects, it is difficult to make a difference in strength between the winding start edge and the winding end edge and other portions.
[0009]
In another aspect of the invention, the winding start edge and the winding end edge of the tubular non-woven fabric are formed in a zigzag pattern. Also in this case, the winding start edge and the winding end edge do not clearly appear linearly, and it is difficult to make a difference in strength. Further, when the reinforcing fibers are fluffed from the edge of the zigzag, the edge becomes even less noticeable.
[0010]
BEST MODE FOR CARRYING OUT THE INVENTION
Natural fibers such as cotton or hemp, organic fibers such as polyester, fluororesin, para-aromatic polyamide and meta-aromatic polyamide, and inorganic fibers such as glass and stainless steel are appropriately used as the reinforcing fibers constituting the nonwoven fabric. Can be. These fibers may be employed alone or in combination of plural types in consideration of the characteristics of the gear. The nonwoven fabric is constituted by accumulating these reinforcing fibers. For the accumulation of the reinforcing fibers, any of a wet method of paper-making in water and a dry method of dispersing and accumulating in the air can be employed. The dry method is more convenient because a waste liquid treatment step is not required.
The nonwoven fabric may be simply a sheet formed by accumulating reinforcing fibers, but this has less entanglement between the reinforcing fibers and low tensile strength. Therefore, it is preferable to increase the tensile strength by combining reinforcing fibers oriented in the plane direction with reinforcing fibers oriented in the thickness direction. Such a nonwoven fabric is usually called a felt and is preferable. The felt can be manufactured by needling an aggregate of reinforcing fibers.
[0011]
Needling applied to the aggregate of reinforcing fibers appropriately sets the needle placement density according to the type of reinforcing fibers to be employed. Needle densities must be reduced for glass fibers or metal fibers that are prone to cutting, but can be increased for aromatic polyamide fibers or the like that are not prone to cutting. The amount of the reinforcing fiber oriented in the thickness direction of the felt can be changed depending on the size of the needle implantation density, and the density and the tensile strength of the felt are appropriately adjusted.
[0012]
A belt-like felt having an appropriate tensile strength is overlapped and wound into a tubular shape, and the tubular body is folded in a bellows shape in the axial direction to form a ring-shaped reinforcing fiber base material. In the lap winding, the reinforcing fiber is fluffed from the edge by scratching or combing the winding end edge of the felt and the winding edge as necessary.
In the above-mentioned tubular body in which the belt-shaped felt is overlapped and wound, the overlapped felt layers are not integrated. However, this is rather convenient for compressing the cylindrical body in the axial direction and folding it neatly in a bellows shape. When the layers are folded in a bellows form, slippage occurs between the felt layers, so that the layers can be folded cleanly in a bellows form, and after folding, the felt layers can be brought into the same state as integrated. Since the reinforcing fibers constituting the belt-like felt are strongly bonded to each other, the orientation of the reinforcing fibers is not disturbed when folded in a bellows shape. In addition, if the tubular body can be finely folded in a bellows shape, the orientation of the reinforcing fibers after the folding is not disturbed.
[0013]
The molding of the ring-shaped molded article is performed by impregnating the reinforcing fiber base material with an appropriate resin. For example, a phenol resin is impregnated and dried in advance on a reinforcing fiber base material, and the phenol resin is put into a molding die. In another method, a reinforcing fiber base is put into a molding die, a metal bush is placed at the center, the molding die is closed, and a liquid resin (crosslinked polyaminoamide, epoxy resin, polyimide, etc.) is injected and heated. Mold.
In still another method, resin fine particles are mixed in during the production of felt. That is, fine particles such as phenolic resin are mixed in the step of papermaking the reinforcing fibers in water in the production by the wet method and in the step of spraying and accumulating the reinforcing fibers in the air in the production by the dry method. The ring-shaped reinforcing fiber base material formed using such a resin fine particle-containing felt can be charged into a molding die and directly heated and pressed.
[0014]
One gear may be formed from one ring-shaped reinforcing fiber base material, or a plurality of ring-shaped reinforcing fiber base materials may be integrally molded to cope with the manufacture of a gear having a large tooth width. it can.
[0015]
【Example】
Example 1
Para-aramid fiber raw cotton (fiber diameter 5 to 20 μm, fiber length 50 mm) and meta-aramid fiber raw cotton (fiber diameter 5 to 20 μm, fiber length 50 mm) are dispersed in the air at a weight ratio of 50/50 and accumulated. This was subjected to needling to prepare a felt 1 having a width of 2000 mm, a thickness of 3 mm, and a unit weight of 150 g / m ² . As shown in FIG. 3, the felt 1 has a configuration in which reinforcing fibers 11 oriented in the thickness direction are connected to reinforcing fibers 12 oriented in the planar direction. The felt 1 is cut into a width of 100 mm and wound in a lap manner as described below. Prior to the lap winding, the winding start edge and the winding end edge of the felt are subjected to a scratching treatment, and the reinforcing fiber is applied. Make it fluffy. The edge of the felt 1 is scratched with a brush 30 having a needle implanted therein, and the reinforcing fibers are fluffed. As shown in FIG. 1 (a), a felt 1 having a fluffing treatment applied to a winding start edge and a winding end edge is wound around a predetermined shaft four times, and a tube having an outer diameter of 90 mm, an inner diameter of 60 mm, and a height of 100 mm is formed. Shape 2. Then, as shown in FIG. 1 (b), the cylindrical body 2 is axially compressed in a preforming mold and folded in a bellows shape to form a ring-shaped reinforcing fiber base having an outer diameter of 90 mm, an inner diameter of 60 mm and a thickness of 20 mm. Material 3.
Next, as shown in FIG. 2, the ring-shaped reinforcing fiber base material 3 stacked together with the metal bush 4 disposed at the center thereof is put into a molding die 5 at 200 ° C., and the mold is clamped. Was injected with a cross-linked polyaminoamide and molded by heating. The gear teeth were formed by mechanical cutting around a ring-shaped molded body formed of the reinforcing fiber base material 3 to obtain a resin gear. The characteristics are shown in Table 1.
[0016]
Example 2
In Example 1, before the felt was overlapped and wound to form the ring-shaped reinforcing fiber base material 3, the felt 1 was cut into a zigzag instead of fuzzing the winding start edge and the winding end edge. Otherwise, a resin gear was manufactured in the same manner as in Example 1. The characteristics are shown in Table 1. FIG. 5A shows a state in which the winding start edge and the winding end edge of the felt 1 are formed in a zigzag and then wound in an overlapping manner. FIG. 5B shows the tubular body 2 wound in a lap, and both end edges are oblique to the axial direction of the tubular body 2.
[0017]
Example 3
In Example 2 above, the winding start edge and the winding end edge of the zigzag cut felt were further scratched to make the reinforcing fibers fluff. Otherwise, a resin gear was manufactured in the same manner as in Example 2. The characteristics are shown in Table 1.
[0018]
Comparative Example 1
In Example 1, a resin gear was manufactured in the same manner as in Example 1, except that the winding start edge and the winding end edge of the felt were not subjected to scratching or zigzag cutting. The characteristics are shown in Table 1.
[0019]
Example 4
A para-aramid fiber chop (fiber diameter 5 to 20 μm, fiber length 3 mm) and a meta-aramid fiber chop (fiber diameter 5 to 20 μm, fiber length 3 mm) are dispersed in water at a weight ratio of 50/50. Was continuously formed into a nonwoven fabric having a width of 960 mm, a thickness of 3 mm, and a unit weight of 150 g / m ² . This non-woven fabric is cut into a width of 100 mm and wound around a predetermined shaft four times to form a cylindrical body having an outer diameter of 90 mm and an inner diameter of 60 mm. This cylindrical body is compressed in the axial direction in a preforming mold to form a ring-shaped reinforcing fiber base material having an outer diameter of 90 m, an inner diameter of 60 mm, and a thickness of 20 mm. Prior to the lap winding, the winding start edge and the winding end edge of the felt were subjected to a scratching treatment to make the reinforcing fibers fluff. In this nonwoven fabric, the bonding between the reinforcing fibers was weak, and when the wrapped cylindrical body was compressed in the axial direction, it could not be folded neatly into a bellows shape, and the orientation of the fibers was disordered.
Using the ring-shaped reinforcing fiber base material, a resin gear was formed in the same manner as in the following examples. The characteristics are shown in Table 1.
[0020]
Conventional example 1
In Example 4, a resin gear was manufactured in the same manner as in Example 4 except that the winding start edge and the winding end edge of the nonwoven fabric were not scratched. The characteristics are shown in Table 1.
[0021]
Conventional example 2 (see FIG. 6)
A yarn obtained by blending para-aramid fibers and meta-aramid fibers at a weight ratio of 50/50 was knit-knitted to form a tubular body 6. The cylindrical body 6 is wound up in the axial direction from the end to form a ring-shaped reinforcing fiber base material 3 having an outer diameter of 90 mm, an inner diameter of 60 mm, and a thickness of 20 mm.
Using the ring-shaped reinforcing fiber substrate, a resin gear was formed in the same manner as in Example 1. The characteristics are shown in Table 1.
[0022]
The measurement of each characteristic shown in Table 1 was performed as follows. The content of the reinforcing fibers in the resin of the resin gears of each example is the same.
The bending strength is obtained by measuring the bending strength (initial strength) of an arc-shaped sample cut out from the tooth portion of the manufactured resin gear. The samples are a sample 1 cut out from a position corresponding to the winding end edge and a sample 2 cut out from another position.
The mounting durability time was measured by a gear acceleration test of an automobile engine (rotation speed: 6000 rpm, oil temperature 130 ° C., tooth root load stress 255 MPa).
[0023]
[Table 1]

[0024]
【The invention's effect】
In the resin gear according to the present invention, since the joint of the ring-shaped reinforcing fiber base material is not conspicuous, there is no difference in strength between a portion corresponding to the joint and a portion other than the joint.
In particular, when felt is selected as the nonwoven fabric (Examples 1 to 3), large mechanical strength is obtained despite the fact that the reinforcing fiber base is the same as that of Example 4 in that the reinforcing fiber yarn is not woven or knitted. Can be held. A configuration in which a tubular body formed by overlapping and winding a felt in which reinforcing fibers are firmly bonded to each other is folded in a bellows shape is effectively acting, and the strength is a reinforcing fiber base structure in which reinforcing fiber yarns are knitted. Although slightly inferior to Conventional Example 2, it is comparable. In addition, the durability of the reinforcing fibers is further improved because there is no coarse or dense reinforcing fibers as seen when weaving or knitting the reinforcing fibers, and it is difficult for moisture and oil to enter the inside from the gear surface.
[Brief description of the drawings]
FIG. 1 is an explanatory view showing a step of producing a ring-shaped reinforcing fiber base material from felt in an example according to the present invention.
FIG. 2 is an explanatory cross-sectional view showing a state in which a reinforcing fiber base material is formed in an example according to the present invention.
FIG. 3 is a conceptual explanatory view showing an orientation state of a reinforcing fiber constituting a felt.
FIG. 4 is an explanatory view showing a state in which an edge of a felt is subjected to a scratching process.
FIG. 5 is an explanatory view showing how to manufacture a reinforcing fiber base material from felt in another example according to the present invention.
FIG. 6 is an explanatory view showing a part of a process of manufacturing a resin gear in Conventional Example 2.
[Explanation of symbols]
1: Felt 11: Reinforcement fiber oriented in the thickness direction 12: Reinforcement fiber oriented in a plane direction 2: Cylindrical body 3: Ring-shaped reinforcement fiber base material 4: Bush 5: Mold 6: Cylindrical body 30 :brush

Claims

In a resin gear having a tooth portion formed by a ring-shaped molded body of a reinforcing fiber base material impregnated with a resin,
The reinforcing fiber base material has a configuration in which a band-shaped nonwoven fabric is overlapped and wound into a tubular shape, and the tubular body is folded in a bellows shape in the axial direction,
A resin gear, wherein the winding start edge and the winding end edge of the tubular non-woven fabric are fuzzed with reinforcing fibers constituting the non-woven fabric.

In a resin gear having a tooth portion formed by a ring-shaped molded body of a reinforcing fiber base material impregnated with a resin,
The reinforcing fiber base material has a configuration in which a band-shaped nonwoven fabric is overlapped and wound into a tubular shape, and the tubular body is folded in a bellows shape in the axial direction,
A resin gear, wherein a winding start edge and a winding end edge of the nonwoven fabric wound in a cylindrical shape are formed in a zigzag pattern.

The resin gear according to claim 2, wherein the reinforcing fibers are fluffed from the edges of the zigzag.

The resinous material according to any one of claims 1 to 3, wherein the belt-shaped nonwoven fabric is a felt having a configuration in which reinforcing fibers oriented in a plane direction are joined with reinforcing fibers oriented in the thickness direction. gear.