JP5188897B2

JP5188897B2 - Constant velocity universal joint boot and constant velocity universal joint

Info

Publication number: JP5188897B2
Application number: JP2008178378A
Authority: JP
Inventors: 真一高部
Original assignee: NTN Corp
Current assignee: NTN Corp
Priority date: 2008-07-08
Filing date: 2008-07-08
Publication date: 2013-04-24
Anticipated expiration: 2028-07-08
Also published as: JP2010019291A

Description

本発明は、等速自在継手用ブーツおよび等速自在継手に関する。 The present invention relates to a constant velocity universal joint boot and a constant velocity universal joint.

自動車や各種産業機械における動力の伝達に用いられる等速自在継手には、継手内部への塵埃等の異物侵入防止や継手内部に封入されたグリースの漏れ防止を目的とし、蛇腹状のブーツが装着される。 Constant velocity universal joints used for power transmission in automobiles and various industrial machines are equipped with bellows-shaped boots to prevent foreign materials such as dust from entering the joints and leakage of grease enclosed in the joints. Is done.

この種のブーツは、等速自在継手の外側継手部材としての外輪に固定される大径部と、内側継手部材としての内輪から延びるシャフトに固定される小径部と、大径部と小径部との間に設けられ、谷部と山部とが交互に形成された蛇腹部とを有する。そして、大径部と小径部とはそれぞれブーツバンドが装着されることによって固定される。 This type of boot includes a large diameter portion fixed to an outer ring as an outer joint member of a constant velocity universal joint, a small diameter portion fixed to a shaft extending from an inner ring as an inner joint member, a large diameter portion and a small diameter portion. And a bellows portion in which valley portions and mountain portions are alternately formed. The large-diameter portion and the small-diameter portion are fixed by attaching a boot band.

等速自在継手には、作動角を取りながら回転したり、軸線方向に摺動したりしながら回転する機能が備わっており、そのため、これに装着されるブーツは、等速自在継手の挙動に追従できる柔軟性を確保するために蛇腹形状をしている。すなわち、蛇腹形状のブーツは、等速自在継手が作動角をとったり摺動したりする動きに追従するために変形する。 The constant velocity universal joint has the function of rotating while taking an operating angle or sliding in the axial direction, so the boot attached to it has the behavior of the constant velocity universal joint. It has a bellows shape to ensure flexibility to follow. That is, the bellows-shaped boot is deformed to follow the movement of the constant velocity universal joint that takes an operating angle or slides.

また、等速自在継手用ブーツには、クロロプレンゴム等を使用したゴム製ブーツや熱可塑性エラストマー材を使用した樹脂製ブーツがあるが、樹脂製ブーツはゴム製ブーツに比べて耐久性に優れるため、適用が拡大している。 The constant velocity universal joint boots include rubber boots using chloroprene rubber and resin boots using thermoplastic elastomer material. Resin boots are more durable than rubber boots. The application is expanding.

しかしながら、等速自在継手用ブーツは、等速自在継手が作動角を取ったりしゅう動したりする動きに追従するための変形に伴い、隣接する山部が干渉することで摩耗を生じたり、谷部内面とシャフトが干渉することで摩耗したり、あるいは、山部や谷部に繰り返し応力が発生することで疲労亀裂を生じたりする。それらが進行するとブーツが破損に至る場合がある。また、高作動角を取ることでブーツが大きく変形し、蛇腹が円滑に折り畳まれ難くなって、蛇腹部に凹みを生じる場合がある。これらの摩耗性や疲労性などの耐久性をより向上したり、安定したブーツ変形状態を確実に保つことのできる蛇腹設計がブーツには求められる。 However, the boots for constant velocity universal joints may wear due to interference between adjacent peaks due to deformation to follow the movement of constant velocity universal joints that take an operating angle or slide. The inner surface of the part and the shaft interfere with each other or wear, or the repeated cracking of the crest or trough causes fatigue cracks. As they progress, the boot may be damaged. Moreover, by taking a high operating angle, the boot may be greatly deformed, and the bellows may not be smoothly folded, resulting in a depression in the bellows part. The boot is required to have a bellows design that can further improve the durability such as wear and fatigue and can reliably maintain a stable boot deformation state.

そこで、この種の樹脂製ブーツとして、従来には、湾曲時の蛇腹部の伸縮バランスを良好なものにしてブーツ寿命を長くしようとするもの（特許文献１）、山部同士の接触圧を低減し、耐久性を向上させるもの（特許文献２）、蛇腹部の引張り側と圧縮側との境目に応力集中によるキンク現象が発生するのを防止しようとするもの（特許文献３）等がある。シャフトが作動角を取ることでブーツが縮む方向の変形を受ける位相を圧縮側と呼び、その１８０°反対側のブーツが引っ張られる位相を引張り側と呼ぶ。 Therefore, as this type of resin boot, conventionally, it is intended to increase the expansion / contraction balance of the bellows part at the time of bending to extend the boot life (Patent Document 1), and reduce the contact pressure between the mountain parts. In addition, there are those that improve durability (Patent Document 2), and those that try to prevent a kink phenomenon due to stress concentration at the boundary between the tension side and the compression side of the bellows part (Patent Document 3). The phase that undergoes deformation in the direction in which the boot shrinks by taking the operating angle of the shaft is called the compression side, and the phase in which the boot opposite to 180 ° is pulled is called the tension side.

特許文献１に記載のものは、蛇腹部を、大径装着部寄り部分と、中央部分と、小径装着部寄り部分とに分け、これらの剛性を、中央部分＞大径装着部寄り部分＞小径装着部寄り部分としている。 The thing of patent document 1 divides a bellows part into the part near a large diameter mounting part, the center part, and the part near a small diameter mounting part, and these rigidity is center part> large diameter mounting part side part> small diameter. The part is closer to the mounting part.

特許文献２に記載のものは、蛇腹部における小径装着部寄りの山谷群の山谷径差が大径装着部寄りの山谷群の山谷径差に比べて小さく形成されているものである。 The thing of patent document 2 is formed so that the mountain-valley diameter difference of the mountain valley group near the small diameter mounting part in the bellows part is smaller than the mountain valley diameter difference of the mountain valley group near the large diameter mounting part.

特許文献３に記載のものは、蛇腹部の山の数ｋを４〜７とするとともに、各山に蛇腹部の大径側から順に１から始まる番号Ｎを付けた場合、２≦Ｎ＜（ｋ＋１）/2を満足する番号の少なくとも一つの山の頂部と谷の底部間の膜長をＮ≧（ｋ＋１）/2を満足する全ての番号の山の頂部と谷の底部間の膜長より短くしたものである。
特開２００２−２５７１５２号公報実開平６−８７７７６号公報特公平８−２６９００号公報 The thing of patent document 3 makes the number k of the bellows part crest 4-7, and when each number is given a number N starting from 1 in order from the large diameter side of the bellows part, 2 ≦ N <( The film length between the top of the at least one peak and the bottom of the valley satisfying the number k + 1) / 2 is determined from the film length between the top of the peak and the bottom of the valley satisfying N ≧ (k + 1) / 2. It is a shortened one.
JP 2002-257152 A Japanese Utility Model Publication No. 6-87776 Japanese Patent Publication No. 8-26900

前記特許文献１に記載のものは、作動角をとってブーツがＳ字屈曲をなした際に、このＳ字屈曲のカーブを緩やかにするものである。すなわち、蛇腹部が湾曲した場合にその圧縮側では小径装着部寄り部分の伸長が抑制されるようにしている。また、蛇腹部が湾曲した場合にその圧縮側で大径装着部寄り部分が小径装着部寄り部分の伸長によって必要以上に潰されないようにしている。 The thing of the said patent document 1 makes the curve of this S-shaped bending gentle when a boot makes an S-shaped bending by taking an operating angle. That is, when the bellows portion is curved, the compression side suppresses the extension of the portion close to the small diameter mounting portion. Further, when the bellows portion is curved, the portion near the large diameter mounting portion on the compression side is prevented from being crushed more than necessary by the extension of the portion near the small diameter mounting portion.

前記特許文献２に記載のものは、作動角が大きくつけられても、圧縮側における山谷径差の小さな小径装着部寄りの山谷群の展開長は少なく、その分だけ大径装着部寄りの山谷群の山どうしが圧縮されるのを助長することがなく、その部分における接触圧を低減させるようにしている。 Even if the operating angle is set to a large value, the one described in Patent Document 2 has a small development length of the mountain valley group near the small diameter mounting portion with a small mountain valley diameter difference on the compression side, and the mountain valley near the large diameter mounting portion correspondingly. It does not help the groups of mountains to be compressed and reduces the contact pressure at that part.

前記特許文献３に記載のものは、ジョイント角が大きな値となる位置まで従動軸が揺動された場合、キンク現象が起き難い蛇腹部の小径側部分が大きく変形することによりブーツの変形が吸収され、キンク現象が起き易い蛇腹部の大径側部分の変形が小さくなるようにしている。そして、キンク現象が起き易い蛇腹部の大径側部分における引張り側と圧縮側との変形度合の差が小さくなり、両者の境目に対する応力集中が低減されてキンク現象の発生が防止されるようにしている。 In the device disclosed in Patent Document 3, when the driven shaft is swung to a position where the joint angle becomes a large value, the small diameter side portion of the bellows portion where the kink phenomenon hardly occurs is greatly deformed, so that the deformation of the boot is absorbed. Thus, the deformation of the large-diameter side portion of the bellows portion where the kink phenomenon easily occurs is reduced. In addition, the difference in the degree of deformation between the tension side and the compression side in the large-diameter side portion of the bellows portion where the kink phenomenon is likely to occur is reduced, and the stress concentration at the boundary between the two is reduced, thereby preventing the occurrence of the kink phenomenon. ing.

このように、前記各特許文献では、圧縮側における蛇腹部の接触圧を低減できるようにしたものである。しかしながら、接触面における接触圧を均等にするものではない。このため、全体の接触圧を低減できても、ある部位においては大きな接触圧が作用するおそれがある。すなわち、全体としての接触圧を低減しても、部分的には大きな接触圧が作用し、この部位において摩耗することになる。 Thus, in each said patent document, it can reduce the contact pressure of the bellows part in the compression side. However, the contact pressure on the contact surface is not equalized. For this reason, even if the overall contact pressure can be reduced, there is a possibility that a large contact pressure acts on a certain part. That is, even if the contact pressure as a whole is reduced, a large contact pressure acts partially and wears at this portion.

したがって、従来においては、摩耗性および疲労性において、十分な性能を発揮できるものではない。特に、高作動角時の蛇腹部の変形状態を適切に保つことが困難であると言える。 Therefore, conventionally, sufficient performance cannot be exhibited in terms of wear and fatigue. In particular, it can be said that it is difficult to appropriately maintain the deformed state of the bellows part at the high operating angle.

本発明は、上記課題に鑑みて、高作動角時でも柔軟に変形しながら対応でき、しかも、摩耗性や疲労性を向上できて、耐久性に優れる等速自在継手用ブーツおよびこのようなブーツを使用可能な等速自在継手を提供する。 In view of the above-described problems, the present invention can cope with a flexible deformation even at a high operating angle, can improve wearability and fatigue, and has excellent durability. To provide a constant velocity universal joint.

本発明の第１の等速自在継手用ブーツは、等速自在継手の外側継手部材に装着される大径部と、等速自在継手の内側継手部材に連結されたシャフトに装着される小径部と、大径部と小径部との間に配置される蛇腹部とを備えた等速自在継手用ブーツにおいて、前記等速自在継手は最大作動角が４５ｄｅｇ以上取ることが可能であり、蛇腹部は、４つ以上の山部と、この山部と軸方向に沿って交互に配設される４つ以上の谷部と、隣合う山部と谷部とを連結する連結部とを備え、高作動角時の圧縮側において、小径部から２番目の山部の頂点が、少なくとも２番目の山部の大径部側において隣接する山部の頂点よりも外径側に突出し、少なくとも小径部から２番目の谷部と３番目の谷部はシャフトに対してほぼ均等に接触し、大径部に最も近い谷部をシャフトに対して非接触とすることで、小径部から２番目の山部が、他の山部を外径側へ案内する変形をもたらし、小径部から２番目の山部と小径部から２番目の谷部とを連結する連結部の外面と、小径部から２番目の谷部と小径部から３番目の山部とを連結する連結部の外面とが、ほぼ均一に面接触することで、連結部間の面圧を下げた状態で均等に分散させたものである。 The first constant velocity universal joint boot of the present invention includes a large diameter portion attached to the outer joint member of the constant velocity universal joint and a small diameter portion attached to the shaft connected to the inner joint member of the constant velocity universal joint. And a constant velocity universal joint boot comprising a bellows portion disposed between the large diameter portion and the small diameter portion, the constant velocity universal joint can take a maximum operating angle of 45 degrees or more, and the bellows portion Comprises four or more ridges, four or more valleys alternately arranged along the ridge and the axial direction, and a connecting portion that connects the adjacent peaks and valleys, On the compression side at the high operating angle, the peak of the second peak from the small diameter part protrudes to the outer diameter side from the peak of the adjacent peak at least on the large diameter part of the second peak, and at least the small diameter part The second trough and the third trough contact the shaft almost evenly and are closest to the large diameter part Part of it to non-contact with the shaft, the second peak portion from the small diameter portion, the other ridges resulted deformation guiding radially outward from the second peak portion and the small diameter portion from the small-diameter portion The outer surface of the connecting portion that connects the second trough portion and the outer surface of the connecting portion that connects the second trough portion from the small diameter portion and the third peak portion from the small diameter portion are substantially in surface contact. Thus, the surface pressure between the connecting portions is evenly dispersed with the surface pressure lowered .

本発明の第２の等速自在継手用ブーツは、等速自在継手の外側継手部材に装着される大径部と、等速自在継手の内側継手部材に連結されたシャフトに装着される小径部と、大径部と小径部との間に配置される蛇腹部とを備えた等速自在継手用ブーツにおいて、前記等速自在継手は最大作動角が４５ｄｅｇ以上取ることが可能であり、蛇腹部は、４つ以上の山部と、この山部と軸方向に沿って交互に配設される４つ以上の谷部と、隣合う山部と谷部とを連結する連結部とを備え、高作動角時の圧縮側において、小径部から２番目の山部の頂点が、小径部から３番目の山部の頂点と４番目の山部の頂点とを結ぶ直線よりも外径側に突出し、少なくとも小径部から２番目の谷部と３番目の谷部はシャフトに対してほぼ均等に接触し、大径部に最も近い谷部をシャフトに対して非接触とすることで、小径部から２番目の山部が、他の山部を外径側へ案内する変形をもたらし、小径部から２番目の山部と小径部から２番目の谷部とを連結する連結部の外面と、小径部から２番目の谷部と小径部から３番目の山部とを連結する連結部の外面とが、ほぼ均一に面接触することで、連結部間の面圧を下げた状態で均等に分散させたものである。 The second constant velocity universal joint boot of the present invention includes a large diameter portion attached to the outer joint member of the constant velocity universal joint and a small diameter portion attached to the shaft connected to the inner joint member of the constant velocity universal joint. And a constant velocity universal joint boot comprising a bellows portion disposed between the large diameter portion and the small diameter portion, the constant velocity universal joint can take a maximum operating angle of 45 degrees or more, and the bellows portion Comprises four or more ridges, four or more valleys alternately arranged along the ridge and the axial direction, and a connecting portion that connects the adjacent peaks and valleys, On the compression side at the high operating angle, the peak of the second peak from the small diameter part protrudes to the outer diameter side from the straight line connecting the peak of the third peak and the peak of the fourth peak from the small diameter part. , at least a second valley and third valley from the small diameter portion is substantially uniform contact to the shaft, closest to the large diameter portion Valleys With non-contact with the shaft, the second peak portion from the small-diameter portion results in deformation for guiding the other ridges to the outer diameter side, the second peak portion and the small diameter portion from the small-diameter portion The outer surface of the connecting portion that connects the second trough portion to the second trough portion, and the outer surface of the connecting portion that connects the second trough portion from the small diameter portion and the third peak portion from the small diameter portion are almost in surface contact with each other. Thus , the surface pressure between the connecting portions is evenly dispersed with the surface pressure lowered .

本発明の等速自在継手用ブーツによれば、高作動角時において、小径部から２番目の山部の頂点が、隣接する山部の頂点よりも外径側に突出する、また小径部から３番目の山部の頂点と４番目の山部の頂点とを結ぶ直線よりも外径側に突出するものであるので、小径部から２番目の山部が、他の山部を外方（外径側）へ案内する変形をもたらし、かつ回転時の円滑な蛇腹変形を可能とする。 According to the constant velocity universal joint boot of the present invention, at the time of a high operating angle, the peak of the second peak from the small diameter part protrudes to the outer diameter side from the peak of the adjacent peak, and from the small diameter part Since it protrudes to the outer diameter side from the straight line connecting the apex of the third peak and the apex of the fourth peak, the second peak from the small diameter part outwards the other peak ( Deformation guiding to the outer diameter side) and smooth bellows deformation during rotation are possible.

これによって、斜面間の相対滑り量が平準化されることで圧縮側の蛇腹全体が均等に面圧が分散されて接触することになり、山部乃至連結部の摩耗性が向上する。しかも、面接触により面圧が下がることでも、摩耗性が向上する。 As a result, the amount of relative slip between the slopes is leveled, and the entire bellows on the compression side is brought into contact with the surface pressure evenly distributed, so that the wearability of the peak portion or the connecting portion is improved. In addition, even when the surface pressure is reduced due to surface contact, the wear resistance is improved.

小径部から２番目の山部から大径部に最も近い谷部までの連結部において、高作動角時
には、各谷部を挟んで隣接する連結部の外面がほぼ均一に面接触することで、連結部間の面圧を下げた状態で均等に分散させるのが好ましく、また、少なくとも小径部から２番目の谷部と３番目の谷部はシャフトに対してほぼ均等の接触力にて接触し、かつこれらの谷部は前記外側継手部材側へ傾斜するようにするのが好ましい。 In the connecting part from the second peak part from the small diameter part to the valley part closest to the large diameter part, when the operating angle is high, the outer surface of the adjacent connecting part across each valley part is in almost uniform surface contact , It is preferable that the surface pressure between the connecting portions is evenly dispersed , and at least the second valley portion and the third valley portion from the small diameter portion are in contact with the shaft with a substantially equal contact force. And it is preferable that these trough parts incline toward the said outer joint member side.

高作動角時において、大径部に最も近い谷部をシャフトに対して非接触とするのが好ましい。大径部に最も近い谷部と大径部とを連結する部位は、作動角をとるにしたがって外径側へ変形し易くなり、回転時のより円滑な蛇腹変形を可能にする。 At a high operating angle, it is preferable that the valley portion closest to the large diameter portion is not in contact with the shaft. The portion connecting the valley portion and the large diameter portion closest to the large diameter portion is likely to be deformed to the outer diameter side as the operating angle is increased, thereby enabling smoother bellows deformation during rotation.

谷部の断面形状をＵ字状とするのが好ましく、また、山部と谷部とを連結する連結部が直線状であるのがよい。 The cross-sectional shape of the valley is preferably U-shaped, and the connecting portion that connects the peak and the valley is linear.

ブーツ材質として、ＪＩＳＫ６２５３に規定されるタイプＤデュロメーターによる硬さが３５以上５０以下である熱可塑性ポリエステル系エラストマーを使用することができる。 As a boot material, a thermoplastic polyester elastomer having a hardness of 35 or more and 50 or less according to a type D durometer defined in JIS K6253 can be used.

θ=４５deg以上の高作動角を取ることのできるタイプ（例えば、ツェッパ型、バーフィールド型などのボールを用いたタイプの固定式等速自在継手）や、外側継手部材の軸線方向にスライドする機構を備えたタイプ（例えば、ダブルオフセット型、トリポード型、クロスグルーブ型などの摺動式等速自在継手）など、あらゆる等速自在継手に使用するブーツに適用できる。特に、θ=４５deg以上の高作動角を取ることのできるタイプに適用することがより効果的である。 A type that can take a high operating angle of θ = 45deg or more (for example, a fixed type constant velocity universal joint using a ball such as a Rzeppa type or a Barfield type) or a mechanism that slides in the axial direction of an outer joint member (For example, sliding type constant velocity universal joints such as a double offset type, tripod type, and cross groove type). In particular, it is more effective to apply to a type that can take a high operating angle of θ = 45 deg or more.

本発明では、山部乃至連結部同士の摩耗性や谷部とシャフトとの摩耗性、山谷部の疲労性などのブーツ耐久性が向上する。また、回転時の円滑な蛇腹変形を可能にすることから、耐凹み性の向上も図ることができ、バランスの良いブーツ性能を保持することが可能となり、ブーツのコンパクト化を更に図ることができる。 In the present invention, the boot durability such as the wearability between the ridges or the connecting portions, the wearability between the valleys and the shaft, and the fatigue property of the ridges and valleys is improved. In addition, since the bellows can be smoothly deformed during rotation, it is possible to improve the dent resistance, maintain a well-balanced boot performance, and further reduce the boot size. .

また、谷部を断面Ｕ字状に形成すれば、より耐久性（谷部の疲労性と蛇腹部の凹み防止）を向上することができる。谷部の断面形状をＵ字状とするとともに、山部と谷部とを連結する連結部が直線状であれば、大きな作動角を取った際に、蛇腹部が円滑に折畳み変形することができる。 Further, if the trough is formed in a U-shaped cross section, the durability (the fatigue of the trough and the prevention of the depression of the bellows) can be improved. If the cross-sectional shape of the valley is U-shaped and the connecting part that connects the peak and the valley is straight, the bellows can be folded and deformed smoothly when a large operating angle is taken. it can.

本発明にかかるブーツは、固定式の等速自在継手や摺動式等速自在継手など、あらゆる等速自在継手に使用するブーツに適用できる。特に、等速自在継手の作動角を大きく取ることのできるタイプに適用することがより効果的である。 The boot according to the present invention can be applied to boots used for all constant velocity universal joints such as a fixed type constant velocity universal joint and a sliding type constant velocity universal joint. In particular, it is more effective to apply to a type that can take a large operating angle of the constant velocity universal joint.

ブーツ材質として、ＪＩＳＫ６２５３に規定されるタイプＤデュロメーターによる硬さが３５以上５０以下である熱可塑性ポリエステル系エラストマーを使用することによって、ブーツは、疲労性や摩耗性、高速回転性（回転時振れ廻り性）に優れ、ブーツとして安定した機能を長期にわたって発揮することができる。 By using a thermoplastic polyester elastomer that has a hardness of 35 or more and 50 or less according to JIS K6253 as a boot material, the boot is made of fatigue, wear and high-speed rotation (running during rotation). It can be used for a long time with a stable function as a boot.

以下、本発明の実施の形態を図１〜図３に基づいて説明する。図１に本発明にかかる等速自在継手用ブーツ（等速自在継手に装着した状態）を示し、図２に等速自在継手用ブーツを使用した等速自在継手を示している。 Hereinafter, embodiments of the present invention will be described with reference to FIGS. FIG. 1 shows a boot for a constant velocity universal joint according to the present invention (when mounted on a constant velocity universal joint), and FIG. 2 shows a constant velocity universal joint using the boot for a constant velocity universal joint.

この等速自在継手は、図２に示すように、内周面に複数の案内溝（トラック溝）４を軸方向に形成した外側継手部材としての外輪１と、外周面に複数の案内溝（トラック溝）５を形成した内側継手部材としての内輪２と、外輪１の案内溝４と内輪２の案内溝５とで協働して形成されるボールトラックに配される複数のボール３と、ボール３を収容するためのポケット８ａを有するケージ８等から構成される。また、内輪２の内周にセレーションやスプライン等のトルク伝達手段を介してシャフト９を結合している。この実施形態の等速自在継手は、案内溝４，５が円弧部と直線部とを有するアンダーカットフリー型（ＵＪ）を示している。 As shown in FIG. 2, the constant velocity universal joint includes an outer ring 1 as an outer joint member in which a plurality of guide grooves (track grooves) 4 are formed on the inner peripheral surface in the axial direction, and a plurality of guide grooves ( A plurality of balls 3 arranged on a ball track formed in cooperation with an inner ring 2 as an inner joint member in which a track groove) 5 is formed, a guide groove 4 of the outer ring 1 and a guide groove 5 of the inner ring 2; A cage 8 having a pocket 8a for accommodating the ball 3 is formed. The shaft 9 is coupled to the inner periphery of the inner ring 2 via torque transmission means such as serrations and splines. The constant velocity universal joint of this embodiment is an undercut free type (UJ) in which the guide grooves 4 and 5 have an arc portion and a straight portion.

等速自在継手用ブーツ１０は、例えば、エステル系、オレフィン系、ウレタン系、アミド系、スチレン系等の熱可塑性エラストマーにて形成される。熱可塑性エラストマーは樹脂とゴムの中間の性質を持っている。熱可塑性エラストマーは、熱可塑性樹脂の通常の成形機にて加工することができる。 The constant velocity universal joint boot 10 is formed of, for example, a thermoplastic elastomer such as ester, olefin, urethane, amide, or styrene. Thermoplastic elastomers have intermediate properties between resin and rubber. The thermoplastic elastomer can be processed with an ordinary thermoplastic resin molding machine.

また、等速自在継手用ブーツ１０は、硬さが、ＪＩＳＫ６２５３に規定されるタイプＤデュロメーターによる硬さが３５以上５０以下である熱可塑性ポリエステル系エラストマーとすることができる。熱可塑性ポリエステル系エラストマーは、加硫ゴムのような柔軟な材料と、熱可塑性樹脂のような高剛性な材料との中間の弾性率を持つ材料である。この熱可塑性ポリエステル系エラストマーは、加硫ゴムと熱可塑性樹脂の両者の特徴を有し、変形を受けても元の形状に復元する弾性、加硫ゴムより高い機械的強度、一般的な熱可塑性樹脂に適用できる全ての成形加工法が適用できる熱可塑性などの特徴を示す材料である。 The constant velocity universal joint boot 10 may be a thermoplastic polyester elastomer having a hardness of 35 or more and 50 or less according to a type D durometer specified in JIS K6253. A thermoplastic polyester elastomer is a material having an intermediate elastic modulus between a flexible material such as vulcanized rubber and a highly rigid material such as a thermoplastic resin. This thermoplastic polyester elastomer has the characteristics of both vulcanized rubber and thermoplastic resin, is elastic to restore its original shape even when deformed, higher mechanical strength than vulcanized rubber, general thermoplasticity It is a material that exhibits characteristics such as thermoplasticity that can be applied to all molding methods applicable to resins.

等速自在継手用ブーツ１０は、等速自在継手の外側継手部材（外輪１）の開口端部に装着される大径部１３と、等速自在継手の内側継手部材（内輪２）に連結されたシャフト９に装着される小径部１４と、大径部１３と小径部１４との間に設けられ、軸方向に沿って交互に配設される山部７と谷部６とを有する蛇腹部１５とを備える。山部７と谷部６とは傾斜部（連結部）１２にて連結されている。 The constant velocity universal joint boot 10 is connected to a large-diameter portion 13 attached to an opening end portion of an outer joint member (outer ring 1) of the constant velocity universal joint and an inner joint member (inner ring 2) of the constant velocity universal joint. A bellows portion having a small-diameter portion 14 attached to the shaft 9, a bellows portion provided between the large-diameter portion 13 and the small-diameter portion 14 and alternately disposed along the axial direction. 15. The mountain portion 7 and the valley portion 6 are connected by an inclined portion (connecting portion) 12.

外輪１の開口部側の外周面には、周方向に沿った溝からなるブーツ取付部１６（周方向凹溝であって、図１等においては、図示簡略化のため、この周方向凹溝の記載を省略している）が設けられ、このブーツ取付部１６に大径部１３が外嵌される。そして、ブーツ１０の大径部１３の外周面に形成された嵌合溝１７にブーツバンド１８を嵌着することによって、大径部１３を外輪１に固定している。 On the outer peripheral surface of the outer ring 1 on the opening side, a boot mounting portion 16 (circumferential concave groove formed of a groove along the circumferential direction. In FIG. Is omitted), and the large-diameter portion 13 is externally fitted to the boot mounting portion 16. Then, the large-diameter portion 13 is fixed to the outer ring 1 by fitting the boot band 18 into the fitting groove 17 formed on the outer peripheral surface of the large-diameter portion 13 of the boot 10.

シャフト９には、外輪１から所定量突出した位置に、周方向に沿ったブーツ取付用溝２０を有するブーツ取付部２２が設けられ、小径部１４がブーツ取付部２２に外嵌される。そして、ブーツ１０の小径部１４の外周面に形成された嵌合溝１９にブーツバンド１８を嵌着することによって、小径部１４をシャフト９に固定している。 The shaft 9 is provided with a boot mounting portion 22 having a boot mounting groove 20 along the circumferential direction at a position protruding from the outer ring 1 by a predetermined amount, and the small diameter portion 14 is externally fitted to the boot mounting portion 22. The small-diameter portion 14 is fixed to the shaft 9 by fitting the boot band 18 into the fitting groove 19 formed on the outer peripheral surface of the small-diameter portion 14 of the boot 10.

蛇腹部１５において、谷部６はその断面形状をＵ字形状としている。また、谷部６と山部７とを連結する連結部１２を直線状としている。なお、大径部１３には大径肩部２３が連設され、この大径肩部２３と、大径部１３と最も近接する谷部６ｅとが連結部１２ｊを介して連結されている。この大径肩部２３としてはほぼ水平方向へ直線状に構成してもよいし、外径側へ僅かに凸状に膨出する形状に構成してもよいし、外径側へ突出する山部でもって構成してもよい。 In the bellows portion 15, the valley portion 6 has a U-shaped cross section. Moreover, the connection part 12 which connects the trough part 6 and the peak part 7 is made into linear form. A large-diameter shoulder portion 23 is connected to the large-diameter portion 13, and the large-diameter shoulder portion 23 and the valley portion 6e closest to the large-diameter portion 13 are connected via a connecting portion 12j. The large-diameter shoulder portion 23 may be configured in a straight line shape in a substantially horizontal direction, may be configured in a shape that slightly protrudes toward the outer diameter side, or a mountain that protrudes toward the outer diameter side. You may comprise by a part.

蛇腹部１５において、山部７を小径部１４側から大径部１３に向かって順に第１山７ａ、第２山７ｂ、第３山７ｃ、第４山７ｄ、第５山７ｅと呼び、谷部６を小径部１４側から大径部１３に向かって順に第１谷６ａ、第２谷６ｂ、第３谷６ｃ、第４谷６ｄ、第５谷６ｅと呼ぶ。 In the bellows portion 15, the mountain portion 7 is called a first mountain 7a, a second mountain 7b, a third mountain 7c, a fourth mountain 7d, and a fifth mountain 7e in this order from the small diameter portion 14 side to the large diameter portion 13. The portion 6 is referred to as a first valley 6a, a second valley 6b, a third valley 6c, a fourth valley 6d, and a fifth valley 6e in order from the small diameter portion 14 toward the large diameter portion 13.

高作動角時においては、図３に示すように変形して、圧縮側と引張り側とが形成される。ここで、シャフト９が作動角を取ることでブーツが縮む方向の変形を受ける位相を圧縮側と呼び、その１８０°反対側のブーツが引っ張られる位相を引張り側と呼ぶ。この際、図４に示すように、第２山７ｂの頂点Ｖｂが、隣接する第３山７ｃの頂点Ｖｃよりも外径側に突出する。更には、第２山７ｂの頂点Ｖｂが、第３山７ｃの頂点Ｖｃと第４山７ｄの頂点Ｖｄとを結ぶ直線Ｌよりも外径側に突出している。 At the time of a high operating angle, it is deformed as shown in FIG. 3 to form a compression side and a tension side. Here, the phase that undergoes deformation in the direction in which the boot shrinks due to the operating angle of the shaft 9 is called the compression side, and the phase in which the boot opposite to 180 ° is pulled is called the tension side. At this time, as shown in FIG. 4, the apex Vb of the second peak 7b protrudes to the outer diameter side from the apex Vc of the adjacent third peak 7c. Further, the vertex Vb of the second peak 7b protrudes more outward than the straight line L connecting the vertex Vc of the third peak 7c and the vertex Vd of the fourth peak 7d.

また、圧縮側においては、小径部１４から２番目の山部７つまり第２山７ｂから大径部１３に最も近い谷部、つまり第５谷６ｅまでの連結部１２において、各谷部６を挟んで隣接する連結部１２の外面がほぼ均一に面接触するものとなっている。 On the compression side, each valley portion 6 is connected to the second peak portion 7 from the small diameter portion 14, that is, the valley portion closest to the large diameter portion 13 from the second peak 7b, that is, the connecting portion 12 from the fifth valley 6e. The outer surfaces of the connecting portions 12 adjacent to each other are in surface contact substantially uniformly.

すなわち、第２山７ｂと第２谷６ｂとを連結する連結部１２ｃの外面と、第２谷６ｂと第３山７ｃとを連結する連結部１２ｄの外面とが、ほぼ均一に面接触する。第３山７ｃと第３谷６ｃとを連結する連結部１２ｅの外面と、第３谷６ｃと第４山７ｄとを連結する連結部１２ｆの外面とが、ほぼ均一に面接触する。第４山７ｄと第４谷６ｄとを連結する連結部１２ｇの外面と、第４谷６ｄと第５山７ｅとを連結する連結部１２ｈの外面とが、ほぼ均一に面接触する。第５山７ｅと第５谷６ｅとを連結する連結部１２ｉの外面と、第５谷６ｅと大径肩部２３とを連結する連結部１２ｊの外面とが、ほぼ均一に面接触する。 That is, the outer surface of the connecting portion 12c that connects the second peak 7b and the second valley 6b and the outer surface of the connecting portion 12d that connects the second valley 6b and the third peak 7c are almost in surface contact. The outer surface of the connecting portion 12e that connects the third mountain 7c and the third valley 6c and the outer surface of the connecting portion 12f that connects the third valley 6c and the fourth mountain 7d are in surface contact substantially uniformly. The outer surface of the connecting portion 12g that connects the fourth peak 7d and the fourth valley 6d and the outer surface of the connecting portion 12h that connects the fourth valley 6d and the fifth peak 7e are almost in surface contact. The outer surface of the connecting portion 12i that connects the fifth mountain 7e and the fifth valley 6e and the outer surface of the connecting portion 12j that connects the fifth valley 6e and the large-diameter shoulder portion 23 are in surface contact substantially uniformly.

また、第２谷６ｂ、第３谷６ｃ、および第４谷６ｄがシャフト９に接触する。この際、第１谷６ａおよび第５谷６ｅはシャフト９に対して非接触としている。第２谷６ｂ、第３谷６ｃ、第４谷６ｄは、外輪１側へ傾斜しているのが好ましい。 Further, the second valley 6b, the third valley 6c, and the fourth valley 6d are in contact with the shaft 9. At this time, the first valley 6 a and the fifth valley 6 e are not in contact with the shaft 9. The second valley 6b, the third valley 6c, and the fourth valley 6d are preferably inclined toward the outer ring 1 side.

ところで、図１に示す状態（作動角が０°である状態）から図３に示すように作動角をとっていけば、第２谷６ｂ、第３谷６ｃ、第４谷６ｄと順次シャフト９に接触していくことなる。これによって、第２谷６ｂ、第３谷６ｃ、第４谷６ｄは、シャフト９に対してほぼ均一な接触力で接触することになる。 By the way, if the operating angle is taken as shown in FIG. 3 from the state shown in FIG. 1 (the operating angle is 0 °), the second trough 6b, the third trough 6c, the fourth trough 6d and the shaft 9 sequentially. It will be in contact with. As a result, the second valley 6b, the third valley 6c, and the fourth valley 6d come into contact with the shaft 9 with a substantially uniform contact force.

また、大径部１３に最も近い谷部（第５谷）６ｅと大径部１３とを連結する部位（大径肩部２３）および連結部１２ｊは、作動角をとるにしたがって外径側へ変形するものである。 Moreover, the site | part (large diameter shoulder part 23) and the connection part 12j which connect the trough part (5th trough) 6e nearest to the large diameter part 13 and the large diameter part 13 and the connection part 12j go to an outer diameter side as an operating angle is taken. It will be deformed.

本発明では、高作動角時において、小径部１４から２番目の山部（第２山）７ｂの頂点Ｖｂが、隣接する山部（第３山）７ｃの頂点Ｖｃよりも外径側に突出する、また小径部１４から３番目の山部（第３山）７ｃの頂点Ｖｃと４番目の山部（第４山）７ｄの頂点Ｖｄとを結ぶ直線Ｌよりも外径側に突出するものであるので、小径部１４から２番目の山部７ｂが、他の山部７を外方（外径側）へ案内する変形をもたらし、かつ回転時の円滑な蛇腹変形を可能とする。 In the present invention, at the high operating angle, the apex Vb of the second peak (second peak) 7b from the small diameter part 14 protrudes to the outer diameter side from the apex Vc of the adjacent peak (third peak) 7c. And projecting from the small diameter portion 14 to the outer diameter side of the straight line L connecting the vertex Vc of the third peak (third peak) 7c and the vertex Vd of the fourth peak (fourth peak) 7d. Therefore, the second peak portion 7b from the small-diameter portion 14 brings about deformation that guides the other peak portion 7 to the outside (outer diameter side), and enables smooth bellows deformation during rotation.

これによって、斜面（連結部の外面）間の相対滑り量が平準化されることで圧縮側の蛇腹全体が均等に面圧が分散されて接触することになり、山部７乃至連結部１２の摩耗性が向上する。しかも、面接触により面圧が下がることでも、摩耗性が向上する。 As a result, the amount of relative slip between the inclined surfaces (outer surfaces of the connecting portions) is leveled, so that the entire bellows on the compression side is uniformly contacted with each other, and the ridges 7 to 12 are connected. Abrasion is improved. In addition, even when the surface pressure is reduced due to surface contact, the wear resistance is improved.

このように、本発明では、山部７乃至連結部１２同士の摩耗性や谷部６とシャフト９との摩耗性、山谷部の疲労性などのブーツ耐久性が向上する。また、回転時の円滑な蛇腹変形を可能にすることから、耐凹み性の向上も図ることができ、バランスの良いブーツ性能を保持することが可能となり、ブーツのコンパクト化を更に図ることができる。 Thus, in this invention, boot durability, such as the wearability of the mountain parts 7 thru | or the connection parts 12, the wearability of the trough part 6 and the shaft 9, and the fatigue nature of a mountain valley part, improves. In addition, since the bellows can be smoothly deformed during rotation, it is possible to improve the dent resistance, maintain a well-balanced boot performance, and further reduce the boot size. .

また、連結部１２ｃの外面と連結部１２ｄとの外面との接触力、連結部１２ｅの外面と連結部１２ｆとの外面との接触力、連結部１２ｇの外面と連結部１２ｈとの外面との接触力、および連結部１２ｉの外面と連結部１２ｊとの外面との接触力が分散できる。これによって、各接触面の面圧を低下させることとができ、摩耗性の向上を図ることができる。 Further, the contact force between the outer surface of the connecting portion 12c and the outer surface of the connecting portion 12d, the contact force between the outer surface of the connecting portion 12e and the outer surface of the connecting portion 12f, the outer surface of the connecting portion 12g and the outer surface of the connecting portion 12h. The contact force and the contact force between the outer surface of the connecting portion 12i and the outer surface of the connecting portion 12j can be dispersed. As a result, the surface pressure of each contact surface can be reduced, and wear can be improved.

高作動角時において谷部６がシャフト９とほぼ均一な接触力にて接触することで谷部６のシャフト９との摩耗を防止し、蛇腹部１５を全体的に外方へ押し上げる効果から、谷部６とシャフト９との接触力を下げると共に、各山部７間の接触力も下げる相乗効果を生む。 From the effect that the valley portion 6 contacts the shaft 9 with a substantially uniform contact force at a high operating angle, thereby preventing the valley portion 6 from being worn against the shaft 9 and pushing the bellows portion 15 outward as a whole. This produces a synergistic effect that lowers the contact force between the valley 6 and the shaft 9 and lowers the contact force between the peaks 7.

大径部１３に最も近い谷部（第５谷）６ｅと大径部１３とを連結する部位（大径肩部２３）および連結部１２ｊは、作動角をとるにしたがって外径側へ変形するものであるので、回転時の円滑な蛇腹変形を可能にする。 The portion (large diameter shoulder portion 23) connecting the valley (fifth valley) 6e closest to the large diameter portion 13 and the large diameter portion 13 and the connection portion 12j are deformed to the outer diameter side as the operating angle is increased. As a result, smooth bellows deformation during rotation is possible.

谷部６を断面Ｕ字状に形成すれば、より耐久性（谷部の疲労性と蛇腹部の凹み防止）を向上することができる。谷部６の断面形状をＵ字状とするとともに、山部７と谷部６とを連結する連結部１２が直線状であれば、大きな作動角を取った際に、蛇腹部１５が円滑に折畳み変形することができる。 If the trough part 6 is formed in a U-shaped cross section, durability (fatigue of the trough part and prevention of dents in the bellows part) can be improved. If the cross-sectional shape of the valley part 6 is U-shaped and the connecting part 12 that connects the peak part 7 and the valley part 6 is a straight line, the bellows part 15 will be smooth when taking a large operating angle. Can be folded and deformed.

ブーツ材質として、ＪＩＳＫ６２５３に規定されるタイプＤデュロメータによる硬さが３５以上５０以下である熱可塑性ポリエステル系エラストマーを使用することによって、ブーツは、疲労性や摩耗性、高速回転性（回転時振れ廻り性）に優れ、ブーツとして安定した機能を長期にわたって発揮することができる。 By using a thermoplastic polyester elastomer that has a hardness of 35 or more and 50 or less according to JIS K6253 as a boot material, the boot is made of fatigue, wear, and high-speed rotation (running rotation) It can be used for a long time with a stable function as a boot.

このため、本発明のブーツは、θ＝４５ｄｅｇ以上の高作動角を取ることのできるタイプ（例えば、ツェッパ型、バーフィールド型等の固定式等速自在継手）や、外側継手部材の軸線方向にスライドする機構を備えたタイプ（例えば、ダブルオフセット型、トリポード型、クロスグルーブ型等の摺動式等速自在継手）など、あらゆる等速自在継手に適用できる。これにより、疲労性や摩耗性に優れた等速自在継手用ブーツを装着した、耐久性に優れる等速自在継手を構成することができる。すなわち、ブーツにおける蛇腹部１５の山部７は、適切な剛性を保持した上で、大きな作動角を取った際に円滑に折れ畳まれることが求められ、それを達成することに本発明のものが適している。 For this reason, the boot of the present invention is of a type that can take a high operating angle of θ = 45 deg or more (for example, a fixed constant velocity universal joint such as a Rzeppa type or a Barfield type) or an axial direction of an outer joint member. The present invention can be applied to all constant velocity universal joints such as a type having a sliding mechanism (for example, a sliding type constant velocity universal joint such as a double offset type, a tripod type, and a cross groove type). Thereby, the constant velocity universal joint excellent in durability equipped with the boot for constant velocity universal joints excellent in fatigue property and wearability can be constituted. That is, the peak portion 7 of the bellows portion 15 in the boot is required to be folded smoothly when taking a large operating angle while maintaining an appropriate rigidity. Things are suitable.

以上、本発明の実施形態につき説明したが、本発明は前記実施形態に限定されることなく種々の変形が可能であって、図１に示す等速自在継手用ブーツでは、蛇腹部１５の山部７および谷部６の数は、５つに限るものではなく、４つ以上であればよく、好ましく４つから７つの間に設定する。また、摺動式等速自在継手の場合は、固定式等速自在継手よりも作動角が大きくないことから、デュロメータＤによる硬さが５０を超える熱可塑性ポリエステル系エラストマーを使用することができる。あるいは、固定式等速自在継手においても、後輪用駆動軸に適用する場合は、作動角が大きくないことから、デュロメータＤによる硬さが５０を超える熱可塑性ポリエステル系エラストマーを使用することができる。もちろん、クロロプレンゴム等を使用したゴム製ブーツであってもよい。 As described above, the embodiment of the present invention has been described. However, the present invention is not limited to the above-described embodiment, and various modifications can be made. In the constant velocity universal joint boot shown in FIG. The number of the parts 7 and the valley parts 6 is not limited to five, but may be four or more, and is preferably set between four and seven. In the case of the sliding type constant velocity universal joint, since the operating angle is not larger than that of the fixed type constant velocity universal joint, it is possible to use a thermoplastic polyester elastomer having a durometer D hardness exceeding 50. Alternatively, even in a fixed type constant velocity universal joint, a thermoplastic polyester elastomer having a durometer D hardness exceeding 50 can be used because the operating angle is not large when applied to a rear wheel drive shaft. . Of course, rubber boots using chloroprene rubber or the like may be used.

また、谷部６を断面Ｕ字状に形成すれば、より耐久性を向上するので、好ましいが、谷部６として断面Ｕ字状に限るものではない。小径部１４に最も近接した山部（第１山）７ａと、小径部１４に最も近接した谷部（第１谷）６ａとを連結する連結部１２ａの外面と、小径部１４に最も近接した谷部（第１谷）６ａと、小径部１４から２番目の山部（第２山）７ｂとを連結する連結部１２ｂの外面とが接触するものであってもよい。 In addition, if the valley portion 6 is formed in a U-shaped cross section, durability is further improved, and thus the valley portion 6 is not limited to a U-shaped cross section. The outer surface of the connecting part 12a that connects the peak part (first peak) 7a closest to the small diameter part 14 and the valley part (first valley) 6a closest to the small diameter part 14 and the closest part to the small diameter part 14 The outer surface of the connection part 12b which connects the trough part (1st trough) 6a and the 2nd peak part (2nd peak) 7b from the small diameter part 14 may contact.

また、前記実施形態では、第２谷６ｂから第４谷６ｄまでシャフト９に接触するものであったが、少なくとも第２谷６ｂと第３谷６ｃがシャフト９に接触するものであればよい。逆に、第１谷６ａから第５谷６ｅまでシャフト９に接触するものであってもよい。 Moreover, in the said embodiment, although it contacted the shaft 9 from the 2nd trough 6b to the 4th trough 6d, the 2nd trough 6b and the 3rd trough 6c should just be in contact with the shaft 9. Conversely, the shaft 9 may be in contact with the first valley 6a to the fifth valley 6e.

本発明の実施形態を示す等速自在継手用ブーツの断面図である。It is sectional drawing of the boot for constant velocity universal joints which shows embodiment of this invention. 前記等速自在継手用ブーツを使用した等速自在継手の断面図である。It is sectional drawing of the constant velocity universal joint using the said boot for constant velocity universal joints. 前記等速自在継手が作動角をとった状態の等速自在継手用ブーツの断面図である。It is sectional drawing of the boot for constant velocity universal joints in the state where the said constant velocity universal joint took the operating angle. 前記等速自在継手が作動角をとった状態の等速自在継手用ブーツの要部拡大断面図である。It is a principal part expanded sectional view of the boot for constant velocity universal joints of the state in which the said constant velocity universal joint took the operating angle.

符号の説明Explanation of symbols

６谷部
７山部
９シャフト
１３大径部
１４小径部
１５蛇腹部 6 Valley part 7 Mountain part 9 Shaft 13 Large diameter part 14 Small diameter part 15 Bellows part

Claims

等速自在継手の外側継手部材に装着される大径部と、等速自在継手の内側継手部材に連結されたシャフトに装着される小径部と、大径部と小径部との間に配置される蛇腹部とを備えた等速自在継手用ブーツにおいて、
前記等速自在継手は最大作動角が４５ｄｅｇ以上取ることが可能であり、蛇腹部は、４つ以上の山部と、この山部と軸方向に沿って交互に配設される４つ以上の谷部と、隣合う山部と谷部とを連結する連結部とを備え、高作動角時の圧縮側において、小径部から２番目の山部の頂点が、少なくとも２番目の山部の大径部側において隣接する山部の頂点よりも外径側に突出し、少なくとも小径部から２番目の谷部と３番目の谷部はシャフトに対してほぼ均等に接触し、大径部に最も近い谷部をシャフトに対して非接触とすることで、小径部から２番目の山部が、他の山部を外径側へ案内する変形をもたらし、小径部から２番目の山部と小径部から２番目の谷部とを連結する連結部の外面と、小径部から２番目の谷部と小径部から３番目の山部とを連結する連結部の外面とが、ほぼ均一に面接触することで、連結部間の面圧を下げた状態で均等に分散させたことを特徴とする等速自在継手用ブーツ。 The large-diameter portion that is attached to the outer joint member of the constant velocity universal joint, the small-diameter portion that is attached to the shaft connected to the inner joint member of the constant-velocity universal joint, and the large-diameter portion and the small-diameter portion. In the boot for a constant velocity universal joint provided with
The constant velocity universal joint can take a maximum operating angle of 45 deg or more, and the bellows part includes four or more ridges, and four or more ridges arranged alternately with the ridges along the axial direction. A trough, and a connecting portion that connects the adjacent crest and trough, and on the compression side at a high operating angle, the apex of the second crest from the small-diameter portion is at least the second crest Projects to the outer diameter side from the apex of the adjacent crests on the diameter side, and at least the second and third troughs from the small diameter part contact the shaft almost evenly and are closest to the large diameter part By making the valley part non-contact with the shaft, the second peak part from the small diameter part causes deformation to guide the other peak part to the outer diameter side, and the second peak part and the small diameter part from the small diameter part. The outer surface of the connecting portion connecting the second trough from the second, the second trough from the small diameter portion and the third crest from the small diameter portion And the outer surface of the connecting portion connecting the substantially uniformly by surface contact, boot for a constant velocity universal joint is characterized in that uniformly dispersed at reduced surface pressure between the connecting portions.

等速自在継手の外側継手部材に装着される大径部と、等速自在継手の内側継手部材に連結されたシャフトに装着される小径部と、大径部と小径部との間に配置される蛇腹部とを備えた等速自在継手用ブーツにおいて、
前記等速自在継手は最大作動角が４５ｄｅｇ以上取ることが可能であり、蛇腹部は、４つ以上の山部と、この山部と軸方向に沿って交互に配設される４つ以上の谷部と、隣合う山部と谷部とを連結する連結部とを備え、高作動角時の圧縮側において、小径部から２番目の山部の頂点が、小径部から３番目の山部の頂点と４番目の山部の頂点とを結ぶ直線よりも外径側に突出し、少なくとも小径部から２番目の谷部と３番目の谷部はシャフトに対してほぼ均等に接触し、大径部に最も近い谷部をシャフトに対して非接触とすることで、小径部から２番目の山部が、他の山部を外径側へ案内する変形をもたらし、小径部から２番目の山部と小径部から２番目の谷部とを連結する連結部の外面と、小径部から２番目の谷部と小径部から３番目の山部とを連結する連結部の外面とが、ほぼ均一に面接触することで、連結部間の面圧を下げた状態で均等に分散させたことを特徴とする等速自在継手用ブーツ。 The large-diameter portion that is attached to the outer joint member of the constant velocity universal joint, the small-diameter portion that is attached to the shaft connected to the inner joint member of the constant-velocity universal joint, and the large-diameter portion and the small-diameter portion. In the boot for a constant velocity universal joint provided with
The constant velocity universal joint can take a maximum operating angle of 45 deg or more, and the bellows part includes four or more ridges, and four or more ridges arranged alternately with the ridges along the axial direction. A trough, and a connecting portion that connects the adjacent crest and trough, and on the compression side at a high operating angle, the apex of the second crest from the small diameter portion is the third crest from the small diameter portion. Projecting to the outer diameter side of the straight line connecting the top of the top and the top of the fourth peak, and at least the second and third valleys from the small diameter part contact the shaft almost equally, By making the valley part closest to the part non-contact with the shaft, the second peak part from the small diameter part causes deformation that guides the other peak part to the outer diameter side, and the second peak from the small diameter part. The outer surface of the connecting portion that connects the second valley portion from the small diameter portion, the second valley portion from the small diameter portion, and the third peak portion from the small diameter portion And an outer surface of the coupling portion coupling is that substantially uniformly surface contact, boot for a constant velocity universal joint is characterized in that uniformly dispersed at reduced surface pressure between the connecting portions.

高作動角時の圧縮側において、小径部から２番目の山部から大径部に最も近い谷部までの連結部において、各谷部を挟んで隣接する連結部の外面がほぼ均一に面接触することで、連結部間の面圧を下げた状態で均等に分散させたことを特徴とする請求項１又は請求項２に記載の等速自在継手用ブーツ。 On the compression side at the high operating angle, the outer surface of the adjacent connecting part across the valleys is almost evenly in contact at the connecting part from the second peak part to the valley part closest to the large diameter part from the small diameter part. Thus, the boot for a constant velocity universal joint according to claim 1 or 2, wherein the boot is uniformly dispersed in a state in which the surface pressure between the connecting portions is lowered .

高作動角時の圧縮側において、少なくとも小径部から２番目の谷部と３番目の谷部はシャフトに対してほぼ均等の接触力にて接触し、かつこれらの谷部は前記外側継手部材側へ傾斜することを特徴とする請求項１〜請求項３のいずれか１項に記載の等速自在継手用ブーツ。 On the compression side at the time of a high operating angle, at least the second valley and the third valley from the small diameter portion are in contact with the shaft with a substantially equal contact force, and these valleys are on the outer joint member side. 4. The constant velocity universal joint boot according to claim 1, wherein the boot for constant velocity universal joints is inclined.

高作動角時の圧縮側において、大径部に最も近い谷部をシャフトに対して非接触とし、大径部に最も近い谷部と大径部とを連結する部位は、作動角をとるにしたがって外径側へ変形することを特徴とする請求項１〜請求項４のいずれか１項に記載の等速自在継手用ブーツ。 On the compression side at a high operating angle, the valley portion closest to the large diameter portion is not in contact with the shaft, and the portion connecting the valley portion closest to the large diameter portion and the large diameter portion takes an operating angle. Accordingly, the constant velocity universal joint boot according to any one of claims 1 to 4, wherein the boot is deformed toward an outer diameter side.

谷部の断面形状がＵ字状を成すことを特徴とする請求項１〜請求項５のいずれか１項に記載の等速自在継手用ブーツ。 The boot for a constant velocity universal joint according to any one of claims 1 to 5, wherein a cross-sectional shape of the valley portion is U-shaped.

ＪＩＳＫ６２５３に規定されるタイプＤデュロメータによる硬さが３５以上５０以下である熱可塑性ポリエステル系エラストマーからなることを特徴とする請求項１〜請求項６のいずれか１項に記載の等速自在継手用ブーツ。 The constant velocity universal joint according to any one of claims 1 to 6, wherein the constant velocity universal joint is made of a thermoplastic polyester elastomer having a hardness of 35 or more and 50 or less according to a type D durometer defined in JIS K6253. Boots.

請求項１〜請求項７のいずれか１項に記載の等速自在継手用ブーツを用いたことを特徴とする等速自在継手。 The constant velocity universal joint using the boot for constant velocity universal joints of any one of Claims 1-7.