JP2008248964A - Boot for constant velocity joint - Google Patents

Boot for constant velocity joint Download PDF

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Publication number
JP2008248964A
JP2008248964A JP2007088815A JP2007088815A JP2008248964A JP 2008248964 A JP2008248964 A JP 2008248964A JP 2007088815 A JP2007088815 A JP 2007088815A JP 2007088815 A JP2007088815 A JP 2007088815A JP 2008248964 A JP2008248964 A JP 2008248964A
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Japan
Prior art keywords
constant velocity
bellows
velocity joint
boot
diameter cylindrical
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Japanese (ja)
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Hiroshi Kumazaki
浩志 熊崎
Satoshi Suzuki
智 鈴木
Osamu Takeuchi
治 竹内
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JTEKT Corp
Toyoda Gosei Co Ltd
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JTEKT Corp
Toyoda Gosei Co Ltd
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Priority to JP2007088815A priority Critical patent/JP2008248964A/en
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Abstract

<P>PROBLEM TO BE SOLVED: To provide a boot for constant velocity joint capable of suppressing leakage of grease. <P>SOLUTION: A first bellows part 41 adjacent to a large cylindrical part 3, a second bellows part 42 adjacent to a small cylindrical part 2, a connection part 43 for connecting the first bellows part 41 and the second bellows part 42 and a contact part 44 protruding from an inner circumferential surface of the connection part 43 to an inner circumferential side of the connection part 43 are provided for a boot main body 4 of the boot 1 for the constant velocity joint. A communication space 430 which is separated by an outer circumferential surface of a shaft 80 and the contact part 44 and communicates inside of the first bellows part 41 and inside of the second bellows part 42 is formed in the contact part 43. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

本発明は、前輪駆動車のドライブシャフト用ジョイントなどに不可欠な等速ジョイントを覆い、等速ジョイントのジョイント部への水や埃の侵入を抑止する等速ジョイント用ブーツに関する。   The present invention relates to a constant velocity joint boot that covers a constant velocity joint indispensable for a drive shaft joint of a front wheel drive vehicle and prevents entry of water and dust into the joint portion of the constant velocity joint.

等速ジョイントのジョイント部は、グリースが封入された蛇腹形状のブーツで覆われている（例えば、特許文献１参照）。等速ジョイントのジョイント部をブーツで覆うことで、ジョイント部への水や埃の侵入を抑止でき、シャフトの大角度かつ滑らかな回転を維持できる。   The joint portion of the constant velocity joint is covered with a bellows-shaped boot filled with grease (for example, see Patent Document 1). By covering the joint portion of the constant velocity joint with boots, water and dust can be prevented from entering the joint portion, and a large angle and smooth rotation of the shaft can be maintained.

図９に示すように、一般的な等速ジョイント用ブーツ１００は、筒状をなしジョイントアウタレース（図略）などに固定される大径筒部１０３と、大径筒部１０３よりも小径の筒状をなしシャフト１８０に固定される小径筒部１０２と、大径筒部１０３と小径筒部１０２とを連結する略円錐台形状のブーツ本体部１０４とを持つ。   As shown in FIG. 9, a general constant velocity joint boot 100 has a cylindrical shape and a large diameter cylindrical portion 103 that is fixed to a joint outer race (not shown) and the like, and a smaller diameter than the large diameter cylindrical portion 103. It has a cylindrical shape and a small diameter cylindrical portion 102 fixed to the shaft 180, and a substantially truncated cone-shaped boot body portion 104 that connects the large diameter cylindrical portion 103 and the small diameter cylindrical portion 102.

等速ジョイントにおけるシャフト１８０とジョイントアウタレースとは同期して回転する。このため、図９に示す等速ジョイント用ブーツ１００は、シャフト１８０およびジョイントアウタレースの回転に伴って回転する。また、シャフト１８０はジョイントアウタレースに対して傾動する。ブーツ本体部１０４は蛇腹形状をなす。このためブーツ本体部１０４は、ジョイントアウタレースとシャフト１８０のなす角度（ジョイント角、図１０中角θ）の変化に応じて変形し、ジョイント部をシールする。   The shaft 180 and the joint outer race in the constant velocity joint rotate in synchronization. For this reason, the constant velocity joint boot 100 shown in FIG. 9 rotates with the rotation of the shaft 180 and the joint outer race. The shaft 180 tilts with respect to the joint outer race. The boot body 104 has a bellows shape. Therefore, the boot main body 104 is deformed according to a change in an angle (joint angle, angle θ in FIG. 10) formed by the joint outer race and the shaft 180, and seals the joint portion.

ところで、図９に示す等速ジョイント用ブーツ１００では、ジョイント角が大きくなると、ブーツ本体部１０４が大きく屈曲変形した状態で回転する。このとき、ブーツ本体部１０４のなかで小径筒部１０２から数えて一つ目の山部（以下、第１山部１４０ａと呼ぶ）は、大きく変形する。その結果、以下に示すような問題が生じていた。   By the way, in the constant velocity joint boot 100 shown in FIG. 9, when the joint angle increases, the boot main body 104 rotates in a state of being greatly bent and deformed. At this time, the first peak part (hereinafter referred to as the first peak part 140a) counted from the small diameter cylinder part 102 in the boot main body part 104 is greatly deformed. As a result, the following problems have occurred.

上述したように、ジョイント角が大きくなるとブーツ本体部１０４が大きく屈曲する。このときのブーツ本体部１０４の屈曲点は、ブーツ本体部１０４の軸方向における中心点ではなく、ブーツ本体部１０４のなかでジョイント部に近い部分（すなわちブーツ本体部１０４のなかで大径筒部１０３側の部分）に形成される。そして、屈曲状態において、ブーツ本体部１０４には、角度の狭まる側（図９中右側、ジョイントアウタレースに対してシャフト１８０が傾く側、以下、圧縮側と呼ぶ）で圧縮応力が作用し、角度の広がる側（図９中左側、以下、引っ張り側と呼ぶ）で引っ張り応力が作用する。   As described above, when the joint angle is increased, the boot body 104 is greatly bent. The bending point of the boot main body 104 at this time is not the center point in the axial direction of the boot main body 104 but the portion close to the joint in the boot main body 104 (that is, the large-diameter cylindrical portion in the boot main body 104). 103 portion). In the bent state, compressive stress acts on the boot main body 104 on the side where the angle is narrowed (the right side in FIG. 9, the side where the shaft 180 is inclined with respect to the joint outer race, hereinafter referred to as the compression side). The tensile stress acts on the spreading side (left side in FIG. 9, hereinafter referred to as the pulling side).

このため、ブーツ本体部１０４のなかで圧縮側かつ大径筒部１０３側に位置する部分では、山部１０４ａが圧縮され、谷部１０４ｂが内周側に引き込まれる。これに伴って、ブーツ本体部１０４のなかで圧縮側かつ小径筒部１０２側に位置する部分でもまた、谷部１０４ｂが内周側に引き込まれる。したがって、第１山部１４０ａのなかで圧縮側に位置する部分は、谷部１０４ｂに引っ張られて大径筒部１０３側に倒れ込む。また、第１山部１４０ａのなかで圧縮側に位置する部分が大径筒部１０３側に倒れ込むことから、第１山部１４０ａのなかで引っ張り側に位置する部分は小径筒部１０２側に倒れ込む。   For this reason, in the part located in the compression side and the large diameter cylinder part 103 side in the boot main-body part 104, the peak part 104a is compressed and the trough part 104b is drawn in to the inner peripheral side. Accordingly, the trough 104b is also drawn to the inner peripheral side of the boot main body 104 at the portion located on the compression side and the small-diameter cylindrical portion 102 side. Therefore, the part located in the compression side in the 1st peak part 140a is pulled by the trough part 104b, and falls in the large diameter cylinder part 103 side. In addition, since the portion located on the compression side in the first peak portion 140a falls to the large-diameter cylindrical portion 103 side, the portion located on the pull side in the first peak portion 140a falls to the small-diameter cylindrical portion 102 side. .

したがって、等速ジョイント用ブーツ１００が圧縮状態で回転すると、第１山部１４０ａは、圧縮側に位置する部分が大径筒部１０３側に倒れ込む状態と、引っ張り側に位置する部分が小径筒部１０２側に倒れ込む状態とを交互に繰り返す。さらに、図１０に示すように、小径筒部１０２におけるブーツ本体部１０４側の端部は、シャフト１８０側に沈み込む状態と、シャフト１８０から離れる方向に浮き上がる状態とを交互に繰り返す。このため小径筒部１０２には、等速ジョイント用ブーツ１００内のグリースを引き込んで、外部に押し出そうとするポンピング作用が働く。よって、図９〜図１０に示す従来の等速ジョイント用ブーツ１００では、グリース漏れが発生するおそれがあった。   Therefore, when the constant velocity joint boot 100 rotates in the compressed state, the first peak portion 140a includes a state in which the portion located on the compression side falls to the large diameter cylindrical portion 103 side and a portion located on the tension side corresponds to the small diameter cylindrical portion. The state of falling to the 102 side is repeated alternately. Further, as shown in FIG. 10, the end portion on the boot main body 104 side of the small-diameter cylindrical portion 102 alternately repeats a state where it sinks toward the shaft 180 side and a state where it floats away from the shaft 180. For this reason, the small-diameter cylindrical portion 102 has a pumping action of drawing the grease in the constant velocity joint boot 100 and pushing it out. Therefore, the conventional constant velocity joint boot 100 shown in FIGS. 9 to 10 may cause grease leakage.

特許文献２には、等速ジョイント用ブーツのブーツ本体部を、第１蛇腹部（胴主体）と第２蛇腹部（胴補助体）と連結部とにより構成する技術が紹介されている。特許文献２に紹介されている等速ジョイント用ブーツによると、ブーツ本体部における第１山部（連結部から数えて１つ目の山部）の大径筒部側への倒れ込みと、小径筒部側への倒れ込みとが、連結部によって遮断される。したがって第１山部の倒れ込みは、第２蛇腹部に伝わり難い。よって、第２蛇腹部では上述したポンピング作用が低減すると考えられる。また、第１山部の大径筒部側への倒れ込みや、小径筒部側への倒れ込みが第２蛇腹部に伝達した場合にも、第２蛇腹部が伸縮して吸収する。このため、特許文献２に紹介されている等速ジョイント用ブーツによると、上述したグリース漏れを抑制できる可能性がある。
特開２００１−３９５０号公報 実開平０３−４９４２４号公報 Patent Document 2 introduces a technique in which a boot body portion of a constant velocity joint boot is constituted by a first bellows portion (body main body), a second bellows portion (body trunk body), and a connecting portion. According to the constant velocity joint boot introduced in Patent Document 2, the first peak portion (the first peak portion counted from the connecting portion) of the boot body portion falls toward the large-diameter tube portion side, and the small-diameter tube. The falling to the part side is blocked by the connecting part. Therefore, it is difficult for the first mountain part to fall down to the second bellows part. Therefore, it is considered that the pumping action described above is reduced in the second bellows part. In addition, when the fall of the first peak portion toward the large diameter cylinder portion or the fall of the first peak portion toward the small diameter cylinder portion is transmitted to the second bellows portion, the second bellows portion expands and contracts and absorbs. For this reason, according to the constant velocity joint boot introduced in Patent Document 2, there is a possibility that the above-described grease leakage can be suppressed.
JP 2001-3950 A Japanese Utility Model Publication No. 03-49424

しかし、特許文献２に紹介されている等速ジョイント用ブーツでは、連結部がシャフトに摺接する。このため連結部とシャフトとの摺動抵抗によって、第２蛇腹部の伸縮が阻害される。第２蛇腹部の伸縮が阻害されると、第２蛇腹部が上述した第１山部の倒れ込みを充分に吸収できず、グリース漏れが発生する。また、特許文献２に紹介されている等速ジョイント用ブーツが圧縮状態で回転すると、第１蛇腹部内のグリースはポンピング作用によって連結部の内部および第２蛇腹部の内部に徐々に押し出されると考えられる。しかし、連結部はシャフトに摺接するため、第１蛇腹部と第２蛇腹部との間におけるグリースの移動は連結部によって阻害される。このため、グリースを内部に保持した状態で第２蛇腹部が伸縮すると、グリースは逃げ場を失って、等速ジョイント用ブーツの外部に押し出される。よって、特許文献２に紹介されている等速ジョイント用ブーツによっても、依然としてグリース漏れを抑制できなかった。   However, in the constant velocity joint boot introduced in Patent Document 2, the connecting portion is in sliding contact with the shaft. For this reason, the expansion and contraction of the second bellows portion is hindered by the sliding resistance between the connecting portion and the shaft. If the expansion and contraction of the second bellows portion is inhibited, the second bellows portion cannot sufficiently absorb the above-described collapse of the first peak portion, and grease leakage occurs. In addition, when the constant velocity joint boot introduced in Patent Document 2 is rotated in a compressed state, the grease in the first bellows portion is gradually pushed out into the connection portion and the second bellows portion by the pumping action. It is done. However, since the connecting portion is in sliding contact with the shaft, the movement of the grease between the first bellows portion and the second bellows portion is hindered by the connecting portion. For this reason, when the second bellows portion expands and contracts with the grease held inside, the grease loses escape and is pushed out of the constant velocity joint boot. Therefore, even with the constant velocity joint boot introduced in Patent Document 2, grease leakage could still not be suppressed.

本発明は上記事情に鑑みてなされたものであり、グリース漏れを抑制できる等速ジョイント用ブーツを提供することを目的とする。   This invention is made | formed in view of the said situation, and it aims at providing the boot for constant velocity joints which can suppress a grease leak.

上記課題を解決する本発明の等速ジョイント用ブーツは、シャフトに固定される小径筒部と、小径筒部と離間して同軸的に配置され小径筒部よりも大径の大径筒部と、小径筒部と大径筒部とを一体的に連結する略円錐台形状のブーツ本体部とを持ち、ブーツ本体部は、大径筒部に隣接する第１蛇腹部と、小径筒部に隣接する第２蛇腹部と、第１蛇腹部と第２蛇腹部とを連結する連結部と、連結部の内周面から連結部の内周側に向けて突出する当接部と、を持ち、連結部の内部には、シャフトの外周面と連結部の内周面と当接部とで区画され第１蛇腹部の内部と第２蛇腹部の内部とを連絡する連絡空間が形成されていることを特徴とする。   The constant velocity joint boot of the present invention that solves the above problems includes a small-diameter cylindrical portion that is fixed to a shaft, a large-diameter cylindrical portion that is coaxially disposed apart from the small-diameter cylindrical portion, and has a larger diameter than the small-diameter cylindrical portion. A boot body portion having a substantially truncated cone shape that integrally connects the small-diameter cylindrical portion and the large-diameter cylindrical portion. The boot main body portion is connected to the first bellows portion adjacent to the large-diameter cylindrical portion and the small-diameter cylindrical portion. And an adjacent second bellows part, a connecting part that connects the first bellows part and the second bellows part, and an abutting part that protrudes from the inner peripheral surface of the connecting part toward the inner peripheral side of the connecting part. In the inside of the connecting portion, there is formed a communication space that is divided by the outer peripheral surface of the shaft, the inner peripheral surface of the connecting portion, and the abutting portion and connects the inside of the first bellows portion and the inside of the second bellows portion. It is characterized by being.

本発明の等速ジョイント用ブーツは、下記の（１）〜（２）の少なくとも一つを備えるのが好ましい。
（１）上記当接部は半球状をなす。
（２）上記連結部の肉厚は、上記第１蛇腹部の肉厚および上記第２蛇腹部の肉厚よりも大きい。 The constant velocity joint boot of the present invention preferably includes at least one of the following (1) to (2).
(1) The contact portion has a hemispherical shape.
(2) The thickness of the connecting portion is larger than the thickness of the first bellows portion and the thickness of the second bellows portion.

本発明の等速ジョイント用ブーツにおけるブーツ本体部は、第１蛇腹部と第２蛇腹部と連結部とを持つ。連結部は第１蛇腹部と第２蛇腹部とを連結する。このため、第１蛇腹部の第１山部（連結部から数えて一つ目の山部）の大径筒部側への倒れ込みと、小径筒部側への倒れ込みとは、連結部で遮断される。よって第２蛇腹部には、第１山部の倒れ込みが伝達され難い。また、第１山部の倒れ込みが第２蛇腹部に伝達した場合にも、第２蛇腹部がこの動きを吸収する。   The boot body portion in the constant velocity joint boot of the present invention has a first bellows portion, a second bellows portion, and a connecting portion. The connecting portion connects the first bellows portion and the second bellows portion. For this reason, the fall of the 1st peak part (the 1st peak part counted from a connection part) of the 1st bellows part to the large diameter cylinder part side and the fall to the small diameter cylinder part side are intercepted by a connection part. Is done. Therefore, it is difficult for the second bellows part to transmit the fall of the first peak part. Further, when the fall of the first peak portion is transmitted to the second bellows portion, the second bellows portion absorbs this movement.

また、本発明の等速ジョイント用ブーツは当接部を持つ。当接部は、連結部の内周面から連結部の内周側に向けて突出する。このため、連結部の内周面とシャフトの外周面との間には当接部が介在する。すなわち本発明の等速ジョイント用ブーツにおいては、連結部の内周面全体がシャフトに接触することはない。よって、等速ジョイント用ブーツとシャフトとの摺動抵抗は小さくなり、第２蛇腹部の伸縮阻害を低減できる。よって、本発明の等速ジョイント用ブーツによると、第２蛇腹部が充分に伸縮する。   Moreover, the boot for constant velocity joints of this invention has an abutting part. The contact portion projects from the inner peripheral surface of the connecting portion toward the inner peripheral side of the connecting portion. For this reason, a contact part exists between the inner peripheral surface of a connection part and the outer peripheral surface of a shaft. That is, in the constant velocity joint boot of the present invention, the entire inner peripheral surface of the connecting portion does not contact the shaft. Therefore, the sliding resistance between the constant velocity joint boot and the shaft is reduced, and the expansion and contraction inhibition of the second bellows portion can be reduced. Therefore, according to the constant velocity joint boot of the present invention, the second bellows part sufficiently expands and contracts.

また、本発明の等速ジョイント用ブーツにおいて、連結部の内部には、連絡空間が形成されている。連絡空間は、シャフトの外周面と連結部の内周面と当接部とで区画され第１蛇腹部の内部と第２蛇腹部の内部とを連絡する。このため、本発明の等速ジョイント用ブーツでは、第１蛇腹部と第２蛇腹部との間でグリースが移動可能である。よって、ポンピング作用によって第１蛇腹部から押し出され、第２蛇腹部の内部に移動したグリースは、第２蛇腹部が圧縮すると連絡空間を通って第１蛇腹部の内部に戻る。   In the constant velocity joint boot of the present invention, a communication space is formed inside the connecting portion. The communication space is partitioned by the outer peripheral surface of the shaft, the inner peripheral surface of the connecting portion, and the contact portion, and connects the inside of the first bellows portion and the inside of the second bellows portion. For this reason, in the constant velocity joint boot of the present invention, the grease can move between the first bellows portion and the second bellows portion. Therefore, the grease pushed out from the first bellows part by the pumping action and moved into the second bellows part returns to the inside of the first bellows part through the communication space when the second bellows part is compressed.

本発明の等速ジョイント用ブーツによると、これらの協働によってグリース漏れを抑制できる。   According to the constant velocity joint boot of the present invention, it is possible to suppress grease leakage by these cooperation.

本発明の等速ジョイント用ブーツが上記（１）を備える場合には、シャフトに対する当接部の接触面積が小さくなる。よって、等速ジョイント用ブーツとシャフトとの摺動抵抗はより一層小さくなり、第２蛇腹部の伸縮阻害をより一層低減できる。よって、上記（１）を備える本発明の等速ジョイント用ブーツは、グリース漏れをより一層低減できる。   When the constant velocity joint boot of the present invention includes the above (1), the contact area of the contact portion with the shaft is reduced. Therefore, the sliding resistance between the constant velocity joint boot and the shaft is further reduced, and the expansion inhibition of the second bellows portion can be further reduced. Therefore, the constant velocity joint boot of the present invention having the above (1) can further reduce grease leakage.

本発明の等速ジョイント用ブーツが上記（２）を備える場合には、連結部の剛性が高くなる。このため、第１山部の倒れ込みを連結部によってより確実に遮断できる。したがって、第１山部の倒れ込みは、第２蛇腹部により一層伝達され難い。よって、上記（２）を備える本発明の等速ジョイント用ブーツは、第２蛇腹部におけるポンピング作用をより一層抑制し、グリース漏れをより一層抑制できる。   When the constant velocity joint boot of the present invention includes the above (2), the rigidity of the connecting portion is increased. For this reason, falling of a 1st peak part can be interrupted | blocked more reliably by a connection part. Therefore, the fall of the first peak portion is more difficult to be transmitted by the second bellows portion. Therefore, the constant velocity joint boot of the present invention having the above (2) can further suppress the pumping action in the second bellows part and further suppress the grease leakage.

以下、本発明の等速ジョイント用ブーツを図面を基に説明する。   The constant velocity joint boot of the present invention will be described below with reference to the drawings.

（実施例１）
実施例１の等速ジョイント用ブーツは、上記（１）および（２）を備える。実施例１の等速ジョイント用ブーツを軸方向に沿って切断した様子を模式的に部分断面図を図１に示す。実施例１の等速ジョイント用ブーツにおける連結部を模式的に表す切り欠き斜視図を図２に示す。実施例１の等速ジョイント用ブーツの使用状態を模式的に表す説明図を図３に示す。 Example 1
The constant velocity joint boot of Example 1 includes the above (1) and (2). FIG. 1 schematically shows a partial cross-sectional view of the constant velocity joint boot of Example 1 cut along the axial direction. FIG. 2 shows a cutaway perspective view schematically showing a connecting portion in the constant velocity joint boot of the first embodiment. FIG. 3 is an explanatory diagram schematically showing the usage state of the constant velocity joint boot of the first embodiment.

実施例１の等速ジョイント用ブーツ１は、小径筒部２と大径筒部３とブーツ本体部４とを持つ。小径筒部２と大径筒部３とブーツ本体部４とは、熱可塑性エラストマーからなり、一体にブロー成形されている。   The constant velocity joint boot 1 according to the first embodiment includes a small diameter cylindrical portion 2, a large diameter cylindrical portion 3, and a boot main body portion 4. The small-diameter cylindrical portion 2, the large-diameter cylindrical portion 3 and the boot main body portion 4 are made of a thermoplastic elastomer and are integrally blow-molded.

小径筒部２は略円筒状をなし、等速ジョイント８のシャフト８０に固定されている。詳しくは、小径筒部２の外周面には環状の小径側溝部２０が形成されている。小径側溝部２０には締結バンドからなる小径側締結部材９０が取り付けられている。小径筒部２は、小径側締結部材９０によってシャフト８０に固定されている。また、小径筒部２の内周面には、小径筒部２の内周側に向けて突出する小径側シール部２１が形成されている。小径側シール部２１は、シャフト８０の外周面に形成されている第１シール用溝部８１に入り込み、小径筒部２とシャフト８０との隙間をシールする。   The small diameter cylindrical portion 2 has a substantially cylindrical shape and is fixed to the shaft 80 of the constant velocity joint 8. Specifically, an annular small-diameter side groove portion 20 is formed on the outer peripheral surface of the small-diameter cylindrical portion 2. A small-diameter side fastening member 90 composed of a fastening band is attached to the small-diameter side groove portion 20. The small diameter cylindrical portion 2 is fixed to the shaft 80 by a small diameter side fastening member 90. Further, a small diameter side seal portion 21 that protrudes toward the inner peripheral side of the small diameter cylindrical portion 2 is formed on the inner peripheral surface of the small diameter cylindrical portion 2. The small diameter side sealing portion 21 enters the first sealing groove 81 formed on the outer peripheral surface of the shaft 80 and seals the gap between the small diameter cylindrical portion 2 and the shaft 80.

大径筒部３は小径筒部２よりも大径の略円筒状をなす。大径筒部３は、小径筒部２と離間して同軸的に配置されている。大径筒部３は略筒状をなし、等速ジョイント８のジョイントアウタレース８２に固定されている。詳しくは、大径筒部３の外周面には環状の大径側溝部３０が形成されている。大径側溝部３０には締結バンドからなる大径側締結部材９１が取り付けられている。大径筒部３は大径側締結部材９１によってジョイントアウタレース８２に固定されている。また、大径筒部３の内周面には、大径筒部３の内周側に向けて突出する大径側シール部３１が形成されている。大径側シール部３１は、ジョイントアウタレース８２の外周面に形成されている第２シール用溝部８３に入り込み、大径筒部３とジョイントアウタレース８２との隙間をシールする。   The large diameter cylindrical portion 3 has a substantially cylindrical shape with a larger diameter than the small diameter cylindrical portion 2. The large diameter cylindrical portion 3 is disposed coaxially with the small diameter cylindrical portion 2. The large-diameter cylindrical portion 3 has a substantially cylindrical shape and is fixed to the joint outer race 82 of the constant velocity joint 8. Specifically, an annular large-diameter side groove portion 30 is formed on the outer peripheral surface of the large-diameter cylindrical portion 3. A large-diameter side fastening member 91 made of a fastening band is attached to the large-diameter side groove portion 30. The large-diameter cylindrical portion 3 is fixed to the joint outer race 82 by a large-diameter side fastening member 91. Further, a large-diameter side seal portion 31 that protrudes toward the inner peripheral side of the large-diameter cylindrical portion 3 is formed on the inner peripheral surface of the large-diameter cylindrical portion 3. The large-diameter side seal portion 31 enters the second seal groove 83 formed on the outer peripheral surface of the joint outer race 82 and seals the gap between the large-diameter cylindrical portion 3 and the joint outer race 82.

ブーツ本体部４は、略円錐台形状をなし小径筒部２と大径筒部３とを一体的に連結している。ブーツ本体部４は、第１蛇腹部４１と、第２蛇腹部４２と、連結部４３と、当接部４４とを持つ。第１蛇腹部４１は大径筒部３に隣接する。第２蛇腹部４２は小径筒部２に隣接する。連結部４３は第１蛇腹部４１と第２蛇腹部４２とを連結する。第１蛇腹部４１は、連結部４３側の端部から順に、第１山部４１１ａ、第１谷部４１１ｂ、第２山部４１２ａ・・・と、山部と谷部とが交互に形成されてなる蛇腹筒状をなす。第２蛇腹部４２は、小径筒部２側の端部から順に、第１副山部４２１ａ、第１副谷部４２１ｂ、第２副山部４２２ａ・・・と、山部と谷部とが交互に形成されてなる蛇腹筒状をなす。第２蛇腹部４２の軸方向長さは、第１蛇腹部４１の軸方向長さよりも小さい。詳しくは、第２蛇腹部４２の軸方向長さは、第１蛇腹部４１の軸方向長さの３０％程度である。第１蛇腹部４１における山部の突出高さは、第２蛇腹部４２における山部の突出高さよりも大きい。連結部４３は肉厚略一定の円筒状をなす。連結部４３の軸方向長さは、第１蛇腹部４１の軸方向長さおよび第２蛇腹部４２の軸方向長さよりも小さい。詳しくは、連結部４３の軸方向長さは、第１蛇腹部４１の軸方向長さの２５％程度であり、第２蛇腹部４２の軸方向長さの８０％程度である。第１蛇腹部４１の肉厚は約１．１ｍｍである。第２蛇腹部４２の肉厚は約１．１ｍｍである。連結部４３の肉厚は約１．５ｍｍである。すなわち、連結部４３の肉厚は第１蛇腹部４１の肉厚および第２蛇腹部４２の肉厚よりも大きい。第１蛇腹部４１の内部にはグリース（図略）が封入されている。   The boot main body 4 has a substantially truncated cone shape, and integrally connects the small diameter cylindrical portion 2 and the large diameter cylindrical portion 3. The boot body 4 includes a first bellows portion 41, a second bellows portion 42, a connecting portion 43, and a contact portion 44. The first bellows portion 41 is adjacent to the large diameter cylindrical portion 3. The second bellows part 42 is adjacent to the small diameter cylinder part 2. The connecting portion 43 connects the first bellows portion 41 and the second bellows portion 42. As for the 1st bellows part 41, the 1st peak part 411a, the 1st trough part 411b, the 2nd peak part 412a ..., and a peak part and a trough part are formed by turns from the edge part by the side of the connection part 43. It has a bellows tube shape. The second bellows part 42 includes, in order from the end on the small-diameter cylindrical part 2 side, a first auxiliary mountain part 421a, a first auxiliary valley part 421b, a second auxiliary mountain part 422a,. It forms a bellows cylinder shape formed alternately. The axial length of the second bellows portion 42 is smaller than the axial length of the first bellows portion 41. Specifically, the axial length of the second bellows portion 42 is about 30% of the axial length of the first bellows portion 41. The protruding height of the peak portion in the first bellows portion 41 is larger than the protruding height of the peak portion in the second bellows portion 42. The connecting portion 43 has a cylindrical shape with a substantially constant thickness. The axial length of the connecting portion 43 is smaller than the axial length of the first bellows portion 41 and the axial length of the second bellows portion 42. Specifically, the axial length of the connecting portion 43 is about 25% of the axial length of the first bellows portion 41 and about 80% of the axial length of the second bellows portion 42. The thickness of the first bellows portion 41 is about 1.1 mm. The wall thickness of the second bellows portion 42 is about 1.1 mm. The thickness of the connecting portion 43 is about 1.5 mm. That is, the thickness of the connecting portion 43 is larger than the thickness of the first bellows portion 41 and the thickness of the second bellows portion 42. Grease (not shown) is sealed inside the first bellows portion 41.

実施例１の等速ジョイント用ブーツ１は１２個の当接部４４をもつ。図２に示すように、各当接部４４は略半球状をなし、連結部４３の内周面から連結部４３の内周側に向けて突出している。１２個の当接部４４のなかの６個は、連結部４３の第１蛇腹部４１側部分に形成されている。この６個の当接部４４は、連結部４３の周方向（以下、単に周方向と略する）に等間隔で配置されている。１２個の当接部４４のなかの他の６個は、連結部４３の第２蛇腹部４２側部分に形成されている。この６個の当接部４４は、周方向に等間隔で配置されている。また、図１および図２に示すように、連結部４３の第２蛇腹部４２側部分に形成されている各当接部４４０の周方向位置は、連結部４３の第１蛇腹部４１側部分に形成されている各当接部４４１の周方向位置と同じである。このため、当接部４４同士の周方向の隙間は、連結部４３の軸方向（以下、単に軸方向と略する）に連続している。各当接部４４の先端部は、シャフト８０の外周面に当接している。   The constant velocity joint boot 1 according to the first embodiment has twelve contact portions 44. As shown in FIG. 2, each contact portion 44 has a substantially hemispherical shape and protrudes from the inner peripheral surface of the connecting portion 43 toward the inner peripheral side of the connecting portion 43. Six of the twelve contact portions 44 are formed on the first bellows portion 41 side portion of the connecting portion 43. The six contact portions 44 are arranged at equal intervals in the circumferential direction of the connecting portion 43 (hereinafter simply referred to as the circumferential direction). The other six of the twelve abutting portions 44 are formed on the second bellows portion 42 side portion of the connecting portion 43. The six contact portions 44 are arranged at equal intervals in the circumferential direction. As shown in FIGS. 1 and 2, the circumferential position of each contact portion 440 formed on the second bellows portion 42 side portion of the connecting portion 43 is the first bellows portion 41 side portion of the connecting portion 43. It is the same as the circumferential direction position of each contact part 441 formed in this. For this reason, the circumferential clearance between the contact portions 44 is continuous in the axial direction of the connecting portion 43 (hereinafter simply referred to as the axial direction). The tip of each contact portion 44 is in contact with the outer peripheral surface of the shaft 80.

連結部４３の内部には、シャフト８０の外周面と、連結部４３の内周面と、当接部４４と、で区画された連絡空間４３０が形成されている。上述したように、隣接する当接部４４同士は周方向および／または軸方向に離間しているため、連絡空間４３０は第１蛇腹部４１の内部と第２蛇腹部４２の内部とを連絡する。   A connecting space 430 defined by the outer peripheral surface of the shaft 80, the inner peripheral surface of the connecting portion 43, and the contact portion 44 is formed inside the connecting portion 43. As described above, since the adjacent contact portions 44 are separated from each other in the circumferential direction and / or the axial direction, the communication space 430 communicates the inside of the first bellows portion 41 and the inside of the second bellows portion 42. .

図３に示すように、実施例１の等速ジョイント用ブーツ１におけるブーツ本体部４は、ジョイント角が大きくなると、大きく屈曲する。屈曲状態におけるブーツ本体部４には、圧縮側（図３中右側）で圧縮応力が作用し、引っ張り側（図３中左側）で引っ張り応力が作用する。このため、第１山部４１１ａのなかで圧縮側に位置する部分は大径筒部３側に倒れ込む。第１山部４１１ａのなかで引っ張り側に位置する部分は小径筒部２側に倒れ込む。しかし、第１蛇腹部４１の小径筒部２側部分は厚肉の連結部４３に連結されているため、第１山部４１１ａの倒れ込みは連結部４３によって遮断される。したがって第２蛇腹部４２に伝達する第１山部４１１ａの倒れ込みは、ごく僅かである。第２蛇腹部４２に伝達した第１山部４１１ａの倒れ込みは、第２蛇腹部４２が伸縮することで吸収される。このため、実施例１の等速ジョイント用ブーツ１を圧縮状態で回転させた場合にも、第２蛇腹部４２の第１副山部４２１ａは大径筒部３側および小径筒部２側に倒れ込まない。よって、実施例１の等速ジョイント用ブーツ１によると、第２蛇腹部４２におけるポンピング作用を抑制し、等速ジョイント用ブーツ１外部へのグリース漏れを抑制できる。   As shown in FIG. 3, the boot body 4 in the constant velocity joint boot 1 of the first embodiment bends greatly as the joint angle increases. The boot body 4 in the bent state is subjected to compressive stress on the compression side (right side in FIG. 3) and tensile stress on the tension side (left side in FIG. 3). For this reason, the part located in the compression side in the 1st peak part 411a falls in the large diameter cylinder part 3 side. A portion located on the pulling side in the first peak portion 411a falls into the small diameter cylindrical portion 2 side. However, since the small-diameter cylindrical portion 2 side portion of the first bellows portion 41 is connected to the thick connecting portion 43, the falling of the first peak portion 411 a is blocked by the connecting portion 43. Therefore, the fall of the first peak portion 411a transmitted to the second bellows portion 42 is very small. The fall of the first peak portion 411a transmitted to the second bellows portion 42 is absorbed by the expansion and contraction of the second bellows portion 42. For this reason, even when the constant velocity joint boot 1 of Example 1 is rotated in a compressed state, the first auxiliary mountain portion 421a of the second bellows portion 42 is located on the large diameter cylindrical portion 3 side and the small diameter cylindrical portion 2 side. Don't fall down. Therefore, according to the constant velocity joint boot 1 of the first embodiment, the pumping action in the second bellows portion 42 can be suppressed, and grease leakage to the outside of the constant velocity joint boot 1 can be suppressed.

なお、実施例１の等速ジョイント用ブーツ１を圧縮状態で回転させると、第１蛇腹部４１の第１山部４１１ａが大径筒部３側と小径筒部２側とに交互に倒れ込む。このため、第１蛇腹部４１の内部に封入されているグリースは、ポンピング作用によって連結部４３の内部（すなわち連絡空間４３０）に押し出され、その一部は第２蛇腹部４２の内部に移動する。この状態で第２蛇腹部４２が圧縮すると、第２蛇腹部４２の内部に移動したグリースは、連絡空間４３０を通って第１蛇腹部４１の内部に戻る。このため、実施例１の等速ジョイント用ブーツ１によると、第２蛇腹部４２の内部に移動したグリースが小径筒部２を経て等速ジョイント用ブーツ１の外部に漏出することはない。   In addition, when the constant velocity joint boot 1 of Example 1 is rotated in a compressed state, the first peak portions 411a of the first bellows portion 41 fall alternately on the large diameter cylindrical portion 3 side and the small diameter cylindrical portion 2 side. For this reason, the grease sealed in the first bellows portion 41 is pushed out into the connection portion 43 (that is, the communication space 430) by the pumping action, and a part of the grease moves into the second bellows portion 42. . When the second bellows portion 42 is compressed in this state, the grease that has moved into the second bellows portion 42 returns to the inside of the first bellows portion 41 through the communication space 430. For this reason, according to the constant velocity joint boot 1 of the first embodiment, the grease that has moved into the second bellows portion 42 does not leak to the outside of the constant velocity joint boot 1 through the small diameter cylindrical portion 2.

さらに、実施例１の等速ジョイント用ブーツ１において、連結部４３の内周面とシャフト８０の外周面との間には当接部４４が介在している。したがって、連結部４３の内周面全体がシャフト８０の外周面に接触することはない。また、当接部４４は略半球状をなすため、当接部４４とシャフト８０との摺動抵抗は非常に小さい。このため、等速ジョイント用ブーツ１とシャフト８０との摺動抵抗もまた非常に小さく、連結部４３が第２蛇腹部４２の伸縮に干渉することはない。さらに、連絡空間４３０をグリースが移動することで、当接部４４とシャフト８０との間隙にグリースが供給される。このため、当接部４４とシャフト８０との摺動抵抗はより一層小さくなる。   Furthermore, in the constant velocity joint boot 1 according to the first embodiment, a contact portion 44 is interposed between the inner peripheral surface of the connecting portion 43 and the outer peripheral surface of the shaft 80. Therefore, the entire inner peripheral surface of the connecting portion 43 does not contact the outer peripheral surface of the shaft 80. Moreover, since the contact part 44 is substantially hemispherical, the sliding resistance between the contact part 44 and the shaft 80 is very small. For this reason, the sliding resistance between the constant velocity joint boot 1 and the shaft 80 is also very small, and the connecting portion 43 does not interfere with the expansion and contraction of the second bellows portion 42. Furthermore, the grease moves through the communication space 430, so that the grease is supplied to the gap between the contact portion 44 and the shaft 80. For this reason, the sliding resistance between the contact portion 44 and the shaft 80 is further reduced.

なお、実施例１の等速ジョイント用ブーツ１では、当接部４４が半球状をなしているが、当接部４４の形状はこれに限定されない。等速ジョイント用ブーツ１とシャフト８０との摺動抵抗を小さくするためには、当接部４４の端部を湾曲形状に形成するのがよい。シャフト８０と当接部４４との当接面積を小さくして、当接部４４をシャフト８０に滑らかに摺動させるためである。   In the constant velocity joint boot 1 according to the first embodiment, the contact portion 44 has a hemispherical shape, but the shape of the contact portion 44 is not limited thereto. In order to reduce the sliding resistance between the constant velocity joint boot 1 and the shaft 80, it is preferable to form the end of the contact portion 44 in a curved shape. This is because the contact area between the shaft 80 and the contact portion 44 is reduced and the contact portion 44 is smoothly slid on the shaft 80.

実施例１の等速ジョイント用ブーツ１における連結部４３の肉厚は、第１蛇腹部４１の肉厚および第２蛇腹部４２の肉厚よりも大きい。このため実施例１の等速ジョイント用ブーツ１における連結部４３は変形し難く、第１山部４１１ａの倒れ込みを連結部４３自身の剛性によっても遮断している。しかし、本発明の等速ジョイント用ブーツ１における連結部４３の肉厚は、第１蛇腹部４１の肉厚および第２蛇腹部４２の肉厚よりも小さくても良い。この場合にも、連結部４３の存在によって第１山部４１１ａの倒れ込みを遮断できるため、グリースの漏出を低減できる。   The thickness of the connecting portion 43 in the constant velocity joint boot 1 of the first embodiment is larger than the thickness of the first bellows portion 41 and the thickness of the second bellows portion 42. For this reason, the connection part 43 in the constant velocity joint boot 1 of Example 1 is hard to deform | transform, and the fall of the 1st peak part 411a is interrupted | blocked also by the rigidity of connection part 43 itself. However, the thickness of the connecting portion 43 in the constant velocity joint boot 1 of the present invention may be smaller than the thickness of the first bellows portion 41 and the thickness of the second bellows portion 42. Also in this case, since the falling of the first peak portion 411a can be blocked by the presence of the connecting portion 43, leakage of grease can be reduced.

なお、連結部４３は、第１蛇腹部４１および第２蛇腹部４２と同一の材料で形成しても良いし、異なる材料で形成しても良い。連結部４３を剛性に優れた材料で形成する場合には、連結部４３がより一層変形し難くなり、上述した第１山部４１１ａの倒れ込みを連結部４３によってより確実に遮断できる。   In addition, the connection part 43 may be formed with the same material as the 1st bellows part 41 and the 2nd bellows part 42, and may be formed with a different material. When the connecting portion 43 is formed of a material having excellent rigidity, the connecting portion 43 becomes more difficult to deform, and the above-described collapse of the first peak portion 411a can be more reliably blocked by the connecting portion 43.

本発明の等速ジョイント用ブーツ１における連結部４３は、軸方向長さを大きくすればするほど、第１山部４１１ａの倒れ込みを確実に遮断できる。好ましくは、連結部４３の軸方向長さは第１蛇腹部４１の軸方向長さの２０％以上であるのがよい。また、本発明の等速ジョイント用ブーツ１における第２蛇腹部４２は、軸方向長さを大きくすればするほど、第２蛇腹部４２に伝達した第１山部４１１ａの倒れ込みを確実に吸収できる。好ましくは、第２蛇腹部４２の軸方向長さは第１蛇腹部４１の軸方向長さの２０％以上であるのがよい。   As the connecting portion 43 in the constant velocity joint boot 1 of the present invention increases in length in the axial direction, the first peak portion 411a can be more reliably prevented from falling. Preferably, the axial length of the connecting portion 43 is 20% or more of the axial length of the first bellows portion 41. Moreover, the 2nd bellows part 42 in the boot 1 for constant velocity joints of this invention can absorb the fall of the 1st peak part 411a transmitted to the 2nd bellows part 42, so that the axial direction length is enlarged. . Preferably, the axial length of the second bellows portion 42 is 20% or more of the axial length of the first bellows portion 41.

実施例１の等速ジョイント用ブーツ１における当接部４４は、周方向と軸方向とに複数個ずつ形成されている。しかし、本発明の等速ジョイント用ブーツ１における当接部４４は１つのみであっても良い。なお、当接部４４を周方向に複数個形成する場合には、当接部４４がシャフト８０に対して周方向に均一に接触する。また、当接部４４を軸方向に複数個形成する場合には、当接部４４がシャフト８０に対して軸方向に均一に接触する。このため、これらの場合には、等速ジョイント用ブーツ１がシャフト８０に滑らかに摺動する利点がある。   A plurality of contact portions 44 in the constant velocity joint boot 1 of the first embodiment are formed in the circumferential direction and the axial direction. However, the contact portion 44 in the constant velocity joint boot 1 of the present invention may be only one. When a plurality of contact portions 44 are formed in the circumferential direction, the contact portions 44 are in uniform contact with the shaft 80 in the circumferential direction. Further, when a plurality of contact portions 44 are formed in the axial direction, the contact portions 44 uniformly contact the shaft 80 in the axial direction. For this reason, in these cases, there is an advantage that the constant velocity joint boot 1 slides smoothly on the shaft 80.

また、実施例１の等速ジョイント用ブーツ１では、周方向に隣接する当接部４４同士の隙間は、軸方向に連続している。しかし、本発明の等速ジョイント用ブーツ１においては、周方向に隣接する当接部４４同士の隙間は、軸方向に連続していなくてもよい。なお、周方向に隣接する当接部４４同士の隙間が軸方向に連続している場合には、連絡空間４３０のなかで隣接する当接部４４同士によって区画される部分が軸方向に連続形成されるため、グリースが第１蛇腹部４１と第２蛇腹部４２との間を移動し易い。したがってこの場合には、グリース漏れをより確実に抑制できる。   In the constant velocity joint boot 1 according to the first embodiment, the gap between the contact portions 44 adjacent in the circumferential direction is continuous in the axial direction. However, in the constant velocity joint boot 1 of the present invention, the gap between the contact portions 44 adjacent in the circumferential direction may not be continuous in the axial direction. In addition, when the clearance gap between the contact parts 44 adjacent in the circumferential direction is continuing in the axial direction, the part divided by the contact parts 44 adjacent in the communication space 430 is continuously formed in the axial direction. Therefore, the grease easily moves between the first bellows portion 41 and the second bellows portion 42. Therefore, in this case, grease leakage can be more reliably suppressed.

（実施例２）
実施例２の等速ジョイント用ブーツは、上記（２）を備える。実施例２の等速ジョイント用ブーツは、当接部の形状以外は実施例１の等速ジョイント用ブーツと同じである。実施例２の等速ジョイント用ブーツを軸方向に沿って切断した様子を模式的に表す部分断面図を図４に示す。実施例２の等速ジョイント用ブーツにおける連結部を模式的に表す切り欠き斜視図を図５に示す。 (Example 2)
The constant velocity joint boot of Example 2 includes the above (2). The constant velocity joint boot of Example 2 is the same as the constant velocity joint boot of Example 1 except for the shape of the contact portion. FIG. 4 is a partial cross-sectional view schematically showing a state where the constant velocity joint boot of Example 2 is cut along the axial direction. FIG. 5 shows a cutaway perspective view schematically showing a connecting portion in the constant velocity joint boot of the second embodiment.

実施例２の等速ジョイント用ブーツ１は、６個の当接部４４を持つ。図４および５に示すように、各当接部４４は円柱を軸方向に沿って分割した形状をなす。各当接部４４は連結部４３の第１蛇腹部４１側から第２蛇腹部４２側に延設されている。各当接部４４は周方向に等間隔で離間している。   The constant velocity joint boot 1 according to the second embodiment has six contact portions 44. As shown in FIGS. 4 and 5, each contact portion 44 has a shape obtained by dividing a cylinder along the axial direction. Each contact portion 44 extends from the first bellows portion 41 side of the connecting portion 43 to the second bellows portion 42 side. The contact portions 44 are spaced apart at equal intervals in the circumferential direction.

実施例２の等速ジョイント用ブーツにおける当接部４４は、連結部４３の第１蛇腹部４１側から第２蛇腹部４２側に延設されている。このため、実施例２の等速ジョイント用ブーツ１における当接部４４は、実施例１の等速ジョイント用ブーツにおける当接部に比べて、シャフト８０との接触面積が大きい。このため実施例２の等速ジョイント用ブーツ１は、実施例１の等速ジョイント用ブーツ１に比べると、シャフト８０との摺動抵抗が大きい。しかし実施例２の等速ジョイント用ブーツ１における当接部４４は、連結部４３の軸方向に延在している。このため、連結部４３は当接部４４によって軸方向に補強され、変形し難い。よって実施例２の等速ジョイント用ブーツ１における連結部４３は、実施例１の等速ジョイント用ブーツにおける連結部に比べて、第１山部４１１ａの倒れ込みをより確実に遮断できる。よって、実施例２の等速ジョイント用ブーツ１は、グリース漏れを抑制できる。   The contact portion 44 in the constant velocity joint boot of the second embodiment extends from the first bellows portion 41 side of the connecting portion 43 to the second bellows portion 42 side. For this reason, the contact portion 44 of the constant velocity joint boot 1 of the second embodiment has a larger contact area with the shaft 80 than the contact portion of the constant velocity joint boot of the first embodiment. For this reason, the constant velocity joint boot 1 of the second embodiment has a larger sliding resistance with the shaft 80 than the constant velocity joint boot 1 of the first embodiment. However, the contact portion 44 in the constant velocity joint boot 1 of the second embodiment extends in the axial direction of the connecting portion 43. For this reason, the connecting portion 43 is reinforced in the axial direction by the abutting portion 44 and is not easily deformed. Therefore, the connecting portion 43 in the constant velocity joint boot 1 according to the second embodiment can more reliably block the first peak portion 411a from falling than the connecting portion in the constant velocity joint boot according to the first embodiment. Therefore, the constant velocity joint boot 1 of Example 2 can suppress grease leakage.

（実施例３）
実施例３の等速ジョイント用ブーツは、連結部の形状以外は実施例１の等速ジョイント用ブーツと同じである。実施例３の等速ジョイント用ブーツを軸方向に沿って切断した様子を模式的に表す部分断面図を図６に示す。 (Example 3)
The constant velocity joint boot of Example 3 is the same as the constant velocity joint boot of Example 1 except for the shape of the connecting portion. FIG. 6 is a partial cross-sectional view schematically showing a state in which the constant velocity joint boot of Example 3 is cut along the axial direction.

実施例３の等速ジョイント用ブーツ１における連結部４３は、連結部４３の内周側部分を構成する連結内周部４３１と、連結部４３の外周側部分を構成する連結外周部４３２と、を持つ。連結内周部４３１は筒状をなし、等速ジョイント用ブーツ１のなかで連結部４３を除く部分（大径筒部３、第１蛇腹部４１、第２蛇腹部４２、当接部４４、小径筒部２）と同一材料からなる。また連結内周部４３１は、等速ジョイント用ブーツ１のなかで連結部４３を除く部分と一体に成形されている。連結外周部４３２は、連結内周部４３１よりも剛性の高い材料（実施例３では金属製の締結バンド）からなる。連結外周部４３２は、連結内周部４３１の外周側に取り付けられ、連結内周部４３１を外周側から補強する。このため、実施例３の等速ジョイント用ブーツ１における連結部４３は剛性に優れ、変形し難い。よって、実施例３の等速ジョイント用ブーツ１における連結部４３もまた、第１山部４１１ａの倒れ込みを確実に遮断できる。よって、実施例３の等速ジョイント用ブーツ１は、グリース漏れを抑制できる。   The connecting portion 43 in the constant velocity joint boot 1 according to the third embodiment includes a connecting inner peripheral portion 431 that forms an inner peripheral side portion of the connecting portion 43, a connecting outer peripheral portion 432 that forms an outer peripheral side portion of the connecting portion 43, and have. The connection inner peripheral part 431 has a cylindrical shape, and a part of the constant velocity joint boot 1 excluding the connection part 43 (large diameter cylindrical part 3, first bellows part 41, second bellows part 42, contact part 44, It consists of the same material as the small-diameter cylindrical part 2). Further, the connection inner peripheral portion 431 is formed integrally with a portion of the constant velocity joint boot 1 excluding the connection portion 43. The connection outer peripheral part 432 is made of a material (metal fastening band in the third embodiment) that is higher in rigidity than the connection inner peripheral part 431. The connection outer peripheral part 432 is attached to the outer peripheral side of the connection inner peripheral part 431, and reinforces the connection inner peripheral part 431 from the outer peripheral side. For this reason, the connection part 43 in the boot 1 for constant velocity joints of Example 3 is excellent in rigidity, and is hard to deform | transform. Therefore, the connection part 43 in the boot 1 for constant velocity joints of Example 3 can also interrupt | block the fall of the 1st peak part 411a reliably. Therefore, the constant velocity joint boot 1 according to the third embodiment can suppress grease leakage.

（実施例４）
実施例４の等速ジョイント用ブーツは、連結部および当接部の材料以外は実施例１の等速ジョイント用ブーツと同じである。実施例４の等速ジョイント用ブーツを軸方向に沿って切断した様子を模式的に表す部分断面図を図７に示す。 Example 4
The constant velocity joint boot of Example 4 is the same as the constant velocity joint boot of Example 1 except for the material of the connecting portion and the contact portion. FIG. 7 is a partial cross-sectional view schematically showing a state in which the constant velocity joint boot of Example 4 is cut along the axial direction.

実施例４の等速ジョイント用ブーツ１における連結部４３および当接部４４は金属からなる。連結部４３および当接部４４は一体に成形されている。また連結部４３および当接部４４は、等速ジョイント用ブーツ１のなかで連結部４３および当接部４４を除く部分（大径筒部３、第１蛇腹部４１、第２蛇腹部４２、小径筒部２）とインサートブロー成形により一体化されている。実施例４の等速ジョイント用ブーツ１の形状は、実施例１の等速ジョイント用ブーツと同じである。   The connecting portion 43 and the contact portion 44 in the constant velocity joint boot 1 of Embodiment 4 are made of metal. The connection part 43 and the contact part 44 are integrally formed. The connecting portion 43 and the abutting portion 44 are portions of the constant velocity joint boot 1 excluding the connecting portion 43 and the abutting portion 44 (the large diameter cylindrical portion 3, the first bellows portion 41, the second bellows portion 42, The small diameter cylindrical portion 2) is integrated with the insert blow molding. The shape of the constant velocity joint boot 1 of the fourth embodiment is the same as that of the constant velocity joint boot of the first embodiment.

実施例４の等速ジョイント用ブーツ１における連結部４３は、金属からなるため剛性に優れ、変形し難い。よって、実施例４の等速ジョイント用ブーツ１における連結部４３もまた、第１山部４１１ａの倒れ込みを確実に遮断できる。よって、実施例４の等速ジョイント用ブーツ１は、グリース漏れを抑制できる。   Since the connecting portion 43 in the constant velocity joint boot 1 of the fourth embodiment is made of metal, it is excellent in rigidity and hardly deformed. Therefore, the connection part 43 in the constant velocity joint boot 1 of Example 4 can also reliably block the fall of the first peak part 411a. Therefore, the constant velocity joint boot 1 of Example 4 can suppress grease leakage.

（比較例）
比較例の等速ジョイント用ブーツは、連結部、当接部および第２蛇腹部を持たず、第１蛇腹部が小径筒部に直接連結されていること以外は実施例１の等速ジョイント用ブーツと同じである。 (Comparative example)
The constant velocity joint boot of the comparative example does not have a connecting portion, an abutting portion, and a second bellows portion, and the first bellows portion is directly connected to the small diameter cylindrical portion. Same as boots.

（グリース漏れ評価試験）
実施例１の等速ジョイント用ブーツ１および比較例の等速ジョイント用ブーツについて、ＦＥＡ（有限要素法）解析により、ジョイント角（ジョイントアウタレース８２とシャフト８０とのなす角）を２０°にし、室温で６００ｒｐｍ回転させたときに、グリース漏れが何時間で発生するかについてのシミュレーションを行った。グリース漏れ評価試験の結果を図８に示す。 (Grease leakage evaluation test)
About the constant velocity joint boot 1 of Example 1 and the constant velocity joint boot of the comparative example, the joint angle (angle formed by the joint outer race 82 and the shaft 80) is set to 20 ° by FEA (finite element method) analysis. A simulation was performed as to how many hours the grease leakage occurred when rotating at 600 rpm at room temperature. The result of the grease leakage evaluation test is shown in FIG.

図８に示すように、比較例の等速ジョイント用ブーツ（すなわち従来の等速ジョイント用ブーツ）では、７０時間でグリース漏れが発生したのに対し、実施例１の等速ジョイント用ブーツ１では、グリース漏れが発生するまでに２００時間を要した。この結果から、連結部４３と当接部４４と第２蛇腹部４２とを持つ本発明の等速ジョイント用ブーツ１は、従来の等速ジョイント用ブーツに比べてグリース漏れを低減できることがわかる。   As shown in FIG. 8, in the constant velocity joint boot of the comparative example (that is, the conventional constant velocity joint boot), grease leakage occurred in 70 hours, whereas in the constant velocity joint boot 1 of Example 1, It took 200 hours for the grease to leak. From this result, it can be seen that the constant velocity joint boot 1 of the present invention having the connecting portion 43, the abutting portion 44 and the second bellows portion 42 can reduce grease leakage as compared with the conventional constant velocity joint boot.

実施例１の等速ジョイント用ブーツを軸方向に沿って切断した様子を模式的に部分断面図である。FIG. 3 is a partial cross-sectional view schematically illustrating a state in which the constant velocity joint boot of Example 1 is cut along an axial direction. 実施例１の等速ジョイント用ブーツにおける連結部を模式的に表す切り欠き斜視図である。FIG. 3 is a cutaway perspective view schematically showing a connecting portion in the constant velocity joint boot of the first embodiment. 実施例１の等速ジョイント用ブーツの使用状態を模式的に表す説明図である。It is explanatory drawing which represents typically the use condition of the boot for constant velocity joints of Example 1. FIG. 実施例２の等速ジョイント用ブーツを軸方向に沿って切断した様子を模式的に表す部分断面図である。It is a fragmentary sectional view which represents typically a mode that the boot for constant velocity joints of Example 2 was cut | disconnected along the axial direction. 実施例２の等速ジョイント用ブーツにおける連結部を模式的に表す切り欠き斜視図である。It is a notch perspective view which represents typically the connection part in the boot for constant velocity joints of Example 2. FIG. 実施例３の等速ジョイント用ブーツを軸方向に沿って切断した様子を模式的に表す部分断面図である。It is a fragmentary sectional view which represents typically a mode that the boot for constant velocity joints of Example 3 was cut along the direction of an axis. 実施例４の等速ジョイント用ブーツを軸方向に沿って切断した様子を模式的に表す部分断面図である。It is a fragmentary sectional view which represents typically a mode that the boot for constant velocity joints of Example 4 was cut | disconnected along the axial direction. グリース漏れ評価試験の結果を表すグラフである。It is a graph showing the result of a grease leak evaluation test. 従来の等速ジョイント用ブーツの使用状態を模式的に表す説明図である。It is explanatory drawing which represents the use condition of the conventional boot for constant velocity joints typically. 図９の要部拡大図である。It is a principal part enlarged view of FIG.

符号の説明Explanation of symbols

１：等速ジョイント用ブーツ ２：小径筒部 ３：大径筒部
４：ブーツ本体部 ４１：第１蛇腹部 ４２：第２蛇腹部
４３：連結部 ４４：当接部 ８０：シャフト
４１１ａ：第１山部 ４３０：連絡空間 1: Boots for constant velocity joints 2: Small diameter cylinder part 3: Large diameter cylinder part
4: Boot body part 41: First bellows part 42: Second bellows part 43: Connection part 44: Contact part 80: Shaft
411a: First mountain part 430: Communication space

Claims (3)

シャフトに固定される小径筒部と、該小径筒部と離間して同軸的に配置され該小径筒部よりも大径の大径筒部と、該小径筒部と該大径筒部とを一体的に連結する略円錐台形状のブーツ本体部とを持ち、
該ブーツ本体部は、該大径筒部に隣接する第１蛇腹部と、該小径筒部に隣接する第２蛇腹部と、該第１蛇腹部と該第２蛇腹部とを連結する連結部と、該連結部の内周面から該連結部の内周側に向けて突出する当接部と、を持ち、
該連結部の内部には、該シャフトの外周面と該連結部の内周面と該当接部とで区画され該第１蛇腹部の内部と該第２蛇腹部の内部とを連絡する連絡空間が形成されていることを特徴とする等速ジョイントブーツ。 A small-diameter cylindrical portion fixed to the shaft; a large-diameter cylindrical portion that is coaxially disposed apart from the small-diameter cylindrical portion and has a larger diameter than the small-diameter cylindrical portion; and the small-diameter cylindrical portion and the large-diameter cylindrical portion. It has a substantially frustoconical boot body that connects together,
The boot main body includes a first bellows portion adjacent to the large diameter cylindrical portion, a second bellows portion adjacent to the small diameter cylindrical portion, and a connecting portion that connects the first bellows portion and the second bellows portion. And an abutting portion protruding from the inner peripheral surface of the connecting portion toward the inner peripheral side of the connecting portion,
In the inside of the connecting portion, a communication space is defined by the outer peripheral surface of the shaft, the inner peripheral surface of the connecting portion, and the corresponding contact portion, and communicates the inside of the first bellows portion and the inside of the second bellows portion. A constant velocity joint boot characterized in that is formed. 前記当接部は半球状をなす請求項１に記載の等速ジョイント用ブーツ。   The constant velocity joint boot according to claim 1, wherein the contact portion has a hemispherical shape. 前記連結部の肉厚は、前記第１蛇腹部の肉厚および前記第２蛇腹部の肉厚よりも大きい請求項１記載の等速ジョイント用ブーツ。   2. The constant velocity joint boot according to claim 1, wherein a thickness of the connecting portion is larger than a thickness of the first bellows portion and a thickness of the second bellows portion.
JP2007088815A 2007-03-29 2007-03-29 Boot for constant velocity joint Pending JP2008248964A (en)

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Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2016013341A1 (en) * 2014-07-23 2016-01-28 Ntn株式会社 Constant velocity universal joint
JP2019060410A (en) * 2017-09-27 2019-04-18 キーパー株式会社 High speed rotation boot
CN111022516A (en) * 2019-12-25 2020-04-17 南京冠盛汽配有限公司 Large-swing-angle dust-proof sleeve sliding type driving shaft

Cited By (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2016013341A1 (en) * 2014-07-23 2016-01-28 Ntn株式会社 Constant velocity universal joint
JPWO2016013341A1 (en) * 2014-07-23 2017-04-27 Ntn株式会社 Constant velocity universal joint
US10544837B2 (en) 2014-07-23 2020-01-28 Ntn Corporation Constant velocity universal joint
JP2019060410A (en) * 2017-09-27 2019-04-18 キーパー株式会社 High speed rotation boot
CN111022516A (en) * 2019-12-25 2020-04-17 南京冠盛汽配有限公司 Large-swing-angle dust-proof sleeve sliding type driving shaft

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