JP3562180B2 - Propeller shaft for vehicles - Google Patents

Description

第二シャフトＰ_２ についても同様の計算を行うと、
Ｍ＝Ｔ×ｔａｎ（θ_３ ／２）
で、第一シャフトＰ_１ と同じ、反時計回り（左回り）のモーメントとなる。
【００２８】
従って、車両上方から観たとき、第三等速自在継手Ｃ_３ を頂点として車両前方向に対して左側へ凸となるプロペラシャフト１の場合、第一及び第二シャフト Ｐ_１ ，Ｐ_２ にはそれぞれ、左回りの２次モーメントＭが発生し、この２次モーメントＭによるプロペラシャフト１の力関係は、図５に示すようになる。
【００２９】
ところで、終減速機３は一般に、プロペラシャフトを側面から観た図６に示すように、プロペラシャフト１から駆動トルクＴを伝達されたときに上向きにワインドアップする傾向があり、しかも、このワインドアップは、駆動トルクＴが大きくなるほど顕著に現れる。そこで、このワインドアップに併せて第三等速自在継手Ｃ_３ を下向きに変位させれば、自在継手での折れ角を大きくして、自在継手の内部フリクションを減少させることができる。
このため、内部フリクションによる自励的な振れ回り振動を防止するためには、駆動トルクＴに起因する２次モーメントＭによって、第三等速自在継手Ｃ_３ が下向きに変位するようにプロペラシャフトを構成することが好ましい。
【００３０】
図５から、２次モーメントＭによるプロペラシャフト１での力関係をみるとき、第三等速自在継手Ｃ_３ の中心からインシュレータ４（センターベアリングＢ_ｃ の中心付近）までの寸法をＬｏ 、第一シャフトＰ_１ の変速機５側端部に加わる力をｆ_１ 、第二シャフトＰ_２ の終減速機３側端部に加わる力をｆ_２ 、センターベアリングＢ_ｃ の中心付近に加わる力をｆ_３ とすると、
第一シャフトＰ_１ のつり合いより、
Ｍ＝Ｌ_１ ×ｆ_１ ・・・・（３）
第二シャフトＰ_２ のつり合いより、
Ｍ＝ｆ_１ ×Ｌ_２ −ｆ_３ ×（Ｌ_２ −Ｌｏ ） ・・・・（４）
これら（３）及び（４）式から、センターベアリングＢ_ｃ 付近での力ｆ_３ は、
ｆ_３ ＝−〔（Ｌ_１ −Ｌ_２ ）×Ｍ〕／〔（Ｌ_２ −Ｌｏ ）×Ｌ_１ 〕・・・・（５）
で表せる。
【００３１】
式（５）では、寸法Ｌ_１ 、Ｌ_２ 及び（Ｌ_２ −Ｌｏ ）と、２次モーメントＭとが正であるから、センターベアリングＢ_ｃ に加わる力ｆ_３ の向きは、右辺分子における（Ｌ_１ −Ｌ_２ ）の大小関係で決定される。
【００３２】
まず、（Ｌ_１ −Ｌ_２ ）＜０となるときは、ｆ_３ ＞０であるから、センターベアリングＢ_ｃ が、図に示すように、このベアリングＢ_ｃ を支持するインシュレータ４から下向きの力を受ける。
しかし、その下向きの力ｆ_３ は、プロペラシャフト１のセンターベアリング Ｂ_ｃ 部分、つまり、第三等速自在継手Ｃ_３ 付近が上向きに変位したときのインシュレータ４からの反力を示す。
従って、Ｌ_１ ＜Ｌ_２ を満たすように第一及び第二軸長寸法Ｌ_１ 、Ｌ_２ を決定すると、終減速機３がワインドアップすると共に第三等速自在継手Ｃ_３ 部分は上向きに変位して、各継手部分での折れ角を小さくしてしまう。
【００３３】
逆に、（Ｌ_１ −Ｌ_２ ）＞０となるときは、ｆ_３ ＜０であるから、センターベアリングＢ_ｃ が、図とは反対に、インシュレータ４から上向きの力を受ける。
この上向きの力ｆ_３ は、プロペラシャフト１のセンターベアリングＢ_ｃ 部分、つまり、第三等速自在継手Ｃ_３ 付近が下向きに変位したときのインシュレータ４からの反力を示す。
従って、車両上方から車両前方向に観たとき、プロペラシャフト１が第三等速自在継手Ｃ_３ を頂点として左側へ凸となる場合、
Ｌ_１ ＞Ｌ_２ を満たすように第一及び第二軸長寸法Ｌ_１ 、Ｌ_２ を決定すると、終減速機３がワインドアップすると共に、駆動トルクＴに起因する２次モーメントによって、第三等速自在継手Ｃ_３ 付近が下向きに変位するから、継手部分での折れ角、特に、第三自在継手Ｃ_３ の折れ角θ_３ を大きくでき、自在継手における内部フリクションの軽減に効果がある。
【００３４】
他方、図７，８は、第二実施形態のプロペラシャフト２について、駆動トルクＴに起因する２次モーメントを説明するための模式図であり、図２と同一部分は同一符号を以て説明する。
【００３５】
プロペラシャフト２を車両上方から観たとき、第一シャフトＰ_１ 及び第二シャフトＰ_２ が第三等速自在継手Ｃ_３ を頂点として車両前方向に対して右側へ凸となる場合、プロペラシャフト２が駆動トルクＴを終減速機３に伝達するとき、プロペラシャフト２は、車両前方から観て時計回り（右回り）に回転し、駆動トルクＴは、第一実施形態と同様に、
Ｔ＝２×ｆ×ｔ×ｃｏｓ（θ_３ ／２） ・・・・（６）
で表される。ここで、ｔは、第三自在継手Ｃ_３ の中心から着力点Ｆまでの距離であって、着力点Ｆは、第一シャフトＰ_１ の直交断面に対してオフセットしているため、車両側面からプロペラシャフト２を観た図８に示すように、第一シャフトＰ_１ には、図面から観て時計回り（右回り）の２次モーメントＭが発生する。
この２次モーメントＭは、

第二シャフトＰ_２ についても同様の計算を行うと、
Ｍ＝Ｔ×ｔａｎ（θ_３ ／２）
で、第一シャフトＰ_１ 側と同じ、時計回り（右回り）のモーメントとなる。
【００３６】
従って、車両上方から観たとき、プロペラシャフト２が第三等速自在継手Ｃ_３ を頂点として車両前方向に対して右側へ凸となる場合、第一シャフトＰ_１ 及び第二シャフトＰ_２ の側面にはそれぞれ、右回りのモーメントＭが発生し、２次モーメントＭによるプロペラシャフト２の力関係は、図９に示すようになる。
【００３７】
このときも同様に、終減速機３は、図６に示すように、プロペラシャフト２から駆動トルクＴを伝達されたときに上向きにワインドアップする傾向があるため、内部フリクションによる自励的な振れ回り振動を防止するためには、終減速機３のワインドアップに併せ、第三等速自在継手Ｃ_３ を下向きに変位させ、継手での折れ角を大きくすることが好ましい。
【００３８】
そこで、図９から、２次モーメントＭによるプロペラシャフト１での力関係をみると、第一実施形態と同様に、
第一シャフトＰ_１ のつり合いより、
Ｍ＝Ｌ_１ ×ｆ_１ ・・・・（８）
第二シャフトＰ_２ のつり合いより、
Ｍ＝ｆ_１ ×Ｌ_２ ＋ｆ_３ ×（Ｌ_２ −Ｌｏ ） ・・・・（９）
これら（８）及び（９）式から、センターベアリングＢ_ｃ 付近での力ｆ_３ は、
ｆ_３ ＝〔（Ｌ_１ −Ｌ_２ ）×Ｍ〕／〔（Ｌ_２ −Ｌｏ ）×Ｌ_１ 〕・・・・（１０）
で表せる。
【００３９】
式（１０）から、センターベアリングＢ_ｃ に加わる力ｆ_３ の向きは、右辺分子における（Ｌ_１ −Ｌ_２ ）の大小関係で決定される。
【００４０】
（Ｌ_１ −Ｌ_２ ）＞０となるときは、ｆ_３ ＞０であるから、センターベアリングＢ_ｃ では、このベアリングＢ_ｃ を支持するインシュレータ４から、図に示すように、下向きの力ｆ_３ を受ける。
しかし、その下向きの力ｆ_３ は、プロペラシャフト２のセンターベアリング Ｂ_ｃ 部分、つまり、第三等速自在継手Ｃ_３ 付近が上向きに変位したことを示す。
従って、Ｌ_１ ＞Ｌ_２ を満たすように第一及び第二軸長寸法Ｌ_１ 、Ｌ_２ を決定すると、終減速機３がワインドアップすると共に、第三等速自在継手Ｃ_３ 部分は上向きに変位して、各継手部分での折れ角を小さくしてしまう。
【００４１】
逆に、（Ｌ_１ −Ｌ_２ ）＜０となるときは、ｆ_３ ＜０であるから、センターベアリングＢ_ｃ が、図と反対に、インシュレータ４から上向きの力を受ける。
この上向きの力ｆ_３ は、プロペラシャフト２のセンターベアリングＢ_ｃ 部分、つまり、第三等速自在継手Ｃ_３ 付近が下向きに変位したことを示す。
従って、車両上方から観たとき、プロペラシャフト２が第三等速自在継手Ｃ_３ を頂点として車両前方向に対して右側へ凸となる場合、
Ｌ_１ ＜Ｌ_２ を満たすように第一及び第二軸長寸法Ｌ_１ 、Ｌ_２ を決定すると、終減速機３がワインドアップすると共に、駆動トルクＴに起因する２次モーメントによって、第三等速自在継手Ｃ_３ 付近が下向きに変位するから、継手部分での折れ角、特に、第三等速自在継手Ｃ_３ での折れ角θ_３ を大きくでき、自在継手における内部フリクションの軽減に効果がある。
【００４２】
以上のことから、第一実施形態におけるプロペラシャフト１は、第一軸長寸法Ｌ_１ が第二軸長寸法Ｌ_２ よりも大きくなるように、第一及び第二軸長寸法Ｌ_１ ，Ｌ_２ がＬ_１ ＞Ｌ_２ の関係を、また、車両上方から観たとき、第一及び第二シャフトＰ_１ ，Ｐ_２ が第三等速自在継手Ｃ_３ を頂点として車両前方向に対して左側へ凸となるように、第三等速自在継手Ｃ_３ での折れ角θ_３ がθ_３ ＜０（θ_１ ＞０， θ_２ ＞０）の関係を満たすようにする。
このことにより、プロペラシャフト１への入力トルクが大きくなるときに、駆動トルクＴにより発生する２次モーメントを利用して、継手部分での折れ角、特に、第三等速自在継手Ｃ_３ での折れ角θ_３ を大きくできるから、自在継手の内部フリクションによる自励的な振れ回り振動を防止し、プロペラシャフト１で発生する振動や、この振動による騒音、特に、入力トルクが大きくなる、例えば、発進時などの加速走行状態で発生する振動及び騒音を軽減できる。
【００４３】
逆に、第二実施形態におけるプロペラシャフト２は、第一軸長寸法Ｌ_１ が第二軸長寸法Ｌ_２ よりも小さくなるように、第一及び第二軸長寸法Ｌ_１ ，Ｌ_２ がＬ_１ ＜Ｌ_２ の関係を、また、車両上方から観たとき、第一及び第二シャフトＰ_１ ，Ｐ_２ が第三等速自在継手Ｃ_３ を頂点として車両前方向に対して右側へ凸となるように、第三等速自在継手Ｃ_３ での折れ角θ_３ がθ_３ ＞０（θ_１ ＜０，θ_２ ＜０）の関係を満たすようにする。
従って、プロペラシャフトが上記のように配置できない状況でも、上記と同様な作用効果を得ることができる。
【００４４】
また、等速自在継手ではない自在継手では、継手部分での折れ角が変化すると共に、入力側と出力側との間のトルクが変動し、しかも、その変動は、継手部分での折れ角が大きくなるほど大きくなり、振動や騒音の一因となる。 これに対して、等速自在継手は、継手部分での折れ角がどのように変化しても、入力側と出力側との間のトルクが変動しないため、継手部分での折れ角が増大しても、トルク変動による振動や騒音を発生させない。
このため、等速自在継手を採用したことによって、プロペラシャフト１または２で発生する振動や騒音を一層軽減できる。
【００４５】
ところで、等速自在継手には、クロスグルーブ型等速自在継手と言われるものがある。クロスグルーブ型等速自在継手は、例えば、特開昭６０−２２２６２２号、実開昭６３−５７８２１号、特開昭５８−１５６７２２号に示すように、円筒形状の内径部材及び外径部材を有し、これら内径部材の外周面及び外径部材の内周面それぞれに、軸線方向に対して傾斜したボール溝を設け、内径及び外径部材とのボール溝を合わせてボール部材で軸受するとき、内径及び外径部材のボール溝が互いに交差する構成の継手である。
即ち、クロスグルーブ型等速自在継手は、軸方向に摺動しない固定型の等速自在継手と異なり、軸方向に摺動するスライド型の等速自在継手であるから、他の等速自在継手と比べて、継手部分で駆動系の軸方向移動を吸収することができる。
このため、等速自在継手としてクロスグルーブ型等速自在継手を採用したプロペラシャフト１または２では、継手部分で駆動系の軸方向移動を吸収しつつ、プロペラシャフトで発生する振動や騒音を軽減することができる。
【００４６】
また、等速自在継手には、ダブルオフセット型等速自在継手と言われるものがある。このダブルオフセット型等速自在継手とは、円筒形状の内径部材及び外径部材を有し、これら内径部材の外周面及び外径部材の内周面それぞれに、軸線方向に対して平行なボール溝を設け、これらボール溝間にボール部材を介在させた構成の継手である。
即ち、ダブルオフセット型等速自在継手も、軸方向に摺動するスライド型の等速自在継手であるから、継手部分で駆動系の軸方向移動を吸収することができる。
このため、等速自在継手としてダブルオフセット型等速自在継手を採用したプロペラシャフトも、前記クロスグルーブ型等速自在継手を採用したと同等な効果が得られる。
【００４７】
上述したところは、本発明の好適な実施形態を示したにすぎず、当業者によれば、請求の範囲において、種々の変更を加えることができる。例えば、他の等速自在継手としては、トリポート型等速自在継手などであってもよい。また、変速機については、手動変速機であっても、自動変速機であっても構わない。
【図面の簡単な説明】
【図１】本発明の第一実施形態を車両上方から観たときの平面図である。
【図２】本発明の第二実施形態を車両上方から観たときの平面図である。
【図３】図１に示したプロペラシャフトの模式図である。
【図４】図１のプロペラシャフトに発生する２次モーメントを側面から示した模式図である。
【図５】図４の２次モーメントによる力関係を示した模式図である。
【図６】終減速機がワインドアップしたときのプロペラシャフトを示す側面図である。
【図７】図２に示したプロペラシャフトの模式図である。
【図８】図２のプロペラシャフトに発生する２次モーメントを側面から示した模式図である。
【図９】図８の２次モーメントによる力関係を示した模式図である。
【図１０】従来のプロペラシャフトを車両上方から観たときの平面図である。
【符号の説明】
１， ２ プロペラシャフト
３ 終減速機
４ インシュレータ
５ 変速機
Ｂ_ｃ センターベアリング
Ｃ_１ 第一等速自在継手
Ｃ_２ 第二等速自在継手
Ｃ_３ 第三等速自在継手
Ｐ_１ 第一シャフト
Ｐ_２ 第二シャフト[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention provides a first shaft connected to an output side of a transmission arranged on the vehicle front side via a first universal joint, and a second universal joint on an input side of a final reduction gear arranged on the vehicle rear side. The present invention relates to a vehicle propeller shaft in which an end adjacent to a second shaft connected via a third universal joint is connected via a third universal joint.
[0002]
[Prior art]
Since the propeller shaft of the front-wheel drive and rear-wheel drive vehicles (FR vehicles) is arranged so as to penetrate in the front-rear direction of the vehicle, for example, "Introduction to the new model NISSAN Sylvia S14 type car" (NISSAN As described in (October 1993), a first shaft connected to the output side of the transmission via a first universal joint and a second shaft connected to the input side of the final reduction gear via a second universal joint. The end adjacent to the shaft is connected via a third universal joint.
[0003]
However, such a propeller shaft has a problem that vibration is easily generated due to its structure. In particular, in the universal joint used as the connecting member, self-excited whirling vibration due to internal friction is likely to occur. In addition, since the internal friction of the universal joint increases in proportion to the input torque to the propeller shaft, the problem of vibration is conspicuous in traveling with acceleration such as starting.
[0004]
By the way, it is known that the internal friction that causes whirling vibration tends to increase sharply as the bending angle at the joint decreases, so in order to prevent whirling vibration, the Is preferably increased.
[0005]
Therefore, conventionally, for example, as shown in FIG. 10, in a propeller shaft in which the first and second shafts P ₁ and P ₂ are connected by a universal joint C ₃ , a joint portion (C ₁ , C ₂ , C ₃ ) are positively angled (θ ₁ , θ ₂ , θ ₃ ) to prevent self-excited whirling vibrations of the propeller shaft.
[0006]
[Problems to be solved by the invention]
However, with conventional propeller shafts, only the bends are made at the joints in consideration of the vehicle space, which is not enough to reduce internal friction and prevent whirling vibration. It was a fact.
[0007]
Therefore, the vehicle propeller shaft according to claim 1 or 2 of the present invention prevents the self-excited whirling vibration due to the internal friction of the universal joint, thereby preventing the vibration generated at the propeller shaft, particularly the input torque. With the aim of reducing vibrations in running conditions where
Further, the vehicle propeller shaft according to any one of claims 3 to 5 is intended to further reduce vibration generated in the propeller shaft by selecting a universal joint in claim 1 or 2. I do.
[0008]
[Means for Solving the Problems]
For this purpose, the vehicle propeller shaft according to claim 1, which is the present invention, includes a first shaft connected to an output side of a transmission disposed on a vehicle front side via a first universal joint, and a vehicle rear side. In the vehicle propeller shaft in which the end adjacent to the second shaft connected via a second universal joint to the input side of the final reduction gear arranged on the side is connected via a third universal joint,
The first shaft length from the center of the first universal joint to the center of the third universal joint is larger than the second shaft length from the center of the third universal joint to the center of the second universal joint. Wherein, when viewed from above the vehicle, the first shaft and the second shaft are arranged so as to have an intersection angle protruding leftward with respect to the vehicle front direction with the third universal joint as an apex. is there.
[0009]
The vehicle propeller shaft according to claim 2, which is the present invention, includes a first shaft connected via a first universal joint to an output side of a transmission arranged on a vehicle front side, and a vehicle rear side. In a vehicle propeller shaft, an end adjacent to the second shaft connected to the input side of the arranged final reduction gear via a second universal joint is connected via a third universal joint,
The first axial length from the center of the first universal joint to the center of the third universal joint is smaller than the second axial length from the center of the third universal joint to the center of the second universal joint. When viewed from above the vehicle, the first shaft and the second shaft are arranged so as to have an intersection angle that is convex to the right with respect to the vehicle front direction with the third universal joint as a vertex. is there.
[0010]
Furthermore, a vehicle propeller shaft according to claim 3 of the present invention is characterized in that, in claim 1 or 2, the universal joint is a constant velocity universal joint.
[0011]
In addition, the propeller shaft for a vehicle according to claim 4 of the present invention is characterized in that, in claim 3, the constant velocity universal joint is a cross groove type constant velocity universal joint.
[0012]
Further, a propeller shaft for a vehicle according to claim 5, which is the present invention, is characterized in that in claim 3, the constant velocity universal joint is a double offset type constant velocity universal joint.
[0013]
【The invention's effect】
The propeller shaft for a vehicle according to claim 1, which is the present invention, wherein the first shaft length is larger than the second shaft length, and when viewed from above the vehicle, the first and second shafts are the third shaft length. By arranging the universal joint at the apex so as to have an intersection angle protruding leftward with respect to the forward direction of the vehicle, when the input torque increases, the secondary moment generated by the drive torque transmitted by the propeller shaft is used. The angle of bending at the joint, especially at the third universal joint, can be increased, preventing self-excited whirling vibrations due to internal friction of the universal joint, and preventing vibration and vibration generated at the propeller shaft. , In particular, vibration and noise in a running state where the input torque increases.
[0014]
Further, the propeller shaft for a vehicle according to claim 2, which is the present invention, the first shaft length is smaller than the second shaft length, and when viewed from above the vehicle, the first and second shafts are: By arranging the third universal joint as an apex so as to have an intersection angle protruding rightward with respect to the forward direction of the vehicle, even in a situation where the propeller shaft cannot be arranged as in claim 1, the same effect as in claim 1 can be obtained. Obtainable.
[0015]
Further, in the vehicle propeller shaft according to claim 3 of the present invention, in claim 1 or 2, the universal joint is a constant velocity universal joint.
In a universal joint that is not a constant velocity universal joint, the bending angle at the joint part changes, and the torque between the input side and the output side fluctuates, and the fluctuation increases as the bending angle at the joint part increases. It becomes large and contributes to vibration and noise.
On the other hand, the constant velocity universal joint increases the bending angle at the joint because the torque between the input side and the output side does not fluctuate regardless of the bending angle at the joint. However, vibration and noise due to torque fluctuation are not generated.
Therefore, in a vehicle propeller shaft employing a constant velocity universal joint, vibration and noise generated by the propeller shaft can be further reduced.
[0016]
Further, in the vehicle propeller shaft according to claim 4 of the present invention, in claim 3, the constant velocity universal joint is a cross groove type constant velocity universal joint.
Unlike the fixed type constant velocity universal joints that do not slide in the axial direction, the cross groove type constant velocity universal joints are slide type constant velocity universal joints that slide in the axial direction. Thus, the axial movement of the drive system can be absorbed by the joint portion.
Therefore, in the propeller shaft employing the cross groove type constant velocity universal joint as the constant velocity universal joint, vibration and noise generated in the propeller shaft can be reduced while absorbing the axial movement of the drive system at the joint portion. .
[0017]
Also, in the vehicle propeller shaft according to claim 5 of the present invention, in claim 3, the constant velocity universal joint is a double offset type constant velocity universal joint.
Since the double offset type constant velocity universal joint is also a slide type constant velocity universal joint that slides in the axial direction, the same effect as in claim 4 can be obtained.
[0018]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, an embodiment of the present invention will be described in detail with reference to the accompanying drawings.
[0019]
FIG. 1 is a plan view of a first embodiment of a vehicle propeller shaft according to the present invention, as viewed from above the vehicle. The propeller shaft 1 of the first embodiment includes an output side of a transmission 5 arranged on the front side of the vehicle. first the first shaft P ₁ that one constant velocity universal via a joint C ₁ connected, the connected through a second constant velocity universal joint C ₂ to the input side of the final reduction gear 3 disposed on the vehicle rear side the neighboring ends of the second shaft P ₂ is connected via a third constant velocity universal joint C ₃ to configure. The propeller shaft 1 at this time, the center bearing B _c provided in the vicinity of the third constant velocity universal joint C _3, and is fixed to the vehicle body (both not shown) via an insulator.
[0020]
The propeller shaft 1, a first axial length dimension L ₁ between the first constant velocity universal center of the joint C ₁ to the center of the third constant velocity universal joint C _3, the center of the third constant velocity universal joint C ₃ larger than the second axial length dimension L ₂ between the center of the second constant velocity universal joint C ₂ from when viewed from above the vehicle, the first shaft P ₁ and the second shaft P ₂ is, third, etc. speed arranged to have a crossing angle that is convex to the left with respect to the vehicle front direction a universal joint C ₃ as the vertex.
[0021]
On the other hand, FIG. 2 is a plan view of a second embodiment of the present invention as viewed from above the vehicle. The propeller shaft 2 of the second embodiment has basically the same configuration as that of the first embodiment. The description is omitted with the same reference numerals.
However, the propeller shaft 2, a first axial length dimension L ₁ smaller than the second axial length dimension L _2, when viewed from above the vehicle, the first shaft P ₁ and the second shaft P ₂ is, third, etc. speed arranged to have a crossing angle that is convex to the right with respect to the vehicle front direction a universal joint C ₃ as the vertex.
[0022]
Here, the first and second shaft lengths L ₁ and L ₂ and the first and second shafts P ₁ and P ₂ in the first and second embodiments form the third constant velocity universal joint C ₃ as a vertex. A method of setting the direction of the intersection angle will be described.
[0023]
As described above, among the vibrations generated by the propeller shaft, in order to prevent self-excited whirling vibration due to internal friction of the constant velocity universal joint, the bending angle at the joint part, particularly, the third constant velocity universal increasing the bending angle at the joint C ₃ (large first and second shaft P _1, the angle of intersection of P ₂ forms a third constant velocity universal joint C ₃ to the vertex) needs to be. Therefore, in the present invention, when the input torque to the propeller shaft increases, the bending angle at the joint portion is increased by using the secondary moment generated by the driving torque T of the propeller shaft.
[0024]
Hereinafter, the angle formed by the center axis O ₁ of the first shaft P _{1 with} respect to the center axis O of the output shaft of the transmission 5 is a bending angle θ ₁ , and the second shaft is formed with respect to the center axis O ₁ of the first shaft P _1. P ₂ of the central axis O ₂ bending the angle is the angle theta _3, the central axis O ₃ of the final reduction gear 3 is to bending angle theta ₂ an angle relative to the central axis O ₂ of the second shaft P _2.
[0025]
FIGS. 3 and 4 are schematic diagrams for explaining the secondary moment M caused by the driving torque T in the propeller shaft 1. The same parts as those in FIG. 1 are described with the same reference numerals. a insulator interposed for fixing to the vehicle body shaft 1 at a portion of the center bearing B _c, the transmission 5, the constant velocity universal joint C _1, C ₂ and a final reduction gear 3 is omitted.
[0026]
In FIG. 3, which is a schematic diagram of FIG. 1, when the propeller shaft 1 transmits the output from the transmission 5 to the final reduction gear 3, the propeller shaft 1 rotates clockwise (clockwise) as viewed from the front of the vehicle. and exchange of forces in the third constant velocity universal joint C ₃ is performed by force applied point F on the first shaft P ₁ bisecting plane of the second shaft P _2.
[0027]
The force applied from the second shaft P ₂ to the first shaft P ₁ When f in the force applied points F, drive torque T is
T = 2 × f × t × cos (θ 3/2) ···· (1)
It is represented by Here, t is a distance from the center of the third universal joint C ₃ to the force applied points F, the force applied points F is, since the offset relative to the first cross section perpendicular to the shaft P _1, from the vehicle side as shown in FIG. 4 as viewed the propeller shaft 1, the first shaft P _1, 2-order moment M counterclockwise (counterclockwise) is generated viewed from the drawings.
This second moment M is

When performing the same calculations for the second shaft P _{2,
M = T × tan (θ 3} /2)
In the same as the first shaft P _1, the moment of the counter-clockwise (counterclockwise).
[0028]
Therefore, when viewed from above the vehicle, if the propeller shaft 1 that is convex to the left with respect to the vehicle front direction a third constant velocity universal joint C ₃ as the vertex, the first and second shaft P _1, to P ₂ is A counterclockwise secondary moment M is generated, and the force relationship of the propeller shaft 1 by the secondary moment M is as shown in FIG.
[0029]
Incidentally, the final reduction gear 3 generally tends to wind up when the drive torque T is transmitted from the propeller shaft 1 as shown in FIG. 6 when the propeller shaft is viewed from the side. Appear more remarkably as the driving torque T increases. Therefore, if displacing the third constant velocity universal joint C ₃ in conjunction with this windup downwards, by increasing the bending angle at the universal joint, it is possible to reduce the internal friction of the universal joint.
Therefore, in order to prevent self-excited whirling vibration by internal friction is the second moment M due to the drive torque T, a propeller shaft to a third constant velocity universal joint C ₃ is displaced downward It is preferable to configure.
[0030]
From Figure 5, when viewing the power relations in the propeller shaft 1 according to second moment M, the dimension from the center of the third constant velocity universal joint C ₃ to the insulator 4 (near the center of the center bearing B _c) Lo, first force the f ₁ applied to transmission 5 side end portion of the shaft P _1, the force applied to the final reduction gear 3 side end portion of the second shaft P ₂ f _2, a force applied near the center of the center bearing B _c f ₃ Then
Than the balancing of the first shaft _{P 1,}
M = L ₁ × f ₁ (3)
Than the balance of the second shaft _{P 2,}
M = f ₁ × L ₂ −f ₃ × (L ₂ −Lo) (4)
These (3) and (4) from the equation, the force _{f 3} in the vicinity of the center bearing _{B c} is
f ₃ = − [(L ₁ −L ₂ ) × M] / [(L ₂ −Lo) × L ₁ ] (5)
Can be represented by
[0031]
In the equation (5), since the dimensions L ₁ , L ₂ and (L ₂ −Lo) and the second moment M are positive, the direction of the force f ₃ applied to the center bearing B _c is (L ₁₋ L ₂ ).
[0032]
_{First, (L 1 -L 2) <} 0 and when it comes _{in, f} 3> because it is 0, the center bearing _{B c,} as shown in FIG, a downward force from the insulator 4 for supporting the bearings _{B c} receive.
However, the downward force f ₃ is a center bearing B _c portion of the propeller shaft 1, that is, showing the reaction force from the insulator 4 when the vicinity third constant velocity universal joint C ₃ is upwardly displaced.
Accordingly, when the first and second shaft lengths L ₁ and L ₂ are determined so as to satisfy L ₁ <L ₂ , the final reduction gear 3 winds up and the third constant velocity universal joint C ₃ is displaced upward. As a result, the bending angle at each joint portion is reduced.
[0033]
_Conversely, when the _{(L 1 -L 2)> 0} , because it is _f 3 <0, the center bearing _{B c,} as opposed to the figure, receives an upward force from the insulator 4.
This upward force f ₃ is a center bearing B _c portion of the propeller shaft 1, that is, showing the reaction force from the insulator 4 when the vicinity third constant velocity universal joint C ₃ is displaced downward.
Therefore, when viewed from above the vehicle in the vehicle front direction, when the propeller shaft 1 is projected to the left side of the third constant velocity universal joint C ₃ as the vertex,
When the first and second axial lengths L ₁ and L ₂ are determined so as to satisfy L ₁ > L ₂ , the final reduction gear 3 winds up, and the second moment due to the driving torque T causes the third and the like to be reduced. since near constant velocity universal joint C ₃ is displaced downward, bending angle at the joint portion, in particular, the third universal possible to increase the bending angle theta ₃ of the joint C _3, is effective in reducing the internal friction in the joint.
[0034]
On the other hand, FIGS. 7 and 8 are schematic diagrams for explaining the secondary moment caused by the drive torque T in the propeller shaft 2 of the second embodiment, and the same parts as those in FIG.
[0035]
When watching the propeller shaft 2 from above the vehicle, if the first shaft P ₁ and the second shaft P ₂ becomes convex to the right with respect to the vehicle front direction a third constant velocity universal joint C ₃ as the vertex, the propeller shaft 2 When transmitting the driving torque T to the final reduction gear 3, the propeller shaft 2 rotates clockwise (clockwise) as viewed from the front of the vehicle, and the driving torque T is, as in the first embodiment,
T = 2 × f × t × cos (θ 3/2) ···· (6)
It is represented by Here, t is a distance from the center of the third universal joint C ₃ to the force applied points F, the force applied points F is, since the offset relative to the first cross section perpendicular to the shaft P _1, from the vehicle side as shown in FIG. 8 as viewed the propeller shaft 2, the first shaft P _1, 2-order moment M clockwise (clockwise) is generated viewed from the drawings.
This second moment M is

When performing the same calculations for the second shaft P _{2,
M = T × tan (θ 3} /2)
In the same as the first shaft P ₁ side and the moment in the clockwise (right-handed).
[0036]
Therefore, when viewed from above the vehicle, if the propeller shaft 2 has a convex shape to the right with respect to the vehicle front direction a third constant velocity universal joint C ₃ as the vertex, the first shaft P ₁ and a second side surface of the shaft P ₂ Generates a clockwise moment M, and the force relationship of the propeller shaft 2 due to the secondary moment M is as shown in FIG.
[0037]
At this time, similarly, the final reduction gear 3 tends to wind up upward when the driving torque T is transmitted from the propeller shaft 2 as shown in FIG. to prevent rotation vibration conjunction with windup of final reduction gear 3, a third constant velocity universal joint C ₃ is displaced downward, it is preferable to increase the bending angle at the joint.
[0038]
Therefore, looking at the force relationship on the propeller shaft 1 due to the second moment M from FIG. 9, as in the first embodiment,
Than the balancing of the first shaft _{P 1,}
M = L ₁ × f ₁ (8)
Than the balance of the second shaft _{P 2,}
M = f ₁ × L ₂ + f ₃ × (L ₂ −Lo) (9)
These (8) and (9), the force _{f 3} in the vicinity of the center bearing _{B c} is
f ₃ = [(L ₁ −L ₂ ) × M] / [(L ₂ −Lo) × L ₁ ] (10)
Can be represented by
[0039]
From equation (10), the direction of the force _{f 3} applied to the center bearing _{B c} is determined by the magnitude of the right-hand side molecules _(L 1 -L _2).
[0040]
When (L ₁ −L ₂ )> 0, f ₃ > 0. Therefore, in the center bearing B _c , a downward force f _{3 is applied} from the insulator 4 supporting the bearing B _c as shown in the drawing. Receive.
However, the downward force f ₃ is a center bearing B _c portion of the propeller shaft 2, that is, indicating that around the third constant velocity universal joint C ₃ is upwardly displaced.
Therefore, when the first and second shaft lengths L ₁ and L ₂ are determined so as to satisfy L ₁ > L ₂ , the final reduction gear 3 winds up, and the third constant velocity universal joint C ₃ portion faces upward. It is displaced, and the angle of bend at each joint is reduced.
[0041]
_Conversely, when the _{(L 1 -L 2) <0} , because it is _f 3 <0, the center bearing _{B c,} as opposed to the figure, receives an upward force from the insulator 4.
This upward force f ₃ is a center bearing B _c portion of the propeller shaft 2, that is, indicating that around the third constant velocity universal joint C ₃ is displaced downward.
Therefore, when viewed from above the vehicle, if the propeller shaft 2 has a convex shape to the right with respect to the vehicle front direction a third constant velocity universal joint C ₃ as the vertex,
When the first and second shaft lengths L ₁ and L ₂ are determined so as to satisfy L ₁ <L ₂ , the final reduction gear 3 winds up, and the third moment and the like are generated by the secondary moment caused by the driving torque T. since near constant velocity universal joint C ₃ is displaced downward, bending angle at the joint portion, in particular, a bending angle theta ₃ in the third constant velocity universal joint C ₃ can be increased, the effect in reducing the internal friction in the joint is there.
[0042]
From the above, the propeller shaft 1 in the first embodiment, as the first axial length dimension L ₁ is greater than the second axial length dimension L _2, first and second axial length dimension L _1, L ₂ Sees the relationship L ₁ > L ₂ , and when viewed from above the vehicle, the first and second shafts P ₁ , P ₂ have the third constant velocity universal joint C ₃ as the apex and to the left with respect to the forward direction of the vehicle. as a convex, bending angle theta ₃ is theta ₃ in the third constant velocity universal joint _{C 3 <0 (θ 1>} 0, θ 2> 0) to satisfy the relationship.
Thus, when the input torque to the propeller shaft 1 increases, by using the second moment generated by the drive torque T, bending angle at the joint portion, in particular, in the third constant velocity universal joint C ₃ since the bending angle theta ₃ can be increased to prevent the self-excited whirling vibration by internal friction of the universal joint, vibration or generated in the propeller shaft 1, noise due to this vibration, in particular, the input torque increases, for example, Vibration and noise generated during an acceleration running state such as at the time of starting can be reduced.
[0043]
Conversely, the propeller shaft 2 in the second embodiment, as the first axial length dimension L ₁ is smaller than the second axial length dimension L _2, first and second axial length dimension L _1, L ₂ is L _{1 <a} relation L _2, also when viewed from above the vehicle, and the projection to the right with respect to the vehicle front direction of the first and second shaft P _1, P ₂ a third constant velocity universal joint C ₃ as the vertex so as to, bending angle theta ₃ in the third constant velocity universal joint _{C 3} is _{θ 3> 0 (θ 1 <} 0, θ 2 <0) to satisfy following.
Therefore, even in a situation where the propeller shaft cannot be arranged as described above, the same operation and effect as described above can be obtained.
[0044]
Also, in a universal joint that is not a constant velocity universal joint, the bending angle at the joint changes, and the torque between the input side and the output side fluctuates. The larger the size, the larger the size, which contributes to vibration and noise. On the other hand, the constant velocity universal joint increases the bending angle at the joint because the torque between the input side and the output side does not fluctuate regardless of the bending angle at the joint. However, vibration and noise due to torque fluctuation are not generated.
For this reason, by employing the constant velocity universal joint, vibration and noise generated in the propeller shaft 1 or 2 can be further reduced.
[0045]
Meanwhile, there is a constant velocity universal joint called a cross groove type constant velocity universal joint. The cross groove type constant velocity universal joint has a cylindrical inner diameter member and an outer diameter member as disclosed in, for example, JP-A-60-222622, JP-A-63-57821, and JP-A-58-156722. Then, on each of the outer peripheral surface of the inner diameter member and the inner peripheral surface of the outer diameter member, a ball groove inclined with respect to the axial direction is provided. This is a joint having a configuration in which ball grooves of an inner diameter member and an outer diameter member cross each other.
That is, unlike the fixed type constant velocity universal joint which does not slide in the axial direction, the cross groove type constant velocity universal joint is a slide type constant velocity universal joint which slides in the axial direction. In comparison with the above, the joint portion can absorb the axial movement of the drive system.
Therefore, in the propeller shaft 1 or 2 employing the cross groove type constant velocity universal joint as the constant velocity universal joint, vibration and noise generated in the propeller shaft are reduced while absorbing the axial movement of the drive system at the joint portion. be able to.
[0046]
Also, there is a constant velocity universal joint called a double offset type constant velocity universal joint. This double offset type constant velocity universal joint has a cylindrical inner diameter member and an outer diameter member, and an outer peripheral surface of the inner diameter member and an inner peripheral surface of the outer diameter member have ball grooves parallel to the axial direction. Is provided, and a ball member is interposed between the ball grooves.
That is, since the double offset type constant velocity universal joint is also a slide type constant velocity universal joint that slides in the axial direction, the joint part can absorb the axial movement of the drive system.
Therefore, a propeller shaft employing a double offset type constant velocity universal joint as the constant velocity universal joint has the same effect as employing the cross groove type constant velocity universal joint.
[0047]
The foregoing merely illustrates preferred embodiments of the present invention, and those skilled in the art will be able to make various modifications within the scope of the appended claims. For example, the other constant velocity universal joint may be a tripod type constant velocity universal joint. Further, the transmission may be a manual transmission or an automatic transmission.
[Brief description of the drawings]
FIG. 1 is a plan view when a first embodiment of the present invention is viewed from above a vehicle.
FIG. 2 is a plan view when the second embodiment of the present invention is viewed from above the vehicle.
FIG. 3 is a schematic view of the propeller shaft shown in FIG.
FIG. 4 is a schematic view showing a secondary moment generated in the propeller shaft of FIG. 1 from a side.
FIG. 5 is a schematic diagram showing a force relationship based on a second moment shown in FIG. 4;
FIG. 6 is a side view showing the propeller shaft when the final reduction gear winds up.
FIG. 7 is a schematic view of the propeller shaft shown in FIG.
FIG. 8 is a schematic diagram showing a secondary moment generated in the propeller shaft of FIG. 2 from a side.
FIG. 9 is a schematic diagram showing a force relationship based on a second moment shown in FIG. 8;
FIG. 10 is a plan view when a conventional propeller shaft is viewed from above a vehicle.
[Explanation of symbols]
1, 2 Propeller shaft 3 Final reducer 4 Insulator 5 Transmission B _c Center bearing C ₁ First constant velocity universal joint C ₂ Second constant velocity universal joint C ₃ Third constant velocity universal joint P ₁ First shaft P _2nd Two shaft

Claims (5)

A first shaft connected via a first universal joint to an output side of a transmission arranged on the front side of the vehicle, and connected via a second universal joint to an input side of a final reducer arranged on the rear side of the vehicle. In a vehicle propeller shaft in which the end adjacent to the second shaft is connected via a third universal joint,
The first shaft length from the center of the first universal joint to the center of the third universal joint is made larger than the second shaft length from the center of the third universal joint to the center of the second universal joint. ,
A propeller for a vehicle, wherein the first shaft and the second shaft are arranged so as to have an intersection angle that is convex to the left with respect to a vehicle front direction with the third universal joint as an apex when viewed from above the vehicle. shaft. A first shaft connected via a first universal joint to an output side of a transmission arranged on the front side of the vehicle, and connected via a second universal joint to an input side of a final reducer arranged on the rear side of the vehicle. In a vehicle propeller shaft in which the end adjacent to the second shaft is connected via a third universal joint,
The first shaft length from the center of the first universal joint to the center of the third universal joint is made smaller than the second shaft length from the center of the third universal joint to the center of the second universal joint. ,
A propeller for a vehicle, wherein the first shaft and the second shaft are arranged so as to have an intersection angle that is convex rightward with respect to a front direction of the vehicle with the third universal joint as an apex when viewed from above the vehicle. shaft. The vehicle propeller shaft according to claim 1, wherein the universal joint is a constant velocity universal joint. The propeller shaft according to claim 3, wherein the constant velocity universal joint is a cross-groove type constant velocity universal joint. The vehicle propeller shaft according to claim 3, wherein the constant velocity universal joint is a double offset type constant velocity universal joint.

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