JPH03199723A - Drive power transmitting device - Google Patents

Abstract

PURPOSE:To contrive elimination of seizure or the like by providing a circulation path in a radial directional location of a rotary member such as an acting piston while cutting off communication of the circulation path and releasing the cutting off when a cutoff member reaches a predetermined temperature. CONSTITUTION:When relative rotation is generated between both the first and second propeller shafts 25, 26, relative rotation is generated between an outer case 11, acting piston 13 and a retainer 15, which are integrally rotatably built in the shaft 25, and an inner shaft 12 and a rotor 14 which are integrally rotatably built in the shaft 26. Accordingly, in a fluid chamber of a pressing force generating means 10a, the acting piston 13 is pressed in the axial direction by forcedly fluidizing viscous fluid in a stay-accumulating chamber R2 at a speed in proportion to the time of relative rotation and by generating pressure distribution in which a pressure in a stay-accumulating chamber R2, successively relatively moving in the peripheral direction, is gradually increased toward the upstream side end of a next vane part 14b from the downstream side end of a vane part 14b being caused by fluidization resistance.

Description

【発明の詳細な説明】 （産業上の利用分野〉 本発明は、同軸的かつ相対回転可能に位置する内外両回
転部材間に配設されて、これら両部材間のトルク伝達を
行う駆動力伝達装置に関する。DETAILED DESCRIPTION OF THE INVENTION (Industrial Application Field) The present invention relates to a driving force transmitting device which is disposed between an inner and an outer rotating member that are coaxially and relatively rotatably located, and which transmits torque between these two members. Regarding equipment.

（従来技術） かかる駆動力伝達装置は、駆動側回転部材と従動側回転
部材間に配設されてこれら両部材の相対回転時これら両
部材を互にトルク伝達可能に連結して、従動側回転部材
を駆動させる連結機構として使用されるものと、駆動側
および従動側回転部材間、周駆動側回転部材間または両
従動側回転部林間に配設されてこれら両部材の相対回転
時これら両部材を互にトルク伝達可能に連結して、これ
ら両部材間の回転差を制限させる差動制限機構として使
用されるもの等に大別される。前者の連結機構は主とし
てリアルタイム式の四輪駆動車における一方の動力伝達
系路に配設され、また後者の差動制限機構は主として車
両における各ディファレンシャルに配設される。(Prior Art) Such a driving force transmission device is disposed between a driving side rotating member and a driven side rotating member, and connects these two members so that torque can be transmitted to each other when these two members rotate relative to each other, so that the driven side rotation It is used as a coupling mechanism to drive the members, and is arranged between the driving side and driven side rotating members, between the circumferential driving side rotating members, or between both driven side rotating parts, and when these two members rotate relative to each other. These two members are broadly classified into those used as differential limiting mechanisms that limit the rotational difference between these two members by connecting them to each other so as to transmit torque. The former coupling mechanism is mainly disposed on one power transmission path in a real-time four-wheel drive vehicle, and the latter differential limiting mechanism is mainly disposed on each differential in the vehicle.

しかして、従来の駆動力伝達装置としては特開昭６３−
２４０４２９号公報に示されているように、同軸的かつ
相対回転可能に位置する内外両回転部材間に配設され、
これら両回転部材の相対回転により作動して両回転部材
をトルク伝達可能に連結する摩擦係合力を発生させると
ともに付与される軸方向の押圧力に応じて前記摩擦係合
力を増減させる摩擦クラッチ、および両回転部材の相対
回転に応じた軸方向の押圧力を発生させて前記摩擦クラ
ッチに付与する押圧力発生手段を備え、同押圧力発生手
段を、前記両回転部材間に液密的に軸方向へ摺動可能か
つ外側回転部材に一体回転可能に組付けられて前記摩擦
クラッチに対向する作動ピストンと、前記外側回転部材
と前記作動ピストンとの間に形成され軸方向に所定間隔
を有して粘性流体が封入される流体室と、半径方向へ延
びる１または複数のベーン部を備え前記流体室にて前記
内側回転部材に一体的に組付けられたロータとにより構
成してなる駆動力伝達装置がある。However, as a conventional driving force transmission device,
As shown in Japanese Patent No. 240429, it is disposed between both inner and outer rotating members that are coaxially and relatively rotatably positioned,
a friction clutch that is actuated by the relative rotation of these two rotating members to generate a frictional engagement force that connects the two rotational members so that torque can be transmitted, and that increases or decreases the frictional engagement force in accordance with the applied axial pressing force; A pressing force generating means is provided for generating an axial pressing force corresponding to the relative rotation of the two rotating members and applying it to the friction clutch, and the pressing force generating means is arranged between the two rotating members in a fluid-tight manner in the axial direction. an actuating piston that is slidably attached to the outer rotating member and is integrally rotatably assembled to the friction clutch and faces the friction clutch; A driving force transmission device comprising a fluid chamber in which a viscous fluid is sealed, and a rotor that includes one or more vane portions extending in the radial direction and is integrally assembled to the inner rotating member in the fluid chamber. There is.

この種形式の駆動力伝達装置においては、両回転部材間
に相対回転が生じると外側回転部材に一体回転可能に組
付けた作動ピストンと、内側回転部材に一体的に組付け
たロータとの間に相対回転が生じ、流体室の前記ロータ
のベーン部にて封入室内の粘性流体が強制的に流動させ
られ、封入室内では流動抵抗等に起因して圧力が発生す
る。すなわち、押圧力発生手段に差動回転数に応じた圧
力が発生する。この圧力は作動ピストンを軸方向に押圧
して摩擦クラッチを押圧させ、同クラッチに両回転部材
をトルク伝達可能に連結する摩擦係合力を発生させる。In this type of driving force transmission device, when relative rotation occurs between both rotating members, the working piston, which is assembled to be integrally rotatable with the outer rotating member, and the rotor, which is integrally assembled with the inner rotating member, are connected. Relative rotation occurs, and the viscous fluid within the containment chamber is forced to flow by the vane portion of the rotor in the fluid chamber, and pressure is generated within the containment chamber due to flow resistance and the like. That is, a pressure corresponding to the differential rotation speed is generated in the pressing force generating means. This pressure pushes the actuating piston in the axial direction, causing the friction clutch to be pressed and generating a frictional engagement force in the clutch that connects both rotating members in a torque-transmitting manner.

かかる摩擦係合力は差動回転数に比例し、両回転部材間
では差動回転数に比例したトルクが一方から他方へ伝達
される。従って、当該駆動力伝達装置は四輪駆動車の一
方の動力伝達系路における駆動側回転部材と従動側回転
部材との連結機構として機能するとともに、駆動側およ
び従動側回転部材間、再駆動側回転部材間または両従動
側回転部材間の差動制限機構としても機能する。This frictional engagement force is proportional to the differential rotation speed, and a torque proportional to the differential rotation speed is transmitted between the two rotating members from one side to the other. Therefore, the driving force transmission device functions as a coupling mechanism between the driving side rotating member and the driven side rotating member in one power transmission path of the four-wheel drive vehicle, and also functions as a connection mechanism between the driving side rotating member and the driven side rotating member. It also functions as a differential limiting mechanism between rotating members or between both driven rotating members.

（発明が解決しようとする課題） ところで、上記した形式の駆動力伝達装置においては、
車両がオフロードにてスタック状態に陥った場合等両回
転部材間に高差動回転が発生した場合には、摩擦クラッ
チは高摩擦状態となって焼付き、その他の焼損を惹起す
る。従って、本発明の目的はかかる問題に対処すること
にある。(Problems to be Solved by the Invention) By the way, in the above-mentioned type of driving force transmission device,
When a high differential rotation occurs between both rotating members, such as when a vehicle is stuck off-road, the friction clutch becomes in a high friction state and seizes or causes other burnout damage. It is therefore an object of the present invention to address such problems.

（課題を解決するための手段） 本発明は上記した形式の駆動力伝達装置において、前記
作動ピストンまたは外側回転部材に各端部が前記流体室
における半径方向の互に異なる部位にそれぞれ連通する
流通路を設けるとともに、同流通路の連通を遮断部材に
て遮断し、かつ同遮断部材として所定の高温に達したと
き前記流通路の遮断を解除する温度感応部材を採用した
ことを特徴とする。(Means for Solving the Problems) The present invention provides a driving force transmission device of the type described above, in which each end of the actuating piston or the outer rotary member communicates with a different portion in the radial direction in the fluid chamber. The present invention is characterized in that a passage is provided, communication of the passage is blocked by a blocking member, and a temperature sensitive member is used as the blocking member to release the blocking of the passage when a predetermined high temperature is reached.

（発明の作用・効果〉 かかる構成によれば、常態において前記流通路の連通が
遮断されていて、押圧力発生手段は設定された機能を発
揮するが、車両がスタック状態に陥って両回転部材間に
高差動回転が発生した場合、摩擦クラッチは高摩擦状態
となって高温となる。(Operations and Effects of the Invention) According to this configuration, communication between the flow passages is blocked in a normal state, and the pressing force generating means performs the set function, but when the vehicle becomes stuck, both rotating members If a high differential rotation occurs during this period, the friction clutch will be in a high friction state and will have a high temperature.

摩擦クラッチが所定の高温になると、遮断部材が所定の
高温に達して流通路の遮断を解除する。この結果、流体
室における外周側と内周側とが流通路を介して連通し、
外周側に偏位している粘性流体が粘性流体の希薄なまた
は皆無に近い内周側へ還流し、流体室内の発生圧力を低
減させる。従って、押圧力発生手段の摩擦クラッチに対
する押圧力が著しく低減し、摩擦クラッチは高摩擦状態
を解消されて焼付き、その他の焼損を生じることがない
。When the friction clutch reaches a predetermined high temperature, the blocking member reaches a predetermined high temperature and releases the blocking of the flow path. As a result, the outer circumferential side and the inner circumferential side of the fluid chamber communicate with each other via the flow path,
The viscous fluid deviating toward the outer circumferential side flows back to the inner circumferential side where the viscous fluid is sparse or almost nonexistent, thereby reducing the pressure generated within the fluid chamber. Therefore, the pressing force of the pressing force generating means against the friction clutch is significantly reduced, and the friction clutch is released from a high frictional state and does not seize or cause other burnout damage.

（実施例〉 以下本発明の実施例を図面に基づいて説明するに、第１
図には本発明にかかる駆動力伝達装置の一実施例が示さ
れている。当該駆動力伝達装置１０は第４図に示すよう
に、リアルタイム式の四輪駆動車の後輪側動力伝達系路
に配設される。(Example) Examples of the present invention will be described below based on the drawings.
The figure shows an embodiment of the driving force transmission device according to the present invention. As shown in FIG. 4, the driving force transmission device 10 is disposed in a rear wheel power transmission path of a real-time four-wheel drive vehicle.

当該車両は前輪側が常時駆動するとともに後輪側が必要
時駆動するもので、エンジン２１の一側に組付けたトラ
ンスアクスル２２はトランスミッションおよびトランス
ファを備え、エンジン２１からの動力をアクスルシャフ
ト２３に出力して前輪２４を駆動させるとともに、第１
プロペラシヤフト２５に出力する。第１プロペラシヤフ
ト２５は駆動力伝達装置１０を介して第２プロペラシヤ
フト２６に連結していて、これら両シャフト２５．２６
がトルク伝達可能な場合動力がリヤディファレンシャル
２７を介してアクスルシャフト２８に出力され、後輪２
９が駆動する。In this vehicle, the front wheels are always driven and the rear wheels are driven when necessary. A transaxle 22 attached to one side of an engine 21 is equipped with a transmission and a transfer, and outputs power from the engine 21 to an axle shaft 23. to drive the front wheels 24, and the first
Output to propeller shaft 25. The first propeller shaft 25 is connected to a second propeller shaft 26 via the drive force transmission device 10, and these two shafts 25, 26
When the torque can be transmitted, the power is output to the axle shaft 28 via the rear differential 27, and the power is transmitted to the rear wheels 2.
9 is driven.

しかして、駆動力伝達装置１０はアウタケース１１およ
びインナシャフト１２からなる環状の作動室内に押圧力
発生手段１０ａおよび摩擦クラッチ１０ｂを備えている
。Thus, the driving force transmission device 10 includes a pressing force generating means 10a and a friction clutch 10b in an annular working chamber made up of an outer case 11 and an inner shaft 12.

アウタケース１１は所定長さの筒部１１ａの一端に内向
フランジ部１１ｂを備えてなり、筒部１１ａの他端が開
口していて他端側内周にネジ部１１ｃが形成され、この
ネジ部１１ｃにはアウタケース１１の他側壁を形成する
リテーナ１５が螺着されている。インナシャフト１２は
所定長さの段付きの筒部１２ａの中間部外周に外向フラ
ンジ部１２ｂを備えてなり、フランジ部１２ｂの外周に
は軸方向へ延びる外スプライン部１２ｃが形成され、か
つ筒部１２ａの一端側内周には軸方向へ延びる内スプラ
イン部１２ｄが形成されている。かかるインナシャフト
１２においては、その筒部１２ａの一端がアウタケース
１１の内向フランジ部１１ｂの内孔内に液密的かつ回転
可能に嵌合されていて、筒部１２ａの他端側外周に組付
けた後述の押圧力発生手段１０ａの構成部材を介してア
ウタケース１１に回転可能に支持されている。インナシ
ャフト１２はその内スプライン部１２ｄにて第２プロペ
ラシヤフト２６の先端部のスプライン２６ａに嵌合して
固定され、かつアウタケース１１は第１プロペラシヤフ
ト２５の後端に固定されている。The outer case 11 includes an inward flange portion 11b at one end of a cylindrical portion 11a having a predetermined length, the other end of the cylindrical portion 11a is open, and a threaded portion 11c is formed on the inner periphery of the other end. A retainer 15 forming the other side wall of the outer case 11 is screwed onto the retainer 11c. The inner shaft 12 includes an outward flange portion 12b on the outer periphery of the intermediate portion of a stepped cylindrical portion 12a having a predetermined length, an outer spline portion 12c extending in the axial direction is formed on the outer periphery of the flange portion 12b, and the cylindrical portion An internal spline portion 12d extending in the axial direction is formed on the inner periphery of one end of the spline 12a. In the inner shaft 12, one end of the cylindrical portion 12a is fluid-tightly and rotatably fitted into the inner hole of the inward flange portion 11b of the outer case 11, and the outer periphery of the other end of the cylindrical portion 12a is assembled. It is rotatably supported by the outer case 11 via a component of a pressing force generating means 10a which will be described later. The inner shaft 12 is fixed at its inner spline portion 12 d by fitting into the spline 26 a at the tip of the second propeller shaft 26 , and the outer case 11 is fixed to the rear end of the first propeller shaft 25 .

押圧力発生手段１０ａは作動ピストン１３およびロータ
１４からなり、かつ摩擦クラッチ１０ｂは湿式多板クラ
ッチ式のもので、多数のクラッチプレート１６およびク
ラッチディスク１７からなる。各クラッチプレート１６
はその外周のスプライン部をアウタケース１１の内周に
設けたスプライン部ｌｉｄに嵌合されて、同ケース１１
に一体回転可能かつ軸方向へ移動可能に組付けられてい
る。各クラッチディスク１７はその内周のスプライン部
をインナシャフト１２の外スプライン部１２Ｃに嵌合さ
れて各クラッチプレート１６間に位置し、同シャフト１
２に一体回転可能かつ軸方向へ移動可能に組付けられて
いる。これらのクラッチプレート１６およびクラッチデ
ィスク１７の収容室Ｒ１にはクラッチ用オイルと気体と
が所定量封入されている。The pressing force generating means 10a is composed of an operating piston 13 and a rotor 14, and the friction clutch 10b is of a wet type multi-plate clutch type, and is composed of a large number of clutch plates 16 and clutch discs 17. Each clutch plate 16
The spline portion on the outer periphery of the outer case 11 is fitted into the spline portion lid provided on the inner periphery of the outer case 11.
It is assembled to be rotatable and movable in the axial direction. Each clutch disk 17 has a spline portion on its inner circumference fitted into an outer spline portion 12C of the inner shaft 12, and is positioned between each clutch plate 16.
2 so as to be integrally rotatable and movable in the axial direction. A predetermined amount of clutch oil and gas are sealed in the storage chamber R1 of the clutch plate 16 and the clutch disc 17.

押圧力発生手段１０ａを槽底する作動ピストン１３はア
ウタケース１１の筒部１１ａの他端側内周に一体回転可
能かつ液密的に軸方向へ摺動可能に、またインナシャフ
ト１２に対してはその外周に液密的に回転可能かつ軸方
向へ摺動可能にそれぞれ組付けられていて、その−側面
１３ａにて図示最右端のクラッチプレート１６に対向し
て当接している。ロータ１４は第１図および第２図に示
すように、環状ボス部１４ａの外周の互に１８０°離れ
た部位にて半径方向へ延びる２枚のベーン部１４ｂを備
えてなり、環状ボス部１４ａにてインナシャフト１２の
筒部１２ａ外周に一体的に組付けられている。かかるロ
ータ１４は作動ピストン１３の他側に設けた環状凹所１
３ｂの深さと略同じ厚みに形成されていて、環状凹所１
３ｂ内に嵌合している。リテーナ１５はその他端側外周
にネジ部１５ａを備え、インナシャフト１２の筒部１２
ａの他端側外周に液密的に軸方向へ摺動可能かつ回転可
能に嵌合され、・アウタケース１１に対してはそのネジ
部１５ａをアウタケース１１のネジ部１１ｃに進退可能
に螺着され、かつ液密的となっている、かかるリテーナ
１５においては、軸方向の位置調整がなされてアウタケ
ース１１にカシメ手段にて固定され、その−側面１５ｂ
にて作動ピストン１３の他側の環状外縁面１３ｃに当接
し、その−側面１５ｂと作動ピストン１３の環状凹所１
３ｂとによりロータ１４が位置する流体室を形成してい
る。この流体室内にはシリコンオイル等高粘性流体が所
定量封入されており、またロータ１４はそのベーン部１
４ｂの外周を環状凹所１３ｂの内周に液密的に接触させ
、かつベーン部１４ｂの両側面と環状凹所１３ｂの他側
面１３ｂ１およびリテーナ１５の一側面１５ｂ間に微小
間隙を形成して、流体室内を２つの滞留室Ｒ２に区画し
ている。The actuating piston 13 that connects the pressing force generating means 10a to the bottom of the tank is rotatable integrally with the inner periphery of the other end side of the cylindrical portion 11a of the outer case 11, and is slidable in the axial direction in a fluid-tight manner, and also with respect to the inner shaft 12. are assembled to the outer periphery of the clutch plate 16 in a liquid-tight manner so as to be rotatable and slidable in the axial direction, and the negative side surface 13a of the clutch plate 16 faces and abuts on the rightmost clutch plate 16 in the figure. As shown in FIGS. 1 and 2, the rotor 14 includes two vane portions 14b extending in the radial direction at positions 180° apart from each other on the outer periphery of the annular boss portion 14a. It is integrally assembled to the outer periphery of the cylindrical portion 12a of the inner shaft 12. Such a rotor 14 has an annular recess 1 provided on the other side of the working piston 13.
The annular recess 1 is formed to have approximately the same thickness as the depth of the annular recess 1.
3b. The retainer 15 has a threaded portion 15a on the outer periphery of the other end, and the cylindrical portion 15 of the inner shaft 12
It is fluid-tightly fitted to the outer periphery of the other end side so as to be slidable and rotatable in the axial direction, and its threaded portion 15a is screwed into the threaded portion 11c of the outer case 11 so that it can move forward and backward. The retainer 15, which is attached to the outer case 11 and is liquid-tight, has its position adjusted in the axial direction and is fixed to the outer case 11 by caulking means.
The annular outer edge surface 13c of the other side of the working piston 13 is brought into contact with the annular recess 1 of the working piston 13, and the - side surface 15b and the annular recess 1 of the working piston 13
3b forms a fluid chamber in which the rotor 14 is located. A predetermined amount of highly viscous fluid such as silicone oil is sealed in this fluid chamber, and the rotor 14 has its vane portion 1
4b is brought into liquid-tight contact with the inner circumference of the annular recess 13b, and a minute gap is formed between both side surfaces of the vane portion 14b, the other side surface 13b1 of the annular recess 13b, and one side surface 15b of the retainer 15. , the fluid chamber is divided into two retention chambers R2.

しかして、作動ピストン１３にはその環状凹所１３ｂの
他側面１３ｂ１に第２環状凹所１３ｄが形成され、同環
状凹所１３ｄには第１図および第３図に示すプラグ１８
が嵌着されている。プラグ１８は環状凹所１３ｄに嵌着
された状態で流体室における半径方向の互に異なる部位
に連通ずる流通路を形成しており、当該流通路は外周側
の環状の第１通路１８ａ、内周側の環状の第２通路１８
ｂ、第１通路１８ａを流体室における外周側に連通させ
る第１連通孔１８ｃ、両通路１８ａ、１８ｂを互に連通
させる第２連通孔１８ｄ、第２通路１８ｂを流体室にお
ける内周側に連通させる第３連通孔１８ｅにて構成され
ている。かかるプラグ１８においては、第２通路１８ｂ
の外周壁にＣ形状の板バネ１９が嵌着されている。板バ
ネ１９は本発明の遮断部材に該当するもので形状記憶合
金にて構成され、常態においては第１図および第３図の
実線で示すように第２連通孔１８ｄを遮閉して流通路の
連通を遮断し、所定の高温に達すると第３図の２点鎖線
で示すように変形し、第２連通孔１８ｄを開放して流通
路を連通させる。なお、板バネ１９はバイメタルによっ
て形成されてもよい かかる構成の駆動力伝達装置１０においては、通常作動
ピストン１３内に形成されている流通路の連通が遮断さ
れていて、第１、第２両プロペラシャフト２５．２６間
に相対回転が生じるとトルク伝達がなされる。すなわち
、これら両シャフト２５．２６間に相対回転が生じると
、第１プロペラシヤフト２５に一体回転可能に組付けら
れているアウタケース１１、作動ピストン１３およびリ
テーナ１５と、第２プロペラシヤフト２６に一体回転可
能に組付けられているインナシャフト１２およびロータ
１４との間に相対回転が生じる。従って、押圧力発生手
段１０ａの流体室内においては、滞留室Ｒ２内の粘性流
体が相対回転数に比例した速度にて強制的に流動させら
れ、周方向に順次相対移行する滞留室Ｒ２内では流動抵
抗に起因してベーン部１４ｂの下流側端から次のベーン
部１４ｂの上流側端に向って漸次増圧される圧力分布が
発生する。この圧力分布の増圧部分は差動回転数に比例
して増大するもので、作動ピストン１３を軸方向へ押圧
する。この結果、作動ピストン１３は摩擦クラッチ１０
ｂを押圧して摩擦クラッチ１０ｂを構成する各クラッチ
プレート１６とクラッチディスク１７をクラッチ用オイ
ルを介して摩擦係合させる。これにより、摩擦クラッチ
１０ｂにおいては差動回転数に比例したトルクをアウタ
ケース１１からインナシャフト１２に伝達し、車両は４
＠駆動状態となる。また、この４輪駆動状態においては
前後輪の差動回転を許容し、タイトコーナブレーキング
現象の発生も防止される。Thus, a second annular recess 13d is formed in the other side surface 13b1 of the annular recess 13b of the actuating piston 13, and a plug 18 shown in FIGS. 1 and 3 is formed in the annular recess 13d.
is fitted. When the plug 18 is fitted into the annular recess 13d, it forms a flow passage that communicates with different radial parts of the fluid chamber, and the flow passage includes an annular first passage 18a on the outer peripheral side and an inner annular passage 18a. Circumferential annular second passage 18
b. A first communication hole 18c that communicates the first passage 18a with the outer circumference side of the fluid chamber; a second communication hole 18d that communicates both passages 18a and 18b with each other; and a second communication hole 18d that communicates the second passage 18b with the inner circumference side of the fluid chamber. It is configured with a third communication hole 18e. In such a plug 18, the second passage 18b
A C-shaped leaf spring 19 is fitted onto the outer peripheral wall of the holder. The leaf spring 19 corresponds to the blocking member of the present invention and is made of a shape memory alloy, and in a normal state, the second communication hole 18d is blocked and the flow path is closed, as shown by the solid line in FIGS. 1 and 3. When it reaches a predetermined high temperature, it deforms as shown by the two-dot chain line in FIG. 3, opens the second communication hole 18d, and communicates the flow path. Note that the leaf spring 19 may be made of bimetal. In the driving force transmission device 10 having such a structure, communication between the flow passage formed in the operating piston 13 is normally cut off, and the first and second portions are connected to each other. Torque transmission occurs when relative rotation occurs between propeller shafts 25,26. That is, when relative rotation occurs between these two shafts 25 and 26, the outer case 11, operating piston 13, and retainer 15, which are assembled to be integrally rotatable with the first propeller shaft 25, and the second propeller shaft 26 are integrally rotated. Relative rotation occurs between the inner shaft 12 and the rotor 14, which are rotatably assembled. Therefore, in the fluid chamber of the pressing force generating means 10a, the viscous fluid in the retention chamber R2 is forced to flow at a speed proportional to the relative rotational speed, and the viscous fluid in the retention chamber R2 moves relative to each other sequentially in the circumferential direction. Due to the resistance, a pressure distribution is generated in which the pressure is gradually increased from the downstream end of the vane section 14b to the upstream end of the next vane section 14b. The increased pressure portion of this pressure distribution increases in proportion to the differential rotation speed, and presses the actuating piston 13 in the axial direction. As a result, the actuating piston 13 is activated by the friction clutch 10.
b is pressed to frictionally engage each clutch plate 16 and clutch disc 17 constituting the friction clutch 10b via clutch oil. As a result, in the friction clutch 10b, torque proportional to the differential rotation speed is transmitted from the outer case 11 to the inner shaft 12, and the vehicle
@ Drive state. Furthermore, in this four-wheel drive state, differential rotation between the front and rear wheels is allowed, and tight corner braking is also prevented from occurring.

ところで、当該駆動力伝達装置１０においては、車両が
スタック状態に陥ってアウタケース１１とインナシャフ
ト１２間に高差動回転が発生し摩擦クラッチ１０ｂが所
定の高温に達すると、板バネ１９が所定の高温に達して
第３図の２点鎖線で示すように変形し、第２連通孔１８
ｄを開放して流通路を連通させる。このため、流体室に
おける外周側と内周側とが流通路を介して連通し、遠心
力の作用等により外周側に偏位している粘性流体が粘性
流体の希薄なまたは皆無に近い内周側へ還流し、流体室
内の発生圧力を低減させる。この結果、押圧力発生手段
１０ａにおける摩擦クラッチ１０ｂに対する押圧力が著
しく低減し、摩擦クラッチ１０ｂは高摩擦状態を解消さ
れて焼付き、その他の焼損を生じることがない、また、
摩擦クラッチ１０ｂの温度が低下して板バネ１９が所定
の高温より低下すると、板バネ１９はその形状を復元し
て第２連通孔１８ｄを遮閉し、流通路の連通を遮断して
押圧力発生手段１０ａの設定された機能を発揮させる。By the way, in the driving force transmission device 10, when the vehicle becomes stuck and a high differential rotation occurs between the outer case 11 and the inner shaft 12 and the friction clutch 10b reaches a predetermined high temperature, the leaf spring 19 moves to a predetermined temperature. reaches a high temperature, deforms as shown by the two-dot chain line in FIG. 3, and the second communication hole 18
d is opened to communicate the flow path. For this reason, the outer circumferential side and the inner circumferential side of the fluid chamber are communicated via the flow path, and the viscous fluid that is deviated toward the outer circumferential side due to the action of centrifugal force, etc. The fluid flows back to the side, reducing the pressure generated within the fluid chamber. As a result, the pressing force applied to the friction clutch 10b by the pressing force generating means 10a is significantly reduced, and the friction clutch 10b is no longer in a high friction state, and seizing or other burnout does not occur.
When the temperature of the friction clutch 10b decreases and the leaf spring 19 falls below a predetermined high temperature, the leaf spring 19 restores its shape and closes the second communication hole 18d, cutting off communication in the flow path and reducing the pressing force. The set function of the generating means 10a is activated.

なお、上記実施例においては流通路を作動ピストン１３
に形成した例について示したが、同流通路をリテーナ１
５に形成してもよい。また、上記実施例においては、ロ
ータ１４を作動ピストン１３とリテーナ１５との間に配
設した例について示したが、ロータ１４をアウタケース
１１の側壁と作動ピストン１３との間に配設し、同作動
ピストン１３とリテーナ１５との間に摩擦クラッチ１０
ｂを配設してもよい。In the above embodiment, the flow path is connected to the actuating piston 13.
An example was shown in which the flow passage was formed in the retainer 1.
5 may be formed. Further, in the above embodiment, an example was shown in which the rotor 14 was disposed between the working piston 13 and the retainer 15, but the rotor 14 was disposed between the side wall of the outer case 11 and the working piston 13, A friction clutch 10 is provided between the actuating piston 13 and the retainer 15.
b may also be provided.

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

第１図は本発明の一実施例に係る駆動力伝達装置の断面
図、第２図は第１図の矢印■−■線方向の断面図、第３
図は同装置における流通路を構成するプラグの断面図、
第４図は同装置を採用した車両の概略図である。 符　　号　　の　　説　　明 １０・・・駆動力伝達装置、１０ａ・・・押圧力発生手
段、１０ｂ・・・摩擦クラッチ、１１・・アウタケース
、１２・・・インナシャフト、１３・・・作動ピストン
、１４・・・ロータ、１４ｂ・・・ベーン部、１５・・
・リテーナ、１６・・クラッチプレート、１７・・・ク
ラッチディスク、１８・・・プラグ、（１８ａ〜１８ｅ
）・流通路、１９・・・板バネ（遮断部材）、２５．２
６・・・プロペラシャフト。FIG. 1 is a cross-sectional view of a driving force transmission device according to an embodiment of the present invention, FIG. 2 is a cross-sectional view taken in the direction of arrows - ■ in FIG.
The figure is a cross-sectional view of the plug that constitutes the flow path in the device.
FIG. 4 is a schematic diagram of a vehicle employing the same device. Explanation of symbols 10... Drive force transmission device, 10a... Pressing force generation means, 10b... Friction clutch, 11... Outer case, 12... Inner shaft, 13... Working piston, 14... Rotor, 14b... Vane part, 15...
・Retainer, 16...Clutch plate, 17...Clutch disc, 18...Plug, (18a to 18e
)・Flow path, 19...Plate spring (blocking member), 25.2
6...Propeller shaft.

Claims (1)

【特許請求の範囲】[Claims] 同軸的かつ相対回転可能に位置する内外両回転部材間に
配設され、これら両回転部材の相対回転により作動して
両回転部材をトルク伝達可能に連結する摩擦係合力を発
生させるとともに付与される軸方向の押圧力に応じて前
記摩擦係合力を増減させる摩擦クラッチ、および両回転
部材の相対回転に応じた軸方向の押圧力を発生させて前
記摩擦クラッチに付与する押圧力発生手段を備え、同押
圧力発生手段を、前記両回転部材間に液密的に軸方向へ
摺動可能かつ外側回転部材に一体回転可能に組付けられ
て前記摩擦クラッチに対向する作動ピストンと、前記外
側回転部材と前記作動ピストンとの間に形成され軸方向
に所定間隔を有して粘性流体が封入される流体室と、半
径方向へ延びる１または複数のベーン部を備え前記流体
室にて前記内側回転部材に一体回転可能に組付けられた
ロータとにより構成してなる駆動力伝達装置において、
前記作動ピストンまたは外側回転部材に各端部が前記流
体室における半径方向の互に異なる部位にそれぞれ連通
する流通路を設けるとともに、同流通路の連通を遮断部
材にて遮断し、かつ同遮断部材として所定の高温に達し
たとき前記流通路の遮断を解除する温度感応部材を採用
したことを特徴とする駆動力伝達装置。It is disposed between the inner and outer rotating members that are coaxially and relatively rotatably positioned, and is actuated by the relative rotation of these rotating members to generate and apply a frictional engagement force that connects the two rotating members so that torque can be transmitted. A friction clutch that increases or decreases the friction engagement force in accordance with an axial pressing force, and a pressing force generating means that generates an axial pressing force in accordance with the relative rotation of both rotating members and applies it to the friction clutch, The pressing force generating means is configured to include an actuating piston that is slidable liquid-tightly in the axial direction between the two rotary members and integrally rotatable with the outer rotary member and faces the friction clutch; and the actuating piston, the fluid chamber having a predetermined interval in the axial direction and containing a viscous fluid therein, and one or more vanes extending in the radial direction, the inner rotating member in the fluid chamber. A driving force transmission device consisting of a rotor and a rotor integrally rotatably assembled to the
A flow path is provided in the actuating piston or the outer rotary member, each end of which communicates with a different portion in the radial direction in the fluid chamber, and communication of the flow path is blocked by a blocking member, and the blocking member A driving force transmission device characterized by employing a temperature sensitive member that releases the blocking of the flow path when a predetermined high temperature is reached.