JPH02199329A - Power transmission mechanism - Google Patents

Abstract

PURPOSE:To lower increase rate of transmission torque in the low differential rotation zone as well as to raise the increase rate of the transmission torque in the high differential rotation zone by providing a spring which applies force in the direction that the first working piston is removed from the second working piston. CONSTITUTION:When relative rotation is generated between both propeller shafts 25 and 26, pressure corresponding to the number of differential rotations is generated in fluid chambers of both pressurizing force generating means 10a and 10b to pressurize both working pistons 13 and 16 in the axial direction. The piston 16 directly pressurizes a frictional clutch 10c and frictionally engages each of clutch plates 19a constituting it with clutch disks 19b through oil for clutch. On the other hand, as the piston 13 is pressurized against a compression spring 19d, it does not aid pressurizing force of the piston 16 till it overcomes the applied force of this spring 19d, but when it overcomes the applied force, it aids pressurizing force of the piston 16 corresponding to the number of differential rotations and further increases frictional engaging force between the plates 19a and the disks 19b.

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
行う動力伝達機構に関する。Detailed Description of the Invention (Industrial Application Field) The present invention relates to a power transmission mechanism that is disposed between an inner and an outer rotating member that are coaxially and relatively rotatably located, and that transmits torque between these members. Regarding.

（従来技術） かかる動力伝達機構は、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、再駆動側回転部材間または両従
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、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
てリャ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 power transmission mechanism is arranged 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. A connection mechanism used as a coupling mechanism to drive the drive side and the driven side rotating member, between the re-driving side rotating member, or between both the driven side rotating parts □ material, and when these two members rotate relative to each other. It is roughly divided into those used as a differential limiting mechanism that connects members so that torque can be transmitted to each other and limits the rotational difference between these two members. 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、従来の動力伝達機構としては特開昭６３−２
４０４２９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一方の回転部材に
一体回転可能に組付けられて前記摩擦クラッチに当接す
る作動ピストンと、前記一方の回転部材に一体回転可能
に設けられて前記作動ピストンとの間に軸方向に所定間
隔を有して粘性流体が封入される流体室を形成するリテ
ーナと、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他方の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動力伝達機構がある
。However, as a conventional power transmission mechanism, JP-A-63-2
As shown in Japanese Patent No. 40429, it is disposed between both the inner and outer rotating members that are coaxially and relatively rotatably located, and is actuated by the relative rotation of these two rotating members to connect the two rotating members so that torque can be transmitted. a friction clutch that generates a frictional engagement force that increases or decreases the frictional engagement force according to the applied pressing force, and a pressing force that generates a pressing force that corresponds to the relative rotation of both rotating members and applies it to the friction clutch. an actuating piston comprising a pressing force generating means, the pressing force generating means being able to slide liquid-tightly in the axial direction between both of the rotating members and integrally rotatable with one of the rotating members, and abutting the friction clutch; a retainer which is provided to be integrally rotatable with the one rotary member and which forms a fluid chamber in which a viscous fluid is sealed and which has a predetermined distance between it and the actuating piston; and a retainer which extends in the radial direction. Alternatively, there is a power transmission mechanism comprising a rotor having a plurality of vane parts and integrally assembled to the other rotating member in the fluid chamber.

この種形式の動力伝達機構においては、両回転部材間に
相対回転が生じると一方の回転部材に一体回転可能に組
付けた作動ピストンおよびリテーナと、他方の回転部材
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区画された粘性流体封
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、同窄擦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。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、当該動力伝達機構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。In this type of power transmission mechanism, when relative rotation occurs between both rotating members, an operating piston and a retainer are attached to one rotating member so that they can rotate integrally, and a rotor is attached to the other rotating member. Relative rotation occurs between the rotor and the viscous fluid in the viscous fluid chamber divided by the vane of the rotor in the fluid chamber, and pressure is generated in the chamber due to flow resistance, etc. do. 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 to press the friction clutch, and generates a frictional engagement force that connects both rotating members to the constricting friction clutch so as to be able to transmit torque. 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 power transmission mechanism 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 members or between both driven rotating members.

（発明が解決しようとする課題） ところで、上記した形式の動力伝達機構を四輪駆動車の
連結機構として採用する場合には、同機構は車両の低速
コーナリング時のタイトコーナブレーキング現象の発生
を防止するとともにぬかるみ等悪路に陥った時の脱出性
能を向上すべく、低差動回転領域における伝達トルクの
増加率を低くしかつ高差動回転領域における伝達トルク
の増加率を高くする特性を備えていることが望ましい。(Problem to be Solved by the Invention) By the way, when the power transmission mechanism of the above type is adopted as a coupling mechanism of a four-wheel drive vehicle, the mechanism must be designed to prevent the occurrence of tight corner braking phenomenon during low-speed cornering of the vehicle. In order to prevent this and improve the ability to escape from rough roads such as mud, we have developed a characteristic that lowers the rate of increase in transmitted torque in low differential rotation ranges and increases the rate of increase in transmitted torque in high differential rotation areas. It is desirable to have one.

従って、本発明の目的は、かかる形式の動力伝達機構に
おいて、上記した特性を付与することにある。Therefore, an object of the present invention is to provide such a power transmission mechanism with the above characteristics.

（課題を解決するための手段） 本発明は上記した摩擦クラッチと押圧力発生手段を備え
た形式の動力伝達機構において、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一方の
回転部材に一体回転可能に組付けられた第１の作動ピス
トンと、前記一方の回転部材に一体的または一体回転可
能に設けられて前記第１の作動ピストンとの間に軸方向
に所定間隔を有して粘性流体が封入される第１の流体室
を形成する第１のリテーナと、半径方向へ延びる１また
は複数のベーン部を備え前記第１の流体室にて前記他方
の回転部材に一体的に組付けられた第１のロータと、前
記第１の作動ピストンと前記摩擦クラッチ間にて前記両
回転部材間に軸方向へ摺動可能かつ一方の回転部材に一
体回転可能に組付けられて前記第１の作動ピストンおよ
び摩擦クラッチに当接する第２の作動ピストンと、同ピ
ストンと前記第１のリテーナ間に軸方向への移動を規制
して組付けられ前記第２の作動ピストンとの間に軸方向
に所定間隔を有して粘性流体が封入される第２の流体室
を形成する第２のリテーナと、半径方向へ延びる１また
は複数のベーン部を備え前記第２の流体室にて前記他方
の回転部材に一体的に組付けられた第２のロータと、前
記第１の作動ピストンを前記第２の作動ピストンから離
間する方向に付勢するスプリングとにより構成したこと
を特徴とする。(Means for Solving the Problems) The present invention provides a power transmission mechanism including the above-described friction clutch and a pressing force generating means, in which the pressing force generating means is arranged axially in a fluid-tight manner between the two rotating members. between a first working piston that is slidably and integrally rotatably assembled to one rotating member and the first working piston that is integrally or integrally rotatably installed with the one rotating member; a first retainer forming a first fluid chamber in which a viscous fluid is sealed at a predetermined interval in the axial direction; and one or more vane portions extending in the radial direction. a first rotor that is integrally assembled to the other rotating member; a first rotor that is slidable in the axial direction between the two rotating members between the first actuating piston and the friction clutch; and that is integrated with the one rotating member; a second actuating piston that is rotatably assembled and abuts the first actuating piston and the friction clutch; and a second actuating piston that is assembled so as to restrict axial movement between the piston and the first retainer. a second retainer forming a second fluid chamber in which a viscous fluid is sealed and having a predetermined spacing between the retainer and the second working piston; and one or more vane portions extending in the radial direction. A second rotor that is integrally assembled to the other rotating member in a second fluid chamber, and a spring that biases the first working piston in a direction away from the second working piston. It is characterized by having been configured.

（発明の作用・効果） かかる構成によれば、両回転部材間に相対回転が生じる
と各流体室に差動回転数に応じた圧力が発生し、第２の
流体室にて発生した圧力が第２の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、かつ第１の流体室
にて発生した圧力が第１の作動ピストンを押圧し、スプ
リングの付勢力に抗して第２の作動ピストンを押圧して
第２の作動ピストンの押圧力を助勢する９この場合、第
１の作動ピストンの押圧力がスプリングの付勢力に打勝
つまでは同作動ピストンは第２の作動ピストンの押圧力
を助勢することがないため、第１の作動ピストンによる
助勢の有無を境にして差動回転数に対する伝達トルク曲
線が２段折れとなり、差動回転数の小さい領域での伝達
トルクの増加率は小さくかつ差動回転数の大きい領域で
の伝達トルクの増加率は大きくなる。(Operations and Effects of the Invention) According to this configuration, when relative rotation occurs between both rotating members, pressure is generated in each fluid chamber according to the differential rotation speed, and the pressure generated in the second fluid chamber is The second working piston is pushed in the axial direction to press the friction clutch, and the pressure generated in the first fluid chamber pushes the first working piston, and the second working piston is pushed against the biasing force of the spring. In this case, the first working piston does not support the pushing force of the second working piston until the pushing force of the first working piston overcomes the biasing force of the spring. Since the pressure is not assisted, the transmission torque curve against the differential rotation speed bends in two stages depending on whether or not assistance is provided by the first working piston, and the rate of increase in the transmission torque in the region where the differential rotation speed is small. is small and the rate of increase in the transmitted torque is large in a region where the differential rotation speed is large.

（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動力伝達機構の一実施例が示され
ている。当該動力伝達機構１０は第５図に示すように、
リャ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 power transmission mechanism according to the present invention. The power transmission mechanism 10, as shown in FIG.
It is installed in the rear wheel power transmission line of real-time four-wheel drive vehicles.

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１１０へラシャフ
ト２５は動力伝達機構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
動力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２９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 110th spatula shaft 25 is connected to the second propeller shaft 26 via the power transmission mechanism 10, and when both shafts 25 and 26 can transmit power, the power is transmitted to the rear differential 27.
The signal is output to the axle shaft 28 via the axle shaft 28, and the rear wheels 29 are driven.

しかして、動力伝達機構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第１押圧
力発生手段１０ａ、第２押圧力発生手段１０ｂおよび摩
擦クラッチ１０ｃを備えている。Thus, the power transmission mechanism 10 includes a first pressing force generating means 10a, a second pressing force generating means 10b, and a friction clutch 10c 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１
２ａ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第１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. The inner shaft 12 has a stepped cylindrical portion 12a having a predetermined length.
An outward flange portion 12b is provided on the outer periphery of the intermediate portion of the
An outer spline portion 12C extending in the axial direction is formed on the outer periphery of the flange portion 12b, and an inner spline portion 12d extending in the axial direction is formed on the inner periphery on one end side of the cylindrical portion 12a. In such an inner shaft 12, the cylindrical portion 1
One end of 2a is the inward flange portion 11b of the outer case 11.
It is fluid-tightly and rotatably fitted into the inner hole of the outer case 11, and rotates to the outer case 11 via a component of a first pressing force generating means 10a, which will be described later, which is assembled to the outer periphery of the other end of the cylindrical portion 12a. Possibly supported. The inner shaft 12 is fixed at its inner spline 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 .

第１押圧力発生手段１０ａは第１作動ピストン１３、第
１０−タ１４および第１リテーナ１５からなるとともに
、第２揮圧力発生手段１０ｂは第２作動ピストン１６、
第２０−タ１７および第２リテーナ１８からなり、かつ
摩擦クラッチ１．　Ｏｃ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１９ａおよびクラッチディス
ク１９ｂからなる。各クラッチプレート１９ａ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１９ｂ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１９ａ間に位置し、同シャフト１２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１９ａおよびクラッチディ
スク１９ｂを収容するクラッチ室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 first pressing force generating means 10a includes a first working piston 13, a tenth rotor 14, and a first retainer 15, and the second volatile force generating means 10b includes a second working piston 16,
The friction clutch 1. Oc is of a wet type multi-plate clutch type and consists of a large number of clutch plates 19a and clutch discs 19b. Each clutch plate 19a has a spline portion on its outer periphery fitted into a spline portion lid provided on the inner periphery of the outer case 11, and is assembled to the case 11 so as to be integrally rotatable and movable in the axial direction. Each clutch disk 19b has a spline portion on its inner circumference fitted into an outer spline portion 12c of the inner shaft 12, is located between each clutch plate 19a, and is assembled to the shaft 12 so as to be rotatable integrally and movable in the axial direction. It is being A predetermined amount of clutch oil and gas are sealed in a clutch chamber R1 that accommodates these clutch plates 19a and clutch discs 19b.

第１押圧力発生手段１．０　ａを構成する第１作動ピス
トン１３は、アウタケース１１の筒部ｉＬａの他端側内
周に一体回転可能かつ液密的に組付けた第１リテーナ１
５の段付環状凹所の大径凹所１５ａ内に液密的かつ軸方
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る。なお、第１リテーナ１５はイン
ナシャフト１２の筒部１２ａの外周に液密的かつ回転可
能に組付けられていて、第１作動ピストン１３とにより
小径凹所１５ｂを流体室に形成している。The first actuating piston 13 constituting the first pressing force generating means 1.0a is attached to the first retainer 1 which is integrally rotatable and liquid-tightly assembled to the inner periphery of the other end side of the cylindrical portion iLa of the outer case 11.
It can be liquid-tightly slidable in the large-diameter recess 15a of the stepped annular recess No. 5 in the axial direction, and can be liquid-tightly rotated and slid in the axial direction around the outer circumference of the inner shaft 12. Assembled as possible. The first retainer 15 is fluid-tightly and rotatably assembled to the outer periphery of the cylindrical portion 12a of the inner shaft 12, and together with the first actuating piston 13 forms a small diameter recess 15b in the fluid chamber.

第１０−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
周に嵌合させてインナシャフト１２に一体的に組付けら
れて、第１リテーナ１５の小径凹所１５ｂ内に嵌合して
いる。この小径凹所１５ｂが形成する流体室内にはシリ
コンオイル等高粘性流体が所定量封入されており、また
第１０−タ１４はそのベーン部１４ｂの外周を小径凹所
１５ｂの内周に液密的に接触させ、かつベーン部１４ｂ
の両側面と小径凹所１５ｂの一側面および第１作動ピス
トン１３の他側面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。As shown in FIGS. 1 and 2, the tenth 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. The boss portion 14a is fitted onto the outer periphery of the cylindrical portion 12a of the inner shaft 12, and is integrally assembled to the inner shaft 12, and is fitted into the small diameter recess 15b of the first retainer 15. A predetermined amount of highly viscous fluid such as silicone oil is sealed in the fluid chamber formed by the small diameter recess 15b, and the outer periphery of the vane portion 14b of the tenth tank 14 is liquid-tightly sealed to the inner periphery of the small diameter recess 15b. and vane portion 14b.
A minute gap is formed between both side surfaces of the small diameter recess 15b, one side of the small diameter recess 15b, and the other side of the first actuating piston 13, thereby dividing the fluid chamber into two retention chambers R2.

第２押圧力発生手段１０ｂを構成する第２作動ピストン
１６はアウタケース１１に一体回転可能かつ軸方向へ移
動可能に、またインナシャフト１２に液密的に回転可能
かつ軸方向へ移動可能に組付けられていて、その−側に
て最他端のクラッチプレート１９ａに当接し、かつその
他側にてスペーサ１９ｃを介して第１作動ピストン１３
に当接している。このスペーサ１９ｃとアウタケース１
１間には圧縮スプリング１９ｄが介装されていて、同ス
プリング１９ｄはスペーサ１９ｃを介して第１作動ピス
トン１３を摩擦クラッチ１０ｃとは反対側へ付勢する。The second actuating piston 16 constituting the second pressing force generating means 10b is assembled to the outer case 11 so as to be integrally rotatable and movable in the axial direction, and to the inner shaft 12 in a liquid-tight manner so as to be rotatable and movable in the axial direction. The first actuating piston 13 is attached to the clutch plate 19a at the other end of the clutch plate 19a on its negative side, and is connected to the first actuating piston 13 via a spacer 19c on the other side.
is in contact with. This spacer 19c and outer case 1
A compression spring 19d is interposed between the pistons 1 and 1, and the spring 19d urges the first actuating piston 13 to the side opposite to the friction clutch 10c via a spacer 19c.

第２作動ピストン１６の他側には段付環状凹所が形成さ
れていて、この大径凹所１６ａ内に第２リテーナ１８が
液密的に嵌合され、かつ゛小径凹所１６ｂ内に第２０−
タ１７が嵌合されている。小径凹所１６ｂは第２作動ピ
ストン１６とにより第２流体室を形成し、インナシャフ
ト１２に一体回転可能に組付けた第２０−タ１７は流体
室内を２つの滞留室Ｒ３に区画している。なお、第２０
−タ１７は小径である点を除き第１０−タ１４と同様の
ものである。第２リテーナ１８はインナシャフト１２の
筒部１２ａの外周に液密的かつ回転可能に組付けられて
おり、かつ他端外周に突設した複数の係合突起部１８ａ
が第１図および第３図に示すように第１作動ピストン１
３の一端に設けた各係合ｍ　１３　ａを通って外周へ延
び、第１リテーナ１５の一端に当接している。これによ
り、第１リテーナ１５、第１作動ピストン１３、第２リ
テーナ１８および第２作動ピストン１６はアウタケース
１１と一体回転可能であるとともに、第１、第２両ロー
タ１５．１７はインナシャフト１２と一体回転可能であ
り、かつ第１作動ピストン１３は圧縮スプリング１．９
　ｄにより第１リテーナ１５側へ所定の力で付勢されて
いる。なお、第２流体室にも高粘性流体が所定量封入さ
れている。A stepped annular recess is formed on the other side of the second actuating piston 16, and a second retainer 18 is fluid-tightly fitted into the larger diameter recess 16a, and a second retainer 18 is fitted into the smaller diameter recess 16b. 20-
17 is fitted. The small-diameter recess 16b forms a second fluid chamber with the second actuating piston 16, and the 20th cylinder 17, which is rotatably assembled to the inner shaft 12, divides the fluid chamber into two retention chambers R3. . In addition, the 20th
The tenth tab 17 is similar to the tenth tab 14 except that it has a smaller diameter. The second retainer 18 is liquid-tightly and rotatably assembled to the outer periphery of the cylindrical portion 12a of the inner shaft 12, and has a plurality of engagement protrusions 18a protruding from the outer periphery of the other end.
is the first working piston 1 as shown in FIGS. 1 and 3.
It extends to the outer periphery through each engagement m 13 a provided at one end of the first retainer 15 and comes into contact with one end of the first retainer 15 . As a result, the first retainer 15, the first working piston 13, the second retainer 18, and the second working piston 16 can rotate integrally with the outer case 11, and both the first and second rotors 15 and 17 are connected to the inner shaft 12. The first working piston 13 is rotatable integrally with the compression spring 1.9.
d is biased toward the first retainer 15 with a predetermined force. Note that a predetermined amount of highly viscous fluid is also sealed in the second fluid chamber.

かかる構成の動力伝達機構１０においては、第１、第２
両プロペラシャフト２５．２６間に相対回転が生じてい
ない場合にはこれら両シャフト２５．２６間のトルク伝
達はないが、両シャフト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、両作動ピストン１３．１６および両リテーナ
１５．１８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および両ロー
タ１４．１７との間に相対回転が生じる。従って、両押
圧力発生手段１０ａ、１０ｂの流体室内においては、滞
留室Ｒ２、Ｒ３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、Ｒ３内では流動抵抗に起因してベーン部
の下流側端から次のベーン部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、両作動ピスト
ン１３．１６を軸方向へ押圧する。しかして、第２作動
ピストン１７は摩擦クラッチ１０ｃを直接押圧して摩擦
クラッチ１Ｏｅを構成する各クラッチプレート１９ａと
クラッチディスク１９ｂをクラッチ用オイルを介して摩
擦係合させる。一方、第１作動ピストン１３は圧縮スプ
リング１９ｄに抗して押圧されるなめ、同スプリング１
９ｄの付勢力に打勝つまでは第２作動ピストン１６の押
圧力を助勢することはないが、上記付勢力に打勝つと差
動回転数に応じて第２作動ピストン１６の押圧力を助勢
し、クラッチプレート１９ａとクラッチディスク１９ｂ
の摩擦係合力を一層強める。第４図には差動回転数に対
する伝達トルクの関係が示されており、１点鎖線および
２点鎖線のグラフは各押圧力発生手段１０ａ、１０ｂが
単独に作動する場合、実線のグラフは両者１０ａ、１０
ｂが協働した場合の伝達トルクを示している。かかるグ
ラフから明らかなように、第２作動ピストンに対する押
圧力の助勢の有無を境として伝達トルクの曲線は２段折
れとなり、差動回転数の小さい領域での伝達トルクの増
加率は小さくかつ差動回転数の大きい領域での伝達トル
クの増加率は大きくなる。この結果、車両の低速コーナ
リング時のタイトコーナブレーキング現象の発生が防止
され、かつぬかるみ等悪路に陥った時の脱出性能が向上
する。In the power transmission mechanism 10 having such a configuration, the first and second
When there is no relative rotation between the two propeller shafts 25, 26, there is no torque transmission between the two shafts 25, 26, but when there is relative rotation between the two shafts 25, 26, torque is transmitted. That is, when relative rotation occurs between these two shafts 25, 26, the outer case 11, both actuating pistons 13, 16, and both retainers 15, 18, which are assembled to be integrally rotatable with the first propeller shaft 25, Relative rotation occurs between the inner shaft 12 and both rotors 14 and 17, which are assembled to the two propeller shafts 26 so as to be able to rotate together. Therefore, in the fluid chambers of both pressing force generating means 10a and 10b, the viscous fluid in the retention chambers R2 and R3 is forced to flow at a speed proportional to the relative rotational speed, and the viscous fluid is gradually moved relative to the circumferential direction. In the chambers R2 and R3, a pressure distribution is generated in which the pressure gradually increases from the downstream end of the vane section to the upstream end of the next vane section due to flow resistance. The pressure increasing part of this pressure distribution increases in proportion to the differential rotation speed and presses both actuating pistons 13, 16 in the axial direction. Thus, the second actuating piston 17 directly presses the friction clutch 10c to frictionally engage each clutch plate 19a and clutch disc 19b, which constitute the friction clutch 1Oe, via the clutch oil. On the other hand, the first actuating piston 13 is pressed against the compression spring 19d.
The pressing force of the second working piston 16 is not assisted until it overcomes the urging force of 9d, but once the urging force is overcome, the pressing force of the second working piston 16 is assisted in accordance with the differential rotation speed. , clutch plate 19a and clutch disc 19b
further strengthens the frictional engagement force. FIG. 4 shows the relationship between the transmission torque and the differential rotation speed. The one-dot chain line and the two-dot chain line graph indicate that when each pressing force generating means 10a, 10b operates independently, and the solid line graph indicates that both of them operate. 10a, 10
b shows the transmitted torque when they work together. As is clear from this graph, the curve of the transmitted torque bends in two stages depending on whether or not the pressing force is applied to the second actuating piston, and the rate of increase in the transmitted torque is small in the region where the differential rotation speed is small, and the difference is small. The rate of increase in transmitted torque increases in a region where the dynamic rotational speed is large. As a result, the tight corner braking phenomenon during low-speed cornering of the vehicle is prevented from occurring, and the escape performance when the vehicle falls into a rough road such as mud is improved.

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

第１図は本発明の一実施例に係る動力伝達機構の断面図
、第２図は第１図の矢印■−■線方向の断面図、第３図
は第１図の矢印■−■線方向の断面図、第４図は差動回
転数に対する伝達トルクを示すグラフ、第５図は同機構
を採用した車両の概略図である。 符号の説明 １０・・・動力伝達機構、１０ａ、１０ｂ・押圧力発生
手段、１０ｃ・・・摩擦クラッチ、１１・・・アウタケ
ース、１２・・・インナシャフト、１３．１６・・・作
動ピストン、１４．１７・ロータ、１４ｂ・・・ベーン
部、１５．１８・・・リテーナ、１９ａ・・・クラッチ
プレート、１９ｂ・・・クラッチディスク、１９ｄ・・
圧縮スプリング、２５．２６・・・プロペラシャフト、
Ｒ２，Ｒ３・・・滞留室。 第４図 第 ご 第 区 １２　・ インナシャフト 作動ピストン ２６　・ プロペラシャフト ・ロータ ４ｂ べ一 １５、　１８ リテーナFIG. 1 is a cross-sectional view of a power transmission mechanism according to an embodiment of the present invention, FIG. 2 is a cross-sectional view along the arrow ■-■ line in FIG. 1, and FIG. 3 is a cross-sectional view along the arrow ■-■ line in FIG. FIG. 4 is a graph showing transmission torque versus differential rotation speed, and FIG. 5 is a schematic diagram of a vehicle employing the same mechanism. Explanation of symbols 10... Power transmission mechanism, 10a, 10b, pressing force generating means, 10c... Friction clutch, 11... Outer case, 12... Inner shaft, 13.16... Working piston, 14.17 Rotor, 14b Vane part, 15.18 Retainer, 19a Clutch plate, 19b Clutch disc, 19d...
Compression spring, 25.26...propeller shaft,
R2, R3... Retention chamber. Figure 4 Section 12 - Inner shaft operating piston 26 - Propeller shaft rotor 4b Beams 15, 18 Retainer

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一
方の回転部材に一体回転可能に組付けられた第１の作動
ピストンと、前記一方の回転部材に一体的または一体回
転可能に設けられて前記第１の作動ピストンとの間に軸
方向に所定間隔を有して粘性流体が封入される第１の流
体室を形成する第１のリテーナと、半径方向へ延びる１
または複数のベーン部を備え前記第１の流体室にて前記
他方の回転部材に一体的に組付けられた第１のロータと
、前記第１の作動ピストンと前記摩擦クラッチ間にて前
記両回転部材間に軸方向へ摺動可能かつ一方の回転部材
に一体回転可能に組付けられて前記第１の作動ピストン
および摩擦クラッチに当接する第２の作動ピストンと、
同ピストンと前記第１のリテーナ間に軸方向への移動を
規制して組付けられ前記第２の作動ピストンとの間に軸
方向に所定間隔を有して粘性流体が封入される第２の流
体室を形成する第２のリテーナと、半径方向へ延びる１
または複数のベーン部を備え前記第２の流体室にて前記
他方の回転部材に一体的に組付けられた第２のロータと
、前記第１の作動ピストンを前記第２の作動ピストンか
ら離間する方向に付勢するスプリングとにより構成して
なる動力伝達機構。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 frictional engagement force according to the pressing force, and a pressing force generating means that generates a pressing force corresponding to the relative rotation of both rotating members and applies it to the friction clutch, the pressing force generating means , a first actuating piston that is slidable in the axial direction in a fluid-tight manner between the two rotating members and is assembled to be rotatable integrally with one of the rotating members; and a first actuating piston that is rotatable integrally or integrally with the one rotating member. a first retainer which is provided in the first working piston and forms a first fluid chamber in which a viscous fluid is sealed, having a predetermined spacing between the retainer and the first working piston;
or a first rotor including a plurality of vane portions and integrally assembled to the other rotating member in the first fluid chamber, and between the first actuating piston and the friction clutch. a second actuating piston that is slidable in the axial direction between the members and is assembled to be integrally rotatable with one of the rotating members and abuts the first actuating piston and the friction clutch;
A second actuating piston is assembled between the piston and the first retainer to restrict movement in the axial direction, and a viscous fluid is sealed between the piston and the second working piston with a predetermined distance in the axial direction. a second retainer forming a fluid chamber and a radially extending one;
or a second rotor including a plurality of vanes and integrally assembled to the other rotating member in the second fluid chamber, and separating the first working piston from the second working piston. A power transmission mechanism consisting of a spring that biases in a direction.