JPH022019B2

JPH022019B2 -

Info

Publication number: JPH022019B2
Application number: JP57076611A
Authority: JP
Inventors: Koichiro Hirozawa
Original assignee: Aisin Seiki Co Ltd
Current assignee: Aisin Corp
Priority date: 1982-05-10
Filing date: 1982-05-10
Publication date: 1990-01-16
Also published as: JPS58193965A

Description

[Detailed description of the invention]

［産業上の利用分野］本発明は、変速装置に関し、詳細には、自動車
に適した変速装置に関する。［従来の技術］自動車の熱費向上および加速性向上のため、ギ
ヤシフト操作の煩雑な多段変速機（トラツク等の
大型車両では６〜12段のものが使用されている）
を使用する代わりに変速比レンジの広い無段変速
機を使用する試みが種々知られている。特に市街
地では変速が煩雑であり、無段変速のニーズが強
い。［発明により解決すべき課題］しかしながら無段変速機の変速比のレンジを広
げると、例えば市街地走行用の低、中速域等の特
定変速比域の使用頻度が高いのでその部分が早期
に摩耗し無段変速機の耐久性が極端に低下すると
いう欠点があつた。さらに、その伝達効率は変速
比１で最大であるがそれから外れると悪化すると
いう欠点がありこれは、トラツク等の大型車両に
とつて致命的な欠点を成すという欠点があつた。従つて、本発明の目的は、無段変速を可能とし
耐久性が高くかつ変速比レンジが広くかつ伝達効
率の高い変速装置を提供することにある。［解決手段］本発明の変速装置は下記の構成により上記目的
を達成する。即ち、本発明の変速装置は、入力軸と出力軸を
第１動力断続手段を介して動力伝達可能に接続す
る無段変速機と、この無段変速機の変速比可変レ
ンジの低速側の外において段差をもつて変速比が
固定され前記入力軸と出力軸を第２動力断続手段
を介して動力伝達可能に接続するロー変速比用ス
テツプ変速機と、前記無段変速機の変速比可変レ
ンジの高速側の外において段差をもつて変速比が
固定され前記入力軸と出力軸を第３動力断続手段
を介して動力伝達可能に接続するハイ変速比用ス
テツプ変速機と、前記第１、第２および第３動力
断続手段を切換えて前記変速機のうちのいずれか
一の変速機を選択作動する切換機構とを備えてい
ることを特徴とする。［好適な実施の態様及び作用・効果］本発明の変速装置の実施の態様としては、例え
ば無段変速機とハイ変速比用ステツプ変速機とロ
ー変速比用ステツプ変速機と各変速機の入力軸又
は出力軸に接続されたクラツチとの組合せ、或い
は無段変速機と、遊星ギヤセツトを１組或いは複
数組合せて成るローおよびハイの変速比用動力列
を有する一対のステツプ変速機と、入力軸と出力
軸との間に無段変速機を介した動力流路を完成す
るための作動装置と、入力軸と出力軸との間にス
テツプ変速機を介した動力流路を完成するための
作動装置との組合せ等がある。切換装置或いは作
動装置としてはクラツチの他遊星ギヤセツトを用
いたもの、その他遊星ギヤセツトとクラツチ或い
はブレーキを組合せたもの等が用いられる。本発明の構成によれば、ロー変速比用またはハ
イ変速比用のステツプ変速機で動力伝達中は無段
変速機に動力伝達が行われず、またロー変速比用
ステツプ変速機は無段変速機の変速比可変レンジ
の低速側の外で動力伝達を行い、ハイ変速比用ス
テツプ変速機は無段変速機に変速比可変レンジの
高速側の外で動力伝達を行うため、無段変速レン
ジの両側に各々ローおよびハイの固定ステツプ変
速レンジが加えられるので変速装置全体としての
変速レンジが広くなる。それと共に、無段変速機
のみによつて変速するとすれば摩耗が生じ易くか
つ伝達効率が悪い高低両端変速比部分を伝達効率
が高いステツプ変速機に切換える。無段変速機の
可変レンジ端から外す段差（比）は、ロー側にて
1.35〜2.0、ハイ側にて1.1〜1.4の程度とすること
が好ましい。そのため、変速装置の耐久性及び伝
達効率は大幅に向上し、さらには車両の燃費およ
び加速性も向上し、大型車両にも無段変速機を適
用可能にするという顕著な効果を有する。以下添付図面を参照して本発明による変速装置
の実施例について説明するが、本発明はこれらに
限定されず広汎な応用が可能である。［実施例］まず第１図において図に示す変速装置１０は無
段変速機１２と、ハイ（オーバードライブ）変速
比用ステツプ変速機１４（以下ハイ用変速機）
と、ロー変速比用ステツプ変速機１６（以下ロー
用変速機）と、後進用変速機１８と各変速機用に
それぞれ設けられたクラツチC_V，C_H，C_Lおよび
C_Rとから成る。入力シヤフト２０および出力シ
ヤフト２２は互いに平行に配置され、これらシヤ
フト２０，２２間に各種変速機１４，１６，１８
が設けられ、後進用クラツチC_R、ハイ（オーバ
ードライブ）用クラツチC_H、および無段変速機
用クラツチC_Vは、入力シヤフト２０上に設けら
れ、ロー用クラツチC_Lは出力シヤフト２２上に
設けられている。これらクラツチは、図示してな
いクラツチ作動装置により択一的に作動され、所
望の一つの変速機のみを作動させる。なお本発明
において、クラツチの配置は本実施列のみに限定
されるものではなく、設計の都合入力シヤフト２
０又は出力シヤフト２２上のいずれに設けてもよ
いが変速機非作動時に内部のギヤ列が空動するこ
とがないような配置にすることが、効率および保
守の点から好ましい。無段変速機１２は、図示する如く、いわゆるＶ
ベルト式変速機であり、円錐プーリ２４の一方又
はその双方を軸方向に移動制御することによりＶ
ベルト２６の係合半径を可変するようになつてい
る。当然ながらこのＶ字ベルト無段変速機は例示
にすぎず、本発明では他の無段変速機も使用でき
る。ロー用変速機１６およびハイ用変速機１４
は、遊星ギヤセツトより構成されている。第５図は、第１図に示した実施例の変速装置に
よる車速一駆動力の関係を示すグラフである。図
中曲線ａはロー用変速機１６作動時の車速−駆動
力の関係を示す曲線であり、曲線ｂは無段変速機
１２作動時の曲線、曲線ｃはハイ（オーバードラ
イブ）用変速機１４作動時の曲線であり、曲線ｄ
は平坦路の走行抵抗を示す。本図から無段変速機
の変速比レンジ外に段差をもつた固定変速比が得
られることが判る。すなわち駆動力の大きいロー
側ではロー変速機１６によつて動力伝達が行われ
るため、無段変速機１２は比較的駆動力が小さい
範囲で動力伝達することになる。又使用頻度の高
いハイ側での走行では変速機１４によつて動力伝
達が行われるため、無段変速機１２による動力伝
達は行われない。これらの結果、変速装置の耐久
性及び伝達効率がハイ・ロー側で大幅に向上す
る。第２図は、この発明による変速装置の他の実施
例を示すものであつて、ロー用のクラツチC_Lが
シヤフト２０側に、ハイ用のクラツチC_Hがシヤ
フト２２側に、配置してある点が第１図の変速機
と異なる。第３図はこの発明による変速装置のさらに他の
実施例を示すものであつて、第１図の実施例とは
シヤフト、変速機及び切換装置の配置が異なつて
いる。まず入力シヤフト２０と出力シヤフト２２
は同一直線上に整合して配置され、入力シヤフト
２０および出力シヤフト２２に対してカウンタシ
ヤフト２８が平行に配置されている。入力シヤフ
ト２０上にはＶベルト式無段変速機１２およびこ
のためのクラツチC_Vが設けられ、入力シヤフト
２０と出力シヤフト２２の間にはロー用変速機１
６′が設けられている。さらに入力シヤフト２０
とカウンタシヤフト２８との間に第２図と同様の
ハイ用変速機１４が設けられている。ロー用変速
機１６′は、入力シヤフト２０の一端に固定され
た太陽歯車３０と、内歯を有し、出力シヤフト２
２の一端と連絡されたリング歯車３２と、両者の
間に噛合された遊星歯車３４とから成り、遊星歯
車３４の支持軸３６は、ブレーキ３８によつて回
動自在又は不能とされる。カウンタシヤフト２８
と出力シヤフト２２の間には、前進用歯車列４０
と後進用歯車列４２が設けられ、カウンタシヤフ
ト２８上の両歯車列の間には、両歯車列のいずれ
かを作動するための切換歯車４４が設けられてい
る。第３図の実施例の作動について説明すると、ま
ずロー変速比を得る場合、ブレーキ３８により遊
星歯車３４の支持軸３６が入力シヤフト２０のま
わりに回動不能とされ、入力シヤフト２０、すな
わち太陽歯車３０の回転トルクは、位置固定して
回転する遊星歯車３４を介して歯車３２すなわち
出力シヤフト２２へ伝えられる。次に上記ロー変
速比およびハイ変速比以外の変速比で前進又は後
進する場合、クラツチC_Vが作動して入力シヤフ
ト２０の回転トルクは、無段変速機１２を介して
カウンタシヤフト２８に伝えられる。またクラツ
チC_Hを接続するとハイ用変速機１４によつてハ
イ変速比が得られる。カウンタシヤフト２８上の
切換装置４４が前進用歯車列４０に接続されてい
ると、カウンタシヤフト２８の回転トルクは前進
用歯車列４０を介して出力シヤフト２２に伝えら
れる。次に切換装置４４が後進用歯車列４２に接
続されていると、カウンタシヤフト２８の回転ト
ルクは、後進用歯車列４２を介して出力シヤフト
２２に伝達される。上記前進又は後進時には、ロ
ー用変速機１６′の遊星歯車３４は、空転する。第４図に示す実施例は、第１図の実施例とはシ
ヤフトおよび変速機等の配置が異なつている。ま
ず入力シヤフト２０と出力シヤフト２２は、同一
直線上に整合して配置され、入力シヤフト２０お
よび出力シヤフト２２に対してカウンタシヤフト
２８が平行に配置されている。入力シヤフト２０
上にはＶベルト無段変速機１２の一方のプーリ２
４およびこの無段変速機用１２クラツチC_Vが設
けられ、入力シヤフト２０と出力シヤフト２２の
間にはハイ用変速機１４′が設けられている。さ
らに入力シヤフト２０とカウンタシヤフト２８と
の間には第２図と同様のロー用変速機１６が設け
られている。このハイ用変速機１４′は、入力シ
ヤフト２０上に回転自在に取付けられ、ハイ（オ
ーバードライブ）用ブレーキ３８′により回転自
在又は不能にされる太陽歯車３０′と、出力シヤ
フト２２の一端に固定され内歯を有するリング歯
車３２′と、両車の間に噛合された遊星歯車３
４′とから成り、遊星歯車３４′は入力シヤフト２
０と回転連結された支持軸３６′上に回転自在に
固定されている。カウンタシヤフト２８と出力シ
ヤフト２２との間には、前進用動力列（チエー
ン）４６と後進用動力列４８とが設けられ、カウ
ンタシヤフト２８上の両動力列４６，４８の間に
は、両動力列のいずれかを作動するための前後進
切換歯車４４が設けられている。次に第４図の実施例の作動について説明する
と、まずクラツチC_Lを接続するとロー用変速機
１６によつてロー変速比が得られる。そしてロー
変速比およびハイ変速比以外の前進又は後進作動
には、クラツチC_Vが作動して、入力シヤフト２
０の回転トルクは無段変速機１２を介してカウン
タシヤフト２８に伝えられる。切換歯車４４が前
進用動力列４６に接続している場合、カウンタシ
ヤフト２８の回転トルクは、チエーンを含む前進
用動力列４６を介して出力シヤフト２２へ伝えら
れ、切換装置４４が後進用動力列４８に接続して
いる場合、カウンタシヤフト２８の回転トルク
は、ギヤ列から成る後進用動力列４８を介して出
力シヤフト２２に伝達される。上記のように無段
変速機１２が作動する間ハイ用変速機１４の遊星
歯車３４′は、入力シヤフト２０のまわりを空転
する。次にクラツチC_Vが解放され、ハイ用ブレーキ
３８′が作動すると、太陽歯車３０′が固定される
ため、遊星歯車３４′は、太陽歯車３０′のまわり
を旋回しつつ回転し対応して歯車３２′が回転し、
入力シヤフト２０の回転トルクは出力シヤフト２
２へ伝達される。この結果、使用頻度の高いハイ
側での走行は変速機１４′を介して行われるので、
無段変速機１２の動力伝達が省かれ、変速装置の
耐久性及び伝達効率が向上する。次に、伝達効率について論ずる。従来のステツプ式多段変速機の変速比の段差
（比）は例で示すと第１表の通りである。 [Industrial Field of Application] The present invention relates to a transmission, and more particularly to a transmission suitable for automobiles. [Conventional technology] To improve heating costs and acceleration of automobiles, multi-speed transmissions with complicated gear shifting operations are used (6-12 speeds are used in large vehicles such as trucks).
Various attempts have been made to use a continuously variable transmission with a wide gear ratio range instead of using a continuously variable transmission. Especially in urban areas, shifting is complicated, and there is a strong need for continuously variable transmission. [Problems to be Solved by the Invention] However, if the range of gear ratios of a continuously variable transmission is expanded, specific gear ratio ranges such as low and medium speed ranges for city driving are used more frequently, so those parts will wear out sooner. However, the disadvantage was that the durability of the continuously variable transmission was extremely reduced. Furthermore, the transmission efficiency is maximum at a gear ratio of 1, but deteriorates as it deviates from that ratio, which is a fatal drawback for large vehicles such as trucks. SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to provide a transmission device that enables continuously variable transmission, has high durability, has a wide gear ratio range, and has high transmission efficiency. [Solution Means] The transmission device of the present invention achieves the above object with the following configuration. That is, the transmission device of the present invention includes a continuously variable transmission in which an input shaft and an output shaft are connected to each other so as to transmit power via a first power intermittent means, and a gear ratio variable range of the continuously variable transmission. a step transmission for a low gear ratio, in which the gear ratio is fixed with a step, and the input shaft and the output shaft are connected to enable power transmission via a second power disconnecting means; and a variable gear ratio range of the continuously variable transmission. a high speed ratio step transmission, in which the speed ratio is fixed with a step outside the high speed side, and the input shaft and the output shaft are connected to enable power transmission via a third power disconnection means; The present invention is characterized by comprising a switching mechanism that selectively operates one of the transmissions by switching between the second and third power intermittent means. [Preferred Embodiments and Actions/Effects] Embodiments of the transmission of the present invention include, for example, a continuously variable transmission, a step transmission for a high gear ratio, a step transmission for a low gear ratio, and an input of each transmission. A pair of step transmissions having a power train for low and high gear ratios consisting of a combination of a clutch connected to a shaft or an output shaft, or a continuously variable transmission and one or more planetary gear sets, and an input shaft. and an actuation device for completing a power flow path via a continuously variable transmission between the input shaft and the output shaft, and an operation device for completing a power flow path between the input shaft and the output shaft via a step transmission. There are combinations with devices, etc. As the switching device or actuating device, a device using a planetary gear set in addition to a clutch, or a device combining a planetary gear set with a clutch or a brake, etc. can be used. According to the configuration of the present invention, while the step transmission for low gear ratio or high gear ratio is transmitting power, power is not transmitted to the continuously variable transmission, and the step transmission for low gear ratio is not transmitted to the continuously variable transmission. The step transmission for high gear ratios transmits power outside the low speed side of the variable gear ratio range, and the step transmission for high gear ratios transmits power to the continuously variable transmission outside the high speed side of the variable gear ratio range. Since low and high fixed step shift ranges are added to each side, the shift range of the entire transmission is widened. At the same time, the high and low end gear ratio portion, which would easily cause wear and have poor transmission efficiency if only a continuously variable transmission were used, is switched to a step transmission with high transmission efficiency. The step (ratio) removed from the end of the variable range of a continuously variable transmission is on the low side.
It is preferable to set it to about 1.35 to 2.0, and 1.1 to 1.4 on the high side. Therefore, the durability and transmission efficiency of the transmission device are significantly improved, and the fuel efficiency and acceleration performance of the vehicle are also improved, which has the remarkable effect of making the continuously variable transmission applicable to large vehicles. Embodiments of a transmission according to the present invention will be described below with reference to the accompanying drawings, but the present invention is not limited thereto and can be widely applied. [Example] First, the transmission device 10 shown in FIG. 1 includes a continuously variable transmission 12 and a step transmission 14 for high (overdrive) gear ratio (hereinafter referred to as high transmission).
, a low gear ratio step transmission 16 (hereinafter referred to as a low transmission), a reverse transmission 18, and clutches C _V , C _H , C _L and each provided for each transmission.
It consists of _CR . The input shaft 20 and the output shaft 22 are arranged parallel to each other, and various transmissions 14, 16, 18 are connected between these shafts 20, 22.
A reverse clutch C _R , a high (overdrive) clutch C _H , and a continuously variable transmission clutch C _V are provided on the input shaft 20 , and a low clutch C _L is provided on the output shaft 22 . It is provided. These clutches are alternatively actuated by a clutch actuator (not shown) to actuate only one desired transmission. Note that in the present invention, the arrangement of the clutch is not limited to this embodiment row only, and may be changed depending on the input shaft 2 due to design considerations.
It may be provided either on the output shaft 22 or on the output shaft 22, but it is preferable from the standpoint of efficiency and maintenance to arrange it so that the internal gear train does not move idly when the transmission is not in operation. As shown in the figure, the continuously variable transmission 12 is a so-called V transmission.
It is a belt type transmission, and by controlling the movement of one or both of the conical pulleys 24 in the axial direction,
The engagement radius of the belt 26 is made variable. Of course, this V-shaped belt continuously variable transmission is merely an example, and other continuously variable transmissions can also be used in the present invention. Low transmission 16 and high transmission 14
consists of a planetary gear set. FIG. 5 is a graph showing the relationship between vehicle speed and driving force by the transmission of the embodiment shown in FIG. In the figure, curve a shows the relationship between vehicle speed and driving force when the low transmission 16 is activated, curve b is the curve when the continuously variable transmission 12 is activated, and curve c is the curve when the high (overdrive) transmission 14 is activated. This is the curve during operation, and the curve d
indicates the running resistance on a flat road. It can be seen from this figure that a fixed gear ratio with steps outside the gear ratio range of the continuously variable transmission can be obtained. That is, since power is transmitted by the low transmission 16 on the low side where the driving force is large, the continuously variable transmission 12 transmits power in a range where the driving force is relatively small. Furthermore, when the vehicle is running on the high side, which is frequently used, power is transmitted by the transmission 14, and therefore, power is not transmitted by the continuously variable transmission 12. As a result, the durability and transmission efficiency of the transmission are significantly improved on the high and low sides. FIG. 2 shows another embodiment of the transmission according to the present invention, in which a low clutch C _L is disposed on the shaft 20 side, and a high clutch C _H is disposed on the shaft 22 side. This differs from the transmission shown in FIG. 1 in this respect. FIG. 3 shows still another embodiment of the transmission according to the invention, which differs from the embodiment shown in FIG. 1 in the arrangement of the shaft, transmission, and switching device. First, input shaft 20 and output shaft 22
are arranged in alignment on the same straight line, and the countershaft 28 is arranged parallel to the input shaft 20 and the output shaft 22. A V-belt type continuously variable transmission 12 and a clutch C _V for this are provided on the input shaft 20, and a low transmission 1 is provided between the input shaft 20 and the output shaft 22.
6' is provided. Furthermore, input shaft 20
A high transmission 14 similar to that shown in FIG. 2 is provided between and the countershaft 28. The low transmission 16' has a sun gear 30 fixed to one end of the input shaft 20, internal teeth, and a sun gear 30 fixed to one end of the input shaft 20.
The ring gear 32 is connected to one end of the ring gear 2, and a planet gear 34 is meshed between the two. counter shaft 28
A forward gear train 40 is provided between the output shaft 22 and the output shaft 22.
and a reverse gear train 42 are provided, and a switching gear 44 for operating either of the two gear trains is provided between the two gear trains on the countershaft 28. To explain the operation of the embodiment shown in FIG. 3, first, when obtaining a low gear ratio, the support shaft 36 of the planetary gear 34 is made unrotatable around the input shaft 20 by the brake 38, and the input shaft 20, that is, the sun gear The rotational torque of 30 is transmitted to the gear 32, that is, the output shaft 22, via the planetary gear 34, which rotates in a fixed position. Next, when moving forward or backward at a gear ratio other than the low gear ratio and high gear ratio, the clutch C _V operates and the rotational torque of the input shaft 20 is transmitted to the countershaft 28 via the continuously variable transmission 12. . Further, when the clutch C _H is connected, a high gear ratio can be obtained by the high gear transmission 14. If the switching device 44 on the countershaft 28 is connected to the forward gear train 40, the rotational torque of the countershaft 28 is transmitted to the output shaft 22 via the forward gear train 40. When the switching device 44 is then connected to the reverse gear train 42 , the rotational torque of the countershaft 28 is transmitted to the output shaft 22 via the reverse gear train 42 . During the forward or reverse movement, the planetary gear 34 of the low transmission 16' idles. The embodiment shown in FIG. 4 differs from the embodiment shown in FIG. 1 in the arrangement of the shaft, transmission, etc. First, the input shaft 20 and the output shaft 22 are arranged in alignment on the same straight line, and the countershaft 28 is arranged parallel to the input shaft 20 and the output shaft 22. input shaft 20
Above is one pulley 2 of the V-belt continuously variable transmission 12.
4 and a 12-clutch _CV for the continuously variable transmission, and a high transmission 14' is provided between the input shaft 20 and the output shaft 22. Furthermore, a low transmission 16 similar to that shown in FIG. 2 is provided between the input shaft 20 and the countershaft 28. This high gear transmission 14' is rotatably mounted on the input shaft 20, and includes a sun gear 30' that is rotatable or disabled by a high (overdrive) brake 38', and a sun gear 30' that is fixed to one end of the output shaft 22. A ring gear 32' having internal teeth, and a planetary gear 3 meshed between both wheels.
4', and the planetary gear 34' is connected to the input shaft 2.
0 and is rotatably fixed on a support shaft 36' that is rotatably connected to the support shaft 36'. A forward power chain 46 and a reverse power train 48 are provided between the countershaft 28 and the output shaft 22. A forward/reverse switching gear 44 is provided for operating either of the rows. Next, the operation of the embodiment shown in FIG. 4 will be described. First, when the clutch C _L is connected, a low gear ratio is obtained by the low transmission 16. For forward or reverse operation other than the low gear ratio and high gear ratio, the clutch C _V operates and the input shaft 2
The zero rotational torque is transmitted to the countershaft 28 via the continuously variable transmission 12. When the switching gear 44 is connected to the forward power train 46, the rotational torque of the countershaft 28 is transmitted to the output shaft 22 via the forward power train 46 including a chain, and the switching device 44 is connected to the reverse power train 46. 48, the rotational torque of the countershaft 28 is transmitted to the output shaft 22 via a reverse power train 48 consisting of a gear train. While the continuously variable transmission 12 operates as described above, the planetary gear 34' of the high transmission 14 idles around the input shaft 20. Next, when the clutch C _V is released and the high brake 38' is activated, the sun gear 30' is fixed, so the planetary gears 34' rotate while turning around the sun gear 30', and the gears correspondingly rotate. 32' rotates,
The rotational torque of the input shaft 20 is the same as that of the output shaft 2.
2. As a result, driving on the high side, which is frequently used, is performed via the transmission 14'.
Power transmission by the continuously variable transmission 12 is omitted, improving the durability and transmission efficiency of the transmission. Next, we will discuss transmission efficiency. The steps (ratios) of the gear ratios of conventional step type multi-speed transmissions are shown in Table 1 as an example.

【表】即ち、変速比の段差が低速段程大きく、高速段
へ行く程小さくなつている。伝達効率について見てみると、固定減速比の歯
車の伝達では、一般に97〜99％の伝達効率である
のに対し、ベルト式変速機では変速比が1.0で効
率が最大（94％）であり、変速比が1.0より大き
くなる程悪くなり（変速比2.0で91％）、また1.0
より小さくなる程悪くなる（変速比0.5で86％）。従つて、変速機全体の変速比の幅を増やそう
とする場合に無段変速機（ベルト式等）の変速比
幅を増やすと、第６図のグラフに示す様にさらに
伝達効率の低下をきたす。逆の見方をすれば、
変速比の幅を同一として考えると、ベルト式無段
変速機の変速比の可変レンジの幅を狭めた方が伝
達効率の良い所が使える。即ち、の考え方で
は、歯車の変速比を無段変速機の変速比の外側に
段差をもつた値にする事により、ベルト式無段変
速機の実際に使用する変速比の可変レンジは小さ
く出来、伝達効率の良い部分のみを用いることが
できる。他方、の考え方では、変速装置全体として変
速比の幅をさらに増やそうとする場合にベルト変
速比の可変レンジ幅はそのままにしておき、ベル
ト式変速機の可変レンジの外側に段差をもつた変
速比の歯車変速機を配しこれへ切換える事によ
り、ベルト式変速機で変速比幅を増やす必要がな
く伝達効率低下が生じない。よつていずれの場合
でも、伝達効率が良くかつ広い変速比のレンジを
備えた変速機を提供出来る。第２表に固定変速比と無段変速機の可変レンジ
の組合せ例を示す。[Table] In other words, the difference in gear ratio becomes larger as the gears move toward lower gears, and becomes smaller as the gears move toward higher gears. Looking at transmission efficiency, gear transmission with a fixed reduction ratio generally has a transmission efficiency of 97 to 99%, whereas belt type transmissions have maximum efficiency (94%) at a transmission ratio of 1.0. , the larger the gear ratio is than 1.0, the worse it becomes (91% at gear ratio 2.0), and 1.0
The smaller it gets, the worse it gets (86% at gear ratio 0.5). Therefore, when trying to increase the gear ratio range of the entire transmission, increasing the gear ratio range of a continuously variable transmission (belt type, etc.) will further reduce the transmission efficiency, as shown in the graph of Figure 6. . If you look at it the other way,
Assuming that the range of the gear ratio is the same, narrowing the range of the variable gear ratio of a belt-type continuously variable transmission allows for better transmission efficiency. In other words, the idea is that by setting the gear ratio of the gear to a value with steps outside of the gear ratio of the continuously variable transmission, the variable range of the gear ratio actually used in the belt-type continuously variable transmission can be made smaller. , only the portion with good transmission efficiency can be used. On the other hand, when trying to further increase the range of gear ratios for the entire transmission, the variable range width of the belt gear ratio remains unchanged, and the belt type transmission has a gear ratio with steps outside the variable range. By installing and switching to a gear transmission, there is no need to increase the gear ratio width with a belt type transmission, and there is no reduction in transmission efficiency. Therefore, in either case, it is possible to provide a transmission with good transmission efficiency and a wide range of gear ratios. Table 2 shows examples of combinations of fixed gear ratios and variable ranges of continuously variable transmissions.

【表】 ○印：固定変速比
[Table] ○: Fixed gear ratio

Claims

[Claims]

1. A continuously variable transmission in which an input shaft and an output shaft are connected to enable power transmission via a first power intermittent means, and a gear ratio is changed with a step outside the low speed side of a variable gear ratio range of this continuously variable transmission. A step transmission for a low gear ratio which is fixed and connects the input shaft and the output shaft so as to transmit power via a second power intermittent means; A high speed ratio step transmission having a fixed speed ratio and connecting the input shaft and the output shaft so as to transmit power via a third power intermittent means; and the first, second and third power intermittent means. A transmission device comprising: a switching mechanism that selectively operates one of the transmissions by switching the transmission.