JP4161594B2 - Slip detection device for continuously variable transmission - Google Patents

Description

【００３４】
この相関係数ｋ(i) は、入力回転数Ｎin(i) と出力回転数Ｎout(i)との比率が、その時点の変速比に一致していれば“１”となり、ベルト２３の滑りなどのいわゆる異常が生じると、その値が次第に小さくなる。そこで、トルクの伝達に伴って無段変速機１で不可避的に生じる微少な滑り（ミクロスリップ）を超えた過剰な滑り（マクロスリップ）が発生しているか否かが判断される（ステップＳ２）。具体的には、上記の相関係数ｋ(i)が予め定めた判断基準値ｋ_mslp_S1より小さいか否かが判断される。
【００３５】
その判断基準値ｋ_mslp_S1は、“１”に近い値であって、例えば“０．９９９”程度の値であり、前記相関係数ｋ(i) がその判断基準値ｋ_mslp_S1以上であることによりステップＳ３で否定的に判断された場合には、無段変速機１に滑りが生じていないことになる。したがってこの場合は、後述するカウンタＭslp_Cnt やフラグＣoh_Flag(i)がクリアーされ（ステップＳ４）、このルーチンを終了する。
【００３６】
これに対してステップＳ３で肯定的に判断された場合には、無段変速機１で滑りが生じていることになる。したがってこの時点で無段変速機１の滑りが検出される。そして、無段変速機１で滑りが生じていることの判定が成立したことにより、フラグＣoh_Flag(i)が“１”にセットされる（ステップＳ５）。ついで、無段変速機１が滑りの生じていない状態から滑りの生じている状態に変化したか否かが、そのフラグＣoh_Flag(i)により判断される（ステップＳ６）。すなわち、直前にフラグＣoh_Flag(i-1)が“０”となっており、かつ現在時点ではフラグＣ oh_Flag(i)が“１”となっているか否かが判断される。これは、フラグＣoh_Flagが現時点に“０”から“１”に切り替わったか否かの判断である。
【００３７】
このステップＳ６で肯定的に判断された場合には、ベルト２３の滑りの判定のための所定制御I が実行される（ステップＳ７）。その所定制御I の例を図２に示してある。先ず、現在時点(i) から所定時間(n) 前の時点(i-n)における変速比γ(i-n)が、ベルト２３の滑りが開始した時点の変速比γ_stat(i-n)として固定される（ステップＳ７１）。すなわち相関係数ｋ(i) に基づいて無段変速機１での滑りが検出されると、その時点から所定時間(n) 前の時点にその滑りが開始したとして、滑りの開始時点が判定されている。
【００３８】
さらに、この滑り開始時点より所定時間(m)前までの変速比γの変化量Δγ_stat が算出される（ステップＳ７２）。すなわち無段変速機１の滑りのないいわゆる安定状態もしくは定常状態での変速比γの変化量が求められる。そして、その変化量Δγ_stat を利用して、滑りの開始時点から現在時点までの各時点における変速比γ_stat(i-n+j)が求められる（ステップＳ７３）。具体的には図２のステップＳ７３に記載してある演算が実行される。
【００３９】
そして、ベルト２３の滑りの開始の判定がおこなわれ、カウンタＭslp_Cnt による時間の計数が開始される（ステップＳ７４）。言い換えれば、ベルト２３の滑りの継続時間を求めるために、時間の測定が開始される。
【００４０】
ついで、ベルト２３の滑りが開始したとされた時点の後の時点を示す上記の“ｊ”の値が、現在時点からベルト滑り開始時点まで遡った時間に相当する値“ｎ”に達したか否かが判断される（ステップＳ７５）。このステップＳ７５で否定的に判断された場合には、その都度、“１”ずつインクリメントして（ステップＳ７５）、ステップＳ７３に戻る。すなわち、ベルト２３の滑りの開始時点(i-n) から現在時点(n) までの各時点の変速比が求められる。
【００４１】
この図２に示すサブルーチンを実行する上記のステップＳ７の後に、無段変速機１で滑りが生じていることを示す変速比予測フラグγst_Flag(i)が“１”にセットされ（ステップＳ８）、リターンする。
【００４２】
一方、ベルト２３の滑りの判定が既に成立していたり、あるいはその滑りの判定が成立していない場合には、上記のステップＳ６で否定的に判断される。その場合、上記の変速比予測フラグγ st_Flag(i-1)が“１”にセットされているか否かが判断される（ステップＳ９）。この変速比予測フラグγst_Flagは、上記のように無段変速機１での滑りが検出され、かつその滑りの開始時点が判定されたことによって“１”にセットされるから、無段変速機１の滑りが既に検出されていれば、先のサイクルでステップＳ８が実行されているために、ステップＳ９で肯定的に判断される。
【００４３】
その場合、相関係数ｋ(i) に基づく滑りの検出時点以降の変速比が推定され、その推定値に基づいて滑りが継続しているか、あるいは終了したかが判断される。すなわち、先ず、変速比推定値γ_stat(i)が求められる（ステップＳ１０）。その演算は、滑りの開始が判定された時点における変速比およびそれ以前における変速比の変化の状態（変速比の変化量）に基づいて求められた直前の変速比推定値γ_stat(i-1)に前記変化量Δγ_stat を加算することによりおこなわれる。これら変速比推定値γ_stat(i-1)および変化量Δγ_stat は、無段変速機１での滑りが開始した時点として判定された時点における動作状態を示す値であり、前述したステップＳ７もしくは図２に示すサブルーチンで求められている。
【００４４】
そして、その変速比推定値γ_stat(i)で入力回転数Ｎin(i) を割った値から出力回転数Ｎout(i)を減算した値もしくはその絶対値が、マクロスリップの判断基準値Ｍslp_rpm以上か否かが判断される（ステップＳ１１）。ここで、入力回転数Ｎin(i) を変速比推定値γ_stat(i)で割った値は、変速比がその推定値γ_stat(i)の場合における出力回転数に相当する値であるから、滑りが生じていなければ、上記の差もしくはその絶対値が判断基準値Ｍslp_rpmより小さくなる。
【００４５】
したがってステップＳ１１で肯定的に判断された場合には、カウンタＭslp_Cnt がインクリメントされる（ステップＳ１２）。すなわち滑り時間のカウントが継続される。
【００４６】
一方、ステップＳ１１で肯定的に判断された場合には、入力回転数Ｎin(i) と出力回転数Ｎout(i)との回転数差が、変速比に対応した値にほぼ一致してきたことになる。すなわち、滑りが収束もしくは終了してミクロスリップ程度になってきていることになる。そこで、この場合は、変速比予測フラグγst_Flag(i)が“０”にリセットされる（ステップＳ１３）。これは、滑り終了の判定に相当する制御である。ついで、ベルトダメージの算出のための所定制御IIが実行される（ステップＳ１４）。その制御例を図３に示してある。
【００４７】
ここでベルトダメージは、滑りによる熱量として算出する例であり、先ず、指標ｌがゼロリセットされ（ステップＳ１４１）、ついでダメージカウンタＤ_Cntがインクリメントされる（ステップＳ１４２）。さらに、滑り時間が算出される（ステップＳ１４３）。前述したようにカウンタＭslp_Cnt が滑り開始時点から終了時点まで継続してカウントをおこなっており、その値は、図１および図２に示すルーチンの繰り返し回数（すなわちサンプリング回数）に相当している。したがってそのカウント値にサンプリング周期Sample_t を掛け合わせることにより、滑りの継続していた時間が求められる。
【００４８】
ついでベルト２３のダメージが算出される（ステップＳ１４４）。これは、エネルギ吸収率ΔＱ(i) およびその積分値であるエネルギ吸収量として算出される。先ず、ベルト滑りの開始時点から滑りの終了に到る各時点でのエネルギ吸収率ΔＱ(i) が次式で求められる。
【式２】

【００４９】
ここで、μは無段変速機１におけるベルト２３と各プーリー１９，２０との間の摩擦係数、Ｒinは駆動プーリー１９に対するベルト２３の巻き掛け半径、Ａinは駆動プーリー１９側の油圧アクチュエータ２１における受圧面積、Ｐd は従動プーリー２０側の油圧アクチュエータ２２の油圧、ｖは所定の係数、ａはベルト２３の挟み角である。
【００５０】
こうして求められたエネルギ吸収率ΔＱの大きい方の値が選択される。
【式３】

【００５１】
そして、そのエネルギ吸収率ΔＱが積分されてエネルギ吸収量Ｑが求められる。
【式４】

【００５２】
上記のダメージの算出をおこなった後、指標ｌが時間のカウント値Ｍslp_Cnt に達したか否かが判断される（ステップＳ１４５）。このステップＳ１４５で否定的に判断された場合には、指標ｌをインクリメントし（ステップＳ１４６）、ステップＳ１４４に戻り、ダメージの算出を継続する。すなわち、滑りの開始から終了に到るまでの間の熱量を算出する。
【００５３】
したがって、無段変速機１に滑りが生じると、その都度、滑りに起因する熱量すなわちダメージが求められる。そのため、そのダメージに基づいて、ベルト２３の交換時期の判定や交換の告知などをおこなうことが可能になる。
【００５４】
このようにして無段変速機１の滑りが終了した場合、あるいは無段変速機１に滑りが生じていない場合、ステップＳ９で否定的に判断される。その場合、変速比予測フラグγst_Flag(i)が“０”にリセットされ（ステップＳ１５）、リターンする。
【００５５】
出力側のトルクの変化に起因して滑りが生じた場合の各回転数や相関係数などの変化と滑り開始の判定および終了の判定の時期の一例をタイムチャートで示せば、図４のとおりである。この図４について説明すると、出力側のトルクの一時的な増大によって出力回転数Ｎout が引き下げられ、それに伴って入力回転数Ｎinが引き下げられる過程で、無段変速機１に滑りが生じると、出力回転数Ｎout が入力回転数Ｎinに対して更に低下するので、相関係数が低下し始める（ｔ1 時点）。これとほぼ同時に変速比γが一時的に増大する。その後、相関係数が判断基準値ｋ_mslp_S1り小さくなるので、無段変速機１での滑りが検出される（ｔ2 時点）。
【００５６】
このように相関係数に基づく滑り判定時点は、ベルト２３の実際の滑りが生じた時点より遅れる。そこでこの発明に係る装置では、相関係数に基づく滑りの検出の時点に対して所定時間(n) だけ前の時点ｔ1 を、滑りの開始時点として判定する。また、その後は、変速比γが滑りのために増大するので、滑りの終了やダメージなどの算出のために使用する変速比として、滑りが検出された時点ｔ2 の変速比ではなく、判定された滑り開始時点ｔ1 における変速比γ_statが使用される。
【００５７】
この後、出力側のトルクが低下することにより、出力回転数Ｎout が復帰し、かつ滑りが終了する（ｔ3 時点）。その時点に求まる相関係数には、滑りが生じている間の出力回転数Ｎout の値が含まれているために、相関係数が前述した判断基準値ｋ_mslp_S1より小さくなっている。すなわち、相関係数からは滑りの終了を判定できない。これに対して前述したように入力回転数Ｎinを変速比γ_statによって割った値と出力回転数Ｎout との差は、判断基準値Ｍslp_rpm より小さくなるので、滑りの終了とほぼ同時（ｔ3 時点）にその判定が成立する。
【００５８】
したがってこの発明に係る装置によれば、無段変速機１における滑りの開始を正確に検出もしくは判定することができ、また滑り終了を同様に正確に検出もしくは判定することができる。そのため、滑りが生じている時間を正確に把握できるので、無段変速機１の熱負荷あるいはダメージを正確に検出することができる。したがって。この発明では、そのダメージの検出の結果に基づいてベルト２３の交換時期の告知や交換時期の判定などをおこなうにように構成してもよい。
【００５９】
ところで上記の制御例では、相関係数に基づくベルト２３の滑りの判定が成立した時点から所定時間(n) 前の時点を滑り開始時点として判定するように構成した。したがってその所定時間(n) が過剰であれば、実際には滑りが開始していない時点を滑り開始時点と判定したり、あるいは反対にその所定時間(n) が過小であれば、滑りが開始しているにも関わらず、滑り開始の判定時点が遅れてしまう。このようないわゆる誤差を可及的に低減するためには、図５に示す制御を実行することとしてもよい。
【００６０】
図５に示すフローチャートは、前述した図２に示すフローチャートに替わるものであって、変速比推定値γ_stat(i-n+j)と実測値γ(i-n+j) との差を評価するステップを、ステップＳ７３の次に挿入したフローチャートである。すなわち、実測値γ(i-n+j) と変速比推定値γ_stat(i-n+j)と差が、所定の判断基準値γ_slp_S 以上か否かが判断される（ステップＳ７３１）。
【００６１】
実測値γ(i-n+j) は、実際の入力回転数Ｎinと出力回転数Ｎout とから求まるものであるから、無段変速機１に滑りが生じていれば、その滑りによる回転数の変化分を含んでいる。これに対して変速比推定値γ_stat(i-n+j)は、判定された滑りの開始時点の変速比と、それ以前の変速比の変化の状態（変速比の変化率）とに基づいて求められたものであるから、滑りによる回転変化分を含んでいない。したがってこれら両者の差は、無段変速機１での滑りもしくはすれに関連する変速比の変動を表している。
【００６２】
したがってその差が所定の判断基準値γ_slp_S 以上であることにより、ステップＳ７３１で肯定的に判断された場合には、相関係数に基づく滑りの検出時点から所定時間(n) 前の時点での変速比の変動が生じているので、ベルト滑りの判定が成立し、かつカウンタＭslp_Cnt によるカウントが開始される（ステップＳ７４）。これに対してステップＳ７３１で否定的に判断された場合には、変速比に変動が生じていないので、ステップＳ７５に進み、滑り開始の判定はおこなわれない。
【００６３】
このように図５に示す制御を図１に示すフローチャートにおけるステップＳ７での所定制御I として実行すれば、滑り開始時点の判定がより正確になる。なお、図５に示す制御によれば、ステップＳ７３１の判断結果を前記所定時間(n) の適否の判定に利用できるので、その所定時間(n) を学習補正することとしてもよい。
【００６４】
ここで、上記の具体例とこの発明との関係を簡単に説明すると、上述したステップＳ７，Ｓ１１，Ｓ７４の各機能的手段が、この発明の滑り時期判定手段に相当し、またステップＳ１４４の機能的手段がこの発明の劣化検出手段に相当する。
【００６５】
なお、この発明は上記の具体例に限定されないのであって、ベルト式無段変速機以外にトラクション式の無段変速機を対象とする滑り検出装置に適用することができる。また、上記の各判断基準値や判断もしくは判定に使用する所定値などは、予め定めた一定値であってもよいが、車両の加減速度やスロットル開度などの運転状態に基づいて変化する変数（マップ値）であってもよい。また、無段変速機の劣化の程度は、熱量に替えて、他の適宜のパラメータを用いてもよい。
【００６６】
【発明の効果】
以上説明したように、請求項１の発明によれば、入出力回転数の相関係数が求められ、その相関係数に基づいて無段変速機での滑りが検出され、その滑りが検出されたことに基づき、その滑りの検出時点より前の他の時点が滑りの開始時点と判定され、もしくは滑り検出時点より後の他の時点が滑りの終了時点として判定されるため、無段変速機で滑りが生じると直ちに、すなわち僅かな滑りの増大によって滑りが検出され、その結果、その滑りの開始した時点あるいは終了した時点を正確に判定することができる。
【００６７】
また、請求項２の発明によれば、入出力回転数の相関係数が求められ、その相関係数に基づいて無段変速機での滑りが検出され、その滑りが検出されたことに基づき、その滑りの検出時点より一定時間前の時点が滑りの開始時点として判定されるため、無段変速機での滑りを迅速に検出でき、あるいはその滑りの開始時点を正確に判定することができる。
【００６８】
さらに、請求項３の発明によれば、入出力回転数の相関係数が求められ、その相関係数に基づいて無段変速機での滑りが検出され、その滑りが検出されたことに基づき、その滑りの検出時点での変速比に基づいて滑りの開始時点もしくは滑りの終了時点が判定されるため、無段変速機で滑りが生じると直ちに、すなわち僅かな滑りの増大によって滑りが検出され、その結果、その滑りが開始した時点あるいは終了した時点を正確に判定することができる。
【００６９】
またさらに、請求項４の発明によれば、入出力回転数の相関係数が求められ、その相関係数に基づいて無段変速機での滑りが検出され、その滑りが検出されたことに基づき、その滑りの検出時点での変速比およびそれまでの変速比の変化の状態に基づいて滑りの開始時点もしくは滑りの終了時点が判定されるため、無段変速機で滑りが生じると直ちに、すなわち僅かな滑りの増大によって滑りが検出され、その結果、その滑りが開始した時点あるいは終了した時点を正確に判定することができる。
【００７０】
そして、請求項５の発明によれば、入出力回転数の相関係数が求められ、その相関係数に基づいて無段変速機での滑りが検出され、その滑りが検出されたことに基づき、例えばその滑りの継続時間を知ることができ、その結果、滑りに起因する劣化の程度を正確に判定することができる。
【００７１】
またそして、請求項６の発明によれば、入出力回転数の相関係数に基づいて滑りが検出されると、その滑り開始時点もしくは終了時点が判定されるから、その滑りの開始もしくは終了の時点に基づいて無段変速機の劣化の程度を正確に判定することができる。
【図面の簡単な説明】
【図１】 この発明の制御装置による制御の一例を説明するためのフローチャートを示す図である。
【図２】 そのベルト滑り開始の判定およびそれに伴う制御のためのサブルーチンの一例を示すフローチャートである。
【図３】 そのベルト滑り終了およびダメージの判定のためのサブルーチンの一例を示すフローチャートである。
【図４】 図１に示す制御による滑りの開始判定時点および滑り終了判定時点の一例を示すタイムチャートである。
【図５】 図２に替わるたのサブルーチンを示すフローチャートである。
【図６】 この発明に係る無段変速機を含む駆動機構を模式的に示す図である。
【符号の説明】
１…無段変速機、 ３…トルクコンバータ、 ４…エンジン（動力源）、 １１…ロックアップクラッチ、 １９…駆動プーリー、 ２０…従動プーリー、 ２３…ベルト、 ２６…駆動輪、 ３１…変速機用電子制御装置（ＣＶＴ−ＥＣＵ）。[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a device for detecting slippage of a continuously variable transmission that transmits torque using frictional force or shearing force of traction oil.
[0002]
[Prior art]
Transmissions such as belt-type continuously variable transmissions or traction-type (toroidal) continuously variable transmissions transmit torque without depending on meshing, so that the torque acts beyond the transmission torque (or torque capacity). May cause excessive slippage. When such excessive slip occurs, power transmission efficiency is reduced or durability is impaired, and particularly in a continuously variable transmission, wear of a transmission member such as a belt and a torque transmission surface increases. There are cases.
[0003]
Japanese Patent Application Laid-Open No. 62-2059 discloses a device for detecting a failure of a continuously variable transmission before a trouble occurs in the running of a vehicle. The invention described in this publication performs a failure determination when the speed ratio obtained from the input / output rotational speed exceeds the maximum value or the minimum value, or when the speed of change of the speed ratio exceeds a set value. , It is configured to issue a warning to the user when the frequency becomes high.
[0004]
[Problems to be solved by the invention]
In the invention described in the above publication, it is possible to detect slippage in the continuously variable transmission. However, it is a slip as a result of a failure of the continuously variable transmission or a slip that is the cause of the failure, and for this reason, the gear ratio exceeds either the upper or lower limit value, or the shift speed is excessively high. Thus, the failure is determined. Therefore, in the above-mentioned conventional apparatus, the slippage of the belt or the like cannot be detected until the gear ratio and the gear shift speed become such extreme values.
[0005]
In a continuously variable transmission, if the clamping pressure for clamping a belt or a power roller that mediates torque transmission is high, slipping is less likely to occur, but on the other hand, power transmission efficiency decreases. Therefore, it is desirable to set the pinching pressure as low as possible within the range where no slip occurs. However, if the torque acting on the continuously variable transmission changes suddenly, the accompanying slip is detected in advance or immediately. There is a need to. For this purpose, it is necessary to detect a slight change in behavior as a slip, such as detecting a change from a so-called micro slip to a macro slip, but the invention described in the above publication focuses on such a technical problem. Not only that, but also temporary or subtle slippage that cannot be said to be a failure cannot be detected.
[0006]
The present invention has been made paying attention to the above technical problem, and an object of the present invention is to provide a slip detection device capable of easily detecting slippage in a continuously variable transmission and the start or end of the slippage. It is what.
[0007]
[Means for Solving the Problem and Action]
  In order to achieve the above object, the present invention is configured to determine the start or end time of the slip based on the detection result of the slip based on the correlation coefficient of the input / output rotational speed of the continuously variable transmission. It is a feature. More specifically, the invention of claim 1 relates to slip detection of a continuously variable transmission that detects slip of the continuously variable transmission based on a correlation coefficient between the input rotational speed and the output rotational speed of the continuously variable transmission. An apparatus based on the detection of slip by the correlation coefficient,Another time point before the detection time point is determined as the slip start time point, or another time point after the detection time point is determined as the slip end time point.A slip detection device including a slip timing determination means.
[0008]
  Therefore, in the invention of claim 1, the correlation coefficient of the input / output rotational speed is obtained, and based on the slip detected in the continuously variable transmission based on the correlation coefficient, the slip is detected,Another time point before the slip detection time is determined as the start time of the slip, or another time point after the detection time is determined as the end time of the slip.. Therefore, the slip is detected as soon as slip occurs in the continuously variable transmission, that is, by a slight increase in slip. In addition, based on the fact that the slip is detected in this manner, the time point at which the slip starts or ends is accurately determined.
[0009]
  According to a second aspect of the present invention, the slip timing determining means according to the first aspect of the present invention provides a slip based on the correlation coefficient.Detection timeThe slip detection device is configured to determine a time point before a certain time as a slip start time point.
[0010]
Therefore, in the invention of claim 2, the correlation coefficient of the input / output rotational speed is obtained, the slip in the continuously variable transmission is detected based on the correlation coefficient, and the slip is detected based on the detected slip. A point of time before the detection point is determined as a slip start point. Therefore, the slip in the continuously variable transmission is detected quickly, and the start time of the slip is accurately determined.
[0011]
Furthermore, the invention of claim 3 is characterized in that the slip timing determining means in claim 1 is based on a gear ratio at a predetermined time before a slip detection time based on the correlation coefficient, The slip detection device is configured to determine an end point.
[0012]
Therefore, in the invention of claim 3, the correlation coefficient of the input / output rotational speed is obtained, the slip in the continuously variable transmission is detected based on the correlation coefficient, and the slip is detected based on the detected slip. The slip start time or the slip end time is determined on the basis of the transmission gear ratio at the time of detection. Therefore, the slip is detected as soon as slip occurs in the continuously variable transmission, that is, by a slight increase in slip. In addition, based on the fact that the slip is detected in this manner, the time point at which the slip starts or ends is accurately determined.
[0013]
Still further, the invention according to claim 4 is characterized in that the slip timing determination means according to the invention of claim 1 has a gear ratio at a predetermined time before a slip detection time based on the correlation coefficient and a speed change before that time. The slip detection device is configured to determine a start time or an end time of the slip based on a change state of the ratio.
[0014]
Therefore, in the invention of claim 4, the correlation coefficient of the input / output rotational speed is obtained, the slip in the continuously variable transmission is detected based on the correlation coefficient, and the slip is detected based on the detected slip. The slip start time or the slip end time is determined on the basis of the gear ratio at the time of detection of this and the state of change of the gear ratio until then. Therefore, the slip is detected as soon as slip occurs in the continuously variable transmission, that is, by a slight increase in slip. In addition, based on the fact that the slip is detected in this manner, the time point at which the slip starts or ends is accurately determined.
[0015]
According to a fifth aspect of the present invention, in any one of the first to fourth aspects of the present invention, the invention further comprises a deterioration determining means for determining the degree of deterioration of the continuously variable transmission based on the correlation coefficient being obtained. This is a slip detection device.
[0016]
Therefore, in the invention of claim 5, the correlation coefficient of the input / output rotational speed is obtained, the slip in the continuously variable transmission is detected based on the correlation coefficient, and based on the detection of the slip, for example, The duration of the slip is known, so that the degree of degradation due to the slip is determined.
[0017]
The invention according to claim 6 is the invention according to claim 3 or 4, further comprising deterioration determining means for determining the degree of deterioration of the continuously variable transmission based on the start time or end time of the slip. This is a slip detection device.
[0018]
Therefore, in the invention of claim 6, when slip is detected based on the correlation coefficient of the input / output rotational speed, the slip start time or end time is determined, and based on the start or end time of the slip. The degree of deterioration of the step transmission is determined.
[0019]
DETAILED DESCRIPTION OF THE INVENTION
Next, the present invention will be described based on specific examples. First, a description will be given of a drive mechanism including a continuously variable transmission targeted by the present invention. The present invention can be directed to a drive mechanism mounted on a vehicle. A continuously variable transmission included in the drive mechanism is , Belt type continuously variable transmission with belt as torque transmission member, and toroidal type (traction type) continuously variable with torque transmission member using power roller as torque transmission member and using shear force of oil (traction oil) It is a transmission. FIG. 6 schematically shows an example of a vehicle drive mechanism including a belt-type continuously variable transmission 1, and the continuously variable transmission 1 is connected to a power by a forward / reverse switching mechanism 2 and a torque converter 3. Connected to source 4.
[0020]
The power source 4 is the same as a power source mounted on a general vehicle, and is an internal combustion engine such as a gasoline engine, a diesel engine or a natural gas engine, an electric motor, or a combination of an internal combustion engine and an electric motor. A mechanism or the like can be employed. In the following description, the power source 4 is referred to as the engine 4.
[0021]
The torque converter 3 connected to the output shaft of the engine 4 has the same structure as that of a conventional torque converter used in general vehicles, and a pump impeller 6 is connected to a front cover 5 to which the output shaft of the engine 4 is connected. A turbine runner 7 that is integrated and faces the pump impeller 6 is disposed adjacent to the inner surface of the front cover 5. The pump impeller 6 and the turbine runner 7 are provided with a large number of blades (not shown). The pump impeller 6 rotates to generate a fluid spiral flow. The spiral runner 7 The turbine runner 7 is rotated by applying torque to the turbine runner 7.
[0022]
In addition, a stator 8 that selectively changes the flow direction of the fluid fed from the turbine runner 7 and flows into the pump impeller 6 is disposed in the inner peripheral portion of the pump impeller 6 and the turbine runner 7. . The stator 8 is connected to a predetermined fixing portion 10 via a one-way clutch 9.
[0023]
The torque converter 3 includes a lockup clutch 11. The lock-up clutch 11 is arranged in parallel with a substantial torque converter including the pump impeller 6, the turbine runner 7, and the stator 8, and is in a state facing the inner surface of the front cover 5. 7 and is pressed against the inner surface of the front cover 5 by hydraulic pressure, so that torque is directly transmitted from the front cover 5 as an input member to the turbine runner 7 as an output member. The torque capacity of the lockup clutch 11 can be controlled by controlling the hydraulic pressure.
[0024]
The forward / reverse switching mechanism 2 is a mechanism that is employed when the rotational direction of the engine 4 is limited to one direction, and outputs the input torque as it is or reversely outputs it. It is configured. In the example shown in FIG. 6, a double pinion type planetary gear mechanism is employed as the forward / reverse switching mechanism 2.
[0025]
That is, the ring gear 13 is arranged concentrically with the sun gear 12, and the pinion gear 14 meshed with the sun gear 12 and the pinion gear 14 and another pinion gear 15 meshed with the ring gear 13 are arranged between the sun gear 12 and the ring gear 13. These pinion gears 14 and 15 are held by a carrier 16 so as to rotate and revolve freely. A forward clutch 17 that integrally connects the two rotating elements (specifically, the sun gear 12 and the carrier 16) is provided, and the direction of the torque that is output by selectively fixing the ring gear 13 A reverse brake 18 for reversing is provided.
[0026]
The continuously variable transmission 1 has the same configuration as a conventionally known belt-type continuously variable transmission, and each of a driving pulley 19 and a driven pulley 20 arranged in parallel to each other includes a fixed sheave, a hydraulic type The movable sheave is moved back and forth in the axial direction by the actuators 21 and 22. Therefore, the groove width of each pulley 19 and 20 is changed by moving the movable sheave in the axial direction, and accordingly, the winding radius of the belt 23 wound around each pulley 19 and 20 (the effective diameter of the pulleys 19 and 20). ) Changes continuously, and the gear ratio changes steplessly. The drive pulley 19 is connected to a carrier 16 that is an output element in the forward / reverse switching mechanism 2.
[0027]
The hydraulic actuator 22 in the driven pulley 20 is supplied with a hydraulic pressure (line pressure or its correction pressure) according to the torque input to the continuously variable transmission 1 via a hydraulic pump and a hydraulic control device (not shown). Yes. Therefore, each sheave in the driven pulley 20 pinches the belt 23, whereby tension is applied to the belt 23, and a pinching pressure (contact pressure) between the pulleys 19 and 20 and the belt 15 is secured. . In other words, the torque capacity corresponding to the clamping pressure is set. On the other hand, the hydraulic actuator 21 in the drive pulley 19 is supplied with pressure oil corresponding to the gear ratio to be set, and is set to a groove width (effective diameter) corresponding to the target gear ratio. .
[0028]
A driven pulley 20 that is an output member of the continuously variable transmission 1 is connected to a gear pair 24 and a differential 25, and the differential 25 is connected to left and right drive wheels 26.
[0029]
Various sensors are provided in order to detect the operation state (running state) of a vehicle on which the continuously variable transmission 1 and the engine 4 are mounted. That is, the engine speed sensor 27 that detects the rotation speed of the engine 4 (input rotation speed of the lockup clutch 11) Ne and outputs a signal, and the rotation speed of the turbine runner 7 (output rotation speed of the lockup clutch 11) are detected. Turbine rotation speed sensor 28 that outputs a signal, input rotation speed sensor 29 that detects the rotation speed Nin of the driving pulley 19 and outputs a signal, and output rotation that detects the rotation speed Nout of the driven pulley 20 and outputs a signal. A number sensor 30 and the like are provided.
[0030]
Control of engagement / release of the forward clutch 17 and reverse brake 18, control of the clamping force of the belt 23, control of torque capacity including engagement / release of the lockup clutch 11, and gear ratio In order to perform this control, a transmission electronic control unit (CVT-ECU) 31 is provided. The electronic control device 31 is configured mainly by a microcomputer as an example, performs calculations according to a predetermined program based on input data and data stored in advance, and various states such as forward, reverse or neutral, Further, control such as setting of the required clamping pressure and setting of the gear ratio is executed. In addition, an engine electronic control unit (E-ECU) 32 for controlling the engine 4 is provided, and data is communicated between the electronic control units 31 and 32.
[0031]
The device of the present invention intended for the above-mentioned continuously variable transmission 1 is configured to detect a slip in the continuously variable transmission 1 and to determine a start time or an end time of the slip. This is to determine the degree of damage, that is, deterioration due to slipping. FIG. 1 shows an example of the control, and the routine shown in the flowchart in FIG. 1 is repeatedly executed every predetermined short time t.
[0032]
In FIG. 1, first, the input rotational speed Nin (i) and the output rotational speed Nout (i) of the continuously variable transmission 1 are measured, and the gear ratio γ (i) is calculated using these measured values. (Step S1). The input / output rotational speeds Nin (i) and Nout (i) are rotational speeds detected by the input rotational speed sensor 29 and the output rotational speed sensor 30.
[0033]
Next, the correlation coefficient k (i) is calculated using the latest N input rotation speeds Nin and output rotation speeds Nout (step S2). The correlation coefficient k (i) is a coefficient obtained by the following equation and represents the mutual relationship between the input rotation speed Nin (i) and the output rotation speed Nout (i).
[Formula 1]

[0034]
The correlation coefficient k (i) is “1” if the ratio between the input rotational speed Nin (i) and the output rotational speed Nout (i) matches the gear ratio at that time, and the belt 23 slips. When a so-called abnormality such as occurs, the value gradually decreases. Therefore, it is determined whether or not excessive slip (macro slip) exceeding the minute slip (micro slip) inevitably generated in the continuously variable transmission 1 with torque transmission occurs (step S2). . Specifically, it is determined whether or not the correlation coefficient k (i) is smaller than a predetermined determination reference value k_mslp_S1.
[0035]
The determination reference value k_mslp_S1 is a value close to “1”, for example, about “0.999”, and the correlation coefficient k (i) is equal to or greater than the determination reference value k_mslp_S1. If the determination is negative, the slippage of the continuously variable transmission 1 has not occurred. Therefore, in this case, a counter Mslp_Cnt and a flag Coh_Flag (i) described later are cleared (step S4), and this routine is finished.
[0036]
  On the other hand, if the determination in step S3 is affirmative, slipping has occurred in the continuously variable transmission 1. Therefore, slipping of the continuously variable transmission 1 is detected at this time. Then, when it is determined that slip is occurring in the continuously variable transmission 1, the flag Coh_Flag (i) is set to “1” (step S5). Next, it is determined by the flag Coh_Flag (i) whether or not the continuously variable transmission 1 has changed from a state in which no slip occurs to a state in which slip occurs (step S6). That is, the flag Coh_Flag (i-1) is “0” immediately before and the flag at the present timeC oh_Flag (i)Is determined to be “1”. This is a determination as to whether or not the flag Coh_Flag has changed from “0” to “1” at the present time.
[0037]
If the determination in step S6 is affirmative, a predetermined control I for determining the slip of the belt 23 is executed (step S7). An example of the predetermined control I is shown in FIG. First, the speed ratio γ (in) at the time (in) a predetermined time (n) before the current time (i) is fixed as the speed ratio γ_stat (in) when the belt 23 starts to slip (step S71). ). That is, when slippage in the continuously variable transmission 1 is detected based on the correlation coefficient k (i), it is determined that the slip has started at a time point that is a predetermined time (n) before that time point. Has been.
[0038]
Further, a change amount Δγ_stat of the speed ratio γ from the start of the slip until a predetermined time (m) is calculated (step S72). That is, the change amount of the speed ratio γ in the so-called stable state or steady state in which the continuously variable transmission 1 does not slip is obtained. Then, using the amount of change Δγ_stat, the gear ratio γ_stat (i−n + j) at each time point from the start time of the slip to the current time point is obtained (step S73). Specifically, the calculation described in step S73 of FIG. 2 is executed.
[0039]
Then, it is determined whether or not the belt 23 has started to slip, and the time counting by the counter Mslp_Cnt is started (step S74). In other words, in order to obtain the duration of the slip of the belt 23, time measurement is started.
[0040]
Next, whether the value of “j” indicating the time point after the time point when the belt 23 started to slip reaches the value “n” corresponding to the time traced back from the current time point to the belt slip start time point. It is determined whether or not (step S75). If a negative determination is made in this step S75, it is incremented by “1” each time (step S75), and the process returns to step S73. That is, the gear ratio at each time point from the start time (i-n) of the belt 23 to the current time point (n) is obtained.
[0041]
After the above-described step S7 for executing the subroutine shown in FIG. 2, a gear ratio prediction flag γst_Flag (i) indicating that slip is occurring in the continuously variable transmission 1 is set to “1” (step S8). Return.
[0042]
  On the other hand, if the determination of the slip of the belt 23 has already been established or if the determination of the slip has not been established, a negative determination is made in step S6 described above. In that case, the gear ratio prediction flag described aboveγ st_Flag (i-1)Is set to "1" (step S9). The speed ratio prediction flag γst_Flag is set to “1” when the slip in the continuously variable transmission 1 is detected and the start time of the slip is determined as described above. If the slippage has been detected, the determination in step S9 is affirmative because step S8 has been executed in the previous cycle.
[0043]
In this case, the gear ratio after the slip detection time based on the correlation coefficient k (i) is estimated, and it is determined whether the slip is continued or ended based on the estimated value. That is, first, the transmission ratio estimated value γ_stat (i) is obtained (step S10). The calculation is based on the gear ratio at the time when the start of the slip is determined and the gear ratio change state before that (the amount of change in the gear ratio) immediately before the gear ratio estimated value γ_stat (i-1) Is performed by adding the change amount Δγ_stat to. The speed ratio estimated value γ_stat (i-1) and the change amount Δγ_stat are values indicating the operation state at the time point determined as the time point when the slip in the continuously variable transmission 1 is started, and the above-described step S7 or FIG. It is calculated by the subroutine shown below.
[0044]
Then, whether the value obtained by subtracting the output rotation speed Nout (i) from the value obtained by dividing the input rotation speed Nin (i) by the transmission ratio estimated value γ_stat (i) or the absolute value thereof is greater than or equal to the macro slip judgment reference value Mslp_rpm It is determined whether or not (step S11). Here, the value obtained by dividing the input speed Nin (i) by the speed ratio estimated value γ_stat (i) is a value corresponding to the output speed when the speed ratio is the estimated value γ_stat (i). If the difference does not occur, the above difference or its absolute value becomes smaller than the judgment reference value Mslp_rpm.
[0045]
Therefore, if the determination in step S11 is affirmative, the counter Mslp_Cnt is incremented (step S12). That is, the slip time is continuously counted.
[0046]
On the other hand, if the determination in step S11 is affirmative, the rotational speed difference between the input rotational speed Nin (i) and the output rotational speed Nout (i) has almost coincided with a value corresponding to the gear ratio. Become. That is, the slip has converged or ended and has become about the micro slip. Therefore, in this case, the gear ratio prediction flag γst_Flag (i) is reset to “0” (step S13). This is control corresponding to determination of the end of slipping. Next, predetermined control II for calculating belt damage is executed (step S14). An example of the control is shown in FIG.
[0047]
Here, the belt damage is an example of calculation as the amount of heat due to slipping. First, the index l is reset to zero (step S141), and then the damage counter D_Cnt is incremented (step S142). Further, the slip time is calculated (step S143). As described above, the counter Mslp_Cnt continuously counts from the slip start point to the end point, and the value corresponds to the number of repetitions of the routine shown in FIGS. Therefore, by multiplying the count value by the sampling period Sample_t, the time during which the slip has continued can be obtained.
[0048]
Next, the damage of the belt 23 is calculated (step S144). This is calculated as an energy absorption rate ΔQ (i) and an energy absorption amount that is an integral value thereof. First, an energy absorption rate ΔQ (i) at each time point from the start point of the belt slip to the end of the slip is obtained by the following equation.
[Formula 2]

[0049]
Here, μ is a coefficient of friction between the belt 23 and each pulley 19, 20 in the continuously variable transmission 1, Rin is a winding radius of the belt 23 around the drive pulley 19, and Ain is in the hydraulic actuator 21 on the drive pulley 19 side. The pressure receiving area, Pd is the hydraulic pressure of the hydraulic actuator 22 on the driven pulley 20 side, v is a predetermined coefficient, and a is the clamping angle of the belt 23.
[0050]
The larger value of the energy absorption rate ΔQ obtained in this way is selected.
[Formula 3]

[0051]
Then, the energy absorption rate ΔQ is integrated to obtain the energy absorption amount Q.
[Formula 4]

[0052]
After calculating the above damage, it is determined whether or not the index 1 has reached the time count value Mslp_Cnt (step S145). If a negative determination is made in step S145, the index l is incremented (step S146), the process returns to step S144, and the calculation of damage is continued. That is, the amount of heat from the start to the end of the slip is calculated.
[0053]
Therefore, whenever a slip occurs in the continuously variable transmission 1, the amount of heat, that is, damage caused by the slip is required. Therefore, based on the damage, it is possible to determine the replacement time of the belt 23 or notify the replacement.
[0054]
If the slip of the continuously variable transmission 1 is completed in this way, or if no slip has occurred in the continuously variable transmission 1, a negative determination is made in step S9. In that case, the gear ratio prediction flag γst_Flag (i) is reset to “0” (step S15), and the process returns.
[0055]
FIG. 4 shows an example of a change in each rotation speed and a correlation coefficient, etc., and a slip start determination and end determination timing when slip occurs due to a change in torque on the output side. It is. Referring to FIG. 4, when the output rotational speed Nout is lowered due to a temporary increase in torque on the output side, and the input rotational speed Nin is lowered accordingly, if slip occurs in the continuously variable transmission 1, Since the rotational speed Nout further decreases with respect to the input rotational speed Nin, the correlation coefficient begins to decrease (at time t1). At substantially the same time, the gear ratio γ temporarily increases. Thereafter, since the correlation coefficient becomes smaller than the judgment reference value k_mslp_S1, slip in the continuously variable transmission 1 is detected (at time t2).
[0056]
Thus, the slip determination time based on the correlation coefficient is delayed from the time when the actual slip of the belt 23 occurs. Therefore, in the apparatus according to the present invention, the time point t1 that is a predetermined time (n) before the time point of slip detection based on the correlation coefficient is determined as the slip start time. After that, since the gear ratio γ increases due to the slip, the gear ratio used for calculating the end of the slip or damage is not the gear ratio at the time t2 when the slip is detected, but is determined. The speed ratio γ_stat at the slip start time t1 is used.
[0057]
Thereafter, the output-side torque is reduced, so that the output rotation speed Nout is restored and the slip is finished (at time t3). Since the correlation coefficient obtained at that time includes the value of the output rotation speed Nout during the occurrence of slipping, the correlation coefficient is smaller than the above-described determination reference value k_mslp_S1. That is, the end of slip cannot be determined from the correlation coefficient. On the other hand, as described above, the difference between the value obtained by dividing the input rotational speed Nin by the transmission gear ratio γ_stat and the output rotational speed Nout is smaller than the judgment reference value Mslp_rpm, and therefore almost simultaneously with the end of the slip (at time t3). That determination is valid.
[0058]
Therefore, according to the device of the present invention, the start of slipping in the continuously variable transmission 1 can be accurately detected or determined, and the end of slipping can be detected or determined in the same manner. Therefore, since the time during which slipping occurs can be accurately grasped, the thermal load or damage of the continuously variable transmission 1 can be accurately detected. Therefore. In the present invention, it may be configured to notify the replacement time of the belt 23 or to determine the replacement time based on the detection result of the damage.
[0059]
By the way, in the above control example, it is configured such that the time point before the predetermined time (n) from the time point when the determination of the slip of the belt 23 based on the correlation coefficient is established is determined as the slip start time point. Therefore, if the predetermined time (n) is excessive, it is determined that the point at which the slip does not actually start is the slip start point, or conversely, if the predetermined time (n) is excessive, the slip starts. Despite this, the determination time point for starting the slip is delayed. In order to reduce such a so-called error as much as possible, the control shown in FIG. 5 may be executed.
[0060]
The flowchart shown in FIG. 5 is an alternative to the flowchart shown in FIG. 2 described above, and evaluates the difference between the transmission ratio estimated value γ_stat (i−n + j) and the actually measured value γ (i−n + j). It is the flowchart which inserted the step after step S73. That is, it is determined whether or not the difference between the actually measured value γ (i−n + j) and the transmission ratio estimated value γ_stat (i−n + j) is equal to or greater than a predetermined determination reference value γ_slp_S (step S731).
[0061]
Since the actual measurement value γ (i−n + j) is obtained from the actual input rotation speed Nin and the output rotation speed Nout, if slippage occurs in the continuously variable transmission 1, the rotation speed due to the slippage is determined. Includes changes. On the other hand, the estimated gear ratio value γ_stat (i−n + j) is based on the determined gear ratio at the start of slipping and the state of change of the previous gear ratio (change ratio of the gear ratio). Since it was obtained, it does not include the amount of rotation change due to slipping. Therefore, the difference between the two represents a change in the gear ratio related to slipping or slipping in the continuously variable transmission 1.
[0062]
Therefore, if the difference is equal to or greater than the predetermined determination reference value γ_slp_S, and if a positive determination is made in step S731, the shift at a time point that is a predetermined time (n) before the slip detection time based on the correlation coefficient. Since the change in the ratio has occurred, the determination of belt slip is established, and the counting by the counter Mslp_Cnt is started (step S74). On the other hand, if a negative determination is made in step S731, there is no change in the gear ratio, so the process proceeds to step S75, and the slip start determination is not performed.
[0063]
Thus, if the control shown in FIG. 5 is executed as the predetermined control I in step S7 in the flowchart shown in FIG. 1, the determination of the slip start time becomes more accurate. According to the control shown in FIG. 5, the determination result in step S731 can be used to determine whether the predetermined time (n) is appropriate. Therefore, the predetermined time (n) may be corrected for learning.
[0064]
Here, the relationship between the above specific example and the present invention will be briefly described. Each functional means of steps S7, S11, and S74 described above corresponds to the slip timing determining means of the present invention, and the function of step S144. The target means corresponds to the deterioration detecting means of the present invention.
[0065]
The present invention is not limited to the above-described specific example, and can be applied to a slip detection device for a traction type continuously variable transmission in addition to a belt type continuously variable transmission. In addition, each of the above determination reference values and predetermined values used for determination or determination may be predetermined constant values, but variables that change based on driving conditions such as vehicle acceleration / deceleration and throttle opening. (Map value) may be used. In addition, the degree of deterioration of the continuously variable transmission may use other appropriate parameters instead of the amount of heat.
[0066]
【The invention's effect】
  As described above, according to the first aspect of the present invention, the correlation coefficient of the input / output rotational speed is obtained, the slip in the continuously variable transmission is detected based on the correlation coefficient, and the slip is detected. When the slip is detectedOther times before the pointWhen the point starts to slipIs determined as a point, or another time point after the slip detection timeAs soon as slip occurs in the continuously variable transmission, that is, slip is detected by a slight increase in slip, and as a result, it is accurately determined when the slip starts or ends. can do.
[0067]
According to the invention of claim 2, the correlation coefficient of the input / output rotational speed is obtained, and the slip in the continuously variable transmission is detected based on the correlation coefficient, and the slip is detected. Since a point of time before the detection of the slip is determined as the start point of the slip, the slip in the continuously variable transmission can be detected quickly, or the start point of the slip can be accurately determined. .
[0068]
Further, according to the invention of claim 3, the correlation coefficient of the input / output rotational speed is obtained, the slip in the continuously variable transmission is detected based on the correlation coefficient, and the slip is detected. Since the slip start time or the slip end time is determined based on the gear ratio at the time when the slip is detected, the slip is detected as soon as slip occurs in the continuously variable transmission, that is, by a slight increase in slip. As a result, it is possible to accurately determine when the slip starts or ends.
[0069]
Further, according to the invention of claim 4, the correlation coefficient of the input / output rotation speed is obtained, and the slip in the continuously variable transmission is detected based on the correlation coefficient, and the slip is detected. Based on the speed ratio at the time of detection of the slip and the state of change of the speed ratio until that time, the slip start time or the end time of the slip is determined, so when a slip occurs in the continuously variable transmission, That is, a slip is detected by a slight increase in the slip, and as a result, it is possible to accurately determine when the slip starts or ends.
[0070]
According to the invention of claim 5, the correlation coefficient of the input / output rotational speed is obtained, and the slip in the continuously variable transmission is detected based on the correlation coefficient, and the slip is detected. For example, the duration of the slip can be known, and as a result, the degree of deterioration due to the slip can be accurately determined.
[0071]
Further, according to the invention of claim 6, when slipping is detected based on the correlation coefficient of the input / output rotational speed, the slip start time or end time is determined. The degree of deterioration of the continuously variable transmission can be accurately determined based on the time.
[Brief description of the drawings]
FIG. 1 is a flowchart illustrating an example of control by a control device of the present invention.
FIG. 2 is a flowchart showing an example of a subroutine for determination of the start of belt slip and control associated therewith.
FIG. 3 is a flowchart showing an example of a subroutine for determining the end of belt slipping and damage.
4 is a time chart showing an example of a slip start determination time point and a slip end determination time point by the control shown in FIG. 1; FIG.
FIG. 5 is a flowchart showing a subroutine instead of FIG.
FIG. 6 is a diagram schematically showing a drive mechanism including a continuously variable transmission according to the present invention.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 ... Continuously variable transmission, 3 ... Torque converter, 4 ... Engine (power source), 11 ... Lock-up clutch, 19 ... Drive pulley, 20 ... Driven pulley, 23 ... Belt, 26 ... Drive wheel, 31 ... For transmission Electronic control unit (CVT-ECU).

Claims (6)

A slip detection device for a continuously variable transmission that detects a slip of the continuously variable transmission based on a correlation coefficient between an input rotational speed and an output rotational speed of the continuously variable transmission,
Based on the fact that slip is detected by the correlation coefficient , another time point before the detection time is determined as the start time of the slip, or another time point after the detection time is determined as the end time of the slip. A slip detection device for a continuously variable transmission, comprising: 2. The continuously variable transmission according to claim 1, wherein the slip timing determination unit is configured to determine a time point a predetermined time before a slip detection time based on the correlation coefficient as a slip start time point. Slip detection device. The slip timing determining means is configured to determine the start time or end time of the slip based on a speed ratio at a predetermined time before a slip detection time based on the correlation coefficient. The slip detection device for a continuously variable transmission according to claim 1. The slip timing determining means is configured to start or end the slip based on a speed ratio at a predetermined time before a slip detection time based on the correlation coefficient and a change state of the speed ratio before that time. The slip detection device for a continuously variable transmission according to claim 1, wherein the time point is determined. The continuously variable transmission according to any one of claims 1 to 4, further comprising a deterioration determination unit that determines a degree of deterioration of the continuously variable transmission based on the correlation coefficient being obtained. Machine slip detection device. 5. The slip of the continuously variable transmission according to claim 3, further comprising a deterioration determination unit that determines a degree of deterioration of the continuously variable transmission based on a start time or an end time of the slip. Detection device.

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