JP4391097B2 - Select assist device for automatic transmission - Google Patents

Description

【００２７】
制御アンプ１４は、検出されたセレクトレバー２のストローク角度と、予め設定された目標アシストトルクマップ（図７参照）とに基づいて、電動モータ７が出力するアシストトルクの目標値である目標アシストトルクTmotを演算する。そして、設定された目標アシストトルクTmotに基づいて、電動モータ７の出力するアシストトルクの出力デューティ比をＰＷＭ（パルス幅変調）方式により制御する。
【００２８】
次に、ディテント機構９の構造について説明する。
図３は、自動変速機のディテント機構９の構造を示す斜視図である。
制御アーム１０の下端部には回転シャフト１５が設けられ、この回転シャフト１５にディテントプレート１６が支持されている。このディテントプレート１６の上端には、カム山１６ａの間に４つのレンジ（Ｐ・Ｒ・Ｎ・Ｄ）に対応した谷部１６ｂが形成されている。そして、この谷部１６ｂにバネ板１７の先端に形成されたディテントピン１８を係合させ、選択されたレンジ位置を保持している。
【００２９】
すなわち、セレクトレバー２を前後に操作することにより、その操作力がリンケージ１１を介してディテントプレート１６に伝達され、このディテントプレート１６が前後に移動することにより、ディテントピン１８がカム山１６ａを乗り越えて隣のレンジに対応した谷部１６ｂへ係合し、係合したレンジ位置がバネ板１７の弾力性により保持される。
【００３０】
ディテントプレート１６には、パーキングポール１９の一端が回動自在に連結されている。このパーキングポール１９は、セレクトレバー２をＰレンジに移動させたとき、カム状プレート２０を介してパーキングギヤ２１の回転を阻止し、図外の駆動輪をロックするものである。これにより、勾配路上にＰレンジで車両を駐車したとき、勾配に応じて駆動輪をロックするように車重負荷が加わり、パーキングポール１９を咬む力として作用する。
【００３１】
次に、作用を説明する。
［セレクトレバーの機械的負荷特性］
図５は、Ｐ→Ｒレンジ方向におけるセレクトレバー２の機械的負荷特性図であり、電動モータ７を駆動していない状態で、セレクトレバー２の支点軸４に入力される機械的負荷力Fmisによる軸トルクをセレクトレバー２のストローク角度ごとに測定したものである。この機械的負荷力Fmisによる軸トルクは、上述した自動変速機８のディテント機構９で発生する負荷力に、リンケージ１１の摩擦力、電動モータ７のイナーシャ等を合成したものであり、電動モータ７によるトルクアシストが無い状態でレンジ切り換えを行うには、この機械的負荷力Fmisによる軸トルク以上の操作力が必要となる。
【００３２】
図５に示すように、セレクトレバー２をＰ→Ｒレンジ方向に操作したときに発生する機械的負荷力Fmisによる軸トルクは、各レンジ間において、初めにセレクトレバー２の操作方向と逆方向（Ｄ→Ｎレンジ方向）に発生し、ピーク後に向きを変えて操作方向と同一方向（Ｐ→Ｒレンジ方向）に発生し、レンジ切り換え位置（停止位置）付近でゼロに収束した状態となる。この特性は、ディテント機構９において、ディテントピン１８がディテントプレート１６のカム山１６ａを乗り越える際に発生する負荷力に起因している。
【００３３】
すなわち、ディテントピン１８がカム山１６ａを乗り越えるまでは、バネ板１７の付勢力により抵抗力が発生し、ディテントピン１８がカム山１６ａを乗り越えた後は、ディテントピン１８が次のカム山１６ａの溝に落ち込んで引き込み力（慣性力）が発生するためである。
【００３４】
［セレクトレバーの理想操作力特性］
図６は、Ｐ→Ｒレンジ方向におけるセレクトレバー２の理想操作力特性図であり、セレクト時に良好な操作特性が得られる運転者の理想操作力Ftによる軸トルクを、セレクトレバー２のストローク角度に応じて予め設定したものである。
【００３５】
［目標アシストトルクマップ］
図７は、Ｐ→Ｒレンジ方向における目標アシストトルクマップである。この目標アシストトルクマップには、セレクトレバー２のストローク角度に応じた目標アシストトルクTmotが設定されている。この目標アシストトルクTmotは、機械的負荷力Fmisによる軸トルクから理想操作力Ftによる軸トルクを減ずることにより求められる。すなわち、この目標アシストトルクTmotを目標値として電動モータ７のアシストトルクを制御することにより、上述した理想操作力Ftによる軸トルクが得られる。
【００３６】
なお、Ｄ→Ｎレンジ方向へのセレクトでは、上述したＰ→Ｒレンジ方向における機械的負荷特性とは異なる機械的負荷特性を有しているため、その機械的負荷特性に応じて目標アシストトルクマップも別途設定する。よって、セレクトレバー２のアシスト制御においては、セレクトレバー２の操作方向を検出し、操作方向に応じた目標アシストトルクマップを用いてアシストトルクの制御を行う必要がある。
【００３７】
セレクトレバー２の操作方向を検出する方法としては、ポテンショメータ１３の取得最新値と前回取得値との増減差分による判定、または、目標アシストトルクマップ上の各レンジ停止位置の中央値に対するポテンショメータ１３の大小判定等で行うことができる。
【００３８】
また、この目標アシストトルクマップは、セレクトレバー２の操作速度に応じて予め複数設定されている。セレクトレバー２の操作速度は、ストローク角度の変化率等から推定することができる。
【００３９】
［セレクトレバーアシスト制御処理］
図８は、制御アンプ１４で実行されるセレクトレバーアシスト制御処理の流れを示すフローチャートである。
【００４０】
ステップＳ１では、ポテンショメータ１３の出力電圧からセレクトレバー２のストローク角度を読み込む。
【００４１】
ステップＳ２では、ストローク角度と前回読み込んだストローク角度の増減差分から、セレクトレバー２の操作方向を演算する。
【００４２】
ステップＳ３では、ストローク角度と前回読み込んだストローク角度の変化率から、セレクトレバー２の操作速度を演算する。
【００４３】
ステップＳ４では、セレクトレバー２の操作方向と操作速度に応じた目標アシストトルクマップを読み込む。
【００４４】
ステップＳ５では、読み込んだ目標アシストトルクマップとストローク角度から目標アシストトルクTmotを設定する。
【００４５】
ステップＳ６では、設定された目標アシストトルクTmotとなるように電動モータ７を駆動して本制御を終了する。
【００４６】
［セレクトレバーアシスト制御作用］
次に、セレクトレバー２を一定の速度で移動させ、Ｐ→Ｒレンジへのセレクトを行う場合を例に挙げて、制御アンプ１４によるセレクトレバーアシスト制御作用を説明する。
【００４７】
図９において、Ｓ_ｐはＰレンジ側固定端、Ｓ_１はＰレンジ停止中央値を示すストローク角度であり、セレクトレバー２がＰレンジにあるとき、セレクトレバー２はストローク角度Ｓ_０の位置で停止している。
【００４８】
セレクトレバー２をＰ→Ｒレンジ方向へ操作すると、ディテントピン１８がディテントプレート１６のカム山１６ａを登り始め、これに伴い機械的負荷力Fmisによる軸トルクがＲ→Ｐレンジ方向に作用し始める。
【００４９】
ストローク角度Ｓ_１では、電動モータ７によるアシストが開始され、アシストトルクがＰ→Ｒレンジ方向に発生する。
【００５０】
ストローク角度Ｓ_１−Ｓ_２間では、機械的負荷力Fmisによる軸トルクが徐々に大きくなり、これに応じてアシストトルクも徐々に大きくなる。
【００５１】
ストローク角度Ｓ_２では、機械的負荷力Fmisによる軸トルクがピーク値となり、これに応じてアシストトルクもピーク値となる。
【００５２】
ストローク角度Ｓ_２−Ｓ_３間では、機械的負荷力Fmisによる軸トルクが徐々に減少し、これに応じてアシストトルクも徐々に減少する。
【００５３】
ストローク角度Ｓ_３では、ディテントピン１８がディテントプレート１６のカム山１６ａの頂点に達し、機械的負荷力Fmisによる軸トルクがゼロとなる。このとき、電動モータ７によるアシストトルクの出力が停止する。
【００５４】
ストローク角度Ｓ_３−Ｓ_４間では、ディテントピン１８がカム山１６ａの谷部１６ｂに引き込まれるため、機械的負荷力Fmisによる軸トルクはＲ→Ｐレンジ方向に発生する。このとき、セレクトレバー２には、機械的負荷力Fmisによる軸トルクのみが作用している。
【００５５】
ストローク角度Ｓ_４では、ディテントピン１８がカム山１６ａの谷部ｂ下端に達して停止する。このとき、ＰレンジからＲレンジへのセレクトが行われ、図外の後退ブレーキが締結される。
【００５６】
［機械的負荷特性に基づくアシスト制御の効果］
ここで、機械的負荷特性に基づくアシスト制御の効果を説明するため、ポテンショメータ１３を用いたセレクトレバー２のストローク角度検出を行わずに、例えば、トルクセンサを用いてセレクトレバー２への入力トルクを検出し、検出された入力トルクに応じて電動モータ７の出力値をフィードバック制御する場合について考える。
【００５７】
レンジセレクト時、セレクトレバー２の支点軸４には、次に列記する▲１▼〜▲３▼を合成したトルクが入力される。
▲１▼運転者の操作力Ftによる軸トルク
▲２▼電動モータ７のアシストトルク
▲３▼機械的負荷力Fmisによる軸トルク
このうち、▲３▼機械的負荷力Fmisによる軸トルクは、図５に示したように、セレクトレバー２の位置によって大きさと向きが大きく変化している。
【００５８】
ところが、トルクセンサは▲１▼運転者の操作力Ftによる軸トルクのみを検出し、▲３▼機械的負荷力Fmisによる軸トルクを検出できないため、機械的負荷力Fmisによる軸トルクが制御に反映されない。従って、セレクトレバー２が機械的負荷力Fmisによる軸トルクの向きが変化するような位置（図９のストローク角度Ｓ_３付近）を通過するとき、セレクトレバー２の操作速度によっては、制御変数が波打つ、いわゆるハンチングが発生し、理想的な操作特性が得られないことがある。
【００５９】
また、機械的負荷力Fmisによる軸トルクがゼロとなる位置、すなわち、ディテントピン１８がディテントプレート１６のカム山１６ａを乗り越えた直後における運転者の操作力が大きいと、それに応じて大きなアシストトルクが発生するため、セレクトレバー２が切り換え位置を通過したとき、運転者の意に反してセレクトレバー２が操作方向に引きずられてしまう。よって、セレクトレバー２が本来の停止位置で停止しない（ディテントピン１８がディテントプレート１６ａの谷部１６ｂ下端を通過してしまう）ため、メリハリのある操作感が得られず、節度感に欠ける。
【００６０】
一方、本実施の形態では、セレクトレバー２のストローク角度に応じた機械的負荷特性に基づいてアシストトルクを制御することにより、機械的負荷力Fmisによる軸トルクに影響されることなく、所望の理想操作力Ftによる軸トルクを実現することができる。
【００６１】
次に、効果を説明する。
本実施の形態の自動変速機のセレクトアシスト装置にあっては、次に列挙する効果を得ることができる。
【００６２】
(1) セレクトレバー２のストローク角度に応じた機械的負荷力Fmisによる軸トルクを予め測定し、この機械的負荷特性に基づいて設定した目標アシストトルクTmotを目標値としてアシストトルクを制御するため、機械的負荷力Fmisによる軸トルクに影響されず、良好な操作特性を得ることができる。
【００６３】
(2) 図９において、セレクトレバー２のストローク角度がＳ_３−Ｓ_４の範囲にあるとき、すなわち、機械的負荷力Fmisによる軸トルクがセレクトレバー２の操作方向と同一方向に作用するとき、アシストトルクの出力を停止することにより、セレクトレバー２が所定位置（ストローク角度Ｓ_４）からオーバーランするのを防止できるので、節度感のある操作特性が得られる。また、セレクトレバー２に機械的負荷力Fmisによる軸トルクのみを作用させ、自然な操作感を得ることができる。
【００６４】
(3) 制御アンプ１４において目標アシストトルクTmotの設定を、図７に示した目標アシストトルクマップに基づいて行うため、制御アンプ１４において複雑な演算が不要であり、応答性の高い制御を行うことができる。
【００６５】
(4) セレクトレバー２の操作速度に応じて複数の目標アシストトルクマップを設けることにより、セレクトレバー２の操作速度に応じて変化する機械的負荷特性に対応でき、操作速度毎に最適な操作特性を設定することができる。
【００６６】
（その他の実施の形態）
以上、本発明の実施の形態を説明してきたが、本発明の具体的な構成は本実施の形態に限定されるものではなく、発明の要旨を逸脱しない範囲の設計変更等があっても、本発明に含まれる。
【００６７】
例えば、本実施の形態では、セレクトレバーをＰ→Ｒレンジ方向に操作したときのアシストについて説明したが、Ｄ→Ｎレンジ方向に操作した場合にも、本実施の形態と同様の効果が得られる。
【００６８】
また、本実施の形態では、機械的負荷力Fmisによる軸トルクの絶対値が所定値よりも小さい場合、電動モータ７によるアシストトルクの出力を停止したが、常にアシストトルクを発生させる構成としてもよい。
【００６９】
また、本実施の形態では、ストローク角度Ｓ_３−Ｓ_４間で、目標アシストトルクTmotをゼロに設定し、電動モータ７によるアシストトルクの出力を停止する構成としたが、目標アシストトルクTmotをセレクトレバー２と逆方向に設定し、機械的負荷力Fmisによる軸トルクによる引き込み力を軽減する方向にアシストトルクを発生させる構成としてもよい。
【図面の簡単な説明】
【図１】本発明の自動変速機のセレクトアシスト装置を適用した自動変速装置の構成を示す側面図である。
【図２】本発明の自動変速機のセレクトアシスト装置を適用した自動変速装置の構成を示す背面図である。
【図３】自動変速機のディテント機構の構造を示す斜視図である。
【図４】ポテンショメータの出力電圧とセレクトレバーのストローク角度との関係を示す図である。
【図５】Ｐ→Ｒレンジ方向におけるセレクトレバーの機械的負荷特性図である。
【図６】Ｐ→Ｒレンジ方向におけるセレクトレバーの理想操作力特性図である。
【図７】Ｐ→Ｒレンジ方向における目標アシストトルクマップである。
【図８】制御アンプで実行されるセレクトレバーアシスト制御処理の流れを示すフローチャートである。
【図９】セレクトレバーアシスト制御作用を示す図である。
【符号の説明】
１ コントロール部
２ セレクトレバー
３ センタクラスタ
４ 支点軸
５ 制御レバー
６ セクタギヤ
７ 電動モータ
８ 自動変速機
９ ディテント機構
１０ 制御アーム
１１ リンケージ
１３ ポテンショメータ
１４ 制御アンプ
１５ 回転シャフト
１６ ディテントプレート
１６ａ カム山
１６ｂ 谷部
１７ バネ板
１８ ディテントピン
１９ パーキングポール
２０ カム状プレート
２１ パーキングギヤ[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an improvement in a select assist device for an automatic transmission.
[0002]
[Prior art]
As a conventional range selector for an automatic transmission, a select lever is provided near the driver's seat in the passenger compartment, and the operating force of the select lever is transmitted through an operating force transmission means such as a cable or a rod. Is known to switch the range (P, R, N, D, etc.) of the automatic transmission.
[0003]
The operation of the select lever requires a large operating force due to the friction of the cable and rod, the resistance generated when the detent pin gets over the cam crest in the detent mechanism, and the like. For this reason, the selector lever is set to a sufficient length, and the lever force is used to convert the occupant's operating force into a large force and perform range selection (see, for example, Patent Document 1). ).
[0004]
[Patent Document 1]
Japanese Patent Laid-Open No. 9-323559 (pages 1 to 3, FIG. 1)
[0005]
[Problems to be solved by the invention]
However, the above prior art requires a long select lever in order to obtain a sufficient lever force, and there is a problem that the degree of freedom of the vehicle interior layout is reduced. In addition, there are many restrictions on the installation location, and it is limited to the side of the driver's seat and the vicinity of the steering column.
[0006]
The present invention has been made paying attention to the above-mentioned problems, and its object is to improve the degree of freedom of layout in the passenger compartment and the design of the select lever, and to achieve an excellent speed change operation characteristic. The object is to provide a machine select assist device.
[0007]
[Means for Solving the Problems]
In order to achieve the above object, in the automatic transmission select assist device according to claim 1 of the present invention, an operation position detecting means for detecting an operation position of a select lever connected to a range switching device of the automatic transmission, A target that determines the target assist torque from the operating position, with the assist actuator that outputs the assist torque that assists the driver's operating force to the select lever, and the target assist torque that is set from the mechanical load characteristics that the select lever receives. An assist torque control unit having an assist torque setting unit and an assist actuator control unit that controls the assist torque without using the input torque with the set target assist torque as a target value is provided.
[0008]
Here, the “mechanical load characteristic of the select lever” means a required operating force for each operating position of the select lever, and the mechanical load force is from the select lever to the range switching device via the power transmission means. Load force, for example, load force due to a detent mechanism, inertia of a mechanism portion including an assist actuator, friction, and the like.
[0009]
According to a second aspect of the present invention, in the select assist device for an automatic transmission according to the first aspect, the target assist torque setting unit has a mechanical load force acting on the select lever acting in the same direction as the operation direction. The target assist torque is set to zero or in the direction opposite to the operation direction of the select lever.
[0010]
According to a third aspect of the present invention, in the automatic transmission select assist device according to the first or second aspect, a target assist torque map is provided in which a target assist torque is set in advance according to the operation position of the select lever. The target assist torque setting unit sets the target assist torque based on the operation position of the select lever and the target assist torque map.
[0011]
According to a fourth aspect of the present invention, in the automatic transmission select assist device according to the third aspect, the operation speed detecting means for detecting the driver's select lever operating speed and a plurality of targets corresponding to the select lever operating speed. An assist torque map, and the target assist torque setting unit switches the target assist torque map according to a select lever operation speed.
[0012]
【The invention's effect】
According to the first aspect of the present invention, in the range selection, the assist torque is output by the assist actuator to assist the driver's select lever operating force.
[0013]
In the conventional manual range select, the range is switched by operating the manual lever connected to the manual valve of the automatic transmission by lever force of the select lever.
[0014]
In contrast, in the present invention, by applying an assist torque by the assist actuator, the operation force required to operate the select lever is reduced, and the select operation can be performed without imposing a burden on the driver without using a large lever force. It becomes. Therefore, since the length of the select lever can be set short, the layout freedom in the vehicle interior and the design of the select lever can be improved.
[0015]
In the present invention, the assist torque control means sets the target assist torque by the target assist torque setting unit based on the operation position of the select lever and the mechanical load characteristic of the select lever. The assist actuator controller controls the assist torque output from the assist actuator using the set target assist torque as a target value.
[0016]
Here, the assist torque is obtained by subtracting the driver's operating force from the mechanical load force of the select lever. Among these, the mechanical load force acting on the select lever that directly affects the operational feeling is preliminarily determined. It can be measured by experiments or the like.
[0017]
Therefore, the mechanical load acting on the select lever is set by setting the assist torque according to the operation position of the select lever so that the operation force characteristic that provides a good feeling of operation according to the mechanical load characteristic of the select lever is obtained. Good operating characteristics can be obtained without being affected by force.
[0018]
According to the second aspect of the present invention, when the mechanical load force acting on the select lever acts in the same direction as the operation direction, the target assist torque is set to zero or the direction opposite to the operation direction of the select lever. Only the pulling force is applied to the lever, or the pulling force (inertial force) due to the mechanical load characteristic of the select lever is appropriately reduced to obtain a natural feeling of operation.
[0019]
According to the third aspect of the present invention, by providing the target assist torque map in advance, the target assist torque setting unit does not require complicated calculation, and control with high responsiveness can be performed.
[0020]
In the invention according to claim 4, by providing a plurality of target assist torque maps according to the operation speed of the select lever, it is possible to cope with mechanical load characteristics that change according to the operation speed of the select lever. It is possible to set optimal operating characteristics.
[0021]
DETAILED DESCRIPTION OF THE INVENTION
Embodiments of the present invention will be described below with reference to the drawings.
First, the configuration will be described.
FIG. 1 is a side view showing a configuration of an automatic transmission to which a select assist device for an automatic transmission according to the present invention is applied, and FIG. 2 is a rear view of the automatic transmission.
[0022]
The control unit 1 has a select lever 2 that is operated by the driver, and is installed, for example, in the upper part of the center cluster 3 beside the driver's seat. The select lever 2 is set to operate in the vehicle front-rear direction around the fulcrum shaft 4 at the lower end. The length of the select lever 2 is set to about 100 mm, and is designed to be about 250 mm shorter than a conventional general select lever. Therefore, the amount of protrusion into the vehicle interior space is smaller than that of the conventional select lever, and the degree of freedom in the vehicle interior layout is great. Moreover, it is compact and can be installed in another position (instrument panel etc.) as needed.
[0023]
The fulcrum shaft 4 of the select lever 2 is fixed with an upper end portion of a control lever 5 that rotates integrally with the fulcrum shaft 4 in the vertical direction. A sector gear 6 is fixed to the fulcrum shaft 4, and an electric motor (assist actuator) 7 that assists the operating force of the driver is connected to the sector gear 6.
[0024]
The lower end of the control lever 5 is connected to the upper end of a control arm 10 of a detent mechanism 9 (see FIG. 3) provided in the front automatic transmission 8 via a rod-like linkage 11. The detent mechanism 9 will be described later.
[0025]
A potentiometer (operation position detecting means) 13 for detecting the stroke angle of the select lever 2 is connected to the fulcrum shaft 4 of the select lever 2. The potentiometer 13 detects the stroke angle at any time when the select lever 2 is operated with 0 degree when the select lever 2 is located at the end of the P (parking) range.
[0026]
FIG. 4 shows the relationship between the output voltage of the potentiometer 13 and the stroke angle of the select lever 2. In the figure, the vertical axis represents the output voltage of the potentiometer 13, the horizontal axis represents the stroke angle of the select lever 2, and the control amplifier 14 selects the select lever based on the correspondence between the output voltage and the stroke angle as shown in the table below. 2 stroke angle is recognized.
[Table 1]

[0027]
Based on the detected stroke angle of the select lever 2 and a preset target assist torque map (see FIG. 7), the control amplifier 14 is a target assist torque that is a target value of the assist torque output by the electric motor 7. Calculate Tmot. Based on the set target assist torque Tmot, the output duty ratio of the assist torque output by the electric motor 7 is controlled by a PWM (pulse width modulation) method.
[0028]
Next, the structure of the detent mechanism 9 will be described.
FIG. 3 is a perspective view showing the structure of the detent mechanism 9 of the automatic transmission.
A rotary shaft 15 is provided at the lower end of the control arm 10, and a detent plate 16 is supported on the rotary shaft 15. At the upper end of the detent plate 16, valleys 16b corresponding to the four ranges (P, R, N, and D) are formed between the cam peaks 16a. Then, the detent pin 18 formed at the tip of the spring plate 17 is engaged with the valley portion 16b, and the selected range position is held.
[0029]
That is, by operating the select lever 2 back and forth, the operating force is transmitted to the detent plate 16 through the linkage 11, and the detent pin 18 moves over the cam mountain 16a by moving the detent plate 16 back and forth. Then, it engages with the valley 16b corresponding to the adjacent range, and the engaged range position is held by the elasticity of the spring plate 17.
[0030]
One end of a parking pole 19 is rotatably connected to the detent plate 16. When the select lever 2 is moved to the P range, the parking pole 19 prevents rotation of the parking gear 21 via the cam-like plate 20 and locks driving wheels (not shown). Thereby, when the vehicle is parked on the slope road in the P range, a vehicle load is applied so as to lock the driving wheel according to the slope, and acts as a force for biting the parking pole 19.
[0031]
Next, the operation will be described.
[Mechanical load characteristics of select lever]
FIG. 5 is a mechanical load characteristic diagram of the select lever 2 in the P → R range direction, and shows the mechanical load force Fmis input to the fulcrum shaft 4 of the select lever 2 when the electric motor 7 is not driven. The shaft torque is measured for each stroke angle of the select lever 2. The shaft torque by the mechanical load force Fmis is obtained by combining the load force generated by the detent mechanism 9 of the automatic transmission 8 with the friction force of the linkage 11 and the inertia of the electric motor 7. In order to perform range switching in the absence of torque assist due to, an operating force greater than the axial torque due to this mechanical load force Fmis is required.
[0032]
As shown in FIG. 5, the axial torque due to the mechanical load force Fmis generated when the select lever 2 is operated in the P → R range direction is initially opposite to the operation direction of the select lever 2 between the ranges ( D → N range direction), changes direction after the peak, occurs in the same direction as the operation direction (P → R range direction), and converges to zero near the range switching position (stop position). This characteristic is caused by the load force generated when the detent pin 18 gets over the cam crest 16 a of the detent plate 16 in the detent mechanism 9.
[0033]
That is, until the detent pin 18 gets over the cam peak 16a, a resistance force is generated by the urging force of the spring plate 17, and after the detent pin 18 gets over the cam peak 16a, the detent pin 18 moves to the next cam peak 16a. This is because a pulling force (inertial force) is generated by falling into the groove.
[0034]
[Ideal operating force characteristics of select lever]
FIG. 6 is an ideal operating force characteristic diagram of the select lever 2 in the P → R range direction. The shaft torque by the driver's ideal operating force Ft, which provides good operating characteristics at the time of selection, is set to the stroke angle of the select lever 2. It is set in advance accordingly.
[0035]
[Target assist torque map]
FIG. 7 is a target assist torque map in the P → R range direction. In this target assist torque map, a target assist torque Tmot corresponding to the stroke angle of the select lever 2 is set. This target assist torque Tmot is obtained by subtracting the shaft torque caused by the ideal operating force Ft from the shaft torque caused by the mechanical load force Fmis. That is, by controlling the assist torque of the electric motor 7 using the target assist torque Tmot as a target value, the shaft torque by the ideal operation force Ft described above can be obtained.
[0036]
Note that the selection in the D → N range direction has a mechanical load characteristic different from the mechanical load characteristic in the P → R range direction described above, and therefore the target assist torque map according to the mechanical load characteristic. Is also set separately. Therefore, in the assist control of the select lever 2, it is necessary to detect the operation direction of the select lever 2 and control the assist torque using a target assist torque map corresponding to the operation direction.
[0037]
As a method of detecting the operation direction of the select lever 2, the determination based on the difference between the latest acquired value of the potentiometer 13 and the previous acquired value, or the magnitude of the potentiometer 13 with respect to the median value of each range stop position on the target assist torque map This can be done by judgment or the like.
[0038]
A plurality of target assist torque maps are set in advance according to the operation speed of the select lever 2. The operation speed of the select lever 2 can be estimated from the change rate of the stroke angle or the like.
[0039]
[Select lever assist control processing]
FIG. 8 is a flowchart showing the flow of the select lever assist control process executed by the control amplifier 14.
[0040]
In step S1, the stroke angle of the select lever 2 is read from the output voltage of the potentiometer 13.
[0041]
In step S2, the operation direction of the select lever 2 is calculated from the difference between the stroke angle and the previously read stroke angle.
[0042]
In step S3, the operation speed of the select lever 2 is calculated from the stroke angle and the rate of change of the previously read stroke angle.
[0043]
In step S4, a target assist torque map corresponding to the operation direction and operation speed of the select lever 2 is read.
[0044]
In step S5, the target assist torque Tmot is set from the read target assist torque map and stroke angle.
[0045]
In step S6, the electric motor 7 is driven to achieve the set target assist torque Tmot, and this control is terminated.
[0046]
[Select lever assist control action]
Next, the select lever assist control action by the control amplifier 14 will be described by taking as an example a case where the select lever 2 is moved at a constant speed and the selection from the P → R range is performed.
[0047]
In Figure 9, S _p is the P range side fixed end, S ₁ is the stroke angle indicating the P-range stop median, when the select lever 2 is in the P range, the select lever 2 is stopped at the position of the stroke angle S ₀ is doing.
[0048]
When the select lever 2 is operated in the P → R range direction, the detent pin 18 begins to climb the cam crest 16a of the detent plate 16, and accordingly, the shaft torque due to the mechanical load force Fmis starts to act in the R → P range direction.
[0049]
In the stroke angle S _1, the assist is started by the electric motor 7, the assist torque is generated in the P → R-range direction.
[0050]
Between the stroke angles S _{1 and} S ₂ , the shaft torque due to the mechanical load force Fmis gradually increases, and the assist torque gradually increases accordingly.
[0051]
In the stroke angle S _2, the axial torque reaches a peak value due to the mechanical load force FMIS, the assist torque reaches a peak value accordingly.
[0052]
Between the stroke angles S _{2 and} S ₃ , the shaft torque due to the mechanical load force Fmis gradually decreases, and the assist torque gradually decreases accordingly.
[0053]
In the stroke angle S _3, the detent pin 18 reaches the apex of the cam nose 16a of the detent plate 16, the shaft torque becomes zero due to the mechanical load force FMIS. At this time, the output of the assist torque by the electric motor 7 stops.
[0054]
Between the stroke angles S _{3 and} S ₄ , the detent pin 18 is drawn into the valley 16b of the cam crest 16a, so that the shaft torque due to the mechanical load force Fmis is generated in the R → P range direction. At this time, only the shaft torque due to the mechanical load force Fmis acts on the select lever 2.
[0055]
In the stroke angle S _4, detent pin 18 is stopped reaches the valley portion b the lower end of the cam nose 16a. At this time, selection from the P range to the R range is performed, and the reverse brake (not shown) is engaged.
[0056]
[Effect of assist control based on mechanical load characteristics]
Here, in order to explain the effect of the assist control based on the mechanical load characteristic, for example, the input torque to the select lever 2 is calculated using a torque sensor without detecting the stroke angle of the select lever 2 using the potentiometer 13. A case will be considered where detection is performed and feedback control is performed on the output value of the electric motor 7 in accordance with the detected input torque.
[0057]
At the time of range selection, torque obtained by combining the following (1) to (3) is inputted to the fulcrum shaft 4 of the select lever 2.
(1) Shaft torque due to driver's operating force Ft (2) Assist torque of electric motor 7 (3) Shaft torque due to mechanical load force Fmis Of these, (3) Shaft torque due to mechanical load force Fmis is shown in FIG. As shown in FIG. 2, the size and direction greatly change depending on the position of the select lever 2.
[0058]
However, the torque sensor (1) detects only the shaft torque due to the driver's operating force Ft, and (3) the shaft torque due to the mechanical load force Fmis cannot be detected, so the shaft torque due to the mechanical load force Fmis is reflected in the control. Not. Therefore, when the select lever 2 passes the position (near the stroke angle S ₃ in FIG. 9), such as a change in the direction of the axial torque due to mechanical loading force FMIS, in some operations the speed of the select lever 2, the control variable waving So-called hunting may occur, and ideal operating characteristics may not be obtained.
[0059]
Further, if the driver's operating force is large at a position where the shaft torque due to the mechanical load force Fmis becomes zero, that is, immediately after the detent pin 18 gets over the cam peak 16a of the detent plate 16, a large assist torque is generated accordingly. Therefore, when the select lever 2 passes the switching position, the select lever 2 is dragged in the operation direction against the driver's will. Therefore, since the select lever 2 does not stop at the original stop position (the detent pin 18 passes through the lower end of the valley portion 16b of the detent plate 16a), a clear operation feeling is not obtained and a sense of moderation is lacking.
[0060]
On the other hand, in the present embodiment, by controlling the assist torque based on the mechanical load characteristic according to the stroke angle of the select lever 2, the desired ideal can be achieved without being influenced by the shaft torque due to the mechanical load force Fmis. A shaft torque can be realized by the operating force Ft.
[0061]
Next, the effect will be described.
In the automatic transmission select assist device of the present embodiment, the following effects can be obtained.
[0062]
(1) To measure the shaft torque by the mechanical load force Fmis according to the stroke angle of the select lever 2 in advance and control the assist torque using the target assist torque Tmot set based on this mechanical load characteristic as a target value. Good operating characteristics can be obtained without being affected by the shaft torque caused by the mechanical load force Fmis.
[0063]
(2) In FIG. 9, when the stroke angle of the select lever 2 is in the range of S ₃ -S ₄ , that is, when the axial torque due to the mechanical load force Fmis acts in the same direction as the operation direction of the select lever 2, By stopping the output of the assist torque, it is possible to prevent the select lever 2 from overrunning from a predetermined position (stroke angle S ₄ ), so that it is possible to obtain modest operational characteristics. Further, only the shaft torque generated by the mechanical load force Fmis is applied to the select lever 2, so that a natural feeling of operation can be obtained.
[0064]
(3) Since the target assist torque Tmot is set in the control amplifier 14 based on the target assist torque map shown in FIG. 7, complicated control is not required in the control amplifier 14, and highly responsive control is performed. Can do.
[0065]
(4) By providing multiple target assist torque maps according to the operating speed of the select lever 2, it is possible to cope with the mechanical load characteristics that change according to the operating speed of the select lever 2, and the optimal operating characteristics for each operating speed. Can be set.
[0066]
(Other embodiments)
Although the embodiment of the present invention has been described above, the specific configuration of the present invention is not limited to the present embodiment, and even if there is a design change or the like without departing from the gist of the invention, It is included in the present invention.
[0067]
For example, in the present embodiment, the assist when the select lever is operated in the P → R range direction has been described. However, the same effect as the present embodiment can be obtained when the select lever is operated in the D → N range direction. .
[0068]
Further, in the present embodiment, when the absolute value of the shaft torque due to the mechanical load force Fmis is smaller than a predetermined value, the output of the assist torque by the electric motor 7 is stopped. However, the assist torque may always be generated. .
[0069]
In the present embodiment, the target assist torque Tmot is set to zero between the stroke angles S _{3 and} S ₄ and the output of the assist torque by the electric motor 7 is stopped. However, the target assist torque Tmot is selected. It is good also as a structure which sets to the direction opposite to the lever 2, and generates assist torque in the direction which reduces the drawing-in force by the shaft torque by mechanical load force Fmis.
[Brief description of the drawings]
FIG. 1 is a side view showing a configuration of an automatic transmission device to which a selection assist device for an automatic transmission according to the present invention is applied.
FIG. 2 is a rear view showing a configuration of an automatic transmission device to which a selection assist device for an automatic transmission according to the present invention is applied.
FIG. 3 is a perspective view showing a structure of a detent mechanism of the automatic transmission.
FIG. 4 is a diagram showing a relationship between an output voltage of a potentiometer and a stroke angle of a select lever.
FIG. 5 is a mechanical load characteristic diagram of a select lever in a P → R range direction.
FIG. 6 is an ideal operating force characteristic diagram of a select lever in a P → R range direction.
FIG. 7 is a target assist torque map in a P → R range direction.
FIG. 8 is a flowchart showing a flow of select lever assist control processing executed by the control amplifier.
FIG. 9 is a diagram illustrating a select lever assist control action.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Control part 2 Select lever 3 Center cluster 4 Support axis 5 Control lever 6 Sector gear 7 Electric motor 8 Automatic transmission 9 Detent mechanism 10 Control arm 11 Linkage 13 Potentiometer 14 Control amplifier 15 Rotating shaft 16 Detent plate 16a Cam mountain 16b Valley part 17 Spring plate 18 Detent pin 19 Parking pole 20 Cam-shaped plate 21 Parking gear

Claims (4)

An operation position detecting means for detecting an operation position of a select lever connected to the automatic transmission range switching device;
An assist actuator that outputs to the select lever an assist torque that assists the driver's operating force;
A target assist torque setting unit configured to determine a target assist torque from an operation position, with a target assist torque set based on mechanical load characteristics received by the select lever as data;
An assist torque control means having an assist actuator control unit that controls the assist torque without using the input torque with the set target assist torque as a target value;
A selection assist device for an automatic transmission. In the automatic transmission select assist device according to claim 1,
The target assist torque setting unit sets the target assist torque to zero or a direction opposite to the operation direction of the select lever when the mechanical load force acting on the select lever acts in the same direction as the operation direction. Select assist device for automatic transmission. In the automatic transmission select assist device according to claim 1 or 2,
A target assist torque map in which a target assist torque according to the operation position of the select lever is set in advance is provided.
The target assist torque setting unit sets a target assist torque based on an operation position of a select lever and a target assist torque map. In the automatic transmission select assist device according to claim 3,
An operation speed detection means for detecting a driver's select lever operation speed;
Multiple target assist torque maps corresponding to the select lever operation speed,
Provided,
The target assist torque setting unit switches a target assist torque map in accordance with a select lever operation speed.

Images