JP4290950B2 - Overturn detection device for motorcycles - Google Patents

Description

ただし、Ｙ，Ｙ’，Ｙ”は出力電圧、ａはオフセット電圧、Ｘは感度、ｂはセンサー傾き（取付誤差確度）を示す。
【００６１】
ここで、Y＋Y"＝2aよりa＝(Y−Y")／2

したがって、ｂ＝１／２＊ｓｉｎ^-1{(Y"−Y)／(Y'−a)}となる。
【００６２】
このようにして求めた傾斜角ｂに基づいて転倒判断のしきい値を変更する。
図７の例は、横置きセンサーにおいて、ｂが＋５°傾いていた場合に、しきい値を±７０°から−６５°と＋７５°に変更したものである。縦置きセンサーの場合（２軸加速度センサーの縦置きセンサー（Ｚ軸センサー）の場合）には、Ｙ軸センサーから左右の傾き方向を判別し、左右方向に応じてしきい値を変更可能である。
【００６３】
図８は、本発明のさらに別の実施形態の説明図である。
この実施形態は、プリント基板１１１上の加速度センサー１１０の取付位置をチェックする際に、予めプリント基板１１１のセンサー実装位置にシルクによるマーキング１０８，１０９を施し、目視又は自動チェックを容易にできるようにしたものである。マーキング１０８，１０９は、加速度センサー１１０の傾き許容範囲や取付角度の目安となる位置に形成する。マーキング形状は、図の（Ａ）（Ｂ）に限定されず、角度が概略的に識別できればどのような形状でもよい。
【００６４】
このようなマーキングを施すことにより、プリント基板に対する加速度センサーの取付誤差が識別され、これに基づいて転倒判別の補正が可能になり、また不良品の判別が容易にできる。
【００６５】
このように加速度センサーを実装してＣＰＵを構成するプリント基板は、ＥＣＵのケース内に収納される。この場合、ＥＣＵケースにガイドを設け、このガイドに沿ってプリント基板をスライドさせてケース内に挿入して位置決めし、樹脂等を充填してプリント基板をケース内のこの位置決めされた所定位置に固定保持することが望ましい。これによりＥＣＵに対するプリント基板の取付誤差による検出誤差が低減する。
【００６６】
転倒センサーを内臓したＥＣＵを車体に搭載する場合、ＥＣＵが車体の重心から離れていると、車体の振動が転倒センサーに影響を与えて検出精度の低下を来たし誤判定の要因となる。
【００６７】
したがって、検出精度を向上させるために、ＥＣＵはなるべく車体の重心付近に取付けることが望ましい。これにより、車体の振動や前後ピッチの影響によるノイズ要因を低減し、検出制度を高めることができる。
【００６８】
図９は、本発明のさらに別の実施形態のフローチャートである。
この実施形態は、従来問題となっていた転倒センサーのオフセットのばらつきや経時変化及び温度特性等によって検出精度が低下していた問題点に対処して、スピードセンサーを用いて転倒センサーの補正をすることにより、検出精度を向上させたものである。
【００６９】
ステップｄ１：スピードセンサーにより車速を検出し、転倒センサー（加速度センサー）により車体の傾きを検出する。
【００７０】
ステップｄ２：スピードセンサーの検出値が所定値（この例では３０km/h）を越えて且つ転倒センサーの出力電圧変化が所定値（この例では１０mV）未満の状態が１０秒以上続いたかどうかを判別する。この状態が１０秒以上続いているときは、車体が真直ぐな姿勢で走行中と判断する。
【００７１】
ステップｄ３：上記ステップｄ３で、車体が真直ぐな姿勢で走行中と判断したとき、転倒センサー出力又はその平均値を中心値（図１、図２の中立位置での出力電圧値）として更新して保存する。
【００７２】
ステップｄ４：この中心値からの変化を検出して転倒（傾きが７０°以上）かどうかを判断する。これにより、センサーの温度特性や取付誤差によるオフセットのばらつきあるいは経時変化等にかかわらず高精度で転倒検出ができる。
【００７３】
ステップｄ５：：転倒と判断した場合、燃料ポンプを停止し、燃料噴射及び点火を停止してエンジンを停止させる。このとき、前述のように、エンジン出力を徐々に落すことが望ましい。
【００７４】
図１０は本発明のさらに別の実施形態のフローチャートである。
この実施形態は、前述の図４の実施形態におけるウィリー等の転倒以外の車体傾斜判断の信頼性をさらに高めたものである。すなわち、図４の実施形態では、車体が逆さま又は９０°以上反転した状態になったときに、転倒と判定しない場合がある。本実施形態は、このような逆さま状態の転倒を確実に判別するものである。
【００７５】
さらに詳しく言うと、車体が１８０°転倒すると、縦置きのＺ軸センサーの出力は、前述の図２に示したように、１ｇＣｏｓ（１８０°）＝−１ｇとなって、転倒状態であることを示す。一方、横置きのＹ軸センサーの出力は、前述の図１に示したように、１ｇＳｉｎ（１８０°）＝０ｇとなって、転倒していない状態と誤判断してしまう。
【００７６】
本実施形態は、このような誤判定を防止するものであり、Ｚ軸センサーにより±９０°以上の傾斜を検出したときには、Ｙ軸センサーに関係なく転倒と判断するものである。
【００７７】
ステップｅ１：２軸加速度センサーを縦置き配置し、検出方向をＺ軸（上下方向）及びＹ軸（左右方向）とする。この加速度センサーの出力電圧をＺ軸及びＹ軸方向について検出する。
【００７８】
ステップｅ２：Ｚ軸方向センサーの検出出力電圧により、逆さまの転倒（±９０°以上の転倒）かどうかを判別する。すなわち、前述の図２（Ａ）のコサイン曲線において、転倒判断角度を±９０°としてこれに対応する出力電圧値（ｇ・ｃｏｓ（±９０°））より小さい状態かどうかを判別する。この状態が２秒以上続いた場合は逆さま転倒と判断する。なお、前述のように、２秒以上続くことを要件としたのは、電圧検出による転倒判断の信頼性を高めるためである。
ここで逆さま転倒と判断した場合には、直ちにステップｅ４に進み燃料ポンプ停止等の転倒制御を行なう。
【００７９】
ステップｅ３：上記ステップｅ２でＺ軸方向のセンサーで逆さまの転倒ではない（±９０°以上傾斜していない）と判別された場合に、さらにＺ軸センサー及びＹ軸方向センサーの検出出力電圧により転倒（±９０°以内の転倒）かどうかを判別する。
【００８０】
すなわち、まず、Ｚ軸方向センサーの検出出力電圧により転倒かどうかを判別する。これは前述のように、図２（Ａ）のコサイン曲線において、転倒判断基準角度となる±７０°に対応する出力電圧値（ｇ・ｃｏｓ（±７０°））より小さい状態かどうかを判別する。この状態が２秒以上続いた場合は転倒と判断する。なお、前述のように、２秒以上続くことを要件としたのは、電圧検出による転倒判断の信頼性を高めるためである。
【００８１】
さらに、このＺ軸センサーによる転倒判断がウィリー又は急坂走行ではないことを確認するために、Ｙ軸センサーが傾斜しているかどうかを判別し、Ｙ軸センサーも傾斜と判別したときのみ転倒と判断する。この場合、転倒判断基準角度を±５０°とする。これにより、判断角度を±７０°としたときよりも、前述の図１のグラフから分かるように、横置きＹ軸センサーの検出精度が高められる。
【００８２】
すなわち、Ｙ軸転倒判断は、前述の図１（Ａ）のサイン曲線において、転倒判断基準角度を±５０°として、これに対応するＹ軸センサーの出力電圧値が（ｇ・ｓｉｎ（５０°））より大きい状態又は（ｇ・ｓｉｎ（−５０°））より小さい状態かどうかにより判別する。この状態が２秒以上続いた場合は転倒と判断する。
【００８３】
上記Ｚ軸センサーで転倒と判別しても、Ｙ軸センサーが左右方向に傾斜していないことを検出した場合は、車体はウィリー等により前後方向に傾斜している状態であり、通常制御のルーチンを繰り返す。
【００８４】
ステップｅ４：：転倒と判断した場合、燃料ポンプを停止し、燃料噴射及び点火を停止してエンジンを停止させる。このとき、前述のように、エンジン出力を徐々に落すことが望ましい。
【００８５】
図１１は、本発明の参考となる技術を示すフローチャートである。また、図１２は、この参考例で用いるｔａｎ（タンジェント）の出力データのグラフである。
【００８６】
自動二輪車に加速度センサーを設けると、エンジンの振動や路面の凹凸等によりセンサー出力にノイズが含まれてしまう。このため、あるしきい値に対して一定時間しきい値を超えた場合に転倒と判断するロジックを組んだ場合、振動によりしきい値より大きくなったり小さくなったりを繰返し、設定された角度では検出できなくなる。この場合、例えばＣＲフィルタ等のローパスフィルタを設けて振動成分を消せば設定したしきい値の転倒角度で検出できる。しかしこの場合、応答時間が長くかかり、検出時間が長くなるという問題を生じる。
【００８７】
そこでこの参考例では、縦置きセンサーの出力と横置きセンサーの出力のタンジェントを求め、このタンジェント出力により転倒を判断することにより、たとえ各センサーが振動を拾ってノイズを生じても、縦置きセンサーと横置きセンサーの変動が相互に打ち消し合って、設定した検出角度で転倒を判別できるようにした。
【００８８】
ステップｆ１：２軸加速度センサーを縦置き配置し、検出方向をＺ軸（上下方向）及びＹ軸（左右方向）とする。この加速度センサーの出力電圧をＺ軸及びＹ軸方向について検出する。
【００８９】
ステップｆ２：Ｚ軸方向センサーの検出出力電圧により、逆さまの転倒（±９０°以上の転倒）かどうかを判別する。すなわち、前述の図２（Ａ）のコサイン曲線において、転倒判断角度を±９０°としてこれに対応する出力電圧値（ｇ・ｃｏｓ（±９０°））より小さい状態かどうかを判別する。この状態が２秒以上続いた場合は逆さま転倒と判断する。なお、前述のように、２秒以上続くことを要件としたのは、電圧検出による転倒判断の信頼性を高めるためである。
【００９０】
ここで逆さま転倒と判断した場合には、直ちにステップｆ４に進み燃料ポンプ停止等の転倒制御を行なう。
【００９１】
ステップｆ３：上記ステップｆ２でＺ軸方向のセンサーで逆さまの転倒ではない（±９０°以上傾斜していない）と判別された場合に、さらにＺ軸センサー及びＹ軸方向センサーの検出出力電圧により転倒（±９０°以内の転倒）かどうかを判別する。
【００９２】
すなわち、まず、図１（Ａ）の横置きのＹ軸センサーの出力電圧と図２（Ａ）の縦置きのＺ軸センサーの出力電圧とを検出し、そのタンジェント（ｔａｎ）＝（Ｙ軸出力電圧）÷（Ｚ軸出力電圧）を演算により求める。このｔａｎ出力値が転倒角度をαとしたとき、１ｇ・ｔａｎ（−α）より小さいか又は１ｇ・ｔａｎαより大きいかを判別する。いずれか一方の条件が２秒以上続いて満たされれば転倒と判断する。２秒以上続くことを要件としたのは、タンジェント出力値による転倒判断の信頼性を高めるためである。両方とも満たされなければ転倒していないと判断する。
【００９３】
グラフで説明すると、図１（Ａ）の横置きＹ軸センサーからのサイン曲線出力と、図２（Ａ）の縦置きＺ軸センサーからのコサイン曲線出力とから得られるタンジェント曲線出力は図１２で表わされる。図１２において、上記ステップｆ２で逆さま転倒ではないと判別されているため、車体角度は−９０°から＋９０°の範囲である。この範囲内で車体の左側（−側）又は右側（＋側）で転倒角度αを越えたかどうかを判別する。
【００９４】
転倒角度αは、スクーター形式か通常のオートバイ形式の車種や、車体寸法あるいは排気量等を考慮して設定する。このαは車種等に応じてプログラム上で書換え可能としてもよい。
【００９５】
このように縦置きを含む２軸のセンサーを用いて両センサー出力のタンジェントにより転倒判断することにより、ノイズが打ち消されるため、振動等によりセンサー出力に変動が生じても確実に転倒を判別することができる。
【００９６】
ステップｆ４：：転倒と判断した場合、燃料ポンプを停止し、燃料噴射及び点火を停止してエンジンを停止させる。このとき、前述のように、エンジン出力を徐々に落すことが望ましい。
【００９７】
次に上記転倒センサーが組み込まれたＥＣＵの車体への取り付け構造について説明する。
図１３は本発明が適用される小型自動二輪車の外観図である。
【００９８】
車体１は、前部にハンドル２を有し、ハンドル２はヘッドパイプ３を挿通するステアリング軸４を介して前輪５に連結される。ヘッドパイプ３に車体フレーム６が結合される。車体フレーム６は車体全体のフレーム構造を形成する。車体前部はカウリング７で覆われる。車体１は、車体フレーム６の外側から車体カバー８で覆われる。車体中央にシート９が備わり、その下側に燃料タンク１０が設けられ、その後方にヘルメットボックス（物入れ）１１が備わる。燃料タンク１０は不図示の燃料ホースを介してインジェクタ（不図示）に燃料を供給する。燃料タンク１０の上部にブリーザホース１２の一端が接続されその他端はキャニスタ１３に接続される。キャニスタ１３はパージホース１４を介して吸気系（例えばスロットルボディ）に連結される。不図示の右側ハンドル部分のスロットルグリップ（又はレバー）にスロットルワイヤ１５が装着され吸気系のスロットルバルブに連結される。同じくハンドル部分のブレーキレバー（不図示）にブレーキケーブル１６が装着され後輪１７のブレーキカムシャフト１８に連結される。
【００９９】
車体中央部の車体フレーム６にエンジンユニット１９が取付けられる。エンジンユニット１９は、エンジン（不図示）とそのクランクケース（不図示）に一体結合された減速機２４からなる。このエンジンユニット１９は、エンジンブラケット２０を介して車体フレーム６の一部を構成する下部車体フレーム部材２１に対しピボット２２廻りに回転可能に懸架される。このエンジンユニット１９の後部に後輪１７が連結されるとともにダンパー２３の下端が枢着される。ダンパー２３の上端は車体フレーム６の一部を構成する後部車体フレーム（不図示）に枢着される。これにより、エンジンユニット１９は後輪１７とともにピボット２２廻りに揺動可能となり、スイングユニット式エンジンが形成される。
【０１００】
減速機２４の上側にエアクリーナ２５が備わる。エアクリーナ２５の前部に外気取入用開口２５ａが開口し、この開口を覆って車体カバー８の内側にゴムあるいは樹脂からなる防塵カバー２６が設けられる。２７はスタンド、２８はキックレバーである。
【０１０１】
図１４及び図１５はそれぞれ、上記本発明に係る燃料噴射エンジンを備えた自動二輪車の要部を示す側面図及び平面図である。また、図１６はその吸気系部分の拡大図である。
【０１０２】
燃料タンク１０の下方にエンジン２９が備わる。このエンジン２９は、燃料噴射インジェクタを備えた４サイクル単気筒エンジンである。エンジン２９のクランクケース（不図示）は例えばＶベルト式の無段減速機構からなる減速機２４と一体結合され全体でスイングユニットエンジン形式のエンジンユニット１９を構成する。減速機２４の前部にダクト３０が接続されその開放端部３０ａから外気を吸引して減速機５内に供給し内部を冷却する。減速機２４の後部出力軸（不図示）は後輪１７の車軸に連結される。
【０１０３】
このスイングユニットエンジン形式のエンジンユニット１９の前部にエンジンブラケット２０が一体結合される。このエンジンブラケット２０に軸３１を介してリンクプレート３２が枢着される。リンクプレート３２はピボット２２を介して下部車体フレーム部材２１に回転可能に取付けられる。
【０１０４】
エンジンユニット１９の後部にダンパー（ショックアブソーバ）２３が備わる。ダンパー２３は、その上端３３が後部車体フレーム部材３４に枢着され、下端３５がエンジンユニット１９の後端部のブラケット３６に枢着される。これにより、エンジンユニット１９はその前側のピボット２２を中心に車体フレームに対し揺動可能に装着される。図１６に示すように、エンジン２９のシリンダ３７はほぼ水平近くまで前傾している。クランク軸３８は、前述のピボット２２を中心にエンジンブラケット２０（図１４）の軸３１とともの矢印Ｄのように揺動する。
【０１０５】
エンジン２９の吸気側にはシリンダヘッドの吸気ポート（不図示）に連通する吸気マニホルド３９及びこれに接続する吸気管４０（図１５、図１６）が備わり、排気側には排気管４１（図１５）が接続される。吸気管４０は屈曲したエルボ状の吸気管であり、図１６に示すように、樹脂の断熱材４２を介して相互にフランジ４３を突き合せ、２本のボルト４４により固定される。４５は動弁カムの整備用カバーである。エンジン２９には水温センサ４６（図１５、図１６）が設けられる。水温センサ４６の検出出力信号は、水温信号ケーブル８９（図１５）及びワイヤハーネス７２を介してエンジン制御ユニット４７（図１５）に送られる。エンジン制御ユニット４７にはさらに後述の吸気温センサ及び吸気圧センサの検出信号ケーブル（不図示）がワイヤハーネス７２を介して接続され、これらの検出データに基づいてスロットルバルブ（不図示）を開閉制御する。
【０１０６】
吸気マニホルド３９には前述の屈曲したエルボ状吸気管４０を介してスロットルボディ４８が接続される。スロットルボディ４８は、ジョイント４９を介してエアクリーナ２５に接続される。吸気管４０にインジェクタ５０が装着される。
【０１０７】
スロットルボディ４８内にはスロットルバルブ（不図示）が装着されるとともに、その上流側にダイヤフラム式サクションピストン５１が装着される。このサクションピストン５１は、後述のように、そのダイヤフラム室５２がスロットルボディ４８の上側に設けられ、このダイヤフラム室５２に大気を導入する大気通路５３の大気取入口（大気開放端部）５４がスロットルボディ４８の下側に設けられる。スロットルバルブの弁軸には、リンク５５を介して不図示のスロットルレバー又はスロットルグリップ等に連結されたスロットルワイヤ１５が接続される。
【０１０８】
エアクリーナ２５前部の空気取入用開口部２５ａはゴム又は樹脂等からなる防塵カバー２６（図１３の一点鎖線）で覆われる。この防塵カバー２６の外側にさらに車体カバーが取付けられる。サクションピストン５１の大気取入口５４はこの防塵カバー２６の内側に開口する。
【０１０９】
サクションピストン５１に隣接してスロットルボディ４８にヒータ式ワックスタイプのオートチョーク５６および吸気圧センサ５７が備わる（図１５）。オートチョーク５６は、スロットルバルブの上流側と下流側とを連通するバイパス管（不図示）を開閉する。吸気圧センサ５７は負圧ホース５８（図１６）を介して吸気マニホルド３９又は吸気管４０に連通する。エアクリーナ２５内に吸気温センサ５９（図１５）が備わる。
【０１１０】
なお、吸気圧センサ５７は吸気マニホルド近傍に設けてもよい。また、リンク５５と反対側のスロットルバルブの弁軸にスロットル位置センサ（不図示）を設けてもよい。この場合、オートチョーク５６は、スロットル位置センサと干渉しないようにスロットルバルブより上流側に設けられる。
【０１１１】
燃料タンク１０は、その前側下部がブラケット６０を介して左右の車体フレーム部材６１に固定される。燃料タンク１０の後方から燃料ホース６２が引出され、インジェクタ５０に燃料を供給する。燃料ホース６２はスティ６３（図１４、図１６）を介して後部車体フレーム部材３４に固定される。６４（図１４）はオーバーフローパイプである。６５（図１５）はバッテリ、６６（図１５）は冷却水のリカバリータンクを示す。車体中央部右側に、図１５に示すように、排気ガス浄化用の二次空気導入システム８６が備わる。この二次空気導入システム８６は負圧ホース８７を介して吸気マニホルドに連通し、吸気負圧に応じてエアホース８８を介して外気を触媒（不図示）に供給して排気ガスを再燃焼させる。
【０１１２】
エアクリーナ２５には、図１４に示すように、ブローバイガスホース９０が接続される。このブローバイガスホース９０は、エンジン２９のクランクケース（不図示）に通じるカムチェーン室（不図示）に連通し、エンジンのクランクケース内等の圧力上昇によるオイルシール脱落やロス馬力を防止する。このブローバイガスホース９０は、エアクリーナ内のエレメント通過後のクリーンサイドに接続され、ブローバイガスは再度燃焼室に導入される。
【０１１３】
燃料タンク１０は、前述の図１３で示したようにブリーザホース１２を介してキャニスタ１３に連通する。このブリーザホース１２の途中にロールオーバーバルブ１２４が設けられる。このロールオーバーバルブ１２４は、転倒時に閉じて燃料タンク１０からの燃料の流出を防止する。
【０１１４】
図１７（Ａ）（Ｂ）は、それぞれエンジン制御ユニットの取付部分を前面側正面図及び左側面図である。
エンジン制御ユニット（ＥＣＵ）４７は、この配置例では前面側に突出する下部４７ｂの厚さが上部４７ａより厚く段差を有する略矩形体形状であって、後面側が矩形平面の取付面４７ｃを形成し、この取付面４７ｃと同一面の左右に耳片１５８が備わる。各耳片１５８は、それぞれボルト１５９により燃料タンク支持用のブラケット６０の内面側に溶接固定されたステー１６０に固定される。ＥＣＵ４７の下部にカプラ１６１を介してワイヤハーネス７２が接続される。
【０１１５】
ブラケット６０は、左右それぞれの後部車体フレーム部材３４に接合された車体フレーム部材６１上に接合される。左右の後部車体フレーム部材３４はそれぞれエルボフレーム１４５を介して前部車体フレーム部材１４０に接合される。エルボフレーム１４５に前述の下部車体フレーム部材２１が接合され、この下部車体フレーム部材２１に前述のエンジンユニット１９（図１３、図１４）を揺動可能に支持するピボット２２が設けられる。１６２はタンデムライダー用足乗せパイプフレームであり、１６３はサイドスタンドである。
【０１１６】
燃料タンク（不図示）は、左右ブラケット６０の上部間に跨って設けた支持部材（不図示）と後部車体フレーム部材３４の上部に設けたスティ６３上に支持されて配設される。
【０１１７】
ＥＣＵ４７内には、その取付面４７ｃと平行に配置した回路基板（不図示）が収容され、この回路基板上に２次元（２軸）加速度センサー（不図示）がその検出面を基板平面と平行にして実装されている。したがって、この２次元加速度センサーからなる転倒センサーは、その検出面を車体前後方向にほぼ垂直な状態で車体左右方向のほぼ中央に、左右両側のブラケット６０で保護された位置に取付けられる。
【０１１８】
図１８（Ａ）（Ｂ）は、それぞれ本発明の別の実施形態に係るＥＣＵ取付構造の後面側正面図及び左側面図である。
この例は、車体フレーム前部を構成するヘッドパイプ１６４の後方に左右それぞれ２本ずつ上側パイプフレーム１６５及び下側パイプフレーム１６６が溶接固定され、これら４本のパイプフレーム１６５，１６６に囲まれた位置にＥＣＵ４７を取付けた構造である。ＥＣＵ４７は、その取付面４７ｃを前面にして耳片１５８がブラケット１６７にボルト１５９で固定される。ブラケット１６７は、二股の下部がそれぞれ左右の下側パイプフレーム１６６にボルト１６８で固定される。ブラケット１６７はさらにその両側縁部等適当なヵ所を下側パイプフレーム１６６に溶接固定してもよい。
【０１１９】
１６９は燃料供給用電磁ポンプである。１７０は、電磁ポンプ１６９と燃料タンク（不図示）間の燃料ホース（不図示）途中に設けたフィルタである。
【０１２０】
この実施形態においても、ＥＣＵ４７は、内部の２次元加速度センサーからなる転倒センサー（不図示）の検出面と平行な取付面４７ｃを車体前後方向とほぼ垂直にして車体左右方向のほぼ中央に、左右のパイプフレーム１６５，１６６で保護された位置に取付けられる。
【０１２１】
【発明の効果】
以上説明したように、本発明では、加速度センサーを転倒センサーとし、これをＥＣＵ内に組込んで一体ユニット化することにより、転倒検出精度の向上及び構成の簡素化が図られ、他の部品配置を制約することなく狭いスペースに効率よくレイアウトできる。これとともに、加速度センサーの配置を縦置き配置、すなわち車体が非傾斜状態のときの加速度検出方向が地面に垂直方向になる配置とすることにより、バンク角を越えて転倒した又は転倒する状態になった場合、転倒状態の判別角度となるバンク角（６５〜７０°）付近における傾斜角度変化に対する検出出力の変化が大きいため、一定のＡ／Ｄ変換出力幅内での角度変化が小さくなり、したがって、変換誤差を小さくすることができ、転倒判断の精度を向上させ信頼性を高めることができる。
【０１２２】
また、２軸又は３軸加速度センサーを用い、１軸については必ず縦置きの検出方向（第１の検出方向）とし、さらに車幅方向又は前後方向についての第２の検出方向の加速度を検出することにより、第１の検出方向の角度検出により転倒角度を超えていた場合に、第２の検出方向での検出結果に基づいて、ウィリー走行や坂道走行による車体の傾斜を転倒と誤って判断することが防止される。
【０１２３】
また、前記転倒の検出は、前記縦置きセンサーの出力に基づく転倒の検出が縦置きセンサーの検出出力電圧と、転倒判断基準角度に対応する出力電圧との大小を比較することにより行われ、さらに、前記横置きセンサーの出力に基づく転倒の検出が前記縦置きセンサーの検出出力に基づいて転倒と判別された後の所定期間内における前記横置きセンサーの検出出力の変化量に基づいて行われる構成によれば、ウィリー走行等による転倒以外の傾斜を判別するための第２の検出方向に関しては傾斜の変化があるかどうかを判別すれば転倒かウィリー等かを識別できるため、基準値からの差を算出することが不要になり、したがって、基準値のオフセット誤差の補正が不要になる。
【０１２４】
さらに、前記第１の検出方向による転倒判断のしきい値を、前記加速度センサーの取付角度に基づいて変更する構成によれば、加速度センサーを組込んだＥＣＵの車体への取付誤差等により、加速度センサーが車体上下方向に対し傾いて取付けられた場合に、傾いた角度に対応して転倒判断のしきい値を変更することにより、検出精度を高めることができる。
【０１２５】
さらに、走行速度が一定値以上で加速度センサーの検出出力の変化量が一定値以下のときの加速度センサーの検出平均値を中心値として保存し、該中心値を前記基準値として転倒判断する構成によれば、走行速度が一定値以上で、加速度センサーの出力変化が一定値以下のとき、車体はほとんど傾斜ていない真直ぐな姿勢で走行中と判断し、このときのセンサー出力の平均値を中心値として保存する。この中心値からの変化を検出することにより、センサーの温度特性や取付誤差によるオフセットのばらつきあるいは経時変化等による検出精度の低下を防止できる。
【０１２８】
さらに、前記ＥＣＵを車体の左右方向の中央部に設けた構成によれば、左右いずれの方向の傾斜転倒に対しても同様に高精度で検出することができ転倒検出の信頼性が高められるとともに左右両側の車体フレームにより機械的に保護され横転時の損傷が防止される。
【０１２９】
さらに、車体中央部左右に配設された車体フレーム部材に燃料タンク取付用ブラケットが固定され、これらの左右のブラケット間に前記ＥＣＵを配設し、各ブラケットにステーを介して該ＥＣＵを固定した構成によれば、車体中央部の燃料タンク取付け用の左右のブラケットを利用してこれらのブラケット間にスペース的に効率よくＥＣＵを配設できるとともに、エンジン周りの水温センサや吸気温センサ等の各種センサ及びインジェクタやスロットルバルブ及び点火コイル等のエンジン駆動部品までの距離が短くなって信号ケーブル等からなるワイヤハーネスが短くでき、エンジン周りのレイアウトが簡素化する。
【図面の簡単な説明】
【図１】 本発明に係る横置き配置の加速度センサーの出力電圧説明図。
【図２】 本発明に係る縦置き配置の加速度センサーの出力電圧説明図。
【図３】 本発明の参考となる技術を説明するための図で、同図は１軸加速度センサーによる転倒判別制御のフローチャート。
【図４】 本発明の２軸加速度センサーによる転倒判別制御のフローチャート。
【図５】 本発明の別の実施形態のブロック構成図。
【図６】 図５の実施形態の動作のフローチャート。
【図７】 本発明のさらに別の実施形態の出力電圧説明図。
【図８】 本発明のさらに別の実施形態の構成説明図。
【図９】 本発明のさらに別の実施形態の動作のフローチャート。
【図１０】 本発明のさらに別の実施形態の動作のフローチャート。
【図１１】 本発明の参考となる技術を示すフローチャート。
【図１２】 図１１の参考例のセンサー出力のグラフ。
【図１３】 本発明に係る小型自動二輪車の外観図。
【図１４】 図１３の自動二輪車の要部側面図。
【図１５】 図１３の自動二輪車の要部平面図。
【図１６】 図１３の自動二輪車のエンジン部分の構成図。
【図１７】 本発明に係るＥＣＵ取付け構造の構成説明図。
【図１８】 本発明の別の実施形態に係るＥＣＵ取付け構造の構成説明図。
【符号の説明】
１：車体、２：ハンドル、３：ヘッドパイプ、４：ステアリング軸、
５：前輪、６：車体フレーム、７：カウリング、８：車体カバー、
９：シート、１０：燃料タンク、１１：ヘルメットボックス、
１２：ブリーザホース、１３：キャニスタ、１４：パージホース、
１５：スロットルワイヤ、１６：ブレーキケーブル、１７：後輪、
１８：ブレーキカムシャフト、１９：エンジンユニット、
２０：エンジンブラケット、２１：下部車体フレーム部材、２２：ピボット、
２３：ダンパー、２４：減速機、２５：エアクリーナｌ、
２５ａ：空気取入用開口、２６：防塵カバー、２７：スタンド、
２８：キックレバー、２９：エンジン、３０：ダクト、３０ａ：開放端部、
３１：軸、３２：リンクプレート、３３：上端、３３ａ：ダンパー取付孔、
３４：後部車体フレーム部材、３５：下端、３６：ブラケット、
３７：シリンダ、３８：クランク軸、３９：吸気マニホルド、４０：吸気管、
４１：排気管、４２：断熱材、４３：フランジ、４４：ボルト、
４５：整備用カバー、４６：水温センサ、４７：エンジン制御ユニット、
４７ａ：上部、４７ｂ：下部、４７ｃ：取付面、
４８：スロットルボディ、４９：ジョイント、４９ａ：ジョイント端部、
５０：インジェクタ、５１：サクションピストン、５２：ダイヤフラム室、
５３：大気通路、５４：大気取入口、５５：リンク、５６：オートチョーク、
５７：吸気圧センサ、５８：負圧ホース、５９：吸気温センサ、
６０：ブラケット、６１：車体フレーム部材、６２：燃料ホース、
６２ａ：固定ホース部、６２ｂ：揺動ホース部、６３：スティ、
６４：オーバーフローパイプ、６５：バッテリ、
６６：リカバリータンク、７２：ワイヤハーネス、７４：スロットルバルブ、
８６：二次空気導入システム、８７：負圧ホース、８８：エアホース、
８９：水温信号ケーブル、９０：ブローバイガスホース、
１０１：加速度センサー、１０２：２軸加速度センサー、１０３：フィルタ、
１０４：Ａ／Ｄ変換器、１０５：キャパシタ、１０６：フィルタ、
１０７：ＣＰＵ、１０８，１０９：マーキング、１１０：加速度センサー、
１１１：プリント基板、１２４：ロールオーバーバルブ、
１４０：前部車体フレーム部材、１４５：エルボフレーム、
１５８：耳片、１５９：ボルト、１６０：ステー、１６１：カプラ、
１６２：タンデムライダー用足乗せパイプフレーム、
１６３：サイドスタンド、１６４：ヘッドパイプ、
１６５：上側パイプフレーム、１６６：下側パイプフレーム、
１６７：ブラケット、１６８：ボルト、１６９：電磁ポンプ、
１７０：フィルタ。[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a motorcycle overturn detection device using an acceleration sensor.
[0002]
[Prior art]
In a motorcycle, an ECU (engine control unit) is provided for fuel injection control and ignition timing control. This ECU drives and controls the injector and ignition coil in accordance with a preset map and control program based on engine speed detection data, throttle opening detection data, intake pipe negative pressure detection data, and the like. Such an ECU includes a semiconductor circuit such as a storage circuit storing a map and a program and an arithmetic circuit for performing data processing on a printed circuit board, and is attached to the vehicle body as a single component. .
[0003]
In addition, a fall sensor is provided in the motorcycle, and when the fall of the vehicle body is detected, fuel injection and ignition are stopped, and the fuel supply electromagnetic pump is stopped to prevent fuel from flowing out when the engine is stopped.
[0004]
A conventional fall sensor has a mechanical structure that uses a weight or pendulum that moves according to the inclination of the vehicle body, and the weight or pendulum switches on when the vehicle falls. The fall sensor having such a mechanical structure is attached to the vehicle body as a separate body from the ECU, and the fall detection data is sent to the ECU, and the ECU controls the engine at the fall based on the detection data.
[0005]
However, the conventional mechanical fall sensor has insufficient aspects in terms of detection accuracy and reliability. Therefore, in order to improve this and improve the accuracy and reliability, it is necessary to prevent the contact failure of the switch and to smoothly operate the weight and the pendulum. For this reason, it is necessary to perform a plating process or a structure without a step, which makes the manufacturing process cumbersome and increases costs. In addition, the size and weight are large, which is a space constraint on other parts.
[0006]
Further, in the conventional ECU mounting structure, since the ECU and the fall sensor are separate bodies, there is a large space restriction when used for a small scooter or the like in which the space around the engine is narrow. In addition, the conventional body tipping sensor uses a mechanical pendulum structure, so it is large and complicated in configuration, and it is vertical to the ground and in the longitudinal direction so that the pendulum can move smoothly in the lateral direction of the body. It had to be installed vertically, the layout was complicated, and the installation was troublesome.
[0007]
On the other hand, an acceleration sensor using a semiconductor element is known. This acceleration sensor detects a magnitude of acceleration by forming a capacitor between electrodes and changing the capacitance according to the acceleration. This acceleration sensor does not have a large mechanical configuration other than the electrodes, and can obtain highly accurate acceleration detection data in the form of a semiconductor element. Therefore, if gravity acceleration is detected by this acceleration sensor, the inclination of the sensor can be detected.
[0008]
Therefore, it has been proposed by the present inventor to use this acceleration sensor as a fall sensor and to integrate it into the ECU (see, for example, Patent Document 1).
[0009]
The acceleration sensor has a detection direction for detecting acceleration, the one-axis sensor detects acceleration in one direction, the two-axis sensor detects acceleration in two orthogonal directions, and the three-axis sensor has three orthogonal directions The acceleration is detected for each. When this acceleration sensor is incorporated in the ECU as a fall sensor and this ECU is mounted on the vehicle body, the acceleration sensor detection direction for one axis is in a vertical arrangement or in the vehicle body in the vertical direction (perpendicular to the ground) with respect to the vehicle body On the other hand, it is considered that the acceleration when the vehicle body is tilted can be detected efficiently by adopting any one of the horizontal placements in the left-right direction (vehicle width direction).
[0010]
Such an acceleration sensor outputs an analog voltage as a detection voltage according to the inclination of the vehicle body. This analog detection voltage is A / D converted and input as a digital signal to a control circuit (CPU) in the ECU to determine the fall state.
[0011]
[Patent Document 1]
JP 2002-71703 A
[0012]
[Problems to be solved by the invention]
However, when an acceleration sensor is used as a fall sensor and a fall is determined from the detection signal, a conversion error based on the A / D conversion width occurs when the detection signal is A / D converted to make a fall decision. Therefore, this conversion error causes a fall angle detection error, which may cause an erroneous determination.
[0013]
The present invention has been made in consideration of the above-described prior art, and an object thereof is to provide a motorcycle fall detection device that reduces the A / D conversion error of a fall sensor composed of an acceleration sensor and increases the accuracy of the fall judgment.
In addition, the present invention provides a motorcycle overturn detection device that can be easily mounted and can be downsized, and can be efficiently laid out in a narrow space without simplifying the configuration and layout of components around the engine and restricting the arrangement of other components. For the purpose of provision.
[0014]
[Means for Solving the Problems]
  In order to achieve the above object, the present invention comprises an ECU for controlling the driving of the engine and a fall sensor for detecting a fall based on the tilt angle of the vehicle body, the fall sensor is constituted by an acceleration sensor, and the acceleration sensor is the ECU. In the motorcycle fall detection device incorporated in the vehicle, the acceleration sensor is used when the vehicle body is in a non-tilt state.InPerpendicular to the groundNadirectionIsFirst detection directionA vertical sensor for detecting the acceleration of thePerpendicular to the first detection directionNadirectionIsDetect acceleration in second detection directionIt has a horizontal sensor and detects a fall based on the output from the vertical sensor and the horizontal sensor.A fall detection device for a motorcycle is provided.
[0015]
According to this configuration, the acceleration sensor is used as a fall sensor, which is incorporated into the ECU and integrated into a single unit, thereby improving the fall detection accuracy and simplifying the configuration, and restricting the arrangement of other components. Can be laid out efficiently in a narrow space. At the same time, the acceleration sensor is placed vertically, that is, the acceleration detection direction when the vehicle body is in a non-tilt state is perpendicular to the ground, so that it falls over the bank angle or falls. In this case, since the change in the detection output with respect to the change in the tilt angle in the vicinity of the bank angle (65 to 70 °), which is the determination angle of the fall state, is large, the change in the angle within a certain A / D conversion output width is small. The conversion error can be reduced, the accuracy of the fall determination can be improved, and the reliability can be improved.
[0016]
In addition, a biaxial or triaxial acceleration sensor is used, and the vertical detection direction (first detection direction) is always set for one axis, and the acceleration in the second detection direction in the vehicle width direction or the front-rear direction is detected. Thus, when the fall angle is exceeded by the angle detection in the first detection direction, the inclination of the vehicle body due to the wheelie running or the slope running is erroneously determined as the fall based on the detection result in the second detection direction. It is prevented.
[0017]
  In a preferred configuration example,The detection of the overturn is performed by comparing the magnitude of the detection output voltage of the vertical sensor and the output voltage corresponding to the fall determination reference angle, based on the output of the vertical sensor. Fall detection based on the output of the horizontal sensorBased on the amount of change in the detection output of the horizontal sensor within a predetermined period after it is determined to fall based on the detection output of the vertical sensorDoneIt is characterized by that.
[0018]
  In this configurationAccording to WillieWith regard to the second detection direction for discriminating a slope other than a fall due to running or the like, it is possible to discriminate whether it is a fall or a wheelie if it is discriminated whether there is a change in the slope, so that the difference from the reference value can be calculated Therefore, it is unnecessary to correct the offset error of the reference value.
[0019]
In a further preferred configuration example, the threshold value for the fall determination based on the first detection direction is changed based on the mounting angle of the acceleration sensor.
[0020]
According to this configuration, when the acceleration sensor is mounted tilted with respect to the vertical direction of the vehicle body due to the mounting error of the ECU incorporating the acceleration sensor to the vehicle body, the threshold value for the fall determination corresponding to the tilted angle By changing, detection accuracy can be increased. In this case, the left and right tilt directions are discriminated from the output in the second detection direction, and the threshold value is changed according to the left and right.
[0021]
  In a more preferable configuration example, the traveling speed is a certain value or more.And within a predetermined periodThe detection average value of the acceleration sensor when the change amount of the detection output of the acceleration sensor is a certain value or less is stored as a center value, and the fall determination is performed using the center value as the reference value.
[0022]
According to this configuration, when the traveling speed is equal to or higher than a certain value and the output change of the acceleration sensor is equal to or smaller than the certain value, the vehicle body is determined to be traveling in a straight posture with little inclination, and the average value of the sensor output at this time Is stored as the center value. By detecting this change from the center value, it is possible to prevent a decrease in detection accuracy due to variations in offset due to temperature characteristics or mounting errors of the sensor or changes over time.
[0028]
According to this configuration, a two-dimensional (two-axis) acceleration sensor is used as a fall sensor incorporated in the ECU, and the two-dimensional detection surface is disposed substantially perpendicular to the longitudinal direction of the vehicle body so that the ECU can be attached to the vehicle body frame. It is securely fixed to the vehicle body and the reliability of mounting and detection is improved. Further, the ECU can be easily arranged by increasing the degree of freedom of mounting by tilting the ECU containing the fall sensor somewhat in the front-rear direction corresponding to the surrounding component arrangement space and attaching it to the vehicle body frame.
[0029]
In a further preferred configuration example, the ECU is provided in a central portion in the left-right direction of the vehicle body.
[0030]
According to this configuration, it is possible to detect with high accuracy even in the case of tilting in either the left or right direction, improving the reliability of the falling detection, and being mechanically protected by the body frames on both the left and right sides. Damage is prevented.
[0031]
In a more preferable configuration example, a fuel tank mounting bracket is fixed to a vehicle body frame member disposed on the left and right of the center of the vehicle body, the ECU is disposed between the left and right brackets, and each bracket is connected to the bracket via a stay. The feature is that the ECU is fixed.
[0032]
  According to this configuration, the left and right brackets for mounting the fuel tank in the center of the vehicle body can be used to efficiently arrange the ECU between the brackets, and the water temperature sensor, the intake air temperature sensor, etc. The distance to the engine drive parts such as various sensors, injectors, throttle valves, and ignition coils is shortened, so that the wire harness including the signal cable can be shortened, and the layout around the engine is simplified.
  In a further preferred configuration, the second detection direction is a width direction of the vehicle body when the vehicle body is in a non-tilt state.
[0033]
DETAILED DESCRIPTION OF THE INVENTION
  Embodiments of the present invention will be described below with reference to the drawings.
  First, the technology which is the premise of the present invention will be described with reference to FIGS.
  FIG. 1 is an explanatory diagram of sensor output when a uniaxial acceleration sensor is placed horizontally. (A) is an output waveform, (B) is an explanatory view of a state in which the vehicle body is tilted to the right by an angle θ.
[0034]
  As shown in FIG.The acceleration sensor 101 is attached to the vehicle body in a horizontal arrangement in which the detection direction ab is horizontally arranged in a non-tilted state (neutral position) where the vehicle body is straight. Therefore, the sensor output is an output voltage V = g · sin θ with respect to the inclination angle θ of the vehicle body, and the output voltage characteristic draws a sine curve as shown in FIG. The motorcycle is considered to fall over when the vehicle body is tilted beyond the bank angle (about 65 to 70 °). Therefore, if the sensor output at 70 ° as the discrimination reference is the discrimination output Vc,
  Vc = g · sin 70 ° = 0.94 g.
[0035]
Here, when the A / D conversion error is ± 10 mV (± 0.03 g), the angle error is (0.94-0.03) g≈g · sin 65 °.
(0.94 + 0.03) g ≒ g · sin75 °
It becomes. Therefore, the angle error based on A / D conversion is 70 ± 5 °.
[0036]
FIG. 2 is an explanatory diagram of sensor output when the uniaxial acceleration sensor is vertically arranged. (A) is an output waveform, (B) is an explanatory view of a state in which the vehicle body is tilted to the left by an angle θ.
[0037]
  As shown in FIG.The acceleration sensor 101 is attached to the vehicle body in a vertical arrangement in which the detection direction ab is arranged perpendicular to the ground in a non-tilt state (neutral position) where the vehicle body is straight. Therefore, the sensor output becomes the output voltage V = g · cos θ with respect to the vehicle body inclination angle θ, and the output voltage characteristic draws a cosine curve as shown in FIG. The motorcycle is considered to fall over when the vehicle body is tilted beyond the bank angle (about 65 to 70 °). Therefore, if the sensor output at 70 ° as the discrimination reference is the discrimination output Vc,
  Vc = g · cos 70 ° = 0.34 g.
[0038]
Here, when the A / D conversion error is ± 10 mV (± 0.03 g), the angle error is (0.34−0.03) g≈g · cos 72 °.
(0.34 + 0.03) g ≒ g · cos68 °
It becomes. Therefore, the angle error based on A / D conversion is 70 ± 2 °.
[0039]
  That is, the angle error based on the A / D conversion in the case of the vertical installation shown in FIG. 2 is smaller than that in the case of the horizontal installation shown in FIG. Therefore,By obtaining the vehicle body tilt angle using an acceleration sensor placed vertically (Z direction),An A / D conversion error can be reduced and detection accuracy can be increased. When a 2-axis (Y, Z direction) or 3-axis (X, Y, Z direction) acceleration sensor is used, one detection direction (firstofThe detection direction is always set vertically (Z direction), and the second detection direction is the horizontal vehicle width direction (Y direction) or the front-rear direction (X direction).
[0040]
When a 2-axis or 3-axis acceleration sensor is used, if a tilt greater than the fall angle is detected by a sensor in the Z direction, and if the sensor in the X or Y direction does not detect the tilt, the wheelie travel or the steep hill travel Therefore, the vehicle continues to run with normal control without performing the processing (stopping the fuel pump, stopping fuel injection, stopping ignition, etc.) at the time of falling.
[0041]
The detection direction of the biaxial acceleration sensor is set to the Z and X directions, and when the detection output in the X direction changes (when a tilt in the front-rear direction is detected), it is possible to determine that the slope is a steep slope or a wheelie and not consider it a fall. is there.
[0042]
  FIG. 3 illustrates the present invention.An example of the technology used as a referenceIt is a flowchart.
thisReference exampleIs a fall judgment only by the sensor detection of one axis (Z-axis direction).
  Step a1: The output voltage is detected from a fall sensor in which a one-axis acceleration sensor is vertically arranged, or from a sensor in the Z-axis direction, which is the first detection direction in a two-axis or three-axis acceleration sensor.
[0043]
Step a2: It is determined whether or not the vehicle falls due to the detection output voltage of the Z-axis direction sensor. That is, it is determined whether or not the cosine curve in FIG. 2A is smaller than the output voltage value (g · cos (± 70 °)) corresponding to ± 70 ° that is the fall determination reference angle. If this state continues for 2 seconds or more, it is determined that the vehicle has fallen. The requirement that it last for 2 seconds or more is to increase the reliability of the fall determination by voltage detection.
[0044]
Step a3: When it is determined that the vehicle has fallen, the fuel pump is stopped, fuel injection and ignition are stopped, and the engine is stopped. At this time, it is desirable to gradually reduce the engine output. For example, the application of the drive pulse signal to the ignition coil in the ignition cycle by the normal control is stopped at an appropriate interval to control the thinning of the ignition, and the output is reduced by reducing the number of times of ignition by the normal control. At this time, the thinning interval at which ignition is stopped is initially cut at a long interval, and thinned out to gradually shorten the interval. This prevents the vehicle body from becoming unstable due to a rapid output drop in the case of malfunction or the like. Instead of or in combination with such ignition control, thinning out of fuel injection may be performed in the same manner. In this case, the output is lowered by gradually reducing the application of the drive pulse signal to the solenoid of the injector. In the case of a vehicle equipped with an electronic throttle, the output may be reduced by controlling the electronic throttle.
[0045]
  FIG. 4 relates to the present invention.Control example of the overturn control deviceIt is a flowchart of.
This embodiment uses the output from the biaxial (Y-axis direction and Z-axis direction) detection sensor, and uses FIG.Reference exampleIn addition to the fall determination based only on the Z-axis sensor, a fall determination condition based on the Y-axis sensor is added. Thereby, the inclination of the vehicle body by wheelie driving or steep slope driving can be distinguished from falling.
  Step b1: A biaxial acceleration sensor is placed vertically, and the detection directions are a Z axis (vertical direction) and a Y axis (horizontal direction). The output voltage of the acceleration sensor is detected in the Z-axis and Y-axis directions.
[0046]
Step b2: It is determined whether or not the vehicle falls due to the detection output voltage of the Z-axis direction sensor. That is, it is determined whether or not the cosine curve in FIG. 2A is smaller than the output voltage value (g · cos (± 70 °)) corresponding to ± 70 ° that is the fall determination reference angle. If this state continues for 2 seconds or more, it is determined that the vehicle has fallen. Note that, as described above, the requirement to continue for 2 seconds or more is to increase the reliability of the fall determination by voltage detection.
[0047]
Step b3: If it is determined in the step b2 that the sensor is overturned by the Z-axis direction sensor, it is further determined whether or not the system is overturned based on the detected output voltage of the Y-axis direction sensor. That is, in the above-described sine curve of FIG. 1A, the output voltage value (g · sin (70 °)) corresponding to ± 70 ° that is the fall determination reference angle is greater than (g · sin (−70 °)). )) Determine if the state is smaller. If this state continues for 2 seconds or more, it is determined that the vehicle has fallen.
[0048]
If it is determined in step b2 that the vehicle has fallen, but the Y-axis sensor detects that the vehicle is not tilted in the left-right direction, the vehicle body is tilted in the front-rear direction due to a wheelie or the like. repeat.
[0049]
Step b4 :: When it is determined that the vehicle has fallen, the fuel pump is stopped, fuel injection and ignition are stopped, and the engine is stopped. At this time, as described above, it is desirable to gradually reduce the engine output.
[0050]
FIG. 5 is a block diagram of another embodiment of the present invention.
In this embodiment, when a 2-axis or 3-axis acceleration sensor is used, the input to the CPU for determining the fall is divided into two systems of DC input and AC input.
[0051]
  2 axis acceleration sensor as shown102Z-axis output from the Z-axis sensor is a noise removal filter103A / D converter via104To the CPU in the ECU after A / D conversion107And the fall state is determined by arithmetic processing. This system is a DC input system.
[0052]
  On the other hand, 2-axis acceleration sensor102Y-axis output from the Y-axis sensor is a smoothing capacitor105And filters106A / D converter via104, where it is A / D converted and the CPU in the ECU107And the fall state is determined by arithmetic processing. This system is an AC input system.
[0053]
The Y-axis sensor is an auxiliary sensor for performing a wheelie determination as described above to prevent malfunction. Therefore, it is sufficient to determine whether the vehicle body is tilted from a straight state during traveling. Therefore, an input from the Y-axis sensor to the CPU is an AC input, and a wheelie or the like is discriminated based on an output voltage change amount. This eliminates the need to obtain the difference between the output voltage and the first reference value, and eliminates the need for correcting the offset error of the reference value.
[0054]
FIG. 6 is a flowchart showing the operation of the fall detection device of FIG.
Step c1: A biaxial acceleration sensor is placed vertically, and the detection directions are a Z axis (vertical direction) and a Y axis (horizontal direction). The output voltage of the acceleration sensor is detected in the Z-axis and Y-axis directions.
[0055]
Step c2: It is determined whether or not the vehicle falls due to the detected output voltage of the Z-axis direction sensor. That is, it is determined whether or not the cosine curve in FIG. 2A is smaller than the output voltage value (g · cos (± 70 °)) corresponding to ± 70 ° that is the fall determination reference angle. If this state continues for 2 seconds or more, it is determined that the vehicle has fallen. Note that, as described above, the requirement to continue for 2 seconds or more is to increase the reliability of the fall determination by voltage detection.
[0056]
Step c3: If it is determined in the step c2 that the sensor in the Z-axis direction has fallen, it is further determined whether or not the vehicle has fallen based on the detected output voltage of the Y-axis sensor. In this case, it is determined whether or not the output voltage of the horizontal Y-axis sensor has changed by a predetermined value (for example, 200 mV) in the sine curve of FIG. 1A described above, and the difference from the neutral position is not obtained. If there is no change in the inclination in the lateral direction (left and right of the vehicle body) (if 200 mV or less), the fall detection in step c2 is the inclination of the vehicle body in the front-rear direction due to a wheelie or the like, and the overturn process is not performed. Repeat the normal control routine.
[0057]
Step c4 :: When it is determined that the vehicle has fallen, the fuel pump is stopped, fuel injection and ignition are stopped, and the engine is stopped. At this time, as described above, it is desirable to gradually reduce the engine output.
[0058]
FIG. 7 is an explanatory diagram of still another embodiment of the present invention.
In this embodiment, the detection accuracy drop due to the attachment error of the acceleration sensor is prevented by changing the threshold value of the detection voltage of the acceleration sensor.
[0059]
In this method, first, the mounting error angle of the acceleration sensor is measured, and based on this, the threshold value is changed by that angle. For the installation error angle, in the case of a horizontal sensor, the sensor output is measured at three points of −90 °, 0 °, and + 90 °, and the attachment error angle is obtained from the measurement result by calculation processing. In the case of a vertical sensor, the sensor output is measured at three points of 0 °, 90 °, and 180 °, and the mounting error angle is obtained from the measurement result by calculation processing.
[0060]
Arithmetic processing will be described using horizontal placement as an example.

However, Y, Y ′, Y ″ are output voltages, a is an offset voltage, X is sensitivity, and b is sensor inclination (attachment error accuracy).
[0061]
Here, from Y + Y "= 2a, a = (Y-Y") / 2

Therefore, b = 1/2 * sin^-1{(Y "-Y) / (Y'-a)}.
[0062]
Based on the inclination angle b obtained in this way, the threshold value for the fall determination is changed.
In the example of FIG. 7, the threshold value is changed from ± 70 ° to −65 ° and + 75 ° when b is inclined + 5 ° in the horizontal sensor. In the case of a vertical sensor (in the case of a vertical sensor (Z-axis sensor) of a two-axis acceleration sensor), it is possible to determine the left / right tilt direction from the Y-axis sensor and change the threshold according to the left / right direction. .
[0063]
FIG. 8 is an explanatory diagram of still another embodiment of the present invention.
In this embodiment, when the mounting position of the acceleration sensor 110 on the printed circuit board 111 is checked, markings 108 and 109 with silk are applied to the sensor mounting position of the printed circuit board 111 in advance so that visual or automatic check can be easily performed. It is a thing. The markings 108 and 109 are formed at positions that serve as a guide for the allowable tilt range and the mounting angle of the acceleration sensor 110. The marking shape is not limited to (A) and (B) in the figure, and may be any shape as long as the angle can be roughly identified.
[0064]
By applying such marking, an error in attaching the acceleration sensor to the printed circuit board is identified, and it is possible to correct the fall determination based on the error, and to easily determine the defective product.
[0065]
Thus, the printed circuit board which comprises an acceleration sensor and comprises CPU is accommodated in the case of ECU. In this case, a guide is provided in the ECU case, and the printed circuit board is slid along the guide, inserted into the case, positioned, and filled with resin or the like to fix the printed circuit board at the predetermined position in the case. It is desirable to hold. Thereby, the detection error due to the mounting error of the printed circuit board with respect to the ECU is reduced.
[0066]
When an ECU incorporating a fall sensor is mounted on a vehicle body, if the ECU is away from the center of gravity of the vehicle body, the vibration of the vehicle body will affect the fall sensor, resulting in a decrease in detection accuracy and causing a false determination.
[0067]
Therefore, in order to improve detection accuracy, it is desirable that the ECU is attached as close to the center of gravity of the vehicle body as possible. Thereby, the noise factor by the influence of the vibration of the vehicle body and the front and rear pitch can be reduced, and the detection system can be enhanced.
[0068]
FIG. 9 is a flowchart of yet another embodiment of the present invention.
This embodiment addresses the problem that the detection accuracy has decreased due to variations in offset of the fall sensor, changes with time, temperature characteristics, etc., which has been a problem in the past, and corrects the fall sensor using a speed sensor. Thus, the detection accuracy is improved.
[0069]
Step d1: The vehicle speed is detected by the speed sensor, and the inclination of the vehicle body is detected by the fall sensor (acceleration sensor).
[0070]
Step d2: Determine whether or not the state in which the detected value of the speed sensor exceeds a predetermined value (30 km / h in this example) and the change in the output voltage of the fall sensor is less than the predetermined value (10 mV in this example) continues for 10 seconds or more. To do. When this state continues for 10 seconds or more, it is determined that the vehicle is traveling in a straight posture.
[0071]
Step d3: When it is determined in step d3 that the vehicle body is running in a straight posture, the fall sensor output or its average value is updated as the center value (the output voltage value at the neutral position in FIGS. 1 and 2). save.
[0072]
Step d4: A change from the center value is detected to determine whether the vehicle falls over (inclination is 70 ° or more). As a result, it is possible to detect a fall with high accuracy regardless of offset variations or changes with time due to temperature characteristics of the sensor or mounting errors.
[0073]
Step d5 :: When it is determined that the vehicle has fallen, the fuel pump is stopped, fuel injection and ignition are stopped, and the engine is stopped. At this time, as described above, it is desirable to gradually reduce the engine output.
[0074]
FIG. 10 is a flowchart of still another embodiment of the present invention.
This embodiment further enhances the reliability of the vehicle body tilt determination other than the fall of the wheelie or the like in the embodiment of FIG. 4 described above. That is, in the embodiment of FIG. 4, when the vehicle body is turned upside down or turned over 90 °, it may not be determined to fall. In the present embodiment, such an upside-down fall is reliably determined.
[0075]
More specifically, when the vehicle body falls 180 °, the output of the vertical Z-axis sensor is 1 g Cos (180 °) = − 1 g as shown in FIG. Show. On the other hand, as shown in FIG. 1 described above, the output of the horizontal Y-axis sensor is 1 gSin (180 °) = 0 g, which is erroneously determined as not falling.
[0076]
In the present embodiment, such erroneous determination is prevented, and when a tilt of ± 90 ° or more is detected by the Z-axis sensor, the fall is determined regardless of the Y-axis sensor.
[0077]
Step e1: A biaxial acceleration sensor is placed vertically, and the detection directions are a Z axis (vertical direction) and a Y axis (horizontal direction). The output voltage of the acceleration sensor is detected in the Z-axis and Y-axis directions.
[0078]
Step e2: It is discriminated whether it is upside down (over 90 ° or more) based on the detected output voltage of the Z-axis direction sensor. That is, in the above-described cosine curve of FIG. 2A, it is determined whether or not the overturn determination angle is ± 90 ° and is less than the corresponding output voltage value (g · cos (± 90 °)). If this state continues for more than 2 seconds, it is determined that the person has fallen upside down. Note that, as described above, the requirement to continue for 2 seconds or more is to increase the reliability of the fall determination by voltage detection.
If it is determined that the vehicle is toppled upside down, the process immediately proceeds to step e4 to perform overturning control such as stopping the fuel pump.
[0079]
Step e3: If it is determined in the step e2 that the sensor in the Z-axis direction does not fall upside down (inclined by more than ± 90 °), it will further fall according to the detection output voltage of the Z-axis sensor and Y-axis direction sensor. It is determined whether or not (falling within ± 90 °).
[0080]
That is, first, it is determined whether or not the vehicle falls due to the detected output voltage of the Z-axis direction sensor. As described above, in the cosine curve in FIG. 2A, it is determined whether or not the output voltage value (g · cos (± 70 °)) corresponding to ± 70 °, which is the fall determination reference angle, is smaller. . If this state continues for 2 seconds or more, it is determined that the vehicle has fallen. Note that, as described above, the requirement to continue for 2 seconds or more is to increase the reliability of the fall determination by voltage detection.
[0081]
Further, in order to confirm that the fall determination by the Z-axis sensor is not a wheelie or a steep slope, it is determined whether or not the Y-axis sensor is tilted, and the fall is determined only when the Y-axis sensor is also determined to be tilted. . In this case, the fall determination reference angle is set to ± 50 °. As a result, as can be seen from the graph of FIG. 1 described above, the detection accuracy of the laterally placed Y-axis sensor is higher than when the determination angle is ± 70 °.
[0082]
That is, the Y-axis overturn determination is performed by setting the reference angle for overturn determination to ± 50 ° in the sine curve of FIG. ) Greater than or less than (g · sin (−50 °)). If this state continues for 2 seconds or more, it is determined that the vehicle has fallen.
[0083]
Even if it is determined that the Z-axis sensor has fallen, if the Y-axis sensor detects that the vehicle is not tilted in the left-right direction, the vehicle body is tilted in the front-rear direction due to a wheelie or the like. repeat.
[0084]
Step e4 :: When it is determined that the vehicle has fallen, the fuel pump is stopped, fuel injection and ignition are stopped, and the engine is stopped. At this time, as described above, it is desirable to gradually reduce the engine output.
[0085]
  FIG. 11 shows the present invention.Indicates a reference technologyIt is a flowchart. In addition, FIG.Reference example5 is a graph of output data of tan (tangent) used in FIG.
[0086]
When an acceleration sensor is provided in a motorcycle, noise is included in the sensor output due to engine vibration, road surface unevenness, and the like. For this reason, when a logic is set to determine that a certain threshold has been exceeded for a certain period of time, it will be larger or smaller than the threshold due to vibration, and at a set angle. It cannot be detected. In this case, for example, if a low-pass filter such as a CR filter is provided to eliminate the vibration component, it can be detected at the set threshold fall angle. However, in this case, there is a problem that it takes a long response time and the detection time becomes long.
[0087]
  So thisReference exampleThen, by obtaining the tangent of the output of the vertical sensor and the output of the horizontal sensor, and judging the fall by this tangent output, even if each sensor picks up vibration and causes noise, the vertical sensor and horizontal sensor The fluctuations of each other cancel each other out so that the fall can be discriminated at the set detection angle.
[0088]
Step f1: A biaxial acceleration sensor is placed vertically, and the detection directions are a Z axis (vertical direction) and a Y axis (horizontal direction). The output voltage of the acceleration sensor is detected in the Z-axis and Y-axis directions.
[0089]
Step f2: It is discriminated whether it is upside down (over 90 ° or more) based on the detection output voltage of the Z-axis direction sensor. That is, in the above-described cosine curve of FIG. 2A, it is determined whether or not the overturn determination angle is ± 90 ° and is less than the corresponding output voltage value (g · cos (± 90 °)). If this state continues for more than 2 seconds, it is determined that the person has fallen upside down. Note that, as described above, the requirement to continue for 2 seconds or more is to increase the reliability of the fall determination by voltage detection.
[0090]
If it is determined that the vehicle has been turned upside down, the process immediately proceeds to step f4 to perform the overturn control such as stopping the fuel pump.
[0091]
Step f3: If it is determined in the above step f2 that the sensor in the Z-axis direction is not upside down (inclined by more than ± 90 °), it is further overturned by the detected output voltage of the Z-axis sensor and the Y-axis direction sensor. It is determined whether or not (falling within ± 90 °).
[0092]
That is, first, the output voltage of the horizontal Y-axis sensor in FIG. 1 (A) and the output voltage of the vertical Z-axis sensor in FIG. 2 (A) are detected, and the tangent (tan) = (Y-axis output). Voltage) / (Z-axis output voltage) is obtained by calculation. It is determined whether the tan output value is smaller than 1 g · tan (−α) or larger than 1 g · tan α when the fall angle is α. If any one of the conditions is satisfied continuously for 2 seconds or more, it is determined that the vehicle falls. The requirement to continue for 2 seconds or more is to increase the reliability of the fall determination based on the tangent output value. If both are not satisfied, it is judged that the person has not fallen.
[0093]
Explaining in the graph, the tangent curve output obtained from the sine curve output from the horizontal Y-axis sensor in FIG. 1A and the cosine curve output from the vertical Z-axis sensor in FIG. Represented. In FIG. 12, the vehicle body angle is in the range of −90 ° to + 90 ° because it is determined in step f2 that the vehicle does not fall upside down. Within this range, it is determined whether the falling angle α has been exceeded on the left side (−side) or the right side (+ side) of the vehicle body.
[0094]
The overturning angle α is set in consideration of the vehicle type of the scooter type or the normal motorcycle type, the body size, the displacement or the like. This α may be rewritable on the program according to the vehicle type or the like.
[0095]
In this way, by using a biaxial sensor that includes a vertical position to determine the fall by the tangent of both sensor outputs, noise is canceled out, so even if the sensor output fluctuates due to vibration or the like, the fall is reliably determined. Can do.
[0096]
Step f4 :: When it is determined that the vehicle has fallen, the fuel pump is stopped, fuel injection and ignition are stopped, and the engine is stopped. At this time, as described above, it is desirable to gradually reduce the engine output.
[0097]
Next, a structure for mounting the ECU incorporating the fall sensor on the vehicle body will be described.
FIG. 13 is an external view of a small motorcycle to which the present invention is applied.
[0098]
The vehicle body 1 has a handle 2 at the front, and the handle 2 is connected to a front wheel 5 via a steering shaft 4 through which a head pipe 3 is inserted. A body frame 6 is coupled to the head pipe 3. The body frame 6 forms a frame structure of the entire vehicle body. The front part of the vehicle body is covered with a cowling 7. The vehicle body 1 is covered with a vehicle body cover 8 from the outside of the vehicle body frame 6. A seat 9 is provided at the center of the vehicle body, a fuel tank 10 is provided on the lower side, and a helmet box (case) 11 is provided on the rear side. The fuel tank 10 supplies fuel to an injector (not shown) via a fuel hose (not shown). One end of the breather hose 12 is connected to the upper portion of the fuel tank 10, and the other end is connected to the canister 13. The canister 13 is connected to an intake system (for example, a throttle body) via a purge hose 14. A throttle wire 15 is attached to a throttle grip (or lever) of a right handle portion (not shown) and is connected to a throttle valve of an intake system. Similarly, a brake cable 16 is attached to a brake lever (not shown) of the handle portion and is connected to a brake cam shaft 18 of the rear wheel 17.
[0099]
An engine unit 19 is attached to the vehicle body frame 6 at the center of the vehicle body. The engine unit 19 includes an engine (not shown) and a speed reducer 24 integrally coupled to a crankcase (not shown). The engine unit 19 is suspended via an engine bracket 20 so as to be rotatable around a pivot 22 with respect to a lower body frame member 21 constituting a part of the body frame 6. The rear wheel 17 is connected to the rear portion of the engine unit 19 and the lower end of the damper 23 is pivoted. The upper end of the damper 23 is pivotally attached to a rear body frame (not shown) constituting a part of the body frame 6. As a result, the engine unit 19 can swing around the pivot 22 together with the rear wheel 17 to form a swing unit type engine.
[0100]
An air cleaner 25 is provided above the speed reducer 24. An outside air intake opening 25 a is opened at the front of the air cleaner 25, and a dustproof cover 26 made of rubber or resin is provided inside the vehicle body cover 8 so as to cover the opening. Reference numeral 27 denotes a stand, and 28 denotes a kick lever.
[0101]
FIGS. 14 and 15 are a side view and a plan view, respectively, showing a main part of the motorcycle equipped with the fuel injection engine according to the present invention. FIG. 16 is an enlarged view of the intake system portion.
[0102]
An engine 29 is provided below the fuel tank 10. The engine 29 is a four-cycle single cylinder engine having a fuel injection injector. A crankcase (not shown) of the engine 29 is integrally coupled with a speed reducer 24 composed of, for example, a V-belt type continuously variable speed reduction mechanism, and constitutes an engine unit 19 of a swing unit engine type as a whole. A duct 30 is connected to the front portion of the speed reducer 24, and outside air is sucked from the open end 30a and supplied to the speed reducer 5 to cool the inside. A rear output shaft (not shown) of the speed reducer 24 is connected to the axle of the rear wheel 17.
[0103]
An engine bracket 20 is integrally coupled to a front portion of the engine unit 19 of the swing unit engine type. A link plate 32 is pivotally attached to the engine bracket 20 via a shaft 31. The link plate 32 is rotatably attached to the lower body frame member 21 via the pivot 22.
[0104]
A damper (shock absorber) 23 is provided at the rear of the engine unit 19. The upper end 33 of the damper 23 is pivotally attached to the rear body frame member 34, and the lower end 35 is pivotally attached to a bracket 36 at the rear end portion of the engine unit 19. As a result, the engine unit 19 is mounted so as to be swingable with respect to the vehicle body frame around the pivot 22 on the front side. As shown in FIG. 16, the cylinder 37 of the engine 29 is tilted forward almost to the horizontal. The crankshaft 38 swings around the pivot 22 as shown by the arrow D together with the shaft 31 of the engine bracket 20 (FIG. 14).
[0105]
An intake manifold 39 communicating with an intake port (not shown) of the cylinder head and an intake pipe 40 (FIGS. 15 and 16) connected thereto are provided on the intake side of the engine 29, and an exhaust pipe 41 (FIG. 15) is provided on the exhaust side. ) Is connected. The intake pipe 40 is a bent elbow-shaped intake pipe. As shown in FIG. 16, the flange 43 is abutted against each other via a resin heat insulating material 42 and fixed by two bolts 44. Reference numeral 45 denotes a valve cam maintenance cover. The engine 29 is provided with a water temperature sensor 46 (FIGS. 15 and 16). The detection output signal of the water temperature sensor 46 is sent to the engine control unit 47 (FIG. 15) via the water temperature signal cable 89 (FIG. 15) and the wire harness 72. Further, a detection signal cable (not shown) of an intake air temperature sensor and an intake pressure sensor, which will be described later, is connected to the engine control unit 47 via a wire harness 72, and the throttle valve (not shown) is controlled to open and close based on these detection data. To do.
[0106]
A throttle body 48 is connected to the intake manifold 39 via the bent elbow-shaped intake pipe 40 described above. The throttle body 48 is connected to the air cleaner 25 via a joint 49. An injector 50 is attached to the intake pipe 40.
[0107]
A throttle valve (not shown) is mounted in the throttle body 48, and a diaphragm type suction piston 51 is mounted on the upstream side thereof. As will be described later, the suction piston 51 has a diaphragm chamber 52 provided on the upper side of the throttle body 48, and an air inlet (atmosphere open end) 54 of an air passage 53 for introducing the air into the diaphragm chamber 52 is a throttle. Provided on the lower side of the body 48. A throttle wire 15 connected to a throttle lever (not shown) or a throttle grip is connected to a valve shaft of the throttle valve via a link 55.
[0108]
The air intake opening 25a at the front of the air cleaner 25 is covered with a dust-proof cover 26 (dotted line in FIG. 13) made of rubber or resin. A vehicle body cover is further attached to the outside of the dust cover 26. The air intake 54 of the suction piston 51 opens inside the dust cover 26.
[0109]
Adjacent to the suction piston 51, the throttle body 48 is provided with a heater-type wax type auto choke 56 and an intake pressure sensor 57 (FIG. 15). The auto choke 56 opens and closes a bypass pipe (not shown) that communicates the upstream side and the downstream side of the throttle valve. The intake pressure sensor 57 communicates with the intake manifold 39 or the intake pipe 40 via a negative pressure hose 58 (FIG. 16). An intake air temperature sensor 59 (FIG. 15) is provided in the air cleaner 25.
[0110]
The intake pressure sensor 57 may be provided in the vicinity of the intake manifold. Further, a throttle position sensor (not shown) may be provided on the valve shaft of the throttle valve opposite to the link 55. In this case, the auto choke 56 is provided upstream of the throttle valve so as not to interfere with the throttle position sensor.
[0111]
The front lower portion of the fuel tank 10 is fixed to the left and right vehicle body frame members 61 via the bracket 60. A fuel hose 62 is pulled out from the rear of the fuel tank 10 to supply fuel to the injector 50. The fuel hose 62 is fixed to the rear body frame member 34 via a stay 63 (FIGS. 14 and 16). Reference numeral 64 (FIG. 14) denotes an overflow pipe. Reference numeral 65 (FIG. 15) denotes a battery, and 66 (FIG. 15) denotes a cooling water recovery tank. As shown in FIG. 15, a secondary air introduction system 86 for purifying exhaust gas is provided on the right side of the center of the vehicle body. The secondary air introduction system 86 communicates with the intake manifold via a negative pressure hose 87, and supplies outside air to a catalyst (not shown) via an air hose 88 in accordance with the intake negative pressure to reburn the exhaust gas.
[0112]
As shown in FIG. 14, a blow-by gas hose 90 is connected to the air cleaner 25. The blow-by gas hose 90 communicates with a cam chain chamber (not shown) that leads to a crankcase (not shown) of the engine 29, and prevents oil seal drop and loss horsepower due to a pressure increase in the crankcase of the engine. This blow-by gas hose 90 is connected to the clean side after passing through the element in the air cleaner, and the blow-by gas is again introduced into the combustion chamber.
[0113]
The fuel tank 10 communicates with the canister 13 via the breather hose 12 as shown in FIG. A rollover valve 124 is provided in the middle of the breather hose 12. The rollover valve 124 is closed at the time of falling to prevent the fuel from flowing out from the fuel tank 10.
[0114]
17A and 17B are a front side view and a left side view, respectively, of a mounting portion of the engine control unit.
In this arrangement example, the engine control unit (ECU) 47 has a substantially rectangular body shape in which the thickness of the lower portion 47b protruding to the front side is thicker than that of the upper portion 47a, and the rear surface side forms a rectangular flat mounting surface 47c. The ear pieces 158 are provided on the left and right of the same surface as the mounting surface 47c. Each ear piece 158 is fixed to a stay 160 which is welded and fixed to the inner surface side of the bracket 60 for supporting the fuel tank by a bolt 159. A wire harness 72 is connected to the lower part of the ECU 47 via a coupler 161.
[0115]
The bracket 60 is joined on a vehicle body frame member 61 joined to the left and right rear vehicle body frame members 34. The left and right rear body frame members 34 are joined to the front body frame members 140 via elbow frames 145, respectively. The aforementioned lower body frame member 21 is joined to the elbow frame 145, and a pivot 22 is provided on the lower body frame member 21 so as to swingably support the engine unit 19 (FIGS. 13 and 14). 162 is a tandem rider's footrest pipe frame, and 163 is a side stand.
[0116]
The fuel tank (not shown) is supported and disposed on a support member (not shown) provided between the upper parts of the left and right brackets 60 and a stay 63 provided on the upper part of the rear body frame member 34.
[0117]
A circuit board (not shown) arranged in parallel with the mounting surface 47c is accommodated in the ECU 47, and a two-dimensional (two-axis) acceleration sensor (not shown) is placed on this circuit board with its detection surface parallel to the board plane. Has been implemented. Therefore, the fall sensor composed of the two-dimensional acceleration sensor is mounted at a position protected by the brackets 60 on both the left and right sides at the center of the vehicle body in the left-right direction with the detection surface being substantially perpendicular to the vehicle body front-rear direction.
[0118]
18A and 18B are a rear side front view and a left side view, respectively, of an ECU mounting structure according to another embodiment of the present invention.
In this example, two upper pipe frames 165 and two lower pipe frames 166 are fixed by welding to the rear of the head pipe 164 constituting the front part of the vehicle body frame, and are surrounded by these four pipe frames 165 and 166. The ECU 47 is attached to the position. In the ECU 47, the ear piece 158 is fixed to the bracket 167 with a bolt 159 with the mounting surface 47 c as the front surface. The bracket 167 has a bifurcated lower part fixed to the left and right lower pipe frames 166 with bolts 168. The bracket 167 may be welded and fixed to the lower pipe frame 166 at appropriate portions such as both side edges.
[0119]
Reference numeral 169 denotes a fuel supply electromagnetic pump. Reference numeral 170 denotes a filter provided in the middle of a fuel hose (not shown) between the electromagnetic pump 169 and a fuel tank (not shown).
[0120]
In this embodiment as well, the ECU 47 has a mounting surface 47c parallel to the detection surface of a fall sensor (not shown) formed of an internal two-dimensional acceleration sensor substantially perpendicular to the longitudinal direction of the vehicle body, and substantially in the center of the lateral direction of the vehicle body. It is attached to a position protected by the pipe frames 165 and 166.
[0121]
【The invention's effect】
As described above, in the present invention, the acceleration sensor is used as a fall sensor, and this is incorporated into the ECU to form an integrated unit, thereby improving the fall detection accuracy and simplifying the configuration. Can be laid out efficiently in a narrow space without any restrictions. At the same time, the acceleration sensor is placed vertically, that is, the acceleration detection direction when the vehicle body is in a non-tilt state is perpendicular to the ground, so that it falls over the bank angle or falls. In this case, since the change in the detection output with respect to the change in the tilt angle in the vicinity of the bank angle (65 to 70 °), which is the determination angle of the fall state, is large, the change in the angle within a certain A / D conversion output width is small. The conversion error can be reduced, the accuracy of the fall determination can be improved, and the reliability can be improved.
[0122]
In addition, a biaxial or triaxial acceleration sensor is used, and the vertical detection direction (first detection direction) is always set for one axis, and the acceleration in the second detection direction in the vehicle width direction or the front-rear direction is detected. Thus, when the fall angle is exceeded by the angle detection in the first detection direction, the inclination of the vehicle body due to the wheelie running or the slope running is erroneously determined as the fall based on the detection result in the second detection direction. It is prevented.
[0123]
  Also,The detection of the overturn is performed by comparing the magnitude of the detection output voltage of the vertical sensor and the output voltage corresponding to the fall determination reference angle, based on the output of the vertical sensor. The detection of the fall based on the output of the horizontal sensor is performed based on the amount of change in the detection output of the horizontal sensor within a predetermined period after it is determined that the vehicle has fallen based on the detection output of the vertical sensor.To the configurationAccording to WillieWith regard to the second detection direction for discriminating a slope other than a fall due to running or the like, it is possible to discriminate whether it is a fall or a wheelie if it is discriminated whether there is a change in the slope, so that the difference from the reference value can be calculated Therefore, it is unnecessary to correct the offset error of the reference value.
[0124]
Further, according to the configuration in which the threshold value for the fall determination based on the first detection direction is changed based on the mounting angle of the acceleration sensor, the acceleration due to the mounting error of the ECU incorporating the acceleration sensor to the vehicle body, etc. When the sensor is attached to be tilted with respect to the vertical direction of the vehicle body, the detection accuracy can be improved by changing the threshold value of the fall determination according to the tilted angle.
[0125]
Furthermore, the average value detected by the acceleration sensor when the running speed is equal to or greater than a certain value and the change amount of the detection output of the acceleration sensor is equal to or less than the certain value is stored as a center value, and the fall determination is performed using the center value as the reference value According to this, when the running speed is above a certain value and the change in output of the acceleration sensor is below a certain value, the vehicle body is judged to be running in a straight posture with little inclination, and the average value of the sensor output at this time is the central value. Save as. By detecting this change from the center value, it is possible to prevent a decrease in detection accuracy due to variations in offset due to temperature characteristics or mounting errors of the sensor or changes over time.
[0128]
Furthermore, according to the configuration in which the ECU is provided in the center portion in the left-right direction of the vehicle body, it is possible to detect with high accuracy even in the case of tilting in the left-right direction, and the reliability of the fall detection is improved. Mechanical protection is provided by the left and right body frames to prevent damage during rollover.
[0129]
Further, a fuel tank mounting bracket is fixed to a vehicle body frame member disposed on the left and right of the vehicle body center portion, the ECU is disposed between the left and right brackets, and the ECU is fixed to each bracket via a stay. According to the configuration, the left and right brackets for mounting the fuel tank in the center of the vehicle body can be used to efficiently arrange the ECU between these brackets, and various types of sensors such as a water temperature sensor and an intake air temperature sensor around the engine The distance to the engine driving parts such as the sensor, injector, throttle valve, and ignition coil is shortened, so that the wire harness including the signal cable can be shortened, and the layout around the engine is simplified.
[Brief description of the drawings]
FIG. 1 is an explanatory view of an output voltage of a laterally arranged acceleration sensor according to the present invention.
FIG. 2 is an explanatory diagram of an output voltage of an acceleration sensor arranged vertically according to the present invention.
FIG. 3 of the present inventionThis is a diagram for explaining the reference technology.The flowchart of the fall determination control by a 1 axis | shaft acceleration sensor.
FIG. 4 is a flowchart of the fall determination control by the biaxial acceleration sensor of the present invention.
FIG. 5 is a block diagram of another embodiment of the present invention.
6 is a flowchart of the operation of the embodiment of FIG.
FIG. 7 is an explanatory diagram of an output voltage according to still another embodiment of the present invention.
FIG. 8 is a configuration explanatory diagram of still another embodiment of the present invention.
FIG. 9 is a flowchart of the operation of still another embodiment of the present invention.
FIG. 10 is a flowchart of the operation of still another embodiment of the present invention.
FIG. 11 shows the present invention.Indicates a reference technologyflowchart.
12 is a graph of sensor output of the reference example of FIG.
FIG. 13 is an external view of a small motorcycle according to the present invention.
Fig. 14 is a side view of the main part of the motorcycle shown in Fig. 13;
Fig. 15 is a plan view of the main part of the motorcycle shown in Fig. 13;
Fig. 16 is a configuration diagram of an engine portion of the motorcycle shown in Fig. 13;
FIG. 17 is a configuration explanatory view of an ECU mounting structure according to the present invention.
FIG. 18 is a configuration explanatory view of an ECU mounting structure according to another embodiment of the present invention.
[Explanation of symbols]
1: body, 2: handle, 3: head pipe, 4: steering shaft,
5: Front wheel, 6: Body frame, 7: Cowling, 8: Body cover,
9: Seat, 10: Fuel tank, 11: Helmet box,
12: Breather hose, 13: Canister, 14: Purge hose,
15: throttle wire, 16: brake cable, 17: rear wheel,
18: Brake camshaft, 19: Engine unit,
20: engine bracket, 21: lower body frame member, 22: pivot,
23: Damper, 24: Reducer, 25: Air cleaner l,
25a: Air intake opening, 26: Dust cover, 27: Stand,
28: kick lever, 29: engine, 30: duct, 30a: open end,
31: shaft, 32: link plate, 33: upper end, 33a: damper mounting hole,
34: Rear body frame member, 35: Lower end, 36: Bracket,
37: cylinder, 38: crankshaft, 39: intake manifold, 40: intake pipe,
41: exhaust pipe, 42: heat insulating material, 43: flange, 44: bolt,
45: Cover for maintenance, 46: Water temperature sensor, 47: Engine control unit,
47a: upper part, 47b: lower part, 47c: mounting surface,
48: throttle body, 49: joint, 49a: joint end,
50: Injector, 51: Suction piston, 52: Diaphragm chamber,
53: Air passage, 54: Air intake, 55: Link, 56: Auto choke,
57: Intake pressure sensor, 58: Negative pressure hose, 59: Intake temperature sensor,
60: bracket, 61: body frame member, 62: fuel hose,
62a: fixed hose part, 62b: swinging hose part, 63: stay,
64: overflow pipe, 65: battery,
66: Recovery tank, 72: Wire harness, 74: Throttle valve,
86: Secondary air introduction system, 87: Negative pressure hose, 88: Air hose,
89: Water temperature signal cable, 90: Blow-by gas hose,
101: Acceleration sensor, 102: Two-axis acceleration sensor, 103: Filter,
104: A / D converter, 105: capacitor, 106: filter,
107: CPU, 108, 109: marking, 110: acceleration sensor,
111: Printed circuit board, 124: Rollover valve,
140: front body frame member, 145: elbow frame,
158: Ear piece, 159: Bolt, 160: Stay, 161: Coupler,
162: A pedestal pipe frame for tandem riders,
163: Side stand, 164: Head pipe,
165: Upper pipe frame, 166: Lower pipe frame,
167: Bracket, 168: Bolt, 169: Electromagnetic pump,
170: Filter.

Claims (7)

An ECU that controls the engine and a fall sensor that detects the fall based on the tilt angle of the vehicle body,
The fall sensor is composed of an acceleration sensor,
In the motorcycle overturn detection device incorporating the acceleration sensor in the ECU,
The acceleration sensor includes a vertical sensor that detects acceleration in a first detection direction that is a direction perpendicular to the ground when the vehicle body is in a non-tilt state, and a second sensor that is perpendicular to the first detection direction. A fall detection device for a motorcycle, comprising a horizontal sensor for detecting acceleration in a detection direction, and detecting a fall based on the vertical sensor and an output from the horizontal sensor. The detection of the overturn is performed by comparing the magnitude of the detection output voltage of the vertical sensor and the output voltage corresponding to the fall determination reference angle, based on the output of the vertical sensor. The detection of the fall based on the output of the horizontal sensor is performed based on the amount of change in the detection output of the horizontal sensor within a predetermined period after it is determined that the vehicle has fallen based on the detection output of the vertical sensor. The motorcycle overturn detection device according to claim 1.   The fall detection device for a motorcycle according to claim 1 or 2, wherein a threshold value for judging fall by the first detection direction is changed based on a mounting angle of the acceleration sensor.   When the traveling speed is equal to or greater than a certain value and the amount of change in the detection output of the acceleration sensor within a predetermined period is equal to or less than the certain value, the detected value of the acceleration sensor is stored as center value data, The overturn detection device for a motorcycle according to claim 2 or 3, wherein the overturn is determined as a value. The motorcycle overturn detection device according to any one of claims 1 to 4 , wherein the ECU is provided at a central portion in a left-right direction of the vehicle body. The fuel tank mounting brackets are fixed to the vehicle body frame members arranged on the left and right of the vehicle body center, the ECU is arranged between the left and right brackets, and the ECU is fixed to each bracket via a stay. The motorcycle overturn detection device according to any one of claims 1 to 5 , characterized in that: The motorcycle overturn detection device according to any one of claims 1 to 6 , wherein the second detection direction is a width direction of the vehicle body when the vehicle body is in a non-tilt state.

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