JP3862040B2 - Fluid pressure source device - Google Patents

Description

と、圧力検出信号が低圧を表わすものから高圧を表わすもに切換ったときのモ−タ負荷電流値Ｉmaに基づいて、アキュムレ−タ圧がＰ５＝Ｐ４＋ΔＰmになるときのモ−タ負荷電流値Ｉ_Tおよび該Ｐ５になるまでの経過時間（遅延時間）Ｔ_dを算出することができる。ここで、Ｋi＝（Ｉ_TS／Ｉps）およびＫt＝（Ｔds／Ｉps）は、設計上又は試作結果に従って定める設定値（固定値）である。
【００１５】
なお、上述の説明では、アキュムレ−タ圧に対してモ−タ負荷電流が比例し、所定圧に対するモ−タ負荷電流が小さいとポンプの吐出流量（アキュムレ−タの昇圧速度）が高いと仮定したものであり、アキュムレ−タ圧に対してモ−タ負荷電流が非線形の場合、あるいは、所定圧に対するモ−タ負荷電流にアキュムレ−タの昇圧速度が逆比例しない場合には、これらの特性に応じて別途演算式又は検出電流値Ｉma対推定電流，遅延時間値Ｉ_T，Ｔ_dを書込んだデ−タテ−ブル（デ−タメモリ）を用意して、圧力検出信号が低圧を表わすものから高圧を表わすもに切換ったときのモ−タ負荷電流値Ｉmaに基づいて推定電流，遅延時間値Ｉ_T，Ｔ_dを導出するようにすればよい。
【００１６】
いずれにしても、圧力スイッチ(ＰＨ)の圧力検出信号が低圧を表わすものから高圧を表わすものに切換ったとき（圧力Ｐ４）の電気モ−タの負荷電流値Ｉmaに基づいて遅延時間Ｔ_dを定めて、該切換わりから遅延時間Ｔ_d後に電気モ−タを消勢することにより、アキュムレ−タ圧がＰ５＝Ｐ４＋ΔＰm、又はそれに近い値のときにポンプ駆動が停止し、アキュムレ−タ圧が実質上Ｐ４〜Ｐ５の範囲内に維持される。圧力スイッチ(ＰＨ)には、ヒステリシス幅を大きくするための機械要素を加える必要はないので、圧力スイッチのコストアップや精度低下あるいは信頼性の低下などは無い。
【００１７】
【発明の実施の形態】
（２）流体ポンプ(HP)，これを駆動する電気モ−タ(M)，該流体ポンプの吐出圧を受けるアキュムレ−タ(ACC)，該アキュムレ−タ又はそれに連通した流体圧ラインの圧力を検出する圧力スイッチ(ＰＨ)、および、該圧力スイッチ(ＰＨ)の圧力検出信号に応じてそれが高圧を表わすものから低圧を表わすものに切換ると前記電気モ−タの付勢を開始するポンプ制御手段(ECU)、を備える流体圧源装置において、
前記圧力スイッチ(ＰＨ)の圧力検出信号が低圧を表わすものから高圧を表わすものに切換ったときの前記電気モ−タ(M)の負荷電流値(Ima)に基づいて前記圧力を更に設定値ΔＰｍ分昇圧した場合の負荷電流値Ｉ_Tを推定演算し、前記電気モ−タの負荷電流値が該値Ｉ_Tに達したときに電気モ−タを消勢する昇圧停止手段(ECU)、を備えることを特徴とする。
【００１８】
この態様によれば、圧力スイッチ(ＰＨ)の圧力検出信号が低圧を表わすものから高圧を表わすものに切換ったとき（圧力Ｐ４）の電気モ−タの負荷電流値Ｉmaに基づいて、例えば上記(2)式に従がい遅延時間Ｔ_dを定めて、該切換わりから遅延時間Ｔ_d後に電気モ−タを消勢することにより、アキュムレ−タ圧がＰ５＝Ｐ４＋ΔＰm、又はそれに近い値のときにポンプ駆動が停止し、アキュムレ−タ圧が実質上Ｐ４〜Ｐ５の範囲内に維持される。圧力スイッチ(ＰＨ)には、ヒステリシス幅を大きくするための機械要素を加える必要はないので、圧力スイッチのコストアップや精度低下あるいは信頼性の低下などは無い。
【００１９】
（３）流体ポンプ(HP)，これを駆動する電気モ−タ(M)，該流体ポンプの吐出圧を受けるアキュムレ−タ(ACC)，該アキュムレ−タ又はそれに連通した流体圧ラインの圧力を検出する圧力スイッチ(ＰＨ)、および、該圧力スイッチ(ＰＨ)の圧力検出信号に応じてそれが高圧を表わすものから低圧を表わすものに切換ると前記電気モ−タの付勢を開始するポンプ制御手段(ECU)、を備える流体圧源装置において、
前記圧力スイッチ(ＰＨ)の圧力検出信号が低圧を表わすものから高圧を表わすものに切換ったときの前記電気モ−タの負荷電流値(Ima)に基づいて遅延時間Ｔ_dを定めかつ前記圧力を更に設定値ΔＰｍ分昇圧した場合の負荷電流値Ｉ_Tを推定演算し、該切換わりから遅延時間Ｔ_d経過後前記電気モ−タの負荷電流値が該値Ｉ_Tに達したときに電気モ−タを消勢する昇圧停止手段(ECU)、を備えることを特徴とする。
【００２０】
この態様によれば、圧力スイッチ(ＰＨ)の圧力検出信号が低圧を表わすものから高圧を表わすものに切換ったとき（圧力Ｐ４）の電気モ−タの負荷電流値Ｉmaに基づいて、例えば上記(2)式に従がい遅延時間Ｔ_dを定め、例えば上記(1)式に従がい推定電流値Ｉ_Tを定めて、該切換わりから遅延時間Ｔ_dを経た後にモ-タ負荷電流値が推定電流値Ｉ_T以上であるときに電気モ−タを消勢することにより、アキュムレ−タ圧がＰ５＝Ｐ４＋ΔＰm、又はそれに近い値のときにポンプ駆動が停止し、アキュムレ−タ圧が実質上Ｐ４〜Ｐ５の範囲内に維持される。圧力スイッチ(ＰＨ)には、ヒステリシス幅を大きくするための機械要素を加える必要はないので、圧力スイッチのコストアップや精度低下あるいは信頼性の低下などは無い。遅延時間Ｔ_dの経過と、モ−タ負荷電流値がＩ_T以上の２条件の成立をポンプ駆動停止の条件とするので、ΔＰm分の昇圧が確実に行なわれる。すなわち広いヒステリシス幅が確実に確保される。
【００２１】
（４）昇圧停止手段(ECU)は、正常時には圧力がＰ４に上昇したときに圧力検出信号を低圧を表わすものから高圧を表わすものに切換える圧力スイッチ(LP1)の、該圧力検出信号が低圧を表わすものでポンプ制御手段(ECU)が電気モ−タ(M)を付勢している間、電気モ−タ(M)の負荷電流値Ｉmが、Ｐ４に設定値ΔＰｍを加えた圧力Ｐ４＋ΔＰｍに相当する値Ｉ_Tより高い設定値Ｉ_TU以上になると電気モ−タを消勢する、上記（１），（２）又は（３）記載の流体圧源装置。
【００２２】
圧力スイッチ(LP1)の接片の移動不良又は信号線の断線など（以下単に断線異常と称す）により、アキュムレ−タ圧が設定圧Ｐ４を越えても圧力検出信号が低圧を表わすものから高圧を表わすものに切換らないと、上記（１），（２）および（３）に記述したポンプ駆動停止条件が成立しない。この場合、電気モ−タ(M)の負荷電流値Ｉmが、設定値Ｉ_TU以上になったときに、昇圧停止手段(ECU)が電気モ−タを消勢する。したがって断線異常すなわち低圧検出から高圧検出への切換り不全の故障のときのアキュムレ−タの過圧が防止される。
【００２３】
本発明の他の目的および特徴は、図面を参照した以下の実施例の説明より明らかになろう。
【００２４】
【実施例】
−第１実施例−
図１に、本発明の第１実施例の流体圧源装置を装備した、車両上の車輪ブレ−キ圧制御装置の全体構成を示す。エンジンＥＧはスロットル制御装置ＴＨ及び燃料噴射装置ＦＩを備えた内燃機関で、スロットル制御装置ＴＨにおいてはアクセルペダルＡＰの操作に応じてメインスロットルバルブＭＴの開度が制御される。また、電子制御装置ＥＣＵの出力に応じて、スロットル制御装置ＴＨのサブスロットルバルブＳＴが駆動されその開度が制御されると共に、燃料噴射装置ＦＩが駆動され燃料噴射量が制御されるように構成されている。エンジンＥＧは、変速制御装置ＧＳ及びディファレンシャルギヤＤＦを介して車両後方の車輪ＲＬ，ＲＲに連結されている。
【００２５】
車輪ＦＬ，ＦＲ，ＲＬ，ＲＲに夫々車輪ブレ−キのホイールシリンダＷｆＬ，Ｗｆｒ，ＷｒＬ，Ｗｒｒが装着されており、これらのホイールシリンダＷｆＬ等は、ブレーキ液圧回路ＰＣに接続されている。尚、車輪ＦＬは運転席からみて前方左側の車輪（前左車輪）を示し、以下、ＦＲは前右車輪、ＲＬは後左車輪、ＲＲは後右車輪である。
【００２６】
車輪ＦＬ，ＦＲ，ＲＬ，ＲＲには、車輪の所定小角度の回転につき１パルスの電気信号を発生するパルス発生器ＷＳ１及至ＷＳ４が結合され、これらが電気パルスを電子制御装置ＥＣＵに与える。電子制御装置ＥＣＵのマイクロコンピュ−タＣＭＰは、パルス発生器ＷＳ１が１パルスを与えると割込処理を実行して、そのときの計時値（クロックパルスカウント値）を、ＷＳ１宛てのパルス周期レジスタに書込んでクロックパルスのカウントアップを再スタ−トする。これにより、ＷＳ１宛てのパルス周期レジスタには常に、パルス発生器ＷＳ１が発生するパルスの最新の１周期の時間を表わすデ−タが書込まれている。マイクロコンピュ−タＣＭＰは、車輪ＦＬの回転速度ＶｗｆＬを演算するときには、ＷＳ１宛てのパルス周期レジスタのデ−タが表わす値の逆数に比例係数を乗じて、回転速度ＶｗｆＬを算出する。パルス発生器ＷＳ２〜ＷＳ４が発生するパルスに対しても同様な割込処理を実行し、同様に、車輪ＦＲ，ＲＬ，ＲＲの回転速度Ｖｗｆｒ，ＶｗｒＬ，Ｖｗｒｒを算出する。
【００２７】
ブレーキペダルＢＰが踏み込まれたときオンとなるブレーキスイッチＢＳ，アキュムレ−タ出力圧の高低を検出する圧力スイッチＰＨ及び車両のヨーレートを検出するヨーレートセンサＹＳ等が電子制御装置ＥＣＵに接続されている。ヨーレートセンサＹＳは、車両重心を通る鉛直軸回りの車両回転角（ヨー角）の変化速度、即ちヨー角速度（ヨーレート）を検出しこれを表わす電気信号を電子制御装置ＥＣＵに与える。マイクロコンピュ−タＣＭＰは、ヨ−レ−トを読込むとき、ヨーレートセンサＹＳが発生する電気信号をデジタル変換して、デジタルデ−タを読込む。
【００２８】
電子制御装置ＥＣＵは、図１に示すように、バスを介して相互に接続されたマイクロプロセッサＣＰＵ，メモリＲＯＭ，ＲＡＭ，入力ポートＩＰＴ及び出力ポートＯＰＴ等から成るマイクロコンピュータＣＭＰを備えている。
【００２９】
ブレーキスイッチＢＳ，圧力スイッチＰＨ，パルス発生器ＷＳ１及至ＷＳ４，ヨーレートセンサＹＳ等の出力信号は、増幅回路ＡＭＰを介して夫々入力ポートＩＰＴからマイクロプロセッサＣＰＵのＡ／Ｄ変換ポ−トに与えられ、ＣＰＵはこれらの出力信号のレベルをデジタルデ−タに変換して読込む。ＣＰＵはその出力ポートＯＰＴから、リレ−ドライバＲＤに、リレ−オン（ポンプ駆動＝モ−タ付勢：ＯＮ）／オフ（ポンプ停止＝モ−タ消勢：ＯＦＦ）信号を与え、リレ−ドライバＲＤが、ＯＮ信号がある間リレ−ＲＹのリレ−コイルに通電する。これによりリレ−ＲＹの接片が閉じて電気モ−タＭに通電する。ＣＰＵはまた、その出力ポートＯＰＴからブレ−キ液圧回路ＰＣの電磁弁（１２個）に通電するソレノイドドライバに制御信号を与え、またスロットル制御装置ＴＨに対する制御信号を、スロットル制御装置ＴＨのサブスロットルＭＴを開閉駆動する電気モ−タに宛てたモ−タドライバＡＣＴに与える。
【００３０】
マイクロコンピュータＣＭＰのＲＯＭには、後述する種々の処理を実行する制御プログラムおよび固定定数等のデ−タが格納されており、マイクロプロセッサＣＰＵは、図示しないイグニッションスイッチが閉成され、これにより図示しない電源回路が動作電圧を与える間該プログラムを実行する。ＲＡＭは、ＲＯＭから読出したプログラム，ＲＯＭに格納されているデ−タ，入力ポ−トを介して読込んだデ−タならびにＣＰＵが生成したデ−タを一時的に記憶する。
【００３１】
モ−タＭの通電回路には、モ−タＭの通電電流値に比例する電圧を発生する電流検出用の抵抗Ｒがあり、その電圧が入力ポ−トを介してマイクロプロセッサＣＰＵのＡ／Ｄ変換ポ−トに与えられる。マイクロプロセッサＣＰＵは、モ−タ電流値を参照する必要があるとき、該電圧をデジタルデ−タ（モ−タ電流デ−タ）に変換して読込む。
【００３２】
図２に、ブレーキ液圧回路ＰＣの構成を示す。ブレーキペダルＢＰが踏込まれるとブースタＨＢが踏込圧に実質上比例する圧力を発生して、この圧力でマスタシリンダＭＣのピストンを駆動する。ブースタＨＢには液圧源ＰＳが接続されており、液圧源ＰＳは液圧ポンプＨＰ，駆動モ−タＭ，及びアキュレムレータＡＣＣを有する。アキュムレータＡＣＣと低圧リザーバＲＳとの間にはリリーフバルブＲＶが介装されている。液圧ポンプＨＰは、電気モータＭによって駆動され、低圧リザーバＲＳのブレーキ液を吸引し加圧して逆止弁ＣＶ６を介してアキュレムレータＡＣＣに与える。ＣＰＵは、アキュムレ−タＡＣＣ又はその給圧ラインの圧力を検出する圧力スイッチＰＨのオン（高圧）／オフ（低圧）を監視して、それがオンからオフになるとドライバＡＣＴを介して電気モータＭを駆動する。これによりアキュムレ−タＡＣＣの液圧が上昇する。
【００３３】
またＣＰＵは、圧力スイッチＰＨが低圧側に切換らない場合には、ブレ−キペダルＢＰを踏み込むことにより作動するブレ−キスイッチＢＳの開閉が、所定の回数に達するとドライバＡＣＴを介して電気モータＭを駆動する。これによりアキュムレ−タＡＣＣの液圧が上昇する。そして電動モータＭの駆動後、所定の時間が経過するとＣＰＵはドライバＡＣＴを介して電気モータＭを停止する。ＣＰＵのこの駆動制御により、アキュムレ−タＡＣＣの液圧は、常時所定範囲内に維持される。
【００３４】
液圧ブースタＨＢは、液圧源ＰＳの出力液圧（アキュムレ−タＡＣＣの液圧）をソ−ス圧として、ブレ−キペダルＢＰの踏込圧（制御圧）に比例した出力圧を発生し、これによってマスタシリンダＭＣが倍力駆動される。
【００３５】
マスタシリンダＭＣと前輪ホイールシリンダＷｆｒ，ＷｆＬの各々を接続する前輪側の液圧回路には、電磁切換弁ＳＡ１及びＳＡ２が介装されており、これらは制御圧ラインＰｆｒ及びＰｆＬを介して夫々電磁開閉弁ＰＣ１，ＰＣ５及び電磁開閉弁ＰＣ２，ＰＣ６に接続されている。また、液圧ブースタＨＢとホイールシリンダＷｆｒ等の各々を接続する液圧路には、電磁開閉弁ＳＡ３，給排制御用の電磁開閉弁ＰＣ１及至ＰＣ８が介挿されており、後輪側には比例減圧弁ＰＶが介装されている。そして、電磁開閉弁ＳＴＲを介して液圧源ＰＳの液圧が電磁開閉弁ＳＡ３の下流側に印加される。
【００３６】
前輪側液圧系において、電磁開閉弁ＰＣ１及びＰＣ２は、電磁開閉弁ＳＴＲに接続されている。電磁開閉弁ＳＴＲは２ポート２位置の電磁開閉弁であり、その電気コイルに通電がない非作動（オフ）時は弁閉（遮断）で、その電気コイルに通電がある作動（オン）時は弁開（通流）であって電磁開閉弁ＰＣ１及びＰＣ２がアキュムレータＡＣＣに連通する。
【００３７】
電磁切換弁ＳＡ１及び電磁切換弁ＳＡ２は、３ポート２位置の電磁切換弁で、その電気コイルに通電がない非作動（オフ）時は、図２に示す第１位置にあって前輪ホイールシリンダＷｆｒ，ＷｆＬは何れもマスタシリンダＭＣに連通しているが、電気コイルに通電がある作動（オン）時は、第２位置に切換わって、ホイールシリンダＷｆｒ，ＷｆＬは何れもマスタシリンダＭＣから遮断され、代りに夫々電磁開閉弁ＰＣ１及びＰＣ５，電磁開閉弁ＰＣ２及びＰＣ６と連通する。
【００３８】
これら電磁開閉弁ＰＣ１及びＰＣ２に対して並列に逆止弁ＣＶ１及びＣＶ２が接続されており、逆止弁ＣＶ１の流入側が制御圧ラインＰｆｒに、逆止弁ＣＶ２の流入側が制御圧ラインＰｆＬに夫々接続されている。逆止弁ＣＶ１は、電磁切換弁ＳＡ１がオン（第２位置）である場合において、ブレーキペダルＢＰが開放されたときには、前右車輪のホイールシリンダＷｆｒのブレーキ液圧を液圧ブースタＨＢの出力液圧の低下に迅速に追従させるために設けられたもので、液圧ブースタＨＢ方向へのブレーキ液の流れは許容されるが逆方向の流れは阻止される。 逆止弁ＣＶ２は、前左車輪のホイールシリンダＷｆＬについて、同様に逆流阻止を行なう。
【００３９】
後輪側液圧系の電磁開閉弁ＳＡ３は、２ポート２位置の電磁開閉弁で、その電気コイルに通電がない非作動（オフ）時には、図２に示す弁開（通流）であって、電磁開閉弁ＰＣ３，ＰＣ４は比例減圧弁ＰＶを介して液圧ブースタＨＢと連通する。このとき、電磁開閉弁ＳＴＲは図２に示すようにオフ（弁閉）とされ、比例減圧弁ＰＶはアキュムレータＡＣＣとの連通が遮断されている。電磁開閉弁ＳＡ３が、オンとなって弁閉（遮断）になると、電磁開閉弁ＰＣ３，ＰＣ４は液圧ブースタＨＢとの連通が遮断され、比例減圧弁ＰＶを介して電磁開閉弁ＳＴＲに接続され、この電磁開閉弁ＳＴＲがオン（通流）になったときにアキュムレータＡＣＣと連通する。
【００４０】
また、電磁開閉弁ＰＣ３及びＰＣ４に対して並列に逆止弁ＣＶ３及びＣＶ４が接続されており、逆止弁ＣＶ３の流入側がホイールシリンダＷｒｒに、逆止弁ＣＶ４の流入側がホシールシリンダＷｒＬに夫々接続されている。これらの逆止弁ＣＶ３，ＣＶ４は、ブレーキペダルＢＰが開放されたときには、ホイールシリンダＷｒｒ，ＷｒＬのブレーキ液圧を液圧ブースタＨＢの出力液圧の低下に迅速に追従させるために設けられたもので、電磁開閉弁ＳＡ３方向へのブレーキ液の流れを許し逆方向の流れは阻止する。更に、逆止弁ＣＶ５が電磁開閉弁ＳＡ３に並列に設けられており、電磁開閉弁ＳＡ３がオン（遮断）のときにも、ブレーキペダルＢＰによる踏み増し（車輪ブレ−キ圧の増圧）が可能である。
【００４１】
上記電磁切換弁ＳＡ１，ＳＡ２及び電磁開閉弁ＳＡ３，ＳＴＲ並びに電磁開閉弁ＰＣ１及至ＰＣ８は、前述の電子制御装置ＥＣＵによってオン／オフ制御される。例えば、ブレーキペダルＢＰが操作されていない状態で行なわれる制動操舵制御（車輪ブレ−キ圧配分制御）時には、液圧ブースタＨＢ及びマスタシリンダＭＣからはブレーキ液圧が出力されないので、電磁切換弁ＳＡ１，ＳＡ２がオン（第２位置）とされ、電磁開閉弁ＳＡ３がオン（遮断）され、そして電磁開閉弁ＳＴＲがオン（通流）とされる。これにより、液圧源ＰＳのアキュムレ−タＡＣＣの液圧が、電磁開閉弁ＳＴＲ並びに通流状態の電磁開閉弁ＰＣ１及至ＰＣ８を介してホイールシリンダＷｆｒ等に供給され得る状態となる。而して、電磁開閉弁ＰＣ１及至ＰＣ８を、繰返してオフ／オンし、この繰返しのオフデュ−ティ（オフ／オン一周期に対するオフ時間の比）を変更することにより、急増圧，パルス増圧（緩増圧），ホ−ルド（保持），パルス減圧（緩減圧），急減圧等を行なうことができる。
【００４２】
例えば、前右車輪Ｗｆｒの車輪ブレ−キ圧を制御するための電磁開閉弁ＰＣ１とＰＣ５に関して説明すれば、ＰＣ１オフ（通流）＆ＰＣ５オフ（遮断）の状態では前右車輪Ｗｆｒの車輪ブレ−キ圧が増圧となる。ここで、前述のオフ／オン一周期に対するオフデュ−ティを１００％とすると、これは連続してオフを保持する状態であり、これが典型的な急増圧である。オフデュ−ティを０％とすると、これは連続してオンを保持する状態であり、オンではＰＣ１オン（遮断）＆ＰＣ５オン（通流）であって前右車輪Ｗｆｒの車輪ブレ−キ圧がＰＣ５を通してリザ−バＲＳに抜けるので、これが典型的な急増減である。すなわち典型的なオフデュ−ティ１００％の急増圧とオフデュ−テ０％（＝オンデュ−ティ１００％）の急減圧を想定すると、単純には、オフデュ−ティが５０％以上１００％未満がパルス増圧（緩増圧），５０％未満０％超がパルス減圧（緩増圧）ということになり、ＰＣ１オン（遮断）＆ＰＣ５オフ（遮断）がホ−ルドである。
【００４３】
しかしながら本実施例では、急増圧，パルス増圧（緩増圧），パルス減圧（緩減圧）および急減圧のそれぞれに一対一に基準オフデュ−ティを定めており、車輪ブレ−キ圧制御中はＣＰＵが、急増圧要，パルス増圧（緩増圧）要，ホ−ルド（保持）要，パルス減圧（緩減圧）要又は急減圧要と、１つのモ−ドを決定し、要としたモ−ドに宛てられている基準オフデュ−ティ（１値）を、更に細かく補正することにより、オフデュ−ティを最終的に定めて、このオフデュ−ティに従って、急増圧要又はパルス増圧要のときには増圧用の電磁開閉弁ＰＣ１をオフ／オン制御し減圧用の電磁開閉弁ＰＣ５は連続オフ（遮断）とし、急減圧要又はパルス減圧要のときには増圧用の電磁開閉弁ＰＣ１は連続オン（遮断）として減圧用の電磁開閉弁ＰＣ５をオフ／オン制御する。ホ−ルド要のときには電磁開閉弁ＰＣ１を連続オン（遮断）および電磁開閉弁ＰＣ５は連続オフ（遮断）とする。前左車輪のホイ−ルシリンダの増圧用の電磁開閉弁ＰＣ２と減圧用の電磁開閉弁ＰＣ６，後右車輪のホイ−ルシリンダの増圧用の電磁開閉弁ＰＣ３と減圧用の電磁開閉弁ＰＣ７、および、後左車輪のホイ−ルシリンダの増圧用の電磁開閉弁ＰＣ４と減圧用の電磁開閉弁ＰＣ８についても、ＣＰＵは同様なオフ／オン制御を行なう。
【００４４】
図３に、図１（および図２）に示す圧力スイッチＰＨの拡大縦断面を示す。圧力スイッチＰＨのダイヤフラムＤＡの右側には、系統圧、すなわちアキュムレ−タＡＣＣの圧力が印加されている。この圧力によりダイヤフラムＤＡ及びロッドＲＯは圧縮コイルスプリングＳＰに抗して図面上左方に移動し、所定の圧力でマイクロスイッチＭＳを押し、その接点を開より閉に切換える。この閉への切換わりは、アキュムレ−タ圧がＰ４未満からＰ４になったときに生じ、Ｐ４以上でスイッチＰＨは閉を維持する。アキュムレ−タＡＣＣの圧力が低下すれば、ロッドＲＯ及びダイヤフラムＤＡはスプリングＳＰによって図面右方に移動し、Ｐ３より高い圧力からＰ３に低下するとマイクロスイッチＭＳの接点を閉から開に切換え、圧力がＰ３以下の間、開を維持する。
【００４５】
図４の（ａ）に、圧力スイッチＰＨと電子制御装置ＥＣＵの電気接続を示す。圧力スイッチＰＨには、図示しない抵抗（１ｋΩ）がマイクロスイッチＭＳの接点と並列に接続されている。図４の（ｂ）は圧力スイッチＰＨの出力電圧を示す。接点が開（低圧時）には圧力スイッチＰＨ両端には出力電圧を生じ、接点が閉（高圧時）には圧力スイッチＰＨ両端の出力電圧はゼロとなる。この接点の切換わりは、実際には図で示すようなヒステリシス特性を有しており、低圧から高圧にアキュムレ−タ圧が上昇するときには、圧力スイッチＰＨの圧力検出信号は、圧力Ｐ４で高レベルＨＩ（開）から低レベルＬＯ（閉）に切換わり、アキュムレ−タ圧が降下するときには、圧力スイッチＰＨの圧力検出信号は、圧力Ｐ３で低レベルＬＯ（閉）から高レベルＨＩ（開）に切換わる。
【００４６】
図５に、電子制御装置ＥＣＵが装備しているマイクロコンピュ−タＣＭＰのマイクロプロセッサＣＰＵの、本発明の要旨に関連するポンプ駆動制御動作のみを示す。電源が投入されるとＣＰＵはシステムプログラムに従って初期設定を行なう（ステップＡ）。なお、以下においてカッコ内には、ステップの語を省略して、ステップＮｏ．記号のみ記す。
【００４７】
次にＣＰＵは、６msecタイマをスタ−トして（Ｂ）、圧力スイッチＰＨの圧力検出信号（高レベルＨＩ：低圧／低レベルＬＯ：高圧）を読込み（Ｃ）、ブレ−キスイッチのブレ−キペダル踏込信号（高レベルＨ：ブレ−キペダル解放／低レベルＬ：ブレ−キペダル踏込み）を読込み（Ｄ）、「モ−タ制御」（Ｅ）を実行する。そして「モ−タ制御」（Ｅ）を出ると、６msecタイマがタイムオ−バするのを待って（Ｆ）、タイムオ−バすると、またステップＢ〜Ｅを上述の順に実行する。したがって、ステップＢ〜Ｅの処理は、６msec周期で繰返し実行される。図６に、「モ−タ制御」（Ｅ）の内容を示す。以下、項分けで、「モ−タ制御」（Ｅ）におけるＣＰＵの処理を説明する。
【００４８】
１．ブレ−キペダル操作回数のカウント
ＣＰＵは、ブレ−キスイッチＢＳの信号が低レベルＬ（ブレ−キペダル踏込みあり）であると、前回は高レベルＨ（ブレ−キペダル踏込みなし）であるかをチェックして（１，２）、そうであると今回ブレ−キペダルが踏込まれ、新たなブレ−キペダル踏込みがあったとして、ブレ−キ回数レジスタＮのデ−タを１インクレメントする（３）。前回も低レベルＬであると、ブレ−キペダル踏込み中であり、すでに解放から踏込みへの切換わり時点にブレ−キペダル踏込み回数Ｎを１インクレメントしているので、ここではブレ−キ回数レジスタＮのデ−タは１インクレメントしない。ブレ−キ回数レジスタＮのデ−タ（ブレ−キ踏込み回数）は、圧力スイッチＰＨが低圧を検出しこれに応じてポンプモ−タＭを付勢（ＯＮ：ポンプ駆動）したときにクリアするので、ブレ−キ回数レジスタＮのデ−タは、圧力スイッチＰＨの圧力検出信号が高圧を表わすＬＯである間のブレ−キペダル踏込回数を表わす値となる。
【００４９】
２．圧力スイッチＰＨが正常なときのアキュムレ−タ圧の昇圧
圧力スイッチＰＨの圧力検出信号がＬＯ（高圧）からＨＩ（低圧）に切換わると（アキュムレ−タ圧がＰ３以下に下ると）、ＣＰＵは、モ−タＭをＯＮにして（４〜６）、レジスタＮ，Ｆ，ＴおよびＭをクリアする（７〜１０）。これによりポンプＨＰが駆動されて、アキュムレ−タ圧が上昇する。圧力スイッチＰＨの圧力検出信号がＨＩ（低圧）の間、すなわち、アキュムレ−タ圧がＰ４に達するまで、ＣＰＵは、「モ−タ制御」（Ｅ）においては、ステップ１〜１１を実行する。圧力スイッチＰＨの圧力検出信号がＬＯ（高圧）に切換わると、すなわちアキュムレ−タ圧がＰ４に達すると、ＣＰＵは、ステップ４から１２に進み、ステップ１２〜１７（１７内では４１と４２のみ）を実行して、ＬＯ（高圧）に切換わってからの経過時間Ｔをカウントする（１５）。そして、「停止処理」（１６）において、ポンプ駆動停止条件が成立すると、モ−タＭをＯＦＦ（ポンプＨＰ停止）とする。
【００５０】
図７に「停止処理」（１６）の内容を示す。ここでは、圧力スイッチＰＨの圧力検出信号がＬＯ（高圧）に切換た直後では、モ−タ電流値Ｉmを読込み、この電流値Ｉmに対応する、アキュムレ−タ圧がＰ５＝Ｐ４＋ΔＰmとなるときのモ−タ電流値Ｉ_T（推定値）および遅延時間Ｔ_d（推定値）を、上記(1)式および(2)式に従って算出し、経過時間計測値Ｔをクリアする（２１〜２６）。なお、ステップ２１のＦsm＝１は、電気モ−タＭがＯＮであることを意味する。その後の「停止処理」（１６）では、モ−タ電流値Ｉmを読込み（２２）、ステップ２３から２７に進み、モ−タ電流値Ｉmが推定算出値Ｉ_T以上であるか、経過時間Ｔが推定遅延時間Ｔ_d以上であるかをチェックして（２８，２９）、いずれか一方が成立すると、モ−タＭをＯＦＦにしてレジスタＦsmおよび経過時間Ｔをクリアする（３０Ａ〜３０Ｃ）。なお、ステップ２７のタイマＴmsは、モ−タＭを起動してからモ−タ電流値が起動電流（高値）から負荷（アキュムレ−タ圧）対応の値に低下するまでの時間（起動時間）よりわずかに長い時限値Ｔms（この実施例では１sec)のプログラムタイマであり、モ−タＭをＯＮにしたときに起動（スタ−ト）しており、モ−タＭをＯＮにしたときから時間Ｔmsが経過しているとタイムオ−バしている。タイムオ−バしていないと、読込み電流値Ｉmが負荷対応値でないので、モ−タ通電停止条件が成立しているか否かのチェック（２８，２９）は行なわず、モ−タＭのＯＮを継続する。
【００５１】
圧力スイッチＰＨが正常である間は、ＣＰＵが圧力スイッチＰＨの圧力検出信号に応じて、それがＨＩ（低圧）に切換わるとポンプＨＰを駆動し（４〜１１）、ＬＯ（高圧）に切換わると、そのときのモ−タ電流値Ｉmに対応する、アキュムレ−タ圧がＰ５＝Ｐ４＋ΔＰｍとなるときのモ−タ電流推定値Ｉ_Tおよび遅延時間Ｔ_dを算出して、モ−タ電流値がＩ_Tになるか、又は経過時間Ｔが遅延時間Ｔ_dになったときに、モ−タＭをＯＦＦにする（１６）。
【００５２】
３．圧力スイッチＰＨの断線異常のときのアキュムレ−タ圧の昇圧
例えば圧力スイッチＰＨが接片開放（開）で接点が閉じなくなるとか、断線した場合には、アキュムレ−タ圧がＰ４を越えても圧力検出信号がＬＯ（高圧）に切換わらずポンプ駆動が続いてしまう。これを防止するために、ステップ１１の「異常処理」がある。その内容を図８に示す。ここでは、モ−タＭの付勢（ＯＮ）を開始したときに、レジスタＦmsに「１」（モ−タＭがＯＮ中）を書込み（３１，３２）、タイマＴsmをスタ−トする（３１〜３４）。そしてタイマＴsmがタイムオ−バした後に、モ−タ電流値Ｉmを読込み、それが、Ｐ５対応の負荷電流基準値Ｉ_TSよりわずかに高い設定値Ｉ_TU以上であるかをチェックして（３２−３５〜３７）、設定値Ｉ_TU以上になったときに、モ−タＭをＯＦＦにして（３８）、圧力スイッチＰＨの断線異常を表わす警報１を発生して（３９）、レジスタＦsmおよびＴ（経過時間カウント用）をクリアする（４０Ａ，Ｂ）。
【００５３】
断線異常でこのようにモ−タＭをＯＦＦにした後は、警報１があるので、ＣＰＵは、圧力スイッチＰＨの圧力検出信号が低圧（ＨＩ）であっても、図６のステップ４から６（モ−タＯＮ）には進まず、「異常処理」（１１）に進み、図８の「異常処理」（１１）において、ステップ３１からステップ４０Ｃに進んで、上述のようにモ−タＭをＯＦＦにしてから現在までのブレ−キペダル操作回数Ｎが、設定値ＫN2（図９参照）に達したかをチェックする（４０Ｃ）。ブレ−キペダル操作回数Ｎが設定値ＫN2に達すると、モ−タＭをＯＮにして（４０Ｄ）、レジスタＮ（ブレ−キペダル操作回数Ｎ）およびＴをクリアする（４０Ｅ，Ｆ）。そしてレジスタＦsmに１書込んでタイマＴmsをスタ−トする（３２〜３４）。その後は、上述のように、タイマＴmsがタイムオ−バした後モ−タ電流値Ｉmが設定値Ｉ_TU以上になったときに、モ−タＭをＯＦＦにする（３６〜３８）。
【００５４】
したがって断線異常（低圧ＨＩ）が継続している間、ポンプ駆動中にモ−タ電流値がＩ_TUに達するとポンプ駆動が停止される。そしてその後、前回のポンプ駆動の開始（４０Ｄ，Ｅ）時点からの、ブレ−キペダル操作回数Ｎが設定値ＫN2に達するとポンプ駆動が開始される。
【００５５】
４．圧力スイッチＰＨの短絡異常のときのアキュムレ−タ圧の昇圧
例えばスイッチの接点溶着，圧力検出信号線の地絡等、何らかの故障で圧力スイッチＰＨの圧力検出信号がＬＯ（高圧）のまま、アキュムレ−タ圧がＰ３未満に下っても、ＨＩ（低圧）に切換わらない場合、上述の２．および３．のポンプ駆動は行なわれなくなるので、ドライバがブレ−キペダルＢＰを踏込むたびに、アキュムレ−タ圧が消費されて低下する。この状態では、この踏込み回数Ｎがカウントアップされている（ステップ１〜３）。
【００５６】
再度図６を参照するとＣＰＵは、「異常処理２」（１７）において、圧力スイッチＰＨの圧力検出信号がＬＯ（高圧）のまま、踏込み回数ＮがＫN（＝ＫN1)を越えると、モ−タＭをＯＮにしてレジスタＮおよびＴをクリアし、レジスタＦには、圧力スイッチ信号異常時のポンプ駆動を表わす「１」を書込む（４１−４３〜４６）。そしてレジスタＭのデ−タを１インクレメントする（４７）。その後は、レジスタＮの値がモ−タＭをＯＮとしたときにクリアされているので、０又は小さい値であるので、ステップ４２から４９に進んで、モ−タＯＮ開始からの経過時間Ｔ（正確にはＴ×6msec)が設定時間ＫT(＝ＫT1，正確にはＫT1×6msec)を越えたかをチェックし、越えた時点にモ−タＭをＯＦＦにする（５０）。以上が図９に示す▲１▼〜▲５▼の経過に相当する処理である。その後は、図９の▲５▼〜▲７▼のように、ブレ−キ踏込み回数ＮがＫN2を越える毎にＫT2の間モ−タＭをＯＮとするために、設定値ＫNをＫN2に更新し（５１）、設定時間ＫTをＫT2に更新する（５２）。
【００５７】
その後、圧力スイッチＰＨの圧力検出信号がＬＯ（高圧）のままであると、ブレ−キ踏込み回数Ｎが設定値ＫN＝ＫN2を越えると、モ−タＭをＯＮにしてレジスタＮおよびＴをクリアし、レジスタＦには、圧力スイッチ信号異常時のポンプ駆動を表わす「１」を書込み（４１−４３〜４６）、レジスタＭのデ−タを１インクレメントする（４７）。レジスタＭのデ−タが所定値Ｍａ以上になると、すなわち、圧力スイッチＰＨの圧力検出信号がＬＯ（高圧）のまま継続しているときの、該信号を異常と見なして、該信号に依存しないでポンプ駆動を行った回数ＭがＭａに達したときに、圧力スイッチの短絡異常を表わす警報２を発生する。上述の第２回目のポンプ駆動を行なうとＣＰＵは、モ−タＯＮ開始からの経過時間Ｔ計測のためにレジスタＴのデ−タを１インクレメントし（１５）、そしてステップ４１，４２を経てステップ４９で経過時間Ｔが設定時間ＫT(＝ＫT2)を越えたかをチェックし、越えた時点にモ−タＭをＯＦＦにする（５０）。
【００５８】
第２回目以降のポンプ駆動は、ブレ−キペダル踏込み回数ＮがＫN2を越える毎に開始されて、設定時間ＫT2の後に停止される。これにより、アキュムレ−タ圧は大略で図９に示す圧力Ｐ２〜Ｐ５の範囲となり、アキュムレ−タ圧が保障される。
【００５９】
アキュムレ−タＡＣＣの液圧を示す図９を参照する。Ｐ４は、圧力スイッチＰＨの圧力検出信号が低圧から高圧に切換わる圧力（定常上限圧）である。▲１▼の圧力Ｐ５＝Ｐ４＋ΔＰmは、負荷へ流体圧が印加される度に消費され、負荷への流体圧印加回数が増えるに従って低下して、▲２▼で圧力Ｐ３となる。圧力Ｐ３は、圧力スイッチＰＨの圧力検出信号が高圧を表わすものから低圧を表わすものに切換わる圧力（定常下限圧）である。圧力スイッチＰＨが正常であれば、この切換により流体ポンプＨＰ（電気モ−タＭ）が駆動されてポンプが回転し、二点鎖線で示すようにアキュムレ−タ圧を上昇させる（▲３▼）。もし圧力スイッチＰＨの圧力検出信号が▲２▼で低圧に切換らない場合には、ポンプが回転しないのでアキュムレ−タ圧は更に低下し、▲４▼で圧力Ｐ１に達する。この圧力Ｐ１を、ブレ−キペダル踏込み回数Ｎから推定する。
【００６０】
ここで、車輪ブレ−キ回路へのアキュムレ−タ圧の１回の印加（ブレ−キペダルＢＰの１回の踏込み期間）の間のアキュムレ−タＡＣＣの圧力低下量がΔＰsで一定であると仮定し、
Ｐ５−Ｐ１＝ΔＰs・ＫN1
として、アキュムレ−タ圧の印加（消費）の回数(N)が圧力Ｐ１対応のＫN1に達したらポンプＨＰを駆動する(▲４▼)。これにより、アキュムレ−タ圧が上昇する。ポンプＨＰを駆動した▲４▼から経過時間Ｔを計測し、アキュムレ−タ圧がＰ５に達する時間ＫT1後にポンプＨＰを止めると仮定すると、この時の圧力は▲５▼、すなわちＰ５である。再びアキュムレ−タ圧はブレ−キペダルの踏込みに連動して消費され、時間と共に次第に低下して圧力Ｐ３となる。圧力スイッチＰＨが故障していれば圧力Ｐ３で切換らないのでアキュムレ−タ圧は更に低下し、圧力Ｐ２（▲６▼）に達する。この圧力Ｐ２をブレ−キペダル踏込回数Ｎから推定し、圧力Ｐ２に達したらポンプＨＰを駆動すると、アキュムレ−タ圧は上昇する。ポンプＨＰを駆動した▲６▼から経過時間Ｔを計測し、アキュムレ−タ圧がＰ５に達する時間ＫT2後にポンプＨＰを止める。この時の圧力は▲７▼、すなわちＰ５である。以後同様に繰返えす。
【００６１】
上述の仮定によれば、ΔＰsが一定値であれば、アキュムレ−タ圧をＰ２〜Ｐ５の範囲内に維持することができる。ところで、ΔＰsが一定でない場合には、▲５▼〜▲７▼の圧力は正確にＰ２〜Ｐ５にはならず、低圧側あるいは高圧側にシフトする。しかし、ブレ−キペダルの１回の踏込みにおける圧力消費量の、統計的な平均値にΔＰsを定めることにより、アキュムレ−タ圧は略Ｐ２〜Ｐ５の範囲に維持され、アキュムレ−タ圧が保障される。
【００６２】
−第２実施例−
図１０に、本発明の第２実施例の「停止処理」（１６）の内容を示す。この図１０の「停止処理」（１６）は、第１実施例の「停止処理」（図７）に置換して用いられるものであり、この「停止処理」以外の第２実施例のハ−ドウェア構成および機能（フロ−チャ−ト）は、第１実施例と同一である。
【００６３】
図１０を参照すると、第２実施例では、圧力スイッチＰＨの圧力検出信号がＬＯ（高圧）に切換た直後にモ−タ電流値Ｉmに対応するアキュムレ−タ圧がＰ５となるときのモ−タ電流値Ｉ_Tおよび遅延時間Ｔ_dを算出し、経過時間計測値Ｔをクリアした（２１〜２６）後の「停止処理」（１６）では、モ−タ電流値Ｉmを読込み（２２）、経過時間Ｔが推定遅延時間Ｔ_dを過ぎしかもモ−タ電流値Ｉmが推定算出値Ｉ_T以上になったときに、モ−タＭをＯＦＦにする（２８，２９，３０Ａ）。経過時間Ｔが、遅延時間Ｔ_dを過ぎてもモ−タ電流値Ｉmが推定算出値Ｉ_Tに達しないときには、経過時間Ｔが、Ｔ_dより長い設定値Ｔ_ULになったときにモ−タＭをＯＦＦにする（３０Ｄ，３０Ａ）。その他の処理は、上述の第１実施例の場合と同様である。
【００６４】
第１実施例（図７）では、経過時間Ｔが遅延時間Ｔ_dに達するまでにモ−タ電流値ＩｍがＩ_Tになった（第１条件が成立した）とき、ならびに、モ−タ電流値ＩmがＩ_Tになる前に経過時間Ｔが遅延時間Ｔ_dに達した（第２条件が成立した）とき、のいずれの場合でも、モ−タＭがＯＦＦされので、モ−タＯＦＦの信頼性が高い。第２実施例（図１０）では、第２条件が成立した後第１条件が成立したときにモ−タＯＦＦとなり、モ−タＯＦＦ条件が厳しい。第２実施例においてモ−タ電流値検出系が故障すると、モ−タＯＮが継続してしまうので、この保護策として、経過時間ＴがＴ_dより長い設定値Ｔ_ULに達すると自動的にモ−タをＯＦＦにするようにしている。これにより第１実施例と同等のモ−タＯＦＦの信頼性を確保している。
【００６５】
以上に説明したいずれの実施例においても、「停止処理」（１６）において、圧力センサＰＨの圧力検出信号の高圧（ＬＯ）への切換り時に、そのときのモ−タ電流値に対応して、目標圧Ｐ５対応のモ−タ電流値Ｉ_Tおよび遅延時間Ｔ_dを算出し、算出値を比較値として、電気モ−タＭのＯＦＦタイミングを定めるので、１個の圧力センサＰＨの圧力検出信号に基づいて、ヒステリシス幅（Ｐ３／Ｐ５）が広いアキュムレ−タ圧力制御を実現することができる。
【００６６】
圧力スイッチＰＨの接片開放，圧力検出信号線の断線等、断線異常が生じて、圧力検出信号がＨＩ（低圧）を示すものとなって、アキュムレ−タ圧の上昇にもかかわらずＬＯ（高圧）に切換わらないと、「異常処理１」（２９）によって、アキュムレ−タ圧のＰ５よりわずかに高い圧力にまでポンプＨＰを駆動するモ−タ負荷電流値Ｉ_TUに、モ−タＭの電流値が上昇すると、そこでモ−タＭがＯＦＦされ、長時間のモ−タ通電（アキュムレ−タの過圧）が回避される（図８のステップ３６〜３８）。しかも断線異常が継続している間警報１が出されており、この間、「異常処理」（２９）によって、ブレ−キペダルの踏込み回数ＮがＫN2に達する毎に、モ−タがＯＮとされて踏込み回数Ｎがクリアされてまた０からカウントアップされる（４０Ｃ〜４０Ｆ）。このモ−タＯＮは、モ−タ負荷電流値がＩ_TUになったときに止められる（３６〜３８）。したがって、圧力スイッチＰＨの断線異常が継続する間の、アキュムレ−タの過圧（モ−タの過負荷通電）ならびに圧力不足が回避される。
【００６７】
圧力スイッチＰＨに接点溶着，圧力検出信号線の短絡等、短絡異常が生じて、圧力検出信号がＬＯ（高圧）を示すものとなって、アキュムレ−タ圧の低下にもかかわらずＨＩ（低圧）に切換わらないようになると、「異常処理２」（１７）でＣＰＵが自動的に、アキュムレ−タ圧を略Ｐ２〜Ｐ５の範囲とするためのポンプＨＰの駆動（ＯＮ）／停止（ＯＦＦ）を行なう（上記４．）。そして警報２を発生する。
【００６８】
したがって１個の圧力スイッチＰＨのみを用いてアキュムレ−タＡＣＣの蓄圧制御を行なう場合でも、圧力スイッチＰＨ系の異常（フェ−ル）に対して、圧力制御の信頼性（セ−フ）が確保される。すなわち低コストとするために少い圧力検出手段を用いて、高い信頼性を実現することができる。
【図面の簡単な説明】
【図１】 本発明の第１実施例を装備した車輪ブレ−キ圧制御装置の構成を示すブロック図である。
【図２】 図１に示すブレ−キ液回路ＰＣの構成を示すブロック図である。
【図３】 図１および図２に示す１つの圧力スイッチＰＨの拡大縦断面図である。
【図４】 （ａ）は圧力スイッチＰＨと電子制御装置ＥＣＵとの接続回路を示す電気回路図であり、（ｂ）は圧力スイッチＰＨの圧力検出信号を示すタイムチャ−トである。
【図５】 図１に示す電子制御装置ＥＣＵに搭載されるマイクロコンピュ−タＣＭＰのＣＰＵの、アキュムレ−タ圧力制御に関する部分の動作を示すフロ−チャ−トである。
【図６】 図５に示す「モ−タ制御」（８）の内容を示すフロ−チャ−トである。
【図７】 図６に示す「停止処理」（１６）の内容を示すフロ−チャ−トである。
【図８】 図６に示す「異常処理」（２９）の内容を示すフロ−チャ−トである。
【図９】 図１に示すアキュムレ−タＡＣＣの圧力変化の概要を示すタイムチャ−トである。
【図１０】 本発明の第２実施例のマイクロコンピュ−タＣＭＰのＣＰＵの、「停止処理」（１６）の内容を示すフロ−チャ−トである。
【図１１】 従来の、圧力スイッチ２個を使用した流体圧源装置の概要を示すブロック図である。
【符号の説明】
ＡＰ：アクセルペダル ＢＰ：ブレ−キペダル
ＢＳ：ブレ−キスイッチ ＣＰＭ：マイクロコンピュ−タ
ＤＡ：ダイアフラム ＤＦ：ディファレンシャルギヤ
ＥＣＵ：電子制御装置 ＥＧ：エンジン
ＦＩ：燃料噴射装置 ＦＬ：前方左車輪
ＦＲ：前方右車輪 ＧＳ：変速制御装置
ＨＢ：液圧ブ−スタ ＭＣ：マスタシリンダ
ＭＳ：マイクロスイッチ ＭＴ：メインスロットルバルブ
ＰＣ：ブレ−キ液圧制御装置 ＰＳ：液圧源
ＲＤ：リレ−ドライバ ＲＬ：後方左車輪
ＲＯ：ロッド ＲＲ：後方右車輪
ＲＳ：リザ−バ ＳＰ：スプリング
ＳＴ：サブスロットルバルブ ＴＨ：スロットル制御装置
Ｒ：モ−タ電流検出用の抵抗
ＷｆＬ，Ｗｆｒ，ＷｒＬ，Ｗｒｒ：ホイ−ルシリンダ
ＷＳ１〜ＷＳ４：車輪速度センサ ＹＳ：ヨ−レイトセンサ[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a fluid pressure source that accumulates an accumulator with a fluid pump and applies a pressure fluid of the accumulator to a fluid circuit, and more particularly, to maintain an accumulator pressure within a set range, The present invention relates to a fluid pressure source device including a pressure switch that detects the pressure of a fluid pressure line that communicates therewith, and pump control means that drives a fluid pump when the pressure is low according to the pressure detection signal.
[0002]
This device is for example a brake circuit that applies brake pressure to the wheel brakes of the vehicle and / or a high brake of a hydro booster for applying brake pressure to the wheel brakes of the vehicle. It can be used as a pressure source. Further, for example, it can be used as a high pressure source of a hydraulic circuit that applies a pressure for supporting a vehicle body to a vehicle suspension.
[0003]
[Prior art]
For example, in a vehicle having a wheel brake system equipped with HB (hydro booster) and ABS (anti-lock brake system) or a vehicle equipped with an active suspension system, a fluid pressure source for applying an operating pressure (high pressure) to the vehicle. An apparatus is provided, and the fluid pump of the apparatus is driven by an on-vehicle engine through an electric motor or a clutch.
[0004]
FIG. 11 shows an outline of a conventional hydraulic pressure source device that drives one fluid pump HP with an electric motor M. The oil in the reservoir RS is boosted by a pump HP driven by a motor M and discharged to a high pressure line. The accumulator ACC is connected to the high-pressure line, and the pressure of the high-pressure line and the accumulator ACC is increased by the operation of the pump HP, and the amount of high-pressure oil in the accumulator ACC is increased (accumulated pressure). The voltage applied to the motor M is turned on / off by the relay RY, and the relay RY is controlled by the control unit ECU. The high-pressure line is coupled to a high-pressure side pressure switch PH and a low-pressure side pressure switch PL, and these pressure detection signals are given to the control unit ECU.
[0005]
Both pressure switches PH and PL have hysteresis characteristics, and when the pressure detection signal of the high pressure side pressure switch PH is switched from high pressure to low pressure, the control unit ECU drives the fluid pump HP (electric motor M). . When the pressure detection signal of the pressure switch PH is switched from low pressure to high pressure, the driving is stopped. The pressure P4 (steady upper limit pressure) at which the pressure detection signal is switched from low pressure to high pressure is higher than the pressure P3 (steady lower limit pressure) at which the pressure detection signal of the pressure switch PH is switched from high pressure to low pressure. The pressure is always maintained between the steady lower limit pressure P3 and the steady upper limit pressure P4.
[0006]
The low pressure side pressure switch PL is for safety protection and generates a pressure detection signal indicating "low pressure" when the pressure drops to a low pressure P1 (abnormal lower limit pressure) lower than the steady lower limit pressure P3, and then the pressure increases. When a high pressure P2 (abnormal upper limit pressure) higher than the abnormal lower limit pressure P1 but lower than the steady lower limit pressure P3 is reached, a pressure detection signal indicating “high pressure” is generated. When the pressure detection signal of the low pressure side pressure switch PL indicates “low pressure”, the control device ECU generates an alarm and drives the fluid pump HP (electric motor M). When the pressure detection signal of the low pressure side pressure switch PL is switched to one indicating “high pressure”, the driving is stopped. When the high pressure side pressure switch PH functions normally and the control device ECU normally performs drive control of the fluid pump HP according to the pressure detection signal, the accumulator pressure does not decrease to the abnormal lower limit pressure P1. However, if the high-pressure side pressure switch PH fails and no pressure detection signal indicating a low pressure (below the steady lower limit pressure P3) is generated, the fluid pump HP is not driven, so the accumulator pressure decreases and the low-pressure side pressure switch When the PL pressure detection signal indicates "low pressure", an alarm is issued and the fluid pump HP is driven. By this pump drive, the required minimum pressure of the accumulator pressure is secured.
[0007]
[Problems to be solved by the invention]
The pressure switch has hysteresis characteristics. For example, the pressure switch PH for normal pressure control will be described. When the accumulator pressure is reduced to P3, the pressure switch is closed, and when it is increased to P4, the pressure switch is opened. When the hysteresis width (pressure difference between P3 / P4) of one switch PH is narrow, the electric motor M is frequently energized (ON) / deenergized (OFF). If the pressure switch PH is added with a mechanical element to increase the hysteresis width, not only will the switch cost increase, but the dimensional error of the additional element will add to the variation in switching pressure between open and closed. In other words, there is a possibility of opening and closing due to a failure of the additional element, so that the accuracy of the switching is likely to deteriorate, for example, the switching reliability is lowered.
[0008]
On the other hand, if the pressure switch PH is in an open abnormality that remains open (low pressure) even if the pressure rises above the steady upper limit pressure P4 due to malfunction of the contact piece or disconnection of the signal line, the electric motor M The urging (ON) continues, the accumulator pressure rises excessively, and an overload is applied to the electric motor M. In order to make up for such problems, it is further expensive to provide a pressure switch or pressure sensor for safety protection.
[0009]
The first object of the present invention is to control the accumulator pressure with a hysteresis width wider than the hysteresis width of the pressure switch, and secondly to realize this at a low cost by using a small number of pressure switches. The third object is to prevent overpressure of the accumulator even if the pressure switch has a failure in switching from low pressure detection to high pressure detection.
[0010]
[Means for Solving the Problems]
(1) The pressure of the fluid pump (HP), the electric motor (M) that drives the fluid pump, the accumulator (ACC) that receives the discharge pressure of the fluid pump, the pressure of the accumulator or the fluid pressure line communicating therewith A pressure switch (PH) to detect, and a pump that starts energizing the electric motor when it switches from one representing high pressure to one representing low pressure in response to a pressure detection signal of the pressure switch (PH) In a fluid pressure source device comprising a control means (ECU),
A delay time T based on the load current value of the electric motor when the pressure detection signal of the pressure switch (PH) is switched from a low pressure signal to a high pressure signal. _d And delay time T from the switching _d A boost stop means (ECU) for de-energizing the electric motor later is provided.
[0011]
In addition, in order to make an understanding easy, the code | symbol of the corresponding element or the corresponding matter of the Example shown in drawing and mentioned later is added in the parenthesis for reference.
[0012]
According to this, when the pressure detection signal of the pressure switch (PH) is switched from a high pressure signal to a low pressure signal, the pump control means (ECU) starts energizing the electric motor. Is driven to increase the accumulator pressure. When this pressure rise causes the pressure detection signal of the pressure switch (PH) to switch from indicating low pressure to indicating high pressure, the boost stop means (ECU) is based on the load current value of the electric motor at that time. Delay time T _d And delay time T from the switching _d Later, the electric motor is turned off.
[0013]
When the accumulator pressure at which the pressure detection signal switches from high pressure to low pressure is P3, and the pressure at which the pressure detection signal switches from low pressure to high pressure is P4, the accumulator pressure decreases to P3. When the fluid pump HP is driven, the accumulator pressure increases, and the accumulator pressure increases to [P4 + T _d When the pressure increases between], the fluid pump stops driving. Therefore, more than the hysteresis width (P4-P3) of the pressure switch (PH), T _d The accumulator pressure is controlled with a wide hysteresis width corresponding to the pressure increase during this period, and the drive frequency of the fluid pump is reduced accordingly.
[0014]
The accumulator pressure is the load of the fluid pump (HP), that is, the load of the electric motor (M), and the load current value of the electric motor corresponds to the accumulator pressure. Here, the motor load current is proportional to the accumulator pressure, and if the motor load current with respect to the predetermined pressure is small, it is considered that the pump discharge flow rate (accumulator boost speed) is high. The reference load current of the electric motor (M) when the pressure is P4 is Ips, and the reference load current of the electric motor when the accumulator pressure is P5 = P4 + ΔPm is I _TS The pump drive time (reference value) for increasing the pressure from pressure P4 to P5 is T _ds Ima is the actual load current when the actual pressure detection signal is switched from low pressure to high pressure, and the load current when the pressure is P5 when pump driving is continued. _T , The pump drive time for increasing pressure from pressure P4 to P5 is T _d Then,

And the motor load current value when the accumulator pressure becomes P5 = P4 + ΔPm based on the motor load current value Ima when the pressure detection signal is switched from the low pressure to the high pressure. I _T And the elapsed time (delay time) T until reaching P5 _d Can be calculated. Where Ki = (I _TS / Ips) and Kt = (Tds / Ips) are set values (fixed values) determined by design or according to the result of trial manufacture.
[0015]
In the above description, it is assumed that the motor load current is proportional to the accumulator pressure, and that the pump discharge flow rate (accumulator boost speed) is high when the motor load current is small with respect to the predetermined pressure. When the motor load current is non-linear with respect to the accumulator pressure, or when the accumulator boost speed is not inversely proportional to the motor load current with respect to the predetermined pressure, these characteristics are obtained. Depending on the calculation formula or detection current value Ima vs. estimated current, delay time value I _T , T _d A data table (data memory) in which is written is prepared, and the estimated current is based on the motor load current value Ima when the pressure detection signal is switched from the low pressure to the high pressure. , Delay time value I _T , T _d May be derived.
[0016]
In any case, the delay time T is based on the load current value Ima of the electric motor when the pressure detection signal of the pressure switch (PH) is switched from low pressure to high pressure (pressure P4). _d And delay time T from the switching _d By subsequently deactivating the electric motor, the pump drive is stopped when the accumulator pressure is P5 = P4 + ΔPm or a value close thereto, and the accumulator pressure is substantially maintained within the range of P4 to P5. The Since there is no need to add a mechanical element for increasing the hysteresis width to the pressure switch (PH), there is no increase in cost, accuracy, or reliability of the pressure switch.
[0017]
DETAILED DESCRIPTION OF THE INVENTION
(2) The pressure of the fluid pump (HP), the electric motor (M) that drives the fluid pump, the accumulator (ACC) that receives the discharge pressure of the fluid pump, the pressure of the accumulator or the fluid pressure line communicating therewith A pressure switch (PH) to detect, and a pump that starts energizing the electric motor when it switches from one representing high pressure to one representing low pressure in response to a pressure detection signal of the pressure switch (PH) In a fluid pressure source device comprising a control means (ECU),
The pressure is further set based on a load current value (Ima) of the electric motor (M) when the pressure detection signal of the pressure switch (PH) is switched from a low pressure signal to a high pressure signal. Load current value I when boosted by ΔPm _T And the load current value of the electric motor is the value I _T And a boost stop means (ECU) for de-energizing the electric motor when reaching the above.
[0018]
According to this aspect, for example, based on the load current value Ima of the electric motor when the pressure detection signal of the pressure switch (PH) is switched from a low pressure signal to a high pressure signal (pressure P4), for example, Delay time T following equation (2) _d And delay time T from the switching _d By subsequently deactivating the electric motor, the pump drive is stopped when the accumulator pressure is P5 = P4 + ΔPm or a value close thereto, and the accumulator pressure is substantially maintained within the range of P4 to P5. The Since there is no need to add a mechanical element for increasing the hysteresis width to the pressure switch (PH), there is no increase in cost, accuracy, or reliability of the pressure switch.
[0019]
(3) The pressure of the fluid pump (HP), the electric motor (M) that drives the fluid pump, the accumulator (ACC) that receives the discharge pressure of the fluid pump, the pressure of the accumulator or the fluid pressure line communicating therewith A pressure switch (PH) to detect, and a pump that starts energizing the electric motor when it switches from one representing high pressure to one representing low pressure in response to a pressure detection signal of the pressure switch (PH) In a fluid pressure source device comprising a control means (ECU),
The delay time T based on the load current value (Ima) of the electric motor when the pressure detection signal of the pressure switch (PH) is switched from a low pressure signal to a high pressure signal. _d And the load current value I when the pressure is further increased by the set value ΔPm _T Is estimated and the delay time T is calculated from the switching. _d After the elapse of time, the load current value of the electric motor is the value I _T And a boost stop means (ECU) for de-energizing the electric motor when reaching the above.
[0020]
According to this aspect, for example, based on the load current value Ima of the electric motor when the pressure detection signal of the pressure switch (PH) is switched from a low pressure signal to a high pressure signal (pressure P4), for example, Delay time T following equation (2) _d For example, according to the above equation (1), the estimated current value I _T And delay time T from the switching _d After passing through the motor load current value, the estimated current value I _T By de-energizing the electric motor when the above is true, the pump drive is stopped when the accumulator pressure is P5 = P4 + ΔPm or a value close thereto, and the accumulator pressure is substantially in the range of P4 to P5. Maintained within. Since there is no need to add a mechanical element for increasing the hysteresis width to the pressure switch (PH), there is no increase in cost, accuracy, or reliability of the pressure switch. Delay time T _d And the motor load current value is I _T Since the establishment of the above two conditions is a condition for stopping the pump drive, the pressure increase by ΔPm is reliably performed. That is, a wide hysteresis width is reliably ensured.
[0021]
(4) The boost stop means (ECU) is a pressure switch (LP1) that switches the pressure detection signal from the low pressure to the high pressure when the pressure rises to P4 when the pressure is normal. In the expression, while the pump control means (ECU) is energizing the electric motor (M), the load current value Im of the electric motor (M) becomes the pressure P4 + ΔPm obtained by adding the set value ΔPm to P4. Corresponding value I _T Higher setting value I _TU The fluid pressure source device according to (1), (2) or (3), wherein the electric motor is de-energized when the above is reached.
[0022]
Even if the accumulator pressure exceeds the set pressure P4 due to improper movement of the contact piece of the pressure switch (LP1) or disconnection of the signal line (hereinafter simply referred to as disconnection abnormality), the pressure detection signal shows a low pressure. Unless switched to the one shown, the pump drive stop condition described in (1), (2) and (3) above is not satisfied. In this case, the load current value Im of the electric motor (M) is the set value I _TU When this happens, the boost stop means (ECU) turns off the electric motor. Therefore, overpressure of the accumulator is prevented when there is a disconnection abnormality, that is, a failure in switching from low pressure detection to high pressure detection.
[0023]
Other objects and features of the present invention will become apparent from the following description of embodiments with reference to the drawings.
[0024]
【Example】
-1st Example-
FIG. 1 shows the overall configuration of a wheel brake pressure control device on a vehicle equipped with the fluid pressure source device of the first embodiment of the present invention. The engine EG is an internal combustion engine provided with a throttle control device TH and a fuel injection device FI. In the throttle control device TH, the opening of the main throttle valve MT is controlled in accordance with the operation of the accelerator pedal AP. Further, the sub-throttle valve ST of the throttle control device TH is driven and its opening degree is controlled according to the output of the electronic control unit ECU, and the fuel injection device FI is driven and the fuel injection amount is controlled. Has been. The engine EG is connected to wheels RL and RR on the rear side of the vehicle via a transmission control device GS and a differential gear DF.
[0025]
Wheel brake wheel cylinders WfL, Wfr, WrL, Wrr are mounted on the wheels FL, FR, RL, RR, respectively, and these wheel cylinders WfL and the like are connected to a brake hydraulic circuit PC. Note that the wheel FL indicates a front left wheel (front left wheel) as viewed from the driver's seat, and FR is a front right wheel, RL is a rear left wheel, and RR is a rear right wheel.
[0026]
The wheels FL, FR, RL, and RR are coupled to pulse generators WS1 to WS4 that generate one pulse of an electric signal for each rotation of the wheel at a predetermined small angle, and these give electric pulses to the electronic control unit ECU. When the pulse generator WS1 gives one pulse, the microcomputer CMP of the electronic control unit ECU executes an interrupt process, and the time value (clock pulse count value) at that time is stored in the pulse cycle register addressed to WS1. Write to restart clock pulse count-up. As a result, data representing the latest one cycle time of the pulse generated by the pulse generator WS1 is always written in the pulse cycle register addressed to WS1. When computing the rotational speed VwfL of the wheel FL, the microcomputer CMP calculates the rotational speed VwfL by multiplying the inverse of the value represented by the data in the pulse period register addressed to WS1 by a proportional coefficient. Similar interrupt processing is executed for the pulses generated by the pulse generators WS2 to WS4, and similarly, the rotational speeds Vwfr, VwrL, and Vwrr of the wheels FR, RL, and RR are calculated.
[0027]
A brake switch BS that is turned on when the brake pedal BP is depressed, a pressure switch PH that detects the level of the accumulator output pressure, a yaw rate sensor YS that detects the yaw rate of the vehicle, and the like are connected to the electronic control unit ECU. The yaw rate sensor YS detects the change speed of the vehicle rotation angle (yaw angle) around the vertical axis passing through the center of gravity of the vehicle, that is, the yaw angular velocity (yaw rate), and gives an electric signal representing this to the electronic control unit ECU. When the microcomputer CMP reads the yaw rate, the electric signal generated by the yaw rate sensor YS is digitally converted to read the digital data.
[0028]
As shown in FIG. 1, the electronic control unit ECU includes a microcomputer CMP including a microprocessor CPU, a memory ROM, a RAM, an input port IPT, an output port OPT, and the like connected to each other via a bus.
[0029]
Output signals from the brake switch BS, pressure switch PH, pulse generators WS1 to WS4, yaw rate sensor YS, etc. are given from the input port IPT to the A / D conversion port of the microprocessor CPU via the amplifier circuit AMP, The CPU converts the levels of these output signals into digital data and reads them. The CPU gives a relay on (pump drive = motor energization: ON) / off (pump stop = motor deactivation: OFF) signal to the relay driver RD from the output port OPT, and the relay driver The RD energizes the relay coil of the relay RY while there is an ON signal. As a result, the contact piece of the relay RY is closed and the electric motor M is energized. The CPU also gives a control signal to the solenoid driver energized from the output port OPT to the solenoid valves (12) of the brake hydraulic circuit PC, and sends a control signal to the throttle control device TH to the sub-control of the throttle control device TH. This is applied to a motor driver ACT addressed to an electric motor that drives the throttle MT to open and close.
[0030]
The ROM of the microcomputer CMP stores a control program for executing various processes, which will be described later, and data such as fixed constants. The microprocessor CPU closes an ignition switch (not shown), thereby not shown. The program is executed while the power supply circuit supplies the operating voltage. The RAM temporarily stores a program read from the ROM, data stored in the ROM, data read via the input port, and data generated by the CPU.
[0031]
The energization circuit of the motor M has a current detection resistor R that generates a voltage proportional to the energization current value of the motor M, and this voltage is supplied to the A / P of the microprocessor CPU via the input port. It is given to the D conversion port. When it is necessary to refer to the motor current value, the microprocessor CPU converts the voltage into digital data (motor current data) and reads it.
[0032]
FIG. 2 shows the configuration of the brake hydraulic circuit PC. When the brake pedal BP is depressed, the booster HB generates a pressure substantially proportional to the depression pressure, and the piston of the master cylinder MC is driven by this pressure. A hydraulic pressure source PS is connected to the booster HB, and the hydraulic pressure source PS includes a hydraulic pressure pump HP, a driving motor M, and an accumulator ACC. A relief valve RV is interposed between the accumulator ACC and the low pressure reservoir RS. The hydraulic pump HP is driven by the electric motor M, sucks and pressurizes the brake fluid in the low pressure reservoir RS, and supplies the brake fluid to the accumulator ACC via the check valve CV6. The CPU monitors the ON (high pressure) / OFF (low pressure) of the pressure switch PH that detects the pressure of the accumulator ACC or its supply pressure line. Drive. As a result, the hydraulic pressure of the accumulator ACC increases.
[0033]
When the pressure switch PH does not switch to the low pressure side, the CPU switches the electric motor M through the driver ACT when the opening / closing of the brake switch BS, which is activated by depressing the brake pedal BP, reaches a predetermined number of times. Drive. As a result, the hydraulic pressure of the accumulator ACC increases. Then, when a predetermined time has elapsed after the electric motor M is driven, the CPU stops the electric motor M via the driver ACT. By this drive control of the CPU, the hydraulic pressure of the accumulator ACC is always maintained within a predetermined range.
[0034]
The hydraulic booster HB generates an output pressure proportional to the depression pressure (control pressure) of the brake pedal BP, using the output hydraulic pressure of the hydraulic pressure source PS (hydraulic pressure of the accumulator ACC) as a source pressure. As a result, the master cylinder MC is boosted.
[0035]
Solenoid valves SA1 and SA2 are interposed in the hydraulic circuit on the front wheel side connecting the master cylinder MC and the front wheel cylinders Wfr and WfL, respectively, and these are electromagnetically connected via control pressure lines Pfr and PfL, respectively. The on-off valves PC1, PC5 and the electromagnetic on-off valves PC2, PC6 are connected. In addition, an electromagnetic on-off valve SA3 and electromagnetic on-off valves PC1 to PC8 for supply / exhaust control are inserted in the hydraulic pressure passages connecting the hydraulic booster HB and the wheel cylinder Wfr. A proportional pressure reducing valve PV is interposed. Then, the hydraulic pressure of the hydraulic pressure source PS is applied to the downstream side of the electromagnetic open / close valve SA3 via the electromagnetic open / close valve STR.
[0036]
In the front wheel side hydraulic system, the electromagnetic on-off valves PC1 and PC2 are connected to the electromagnetic on-off valve STR. The electromagnetic on-off valve STR is a 2-port 2-position electromagnetic on-off valve. When the electric coil is not energized (off), the valve is closed (shut off), and when the electric coil is energized (on) The valves are open (flow), and the electromagnetic on-off valves PC1 and PC2 communicate with the accumulator ACC.
[0037]
The electromagnetic switching valve SA1 and the electromagnetic switching valve SA2 are three-port two-position electromagnetic switching valves. When the electric coil is not energized (off), the electromagnetic switching valve SA1 and the electromagnetic switching valve SA2 are in the first position shown in FIG. , WfL communicates with the master cylinder MC, but when the electric coil is energized (on), it switches to the second position, and the wheel cylinders Wfr, WfL are both disconnected from the master cylinder MC. Instead, they communicate with the electromagnetic on-off valves PC1 and PC5 and the electromagnetic on-off valves PC2 and PC6, respectively.
[0038]
The check valves CV1 and CV2 are connected in parallel to the electromagnetic on-off valves PC1 and PC2. The inflow side of the check valve CV1 is connected to the control pressure line Pfr, and the inflow side of the check valve CV2 is connected to the control pressure line PfL. It is connected. The check valve CV1 is configured such that when the electromagnetic switching valve SA1 is on (second position) and the brake pedal BP is released, the brake fluid pressure of the wheel cylinder Wfr of the front right wheel is output from the hydraulic booster HB. It is provided to quickly follow the pressure drop. The brake fluid flow in the direction of the hydraulic booster HB is allowed but the reverse flow is blocked. The check valve CV2 similarly prevents backflow for the wheel cylinder WfL of the front left wheel.
[0039]
The rear wheel side hydraulic system electromagnetic on-off valve SA3 is a 2-port 2-position electromagnetic on-off valve, and when the electric coil is not energized (off), the valve is open (flow) as shown in FIG. The electromagnetic on-off valves PC3 and PC4 communicate with the hydraulic booster HB via the proportional pressure reducing valve PV. At this time, the electromagnetic on-off valve STR is turned off (valve closed) as shown in FIG. 2, and the proportional pressure reducing valve PV is disconnected from the accumulator ACC. When the electromagnetic on / off valve SA3 is turned on and closed (shut off), the electromagnetic on / off valves PC3 and PC4 are disconnected from the hydraulic booster HB and connected to the electromagnetic on / off valve STR via the proportional pressure reducing valve PV. When the electromagnetic on-off valve STR is turned on (flow), the accumulator ACC is communicated.
[0040]
Further, check valves CV3 and CV4 are connected in parallel to the electromagnetic on-off valves PC3 and PC4. The inflow side of the check valve CV3 is connected to the wheel cylinder Wrr, and the inflow side of the check valve CV4 is connected to the hoseal cylinder WrL. It is connected. These check valves CV3 and CV4 are provided to cause the brake fluid pressure of the wheel cylinders Wrr and WrL to quickly follow the decrease in the output fluid pressure of the hydraulic pressure booster HB when the brake pedal BP is released. Thus, the flow of the brake fluid in the direction of the electromagnetic on-off valve SA3 is allowed and the flow in the reverse direction is prevented. Further, the check valve CV5 is provided in parallel with the electromagnetic on-off valve SA3, and even when the electromagnetic on-off valve SA3 is on (shut off), the stepping by the brake pedal BP (increase of wheel brake pressure) is increased. Is possible.
[0041]
The electromagnetic switching valves SA1 and SA2, the electromagnetic on-off valves SA3 and STR, and the electromagnetic on-off valves PC1 to PC8 are on / off controlled by the electronic control unit ECU. For example, at the time of braking steering control (wheel brake pressure distribution control) performed when the brake pedal BP is not operated, the brake hydraulic pressure is not output from the hydraulic pressure booster HB and the master cylinder MC. , SA2 is turned on (second position), the electromagnetic on-off valve SA3 is turned on (shut off), and the electromagnetic on-off valve STR is turned on (flow). As a result, the hydraulic pressure of the accumulator ACC of the hydraulic pressure source PS can be supplied to the wheel cylinder Wfr and the like via the electromagnetic on-off valve STR and the on-off electromagnetic on-off valves PC1 to PC8. Thus, the electromagnetic on-off valves PC1 to PC8 are repeatedly turned off / on, and by changing the off-duty (the ratio of the off time to the off / on cycle) repeatedly, rapid pressure increase and pulse pressure increase ( Slow pressure increase), hold (hold), pulse pressure reduction (slow pressure reduction), rapid pressure reduction, etc. can be performed.
[0042]
For example, the electromagnetic on-off valves PC1 and PC5 for controlling the wheel brake pressure of the front right wheel Wfr will be described. In the state of PC1 off (flow) and PC5 off (cut off), the wheel brake of the front right wheel Wfr. The pressure increases. Here, assuming that the off-duty for the above-mentioned one off / on cycle is 100%, this is a state in which the off-state is continuously maintained, and this is a typical sudden pressure increase. If the off-duty is 0%, this is a state in which the on-state is continuously kept on. When the on-duty is on, PC1 is on (cut off) & PC5 is on (flow), and the wheel brake pressure of the front right wheel Wfr is PC5. This is a typical sudden increase / decrease because it goes through to the reservoir RS. In other words, assuming a typical off-duty 100% sudden pressure increase and off-duty 0% (= on-duty 100%) sudden decompression, the off-duty is 50% or more and less than 100%. The pressure (slow increase), less than 50% and more than 0% is referred to as pulse pressure reduction (slow increase), and PC1 on (shutoff) & PC5 off (shutoff) is the hold.
[0043]
However, in this embodiment, a reference off-duty is set on a one-to-one basis for each of rapid pressure increase, pulse pressure increase (slow pressure increase), pulse pressure decrease (slow pressure decrease), and sudden pressure decrease, and during wheel brake pressure control. The CPU determines one mode that is required for rapid pressure increase, pulse pressure increase (slow pressure increase), hold (holding) required, pulse pressure reduction (slow pressure reduction) required or rapid pressure reduction required. The reference off-duty (one value) addressed to the mode is further finely corrected to finally determine the off-duty, and according to this off-duty, whether a sudden pressure increase or a pulse pressure increase is required. Sometimes, the electromagnetic on / off valve PC1 for pressure increase is controlled to be turned off / on, and the electromagnetic on / off valve PC5 for pressure reduction is continuously turned off (shut off). ) Electromagnetic on-off valve PC5 for pressure reduction OFF / ON control. When the hold is required, the electromagnetic on-off valve PC1 is continuously turned on (shut off) and the electromagnetic on-off valve PC5 is continuously off (shut off). Electromagnetic on / off valve PC2 and pressure reducing electromagnetic on / off valve PC6 for front left wheel wheel cylinder, pressure increasing electromagnetic on / off valve PC3 and pressure reducing electromagnetic on / off valve PC7, The CPU performs similar off / on control for the electromagnetic open / close valve PC4 for increasing pressure and the electromagnetic open / close valve PC8 for reducing pressure in the wheel cylinder of the rear left wheel.
[0044]
FIG. 3 shows an enlarged longitudinal section of the pressure switch PH shown in FIG. 1 (and FIG. 2). The system pressure, that is, the pressure of the accumulator ACC is applied to the right side of the diaphragm DA of the pressure switch PH. Due to this pressure, the diaphragm DA and the rod RO move to the left in the drawing against the compression coil spring SP, and the microswitch MS is pressed at a predetermined pressure to switch the contact from open to closed. This switching to closing occurs when the accumulator pressure changes from less than P4 to P4, and the switch PH remains closed at P4 or more. If the pressure of the accumulator ACC drops, the rod RO and the diaphragm DA move to the right of the drawing by the spring SP. When the pressure drops from P3 higher than P3 to P3, the contact of the microswitch MS is switched from closed to open. Keep open for less than P3.
[0045]
FIG. 4A shows an electrical connection between the pressure switch PH and the electronic control unit ECU. A resistor (1 kΩ) (not shown) is connected to the pressure switch PH in parallel with the contact of the microswitch MS. FIG. 4B shows the output voltage of the pressure switch PH. When the contact is open (when the pressure is low), an output voltage is generated across the pressure switch PH, and when the contact is closed (when the pressure is high), the output voltage across the pressure switch PH is zero. This switching of the contacts actually has a hysteresis characteristic as shown in the figure. When the accumulator pressure increases from low pressure to high pressure, the pressure detection signal of the pressure switch PH is at a high level at the pressure P4. When switching from HI (open) to low level LO (closed) and the accumulator pressure drops, the pressure detection signal of the pressure switch PH changes from low level LO (closed) to high level HI (open) at pressure P3. Switch.
[0046]
FIG. 5 shows only the pump drive control operation related to the gist of the present invention of the microprocessor CPU of the microcomputer CMP equipped in the electronic control unit ECU. When the power is turned on, the CPU performs initial setting according to the system program (step A). In the following, the step word is omitted in parentheses, and step No. Write only the symbol.
[0047]
Next, the CPU starts a 6 msec timer (B), reads the pressure detection signal (high level HI: low pressure / low level LO: high pressure) of the pressure switch PH (C), and the brake pedal of the brake switch. A depression signal (high level H: brake pedal release / low level L: brake pedal depression) is read (D), and "motor control" (E) is executed. When "motor control" (E) is exited, it waits for the 6 msec timer to time over (F), and when time over, steps B to E are executed in the order described above. Therefore, the processes of steps B to E are repeatedly executed at a 6 msec cycle. FIG. 6 shows the contents of “motor control” (E). Hereinafter, the processing of the CPU in the “motor control” (E) will be described by itemization.
[0048]
1. Counting the number of brake pedal operations
When the signal of the brake switch BS is at a low level L (with brake pedal depressed), the CPU checks whether it was at a high level H (without brake pedal depressed) last time (1, 2). If this is the case, the brake pedal is depressed this time, and it is assumed that a new brake pedal has been depressed, the data in the brake count register N is incremented by 1 (3). If the brake pedal is already depressed at the low level L, the brake pedal depressing count N has been incremented by 1 at the time of switching from release to depressing. This data is not incremented by one. The data (the number of times the brake is depressed) in the brake number register N is cleared when the pressure switch PH detects a low pressure and energizes the pump motor M (ON: pump drive) accordingly. The data in the brake number register N is a value representing the number of times the brake pedal is depressed while the pressure detection signal of the pressure switch PH is LO representing high pressure.
[0049]
2. Increase accumulator pressure when pressure switch PH is normal
When the pressure detection signal of the pressure switch PH is switched from LO (high pressure) to HI (low pressure) (when the accumulator pressure falls below P3), the CPU turns on the motor M (4-6). The registers N, F, T, and M are cleared (7 to 10). As a result, the pump HP is driven to increase the accumulator pressure. While the pressure detection signal of the pressure switch PH is HI (low pressure), that is, until the accumulator pressure reaches P4, the CPU executes steps 1 to 11 in the “motor control” (E). When the pressure detection signal of the pressure switch PH is switched to LO (high pressure), that is, when the accumulator pressure reaches P4, the CPU proceeds from step 4 to step 12 and steps 12 to 17 (only 41 and 42 in 17). ) To count the elapsed time T since switching to LO (high pressure) (15). In the “stop process” (16), when the pump drive stop condition is satisfied, the motor M is turned OFF (pump HP stop).
[0050]
FIG. 7 shows the contents of the “stop processing” (16). Here, immediately after the pressure detection signal of the pressure switch PH is switched to LO (high pressure), the motor current value Im is read, and the accumulator pressure corresponding to this current value Im becomes P5 = P4 + ΔPm. Motor current value I _T (Estimated value) and delay time T _d (Estimated value) is calculated according to the above equations (1) and (2), and the elapsed time measurement value T is cleared (21 to 26). Note that Fsm = 1 in step 21 means that the electric motor M is ON. In the subsequent “stop process” (16), the motor current value Im is read (22), and the process proceeds from step 23 to step 27. _T Or the elapsed time T is the estimated delay time T _d It is checked whether or not this is the case (28, 29), and if either one is established, the motor M is turned off and the register Fsm and the elapsed time T are cleared (30A to 30C). The timer Tms in step 27 is the time (starting time) from when the motor M starts up until the motor current value decreases from the starting current (high value) to a value corresponding to the load (accumulator pressure). It is a program timer with a slightly longer time limit value Tms (1 sec in this embodiment), which is started (started) when the motor M is turned on, and from when the motor M is turned on. When the time Tms has elapsed, the time is over. If the time is not over, the read current value Im is not a load-corresponding value, so the motor energization stop condition is not checked (28, 29), and the motor M is turned on. continue.
[0051]
While the pressure switch PH is normal, when the CPU switches to HI (low pressure) in response to the pressure detection signal of the pressure switch PH, the pump HP is driven (4 to 11) and turned off to LO (high pressure). In other words, the estimated motor current value I when the accumulator pressure is P5 = P4 + ΔPm, corresponding to the motor current value Im at that time. _T And delay time T _d And the motor current value is I _T Or the elapsed time T is the delay time T _d When it becomes, the motor M is turned off (16).
[0052]
3. Increase accumulator pressure when pressure switch PH is broken
For example, if the contact is not closed when the pressure switch PH is open (open) or disconnected, the pressure detection signal does not switch to LO (high pressure) and the pump continues to drive even if the accumulator pressure exceeds P4. End up. In order to prevent this, there is “abnormal processing” in step 11. The contents are shown in FIG. Here, when energization (ON) of the motor M is started, “1” (motor M is ON) is written to the register Fms (31, 32), and the timer Tsm is started ( 31-34). Then, after the timer Tsm has timed over, the motor current value Im is read, which is the load current reference value I corresponding to P5. _TS Slightly higher setpoint I _TU It is checked whether it is above (32-35 to 37), and the set value I _TU When this occurs, the motor M is turned OFF (38), an alarm 1 indicating an abnormal disconnection of the pressure switch PH is generated (39), and the registers Fsm and T (for elapsed time counting) are cleared. (40A, B).
[0053]
After the motor M is turned off in this manner due to the disconnection abnormality, the alarm 1 is present. Therefore, even if the pressure detection signal of the pressure switch PH is a low pressure (HI), the CPU performs steps 4 to 6 in FIG. The process does not proceed to (motor ON), but proceeds to “abnormal process” (11). In “abnormal process” (11) of FIG. 8, the process proceeds from step 31 to step 40C. It is checked whether the brake pedal operation count N from the time of turning OFF to the present reaches the set value KN2 (see FIG. 9) (40C). When the brake pedal operation count N reaches the set value KN2, the motor M is turned ON (40D), and the registers N (brake pedal operation count N) and T are cleared (40E, F). Then, 1 is written in the register Fsm to start the timer Tms (32 to 34). Thereafter, as described above, after the timer Tms has timed over, the motor current value Im becomes the set value I. _TU When this occurs, the motor M is turned off (36-38).
[0054]
Therefore, while the disconnection abnormality (low pressure HI) continues, the motor current value becomes I _TU When this value is reached, the pump drive is stopped. After that, when the brake pedal operation count N reaches the set value KN2 from the start (40D, E) of the previous pump drive, the pump drive is started.
[0055]
4). Increase accumulator pressure when short circuit of pressure switch PH is abnormal
For example, even if the pressure detection signal of the pressure switch PH remains LO (high pressure) and the accumulator pressure falls below P3 due to some failure, such as contact welding of the switch, ground fault of the pressure detection signal line, etc., it becomes HI (low pressure) If not switched, see 2. above. And 3. Therefore, every time the driver steps on the brake pedal BP, the accumulator pressure is consumed and decreases. In this state, the number of steps N is counted up (steps 1 to 3).
[0056]
Referring to FIG. 6 again, in “abnormal processing 2” (17), the CPU detects that the number of steps N exceeds KN (= KN1) while the pressure detection signal of the pressure switch PH remains LO (high pressure). M is turned ON to clear the registers N and T, and “1” representing the pump drive when the pressure switch signal is abnormal is written in the register F (41-43 to 46). Then, the data in the register M is incremented by 1 (47). After that, since the value of the register N is cleared when the motor M is turned on, it is 0 or a smaller value. Therefore, the process proceeds from step 42 to 49, and the elapsed time T from the start of the motor ON. It is checked whether (exactly T × 6 msec) has exceeded the set time KT (= KT1, exactly KT1 × 6 msec), and the motor M is turned OFF when it exceeds (50). The above is the processing corresponding to the progress of (1) to (5) shown in FIG. Thereafter, as shown in (5) to (7) in FIG. 9, every time the number of times of brake depression N exceeds KN2, the set value KN is updated to KN2 in order to keep the motor M ON for KT2. (51) and the set time KT is updated to KT2 (52).
[0057]
After that, if the pressure detection signal of the pressure switch PH remains LO (high pressure), the motor M is turned ON and the registers N and T are cleared when the brake depression count N exceeds the set value KN = KN2. Then, "1" indicating the pump drive when the pressure switch signal is abnormal is written in the register F (41-43 to 46), and the data in the register M is incremented by 1 (47). When the data in the register M becomes equal to or greater than the predetermined value Ma, that is, when the pressure detection signal of the pressure switch PH continues to be LO (high pressure), the signal is regarded as abnormal and does not depend on the signal. When the number M of pump driving operations reaches Ma, an alarm 2 indicating a short circuit abnormality of the pressure switch is generated. When the second pump driving described above is performed, the CPU increments the data in the register T by 1 to measure the elapsed time T from the start of the motor ON (15). In step 49, it is checked whether the elapsed time T has exceeded the set time KT (= KT2). When the elapsed time T has exceeded, the motor M is turned off (50).
[0058]
The second and subsequent pump driving is started every time the brake pedal depression number N exceeds KN2, and is stopped after the set time KT2. As a result, the accumulator pressure is approximately in the range of pressures P2 to P5 shown in FIG. 9, and the accumulator pressure is guaranteed.
[0059]
Reference is made to FIG. 9 showing the hydraulic pressure of the accumulator ACC. P4 is a pressure (steady upper limit pressure) at which the pressure detection signal of the pressure switch PH is switched from a low pressure to a high pressure. The pressure P5 = P4 + ΔPm in (1) is consumed every time fluid pressure is applied to the load, decreases as the number of times of applying fluid pressure to the load increases, and becomes pressure P3 in (2). The pressure P3 is a pressure (steady lower limit pressure) at which the pressure detection signal of the pressure switch PH is switched from the high pressure to the low pressure. If the pressure switch PH is normal, the fluid pump HP (electric motor M) is driven by this switching, and the pump rotates to increase the accumulator pressure as indicated by the two-dot chain line ((3)). . If the pressure detection signal of the pressure switch PH is not switched to a low pressure at {circle around (2)}, the accumulator pressure further decreases because the pump does not rotate, and reaches the pressure P1 at {circle around (4)}. This pressure P1 is estimated from the number N of times the brake pedal is depressed.
[0060]
Here, it is assumed that the pressure decrease amount of the accumulator ACC during one application of the accumulator pressure to the wheel brake circuit (one depression period of the brake pedal BP) is constant at ΔPs. And
P5-P1 = ΔPs · KN1
When the number (N) of application (consumption) of the accumulator pressure reaches KN1 corresponding to the pressure P1, the pump HP is driven (4). As a result, the accumulator pressure increases. If the elapsed time T is measured from (4) when the pump HP is driven and the pump HP is stopped after the time KT1 when the accumulator pressure reaches P5, the pressure at this time is (5), that is, P5. Again, the accumulator pressure is consumed in conjunction with the depression of the brake pedal, and gradually decreases with time to become pressure P3. If the pressure switch PH is out of order, the pressure is not switched at the pressure P3, so that the accumulator pressure further decreases to reach the pressure P2 (6). The pressure P2 is estimated from the number N of times the brake pedal is depressed, and when the pressure P2 is reached, when the pump HP is driven, the accumulator pressure increases. The elapsed time T is measured from (6) when the pump HP is driven, and the pump HP is stopped after the time KT2 when the accumulator pressure reaches P5. The pressure at this time is (7), that is, P5. Thereafter, the same is repeated.
[0061]
According to the above assumption, if ΔPs is a constant value, the accumulator pressure can be maintained within the range of P2 to P5. By the way, when ΔPs is not constant, the pressures (5) to (7) do not accurately become P2 to P5 but shift to the low pressure side or the high pressure side. However, by setting ΔPs to the statistical average value of pressure consumption during one depression of the brake pedal, the accumulator pressure is maintained in the range of approximately P2 to P5, and the accumulator pressure is guaranteed. The
[0062]
-Second Example-
FIG. 10 shows the contents of the “stop process” (16) of the second embodiment of the present invention. The “stop process” (16) of FIG. 10 is used in place of the “stop process” (FIG. 7) of the first embodiment. The hardware configuration and function (flow chart) are the same as those in the first embodiment.
[0063]
Referring to FIG. 10, in the second embodiment, the motor when the accumulator pressure corresponding to the motor current value Im becomes P5 immediately after the pressure detection signal of the pressure switch PH is switched to LO (high pressure). Current value I _T And delay time T _d In the “stop process” (16) after the elapsed time measurement value T is cleared (21 to 26), the motor current value Im is read (22), and the elapsed time T is the estimated delay time T. _d The motor current value Im exceeds the estimated calculated value I. _T When this occurs, the motor M is turned off (28, 29, 30A). The elapsed time T is the delay time T _d The motor current value Im remains the estimated calculated value I even after _T Is not reached, the elapsed time T is T _d Longer set value T _UL When this happens, the motor M is turned off (30D, 30A). Other processes are the same as those in the first embodiment.
[0064]
In the first embodiment (FIG. 7), the elapsed time T is the delay time T. _d Until the motor current value Im reaches I _T (When the first condition is satisfied) and the motor current value Im is I _T Elapsed time T becomes delay time T _d Since the motor M is turned off in any case when the value reaches the value (the second condition is satisfied), the reliability of the motor OFF is high. In the second embodiment (FIG. 10), the motor is turned OFF when the first condition is satisfied after the second condition is satisfied, and the motor OFF condition is severe. In the second embodiment, if the motor current value detection system fails, the motor will continue to be turned on. _d Longer set value T _UL The motor is automatically turned off when reaching. Thus, the motor OFF reliability equivalent to that of the first embodiment is ensured.
[0065]
In any of the embodiments described above, in the “stop process” (16), when the pressure detection signal of the pressure sensor PH is switched to a high voltage (LO), the motor current value at that time corresponds. Motor current value I corresponding to target pressure P5 _T And delay time T _d Since the OFF timing of the electric motor M is determined using the calculated value as a comparison value, the accumulator pressure having a wide hysteresis width (P3 / P5) is determined based on the pressure detection signal of one pressure sensor PH. Control can be realized.
[0066]
Disconnection of the pressure switch PH, disconnection of the pressure detection signal line, etc. occur, and the pressure detection signal indicates HI (low pressure), and LO (high pressure) despite the increase in accumulator pressure ), The motor load current value I for driving the pump HP to a pressure slightly higher than P5 of the accumulator pressure by "abnormal processing 1" (29). _TU When the current value of the motor M increases, the motor M is turned off at that time, and motor energization (accumulator overpressure) for a long time is avoided (steps 36 to 38 in FIG. 8). . Moreover, while the disconnection abnormality continues, the alarm 1 is issued. During this period, the motor is turned ON every time the brake pedal depression number N reaches KN2 by the “abnormal process” (29). The number of steps N is cleared and counted up again from 0 (40C to 40F). In this motor ON, the motor load current value is I _TU It stops when it becomes (36-38). Therefore, overpressure of the accumulator (motor overload energization) and insufficient pressure are avoided while the disconnection abnormality of the pressure switch PH continues.
[0067]
Short circuit abnormality such as contact welding on the pressure switch PH, short circuit of the pressure detection signal line, etc. occurs, and the pressure detection signal indicates LO (high pressure), and HI (low pressure) despite the decrease in the accumulator pressure If it is not switched to, the pump automatically drives (ON) / stops (OFF) the pump HP so that the accumulator pressure is in the range of approximately P2 to P5 in "abnormal processing 2" (17). (4. above). Then, alarm 2 is generated.
[0068]
Therefore, even when accumulator ACC pressure accumulation control is performed using only one pressure switch PH, reliability (safety) of pressure control is ensured against an abnormality (failure) in the pressure switch PH system. Is done. That is, high reliability can be realized by using a small number of pressure detection means in order to reduce the cost.
[Brief description of the drawings]
FIG. 1 is a block diagram showing a configuration of a wheel brake pressure control device equipped with a first embodiment of the present invention.
FIG. 2 is a block diagram showing a configuration of a brake liquid circuit PC shown in FIG.
3 is an enlarged longitudinal sectional view of one pressure switch PH shown in FIGS. 1 and 2. FIG.
4A is an electric circuit diagram showing a connection circuit between a pressure switch PH and an electronic control unit ECU, and FIG. 4B is a time chart showing a pressure detection signal of the pressure switch PH.
FIG. 5 is a flowchart showing an operation of a portion related to accumulator pressure control of the CPU of the microcomputer CMP mounted in the electronic control unit ECU shown in FIG. 1;
FIG. 6 is a flowchart showing the contents of “motor control” (8) shown in FIG. 5;
7 is a flowchart showing the contents of “stop processing” (16) shown in FIG. 6;
FIG. 8 is a flowchart showing the contents of “abnormal processing” (29) shown in FIG. 6;
FIG. 9 is a time chart showing an outline of a pressure change of the accumulator ACC shown in FIG. 1;
FIG. 10 is a flowchart showing the contents of “stop processing” (16) of the CPU of the microcomputer CMP of the second embodiment of the present invention.
FIG. 11 is a block diagram showing an outline of a conventional fluid pressure source device using two pressure switches.
[Explanation of symbols]
AP: Accelerator pedal BP: Brake pedal
BS: Brake switch CPM: Microcomputer
DA: Diaphragm DF: Differential gear
ECU: Electronic control unit EG: Engine
FI: Fuel injector FL: Front left wheel
FR: Front right wheel GS: Shift control device
HB: Hydraulic booster MC: Master cylinder
MS: Micro switch MT: Main throttle valve
PC: Brake fluid pressure control device PS: Fluid pressure source
RD: Relay driver RL: Rear left wheel
RO: Rod RR: Rear right wheel
RS: Reservoir SP: Spring
ST: Sub-throttle valve TH: Throttle control device
R: resistance for motor current detection
WfL, Wfr, WrL, Wrr: Wheel cylinder
WS1 to WS4: Wheel speed sensor YS: Yaw rate sensor

Claims (4)

Fluid pump, electric motor for driving the same, accumulator for receiving the discharge pressure of the fluid pump, pressure switch for detecting the pressure of the accumulator or a fluid pressure line communicating therewith, and pressure of the pressure switch In a fluid pressure source device comprising: pump control means for starting energization of the electric motor when it switches from one representing high pressure to one representing low pressure in response to a detection signal;
A delay time _Td is determined on the basis of the load current value of the electric motor when the pressure detection signal of the pressure switch is switched from one representing low pressure to one representing high pressure. A fluid pressure source device comprising: a boost stop means for deactivating the electric motor after _d . Fluid pump, electric motor for driving the same, accumulator for receiving the discharge pressure of the fluid pump, pressure switch for detecting the pressure of the accumulator or a fluid pressure line communicating therewith, and pressure of the pressure switch In a fluid pressure source device comprising: pump control means for starting energization of the electric motor when it switches from one representing high pressure to one representing low pressure in response to a detection signal;
The load current value when the pressure is further boosted by a set value ΔPm based on the load current value of the electric motor when the pressure detection signal of the pressure switch is switched from one representing low pressure to one representing high pressure estimating computes the I _T, the electric motor - electric when the load current value of the motor has reached said value I _T mode - boosting stop means for de-energizing the motor, a fluid pressure source apparatus comprising: a. Fluid pump, electric motor for driving the same, accumulator for receiving the discharge pressure of the fluid pump, pressure switch for detecting the pressure of the accumulator or a fluid pressure line communicating therewith, and pressure of the pressure switch In a fluid pressure source device comprising: pump control means for starting energization of the electric motor when it switches from one representing high pressure to one representing low pressure in response to a detection signal;
A delay time _Td is determined based on the load current value of the electric motor when the pressure detection signal of the pressure switch is switched from a low pressure signal to a high pressure signal, and the pressure is further set to a set value ΔPm. the load current value I _T in the case of pressurized estimation operation, after the delay time T _d elapses from該切Kawari the electric motor - electric when the load current value of the motor has reached said value I _T mode - de-energizes motor A fluid pressure source device, comprising: a pressure stop means for performing the operation. The boost stop means is a pressure switch for switching the pressure detection signal from one representing low pressure to one representing high pressure when the pressure rises to P4 when the pressure is normal. The pressure control signal represents low pressure. - while urging the motor, the electric motor - load current value Im of the motor is equal to or higher than the set value I _TU than the value I _T, which corresponds to the pressure P4 + .DELTA.Pm plus the set value .DELTA.Pm to P4, the electric motor - The fluid pressure source device according to claim 1, wherein the fluid pressure source device is configured to deactivate the data.

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