JP3692888B2 - Control device for electromagnetically driven valve - Google Patents

Description

に示すように生成する（図３参照）。
【００３５】
ここでｚは可動部位置センサ３の出力から演算される可動子５７と可動子５７を引きつけている電磁石との距離（ギャップ）、ｔは時刻、ｖ(t)は可動部速度センサ２が検出した可動部の速度、または可動部位置センサ３が検出した位置信号の出力から演算されるｚの時間微分値である。ｒ₁(z)，ｒ₂(z)はギャップｚの関数として与えられる速度目標関数であり、これら速度目標関数が、本発明における可動部の複数の運動特性目標値に相当する。そして、第１の速度目標関数ｒ₁(z)は、ギャップｚが次第に小さくなり第１の所定値ｚ_s0になった時点ｔ_s0つまり電磁石への通電制御が開始される時点で選択され、ギャップｚが更に減少して第２の所定値ｚ_s0になった時点で第２の速度目標関数ｒ₂(z)が選択されて切り換えられる。前記第１の所定値ｚ_s0はギャップｚが小さくなり電磁力が有効になるギャップ長を基準に選ばれ、実際には１〜３［ｍｍ］程度である。
【００３６】
これら第１の速度目標関数ｒ₁(z)及び第２の速度目標関数ｒ₂(z)は次の条件を満たすように決定される。以下では、ｚ，ｔの関数における(z)，(t)を省略する。
【００３７】
【数２】

と選ぶと、速度目標関数の切り換え点において、速度目標値を連続にすることができる。ここで、ｓはラプラス演算子、ｚ_sは速度目標値を切り換える位置（設計者が与える所定値）、ｚ_eは可動子の制御目標位置（設計者が与える所定値）、ｒ_sは速度目標値を切り換える直前の速度目標値、ζ,ωは、設計者が適当に選ぶ定数である。
【００３８】
第１の速度目標関数ｒ₁は、着座までの時間を短くすることを主眼に設定された、応答の速い２次振動系の応答に基づいて設定された速度目標値であり、ζは、0.7付近、ωは［（ｍ₁＋ｍ₂）／（ｋ₁＋ｋ₂）］^1/2程度の値に選ぶ。ここで、ｍ₁，ｍ₂はそれぞれ可動子と弁の質量、ｋ₁,ｋ₂はそれぞれコイルスプリング５９およびコイルスプリング５６のバネ定数である。
【００３９】
一方、第２の速度目標関数ｒ₂は、着座の速度を小さくすることを主眼に選ばれる。既述のように、式(3),(4)のように選ぶと、速度目標値はｚ_eの位置で滑らかに接続される。式(3)を用いると、ｒ₂は１次応答を元に設定されるので、可動部位置はオーバーシュートせず、漸近的に目標位置に収束するので、着座の衝撃を小さくすることができる。
【００４０】
前記速度目標値生成部４の構成を図４に示す。
また、第２の速度目標関数ｒ₂は、
【００４１】
【数３】

とし、振動の減衰度を決定する定数ζ₂を１より大きくした非振動的な２次応答特性を有した関数を用いてもよい。
【００４２】
以上のようにして設定された速度目標値ｒは、可動部速度センサ２によって検出された実際の可動部速度ｖ（＝ｄｚ／ｄｔ) と比較部４により比較され、比較信号（ｖ−ｒ）が電流目標値生成部６に出力される。電流目標値生成部６では、電流目標値ｉ(t)を、次に示す式(6)のように生成する。
【００４３】
【数４】

ここで、ｋは適当に決める正の定数（フィードバックゲイン）である。なお、ｚ＞ｚ_s0 の区間ではｒ＝ｖ（＝ｄｚ／ｄｔ)であるから通電による速度制御は発生しない。
【００４４】
この電流目標値を電磁石の通電電流として、切替器７を介して閉弁側電磁石電流制御部９または開弁側電磁石電流制御部１０に伝達される。ここで、切替器７は、エンジン制御ＥＣＵ８より開弁指令または閉弁指令を入力し、開弁指令であれば開弁側電磁石電流制御部１０、閉弁指令であれば閉弁側電磁石電流制御部９をそれぞれ選択し、選択された側に電流目標値生成部６が生成する電流目標値を出力する。そして、閉弁側電磁石電流制御部９または開弁側電磁石電流制御部１０がＰＷＭ制御により電源部１３から供給される電流のＯＮ／ＯＦＦ比を制御することにより通電電流の大きさが制御され、結果として可動子に作用する電磁力が制御され、可動部の速度が制御される。
【００４５】
ここで、第1の制御目標位置をｚ_e1、そのときの速度目標値をｒ_e1、第２の制御目標位置をｚ_e2、そのときの速度目標値をｒ_e2とし、２段階の制御目標位置を設定する。例えば、閉弁時には、
ｚ_e1＝0.3[mm] ｒ_e1＝０[m/s]、ｚ_e2＝0.1[mm] ｒ_e2＝０[m/s]と設定する。
【００４６】
なお、制御目標位置の切り換えについては、センサで検出された可動子の位置及び速度から、略ｚ＝ｚ_e1、ｖ＝ｒ_e1となったときに、制御目標位置をｚ＝ｚ_e2に切り換えて設定する。
【００４７】
ここで、第1の制御目標位置ｚ_e1は、弁体が閉弁着座した時点の可動子位置近傍（閉弁着座時の位置よりやや電磁石より）に設定され、これにより、弁体の閉弁着座時の速度を十分小さくできるので、着座の衝撃を小さくでき、衝突音を軽減できる。また、第２の制御目標位置をｚ_e2を、第1の制御目標位置ｚ_e1より小さく設定することで、閉弁着座後に弁体から切り離された可動子は、さらに閉弁用電磁石に近づけられた位置で電磁石と非接触に宙吊り状態で停止するように制御される（以下かかる制御を宙吊り制御という）。この場合、電磁吸引力は、電磁石に接近するほど急激に増大する特性を有するので、可動子を電磁石に接近した位置で停止させるほど、通電電流は小さくて済み、消費電力を節減できる。
【００４８】
しかし、上記可動子の宙吊り制御は、電磁吸引力が増大して可動子を電磁石に接近させる方向に作用コイルスプリングのバネ力と電磁石に電磁吸引力とが釣り合って可動子が停止している状態から、外乱により可動子が電磁石に接近すると、電磁吸引力が増大して可動子をさらに電磁石に接近させる方向に作用し、逆に可動子が電磁石から遠ざかると電磁吸引力が減少して可動子をさらに電磁石から遠ざけるに方向に作用するという不安定系であり、宙吊り状態を維持するためには、速やかなフィードバック応答性が要求される。前記のように、電磁吸引力は、電磁石に接近するほど急激に増大するので、ある程度以上接近すると宙吊り制御が難しくなり、電磁石へ吸着されやすくなる（電磁石から離れる方向は、通電電流を最大限にすることで阻止することが可能であるが、接近する方向は可動子と電磁石との距離が短いこともあって通電電流を弱めても間に合わず、一旦電磁石に吸着されると、再度宙吊り制御を行なうことは不可能となる）。
【００４９】
そこで、より安定した宙吊り制御を行なって可動子の衝突抑止効果を高め、少しでも静粛性を重視するならば、図５のように、第２の制御目標位置をｚ_e2を、大きめの値に設定すればよいが、消費電力をより節減することを重視するならば、図６のように、第２の制御目標位置をｚ_e2を、小さめの値に設定すればよい。後者の場合、宙吊り制御に失敗して電磁石に吸着される場合もありうることになるが、例えば、１０回につき１回の割合で失敗して電磁石に吸着し、衝突音が発生したとしても、最初から着座制御する場合に比較して、１／１０で済むことになる。また、閉弁時は、弁体着座時の衝突音が避けられず、該衝突音発生後瞬時の後に連続的に音を生じても、可動子のみの衝突音は弁体着座時（弁体と可動子の合計の質量が衝突する）の衝突音と比較して小さいこともあって、それほど音が増大した感じがしなくて済む。
【００５０】
更に消費電力の節減を重視するならば、図７に示すように、第２の制御目標位置をｚ_e2を、電磁石との吸着位置として可動子を着座制御するようにしてもよく、その場合でも、速度目標値を０に近づけることで、衝突音を可及的に低減することが可能である。
【００５１】
次に、開弁時の制御の実施の形態について説明する。開弁時は、閉弁時と異なり弁体を着座制御する必要がない。したがって、極力安定した宙吊り制御を行なって、衝突音の発生を確実に防止することを図る。閉弁時から時間をおいた開弁時に、衝突音が発生するのとしないのとでは、感覚的に大きな差があるからである。一方、開弁時は、吸・排気弁の応答性を高めるため、初期の開弁速度を大きくすることが要求される。可動子の制御目標位置を１個設定しただけでは、これら両方の要求を満たすことはできない。
【００５２】
そこで、開弁時も可動子の制御目標位置を２段階に切り換えて設定する。すなわち、先に設定される可動子の第1の制御目標位置ｚ_e1は、開弁用電磁石に接近した小さ目の値に設定し、後で設定される第2の制御目標位置ｚ_e2は、開弁用電磁石からの距離を大きくするように大き目の値に設定する。
【００５３】
このようにすれば、図８に示すように、開弁初期は可動子の第1の制御目標位置ｚ_e1が小さめに設定されることで、可動子及び可動子と一体の弁体の移動速度を大きくして応答性を高めることができ、開弁後期は可動子の第1の制御目標位置ｚ_e2が大きめに設定されることで、安定した宙吊り制御を行なって衝突音の発生を確実に防止することができる。
【００５４】
また、制御としては、図８に示すように、可動子が第1の制御目標位置ｚ_e1に移動して安定してから第2の制御目標位置ｚ_e2に切り換えるのが、容易かつ高精度に行なえるが、図９に示すように、可動子が第1の制御目標位置ｚ_e1に移動すると同時若しくはその前に第2の制御目標位置ｚ_e2に切り換えて、安定した宙吊り制御に早めに移行させるようにしてもよい。
【００５５】
図１０、図１１は、前記制御装置１の動作のフローチャートである。図１０は、所定時間毎に可動部の位置と速度とを読み込んで、速度目標関数の算出、電流目標値の算出及び出力を行う第１のフローを示し、図１１は、エンジン制御ＥＣＵからの弁開閉指令により閉弁側電磁石電流制御部９と開弁側電磁石電流制御部１０とを選択切換する第２のフローを示す。いずれのフローも制御装置１に内蔵される図示されないタイマーにより計測される所定時間を周期として実行される。
【００５６】
まず、図１０を参照して第１のフローについて説明する。
ステップ（図ではＳと記す。以下同様）１では、可動部位置センサ３及び可動部速度センサ２から位置信号ｚ及び速度信号ｖを読み込む。
【００５７】
ステップ２では、前記速度目標値生成部５で速度目標関数ｒを算出する。
ステップ３では、前記比較部４及び電流目標値生成部６の協動により電磁石に通電すべき電流目標値ｉを算出する。
【００５８】
ステップ４では、前記算出された電流目標値ｉを切替器７により選択された閉弁側電磁石電流制御部９または開弁側電磁石電流制御部１０のいずれか一方に供給する。
【００５９】
次に、図１１を参照して第２のフローについて説明する。
ステップ１１では、エンジン制御ＥＣＵ８から弁開閉指令を読み込む。
ステップ１２では、開弁指令か否かを判定し、開弁指令であれば、ステップ１３で開弁側電磁石電流制御部１０を電流目標値生成部６に接続するよう切替器７を切り替える。
【００６０】
ステップ１２の判定で開弁指令でなければ、ステップ１４で閉弁指令か否かを判定し、閉弁指令であれば、ステップ１５で閉弁側電磁石電流制御部９を電流目標値生成部６に接続するよう切替器７を切り替える。
【００６１】
以上のように、第１のフローと、第２のフローとは並列に実行可能であるが、直列に実行することもでき、その場合は、時間待ちを含まない第２のフローを先に実行するのが好ましい。
【００６２】
図１２は、前記第１のフローにおけるステップ２での速度目標関数ｒを算出するサブルーチンを示す。
ステップ２１では、可動子５７と可動子５７を引きつけている電磁石とのギャップｚが、前記第２の所定値ｚ_sより大きいかを判定し、大きいと判定された場合は、ステップ２２で前記式(2)に示した第１の速度目標関数ｒ₁を算出する。ここで、前記ギャップｚが前記第１の所定値ｚ_s0より大きいときには、可動子の実際の速度ｖがｒ₁より大きいので、前記式(8)に従って通電は開始されず、ギャップｚがｚ_s0以下となってから該第１の速度目標関数ｒ₁に応じた通電による速度制御が開始される。
【００６３】
また、ステップ２１の判定がＮＯである場合には、ステップ２３でギャップｚが略第２の所定値ｚ_s以下となったかを判定し、略第２の所定値ｚ_s以下となった場合は、ステップ２４で前記式(3)で示される第２の速度目標関数ｒ₂における定数ｃ₁を前記式(4)に従って算出した後、ステップ２５で該式(3)又は(5)で示される第２の速度目標関数ｒ₂を算出する。
【００６４】
ステップ２３の判定がＮＯである場合、つまりギャップｚが第２の所定値ｚ_sより小さくなった後は、ステップ２６で前記算出された定数ｃ₁を用いて式(3) 又は(5)で示される第２の速度目標関数ｒ₂を算出する。
【００６５】
次に、本発明にかかる可動子の制御目標位置を複数段階に切り換える制御を、図１３に基づいて説明する。
該制御は、前記図１２のステップ２５において、前記式(3) 又は(5)により第２の速度目標関数ｒ₂を算出する際に、可動子の制御目標位置ｚeを切り換える制御である。
【００６６】
ステップ３１では、可動部位置センサ３及び可動部速度センサ２から位置信号ｚ及び速度信号ｖを読み込む。
ステップ３２では、前記信号から可動子の位置ｚと速度ｖが、それぞれ略第1の制御目標位置ｚe₁及び第1の速度目標値ｒe₁になったかを判定する。
【００６７】
ｚe₁及びｒe₁になっていないと判定されたときは、ステップ３３へ進み、制御目標位置ｚeを第1の制御目標位置ｚe₁、速度目標値ｒeを第1の速度目標値ｒe₁に設定する。これにより、前記図１２のステップ２５において、該第1の制御目標位置ｚe₁及び第1の速度目標値ｒe₁を用いて、前記式(3) 又は(5)により第２の速度目標関数ｒ₂が算出される。そして、該算出された第２の速度目標関数ｒ₂によって、図１０のステップ３，４により、電流目標値ｉが算出され、該算出された電流目標値ｉが閉弁側電磁石電流制御部９または開弁側電磁石電流制御部１０のいずれか一方に供給されて通電制御が行なわれる。
【００６８】
また、ステップ３２で、可動子の位置ｚと速度ｖが略ｚe₁及びｒe₁になったと判定されたときは、ステップ３４へ進み、制御目標位置ｚeを第２の制御目標位置ｚe₂、速度目標値ｒeを第２の速度目標値ｒe₂に設定する。これにより、前記図１２のステップ２５において、該第２の制御目標位置ｚe₂及び第２の速度目標値ｒe₂を用いて、前記式(3) 又は(5)により第２の速度目標関数ｒ₂が算出され、前記同様に該算出された第２の速度目標関数ｒ₂によって、図１０のステップ３，４により、電流目標値ｉが算出され、該算出された電流目標値ｉが閉弁側電磁石電流制御部９または開弁側電磁石電流制御部１０のいずれか一方に供給されて通電制御が行なわれる。
【００６９】
なお、可動子の制御目標位置ｚeを切り換える本発明の制御は、速度目標関数ｒを、上記のように２段階に切り換えることをせず、１つの速度目標関数ｒのみを持つものにおいて制御目標位置ｚe複数段階に切り換えることでも適用できる。
【００７０】
尚、本実施形態の変形例として、可動部速度センサ２に代えて可動部位置センサ３の出力信号を時間微分して速度信号を得る微分手段を用いても良いことは、明らかである。
【００７１】
図１４は、本発明に係る電磁駆動弁の制御装置の第２実施形態の構成を説明するブロック図である。本実施形態においては、第１実施形態の可動部速度センサ２に代えて、閉弁側電磁石１１または開弁側電磁石１２に通電される電流値を検出する電磁石電流センサ１６と、可動子速度推定部（オブザーバ）１７とを備えた制御装置１５が用いられている。その他の構成は第１実施形態と同様である。この電磁石電流センサ１６は、閉弁側電磁石電流制御部９または開弁側電磁石電流制御部１０の出力電流を直列低抵抗により検出してもよいし、電磁石１１，１２の磁束を検出して電流に換算する形式でもよい。
【００７２】
本実施形態の特徴は、可動部の速度を直接検出する代わりに、電磁石電流センサ１６が検出した電磁石１１，１２の通電電流と、可動部位置センサ３が検出した可動部の位置とに基づいて、可動子速度推定部１７が可動子の速度を推定することである。
【００７３】
可動部の質量ｍ、可動部に関わるバネ定数ｋ、可動部に関わる粘性定数ｃ、電磁力をＦとすると、可動部の運動は、
【００７４】
【数５】

と表される。
【００７５】
ここでｆ（ｘ，ｉ）は磁気回路の形状や材質などにより決まる関数であり、磁場解析などの手段によりあらかじめ知ることができる。γはバネ力のうち、オフセット荷重成分である。これらの式を元に、可動部の速度は直接可動部速度センサ２で検出する代わりに、位置ｘと電流ｉから以下の式を用いる可動子速度推定部１７で推定することができる。
【００７６】
【数６】

推定された可動子の速度は、第１実施形態と同様に比較部５へ入力され、以下の処理内容は第１実施形態と同様であり、第１実施形態と同様の効果を得ることができる。
【図面の簡単な説明】
【図１】本発明が適用される電磁駆動弁の構成を示す概念図。
【図２】本発明に係る電磁駆動弁の制御装置の第1の実施形態の構成を示すブロック図。
【図３】同上実施形態における速度目標関数の生成法を説明する位置／速度位相面における可動部の軌跡を示すグラフ。
【図４】同上実施形態における速度目標値生成部の構成を示すブロック図。
【図５】同上実施形態における閉弁時の可動子位置の変化の第１の例を示す図。
【図６】同上実施形態における閉弁時の可動子位置の変化の第２の例を示す図。
【図７】同上実施形態における閉弁時の可動子位置の変化の第３の例を示す図。
【図８】同上実施形態における開弁時の可動子位置の変化の第１の例を示す図。
【図９】同上実施形態における開弁時の可動子位置の変化の第２の例を示す図。
【図１０】同上実施形態における速度目標関数の算出、電流目標値の算出及び出力を行う第１のフローを示すフローチャート。
【図１１】同上実施形態における閉弁側電磁石電流制御部と開弁側電磁石電流制御部とを選択切換する第２のフローを示すフローチャート。
【図１２】前記第1のフローの速度目標関数算出のサブルーチン示すフローチャート。
【図１３】同上実施形態における本発明にかかる可動子の制御目標位置の切り換え制御のフローを示すフローチャート。
【図１４】本発明に係る電磁駆動弁の制御装置の第２の実施形態の構成を示すブロック図。
【符号の説明】
１ 制御装置
２ 可動部速度センサ
３ 可動部位置センサ
４ 比較部
５ 速度目標値生成部
６ 電流目標値生成部
７ 切替器
９ 閉弁側電磁石制御部
10 開弁側電磁石制御部
11 閉弁側電磁石
12 開弁側電磁石[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an electromagnetically driven valve control device, and more particularly to an electromagnetically driven valve control device that performs energization control in accordance with the position of a mover.
[0002]
[Prior art]
In a drive system for an intake / exhaust valve of a vehicle engine, an electromagnetically driven valve that drives a valve body by electromagnetic force has been proposed in place of a conventional cam drive system that drives a valve body by a cam. According to this electromagnetically driven valve, the cam mechanism for driving the valve body is not required, and the opening / closing timing of the intake / exhaust valve can be easily optimized according to the operating state of the engine. Improvement and fuel consumption can be improved.
[0003]
As a conventional technique of such an electromagnetically driven valve, “Method for controlling electromagnetic valve driving part of gas exchange valve” (hereinafter referred to as “first prior art”) described in JP-A-10-205314, JP-A-10-220622. An “electromagnetic actuator having a narrow structure” (hereinafter referred to as “second prior art”) disclosed in the publication is disclosed.
[0004]
[Problems to be solved by the invention]
In general, in an electromagnetically driven valve, a part of a valve body or a movable element (movable part) collides with an electromagnet when the valve is closed and when the valve is fully opened. Therefore, noise is generated at the time of collision. Further, if the strength of the movable part and the electromagnet part is tolerate the collision, the weight of the electromagnetically driven valve increases or a large drive power is required.
[0005]
For this reason, in the first and second prior arts, the shape of the electromagnet is changed, the magnetic force is maximized at a position where the movable part does not contact the electromagnet, and the electromagnetically driven valve that is stopped and held before the movable part collides with the electromagnet. It is disclosed.
[0006]
However, it is necessary to generate a large magnetic force in order to stop and hold the movable part before colliding with the electromagnet by the methods of the first conventional technique and the second conventional technique. There was a problem that it was easy to invite high power.
[0007]
The present invention has been made in view of such a conventional problem, and provides an electromagnetically driven valve control device capable of reducing collision noise and wear of a mover and a valve body while reducing power consumption. Objective.
[0008]
[Means for Solving the Problems]
Therefore, the invention according to claim 1
An electromagnet, a mover that is driven by the electromagnet against a reaction force of a spring, and a valve body that is driven in conjunction with the mover, and controls the energization of the electromagnet while detecting the position of the mover. And at the time of movement of the mover in at least one direction, after stopping the seating of the valve body, it is a control device for an electromagnetically driven valve that is detached from the valve body and only the mover stops after moving a predetermined amount ,
At the time of movement in the direction, a control target position set ahead of the mover is set at a position farther from the electromagnet than a control target position set later .
[0009]
According to the invention of claim 1,
While the mover is being driven, the electromagnet is energized and controlled according to the control target position while switching the control target position in a plurality of stages, so that it can be controlled in an optimal state. It is possible to improve body collision noise reduction, wear suppression, responsiveness and the like .
[0010]
In addition, after stopping the seating of the valve body, when only the mover moves and then stops, the control target position set earlier is moved away from the electromagnet from the control target position set later. By setting, the mover is driven toward the newly set control target position after seating the valve body while reducing the impact at the time of seating by reducing the speed immediately before the seating of the valve body.
[0011]
The invention according to claim 2
The control target position set earlier is set in the vicinity of the mover position at the seating stop position of the valve body, and the control target position set later is set at a position immediately before the collision with the electromagnet. Features.
[0012]
According to the invention of claim 2 ,
Control is performed so that the mover is stopped at a position immediately before being attracted to the electromagnet while the valve body is seated at a sufficiently low speed. Thereby, the impact at the time of seating of the valve body can be reduced as much as possible, the collision of the mover can be suppressed to prevent collision noise and wear, and the power consumption can be reduced by bringing the valve body closer to the electromagnet.
[0013]
The invention according to claim 3
The electromagnetically driven valve is an intake / exhaust valve in an engine, and the valve body in the direction is moved when the valve is closed.
[0014]
According to the invention of claim 3 ,
Impact noise when the intake and exhaust valves are closed can be reduced and wear can be suppressed.
The invention according to claim 4
When the movable part moves in at least one direction, the valve stops when the movable element stops at a position immediately before it collides with the electromagnet. When the movable part moves in the direction, the movable element is set at the tip of the movable element. The control target position is set closer to the electromagnet than the control target position set later.
[0015]
According to the invention of claim 4 ,
By setting the control target position set earlier to a position closer to the electromagnet than the control target position set later, it is possible to increase the initial drive speed of the valve body and the mover and improve the responsiveness. By making the mover stop at a position away from the electromagnet, collision noise and wear can be prevented.
[0016]
The invention according to claim 5
The electromagnetically driven valve is an intake / exhaust valve in the engine, and when the valve body moves in the direction, the valve is open.
[0017]
According to the invention of claim 5,
Collision noise and wear can be prevented while ensuring responsiveness when the intake and exhaust valves are opened.
[0018]
DETAILED DESCRIPTION OF THE INVENTION
Next, embodiments of the present invention will be described in detail with reference to the drawings.
FIG. 1 is a diagram showing an overall configuration in which a control device for an electromagnetically driven valve according to the present invention is applied to a vehicle engine.
[0019]
As shown in the figure, the cylinder head 52 fixed to the upper part of the cylinder 51 of the engine is provided with a valve body 54 (only a single valve is shown in FIG. 2) that serves as an intake valve or an exhaust valve. . A spring retainer 55 is fixed to an upper portion of the valve shaft 54a extending above the valve body 54, and a coil spring 56 that urges the valve body 54 toward the valve closing side between the spring retainer 55 and the cylinder head 52. Is provided.
[0020]
A housing 60 serving as a case for an electromagnetically driven valve is provided upright on the cylinder head 52. Inside the housing 60, the valve closing side electromagnet 11 and the valve opening side electromagnet 12 are fixed at positions facing each other vertically with a predetermined interval. Between the valve-closing electromagnet 11 and the valve-opening electromagnet 12, a soft magnetic movable element (armature) 57 is slidably supported by a movable element shaft member 57a.
[0021]
A spring retainer 58 is fixed to the mover shaft member 57a at a position above the valve closing side electromagnet 11, and the mover 57 is attached to the valve opening side between the inner surface of the top wall of the housing 60 and the spring retainer 58. A coil spring 59 is provided.
[0022]
Further, on the top wall of the housing 60, the movable part speed sensor 2 for detecting the speed of the movable part constituted by the valve body 54 and the movable element 57 and outputting the speed signal, the position of the movable part is detected and the position signal is transmitted. An output movable part position sensor 3 is provided, and these speed signal and position signal are output to the control device 1 of the electromagnetically driven valve.
[0023]
Further, the control device 1 receives a valve opening command / valve closing command from the engine control ECU 8, and the control device 1 outputs a current target value to the valve closing side electromagnet current control unit 9 and the valve opening side electromagnet current control unit 10. It is supposed to be.
[0024]
The valve closing side electromagnet current control unit 9 and the valve opening side electromagnet current control unit 10 respectively supply electromagnetic current from the power supply unit 13 to the electromagnets 11 and 12 by PWM control according to the input current target value. Can be controlled.
[0025]
Next, the outline | summary of operation | movement of the electromagnetic drive valve and the control apparatus of an electromagnetic drive valve is demonstrated.
The mover 57 is suspended from the coil springs 56 and 59, and is positioned approximately at the center between the valve-closing electromagnet 11 and the valve-opening electromagnet 12 when the valve-closing electromagnet 11 and the valve-opening electromagnet 12 are not energized. Thus, the dimensions and spring constants of the coil springs 56 and 59 are set.
[0026]
Here, the natural frequency fo of the spring-mass system composed of the coil springs 56 and 59 and the movable part including the valve 54 and the movable element 57 is assumed that the combined spring constant is K and the total inertial mass is m. , Fo = 2π√ (K / m).
[0027]
In the initial operation before starting the engine, the valve-closing electromagnet 11 and the valve-opening electromagnet 12 are alternately energized at a cycle corresponding to the natural frequency fo. Then, by resonating the movable part, the amplitude of the movable part is gradually increased, and the valve is closed or opened at the final stage of the initial operation.
[0028]
Next, when starting the engine or during normal operation, for example, when the valve is opened, the current of the valve-closing electromagnet 11 is first cut, and the movable portion starts to move downward by the spring force of the coil spring. Due to energy loss due to frictional force or the like, the mover 57 cannot be moved to the fully open position of the valve only by the spring force. Therefore, the mover 57 is sufficiently close to the valve-opening electromagnet 12, and the valve-opening electromagnet 12 is energized at a position where the electromagnetic force is effective, thereby assisting the movement of the mover 57.
[0029]
At this time, the control device 1 inputs the position and speed of the mover 57 from the movable part position sensor 3 and the movable part speed sensor 2, and the valve opening side electromagnet current control part so that the speed of the movable part follows the speed target value. The command value is issued to 10. As a result of controlling the current of the valve-opening electromagnet 12 according to the command value of the control device (result of controlling the electromagnetic force of the valve-opening electromagnet 12), the movable part is formed between the valve-opening electromagnet 12 and the movable element 57. It stops at a position where the gap becomes several hundred microns, for example.
[0030]
When the valve is closed, the current of the valve-opening electromagnet 12 is turned off. Although the mover 57 and the valve 54 move upward by the force of the coil spring 59 and the coil spring 56, the mover 57 cannot be moved to the closed position only by the spring force due to energy loss due to frictional force or the like. Therefore, the movable element 57 approaches the valve closing side electromagnet 11 sufficiently, and the valve closing side electromagnet 11 is energized at a position where the electromagnetic force becomes effective, thereby assisting the movement of the movable element 57. First, the valve is in the closed position, and the valve 57 and the mover 57 that have moved together are separated. The mover 57 is assisted by the electromagnetic force and approaches the valve closing side electromagnet 11 as it is. The control device detects the movement of the movable part by the movable part position sensor 3 or the movable part speed sensor 2 so that the valve 54 and the valve seat 52a do not collide (collision at a large speed), and the valve side electromagnetic current control is performed. The current of the valve-closing electromagnet 11 is adjusted by the unit 9. At this time, the speed of the movable part is controlled so that the speed at which the valve body and the valve seat 52a come into contact is, for example, 0.1 [m / s] or less.
[0031]
When the gap between the mover 57 and the valve-closing electromagnet 11 is several hundred microns or less, the target speed of the mover 57 becomes zero, and the gap between the mover 57 and the valve-closing electromagnet 11 is several hundred microns. Therefore, no collision occurs, noise generation is prevented, and wear is prevented.
[0032]
FIG. 2 is a block diagram showing the configuration of the first embodiment of the control device for the electromagnetically driven valve according to the present invention.
In the figure, a control device 1 includes a speed target value generation unit 4 that generates a speed target value of a movable part based on a position signal output from the movable part position sensor 3, and a speed output from the movable part speed sensor 2. A comparison unit 5 that compares a signal with a speed target value, and a current target value generation that generates a current target value to be supplied to the valve closing side electromagnet 11 or the valve opening side electromagnet 12 according to the comparison result of the comparison unit 5 And a switch 7 for switching whether the generated current target value is supplied to the valve closing side electromagnet current control unit 9 or the valve opening side electromagnet current control unit 10.
[0033]
Hereinafter, the function of each part will be described in detail. The speed target value generation unit 4 determines the speed target value r as
[0034]
[Expression 1]

(See FIG. 3).
[0035]
Here, z is the distance (gap) between the mover 57 calculated from the output of the mover position sensor 3 and the electromagnet attracting the mover 57, t is the time, and v (t) is detected by the mover speed sensor 2. It is the time differential value of z calculated from the speed of the movable part or the position signal output detected by the movable part position sensor 3. r ₁ (z) and r ₂ (z) are speed target functions given as a function of the gap z, and these speed target functions correspond to a plurality of motion characteristic target values of the movable part in the present invention. Then, the first speed target function r ₁ (z) is selected at the time t _s0 when the gap z gradually decreases and reaches the first predetermined value z _s0 , that is, when the energization control to the electromagnet is started. When z further decreases and reaches the second predetermined value z _s0 , the second speed target function r ₂ (z) is selected and switched. The first predetermined value z _s0 is selected on the basis of the gap length at which the gap z becomes small and the electromagnetic force becomes effective, and is actually about 1 to 3 [mm].
[0036]
The first speed target function r ₁ (z) and the second speed target function r ₂ (z) are determined so as to satisfy the following condition. Hereinafter, (z) and (t) in the function of z and t are omitted.
[0037]
[Expression 2]

Is selected, the speed target value can be made continuous at the speed target function switching point. Here, (a predetermined value the designer gives) s is the Laplace operator, z _s is a position for switching the speed target value (predetermined value the designer gives) z _e control target position of the movable element, r _s is the speed target The speed target values ζ and ω immediately before switching the values are constants that are appropriately selected by the designer.
[0038]
The first speed target function r ₁ is a speed target value set based on the response of the secondary vibration system having a quick response, which is set mainly to shorten the time until seating, and ζ is 0.7 In the vicinity, ω is selected to a value of about [(m ₁ + m ₂ ) / (k ₁ + k ₂ )] ^1/2 . Here, m ₁ and m ₂ are the masses of the mover and the valve, respectively, and k ₁ and k ₂ are the spring constants of the coil spring 59 and the coil spring 56, respectively.
[0039]
On the other hand, the second speed target function r ₂ is selected mainly for reducing the seating speed. As described above, equation (3), selecting as the (4), the speed target value is smoothly connected at the position of z _e. Using equation (3), r ₂ is set based on the primary response, so the position of the movable part does not overshoot and converges asymptotically to the target position, so that the impact of seating can be reduced. .
[0040]
The configuration of the speed target value generation unit 4 is shown in FIG.
The second speed target function r ₂ is
[0041]
[Equation 3]

It is also possible to use a function having a non-oscillating second-order response characteristic in which a constant ζ ₂ that determines the attenuation of vibration is larger than 1.
[0042]
The speed target value r set as described above is compared with the actual movable part speed v (= dz / dt) detected by the movable part speed sensor 2 by the comparison unit 4, and the comparison signal (v−r). Is output to the current target value generator 6. The current target value generation unit 6 generates a current target value i (t) as shown in the following equation (6).
[0043]
[Expression 4]

Here, k is a positive constant (feedback gain) determined appropriately. In addition, since r = v (= dz / dt) in the section of z> z _s0 , speed control by energization does not occur.
[0044]
This current target value is transmitted to the valve closing side electromagnet current control unit 9 or the valve opening side electromagnet current control unit 10 via the switch 7 as the energization current of the electromagnet. Here, the switch 7 receives a valve opening command or a valve closing command from the engine control ECU 8, and if it is a valve opening command, the valve opening side electromagnet current control unit 10, and if it is a valve closing command, the valve closing side electromagnet current control. Each of the units 9 is selected, and the current target value generated by the current target value generating unit 6 is output to the selected side. Then, the valve closing side electromagnet current control unit 9 or the valve opening side electromagnet current control unit 10 controls the ON / OFF ratio of the current supplied from the power supply unit 13 by PWM control, thereby controlling the magnitude of the energization current. As a result, the electromagnetic force acting on the mover is controlled, and the speed of the movable part is controlled.
[0045]
Here, the first control target position is z _e1 , the speed target value at that time is r _e1 , the second control target position is z _e2 , and the speed target value at that time is r _e2. Set. For example, when the valve is closed,
z _e1 = 0.3 [mm] r _e1 = 0 [m / s] and z _e2 = 0.1 [mm] r _e2 = 0 [m / s].
[0046]
Regarding the switching of the control target position, the control target position is switched to z = ze ₂ when the position and speed of the mover detected by the sensor are substantially z = ze ₁ and v = re _1. Set.
[0047]
Here, the first control target position z _e1 is set in the vicinity of the mover position at the time when the valve element is closed and seated (a little more electromagnet than the position at the time of valve closing and seating). Since the seating speed can be sufficiently reduced, the impact of the seating can be reduced, and the collision sound can be reduced. Further, by setting the second control target position z _e2 to be smaller than the first control target position z _e1 , the mover separated from the valve body after the valve closing seating can be further brought closer to the valve closing electromagnet. It is controlled to stop in a suspended state in a non-contact manner with the electromagnet (hereinafter, such control is referred to as suspended control). In this case, the electromagnetic attraction force has a characteristic that it increases rapidly as it approaches the electromagnet. Therefore, as the mover is stopped at a position close to the electromagnet, the energization current can be reduced and power consumption can be reduced.
[0048]
However, the above-described suspension control of the mover is a state in which the mover is stopped due to the balance between the spring force of the action coil spring and the electromagnetic attracting force of the electromagnet in the direction in which the electromagnetic attracting force increases and the mover approaches the electromagnet. Therefore, when the mover approaches the electromagnet due to disturbance, the electromagnetic attracting force increases and acts in a direction that further moves the mover closer to the electromagnet. Conversely, when the mover moves away from the electromagnet, the electromagnetic attracting force decreases and the mover moves. Is an unstable system that acts in a direction away from the electromagnet, and prompt feedback response is required to maintain the suspended state. As described above, the electromagnetic attraction force increases rapidly as it approaches the electromagnet. Therefore, if it is approached to some extent, suspension control becomes difficult, and it becomes easy to be attracted to the electromagnet (the direction away from the electromagnet maximizes the current flow). However, the approaching direction will not be in time even if the energizing current is weakened due to the short distance between the mover and the electromagnet. It is impossible to do).
[0049]
Therefore, increasing the collision deterrent effect of the movable element by performing more stable suspended control, if emphasize quietness even a little, as shown in FIG. 5, the second control target position z _e2, the larger value set may be, but if you focus on a more reduced power consumption, as shown in FIG. 6, the second control target position z _e2, may be set to a smaller value. In the latter case, the suspension control may fail and be attracted to the electromagnet. For example, even if it fails at a rate of 1 in 10 times and attracts to the electromagnet, and a collision sound is generated, Compared with the case where the seating control is performed from the beginning, it is only 1/10. In addition, when the valve is closed, the collision sound when the valve body is seated is unavoidable, and even if the sound is continuously generated immediately after the occurrence of the collision sound, And the total mass of the mover collide with each other).
[0050]
Further, if importance is attached to the reduction of power consumption, as shown in FIG. 7, the mover may be seated and controlled by setting the second control target position as z _e2 and the attracting position with the electromagnet. By making the speed target value close to 0, it is possible to reduce the collision sound as much as possible.
[0051]
Next, an embodiment of control during valve opening will be described. When the valve is opened, it is not necessary to control the seating of the valve body, unlike when the valve is closed. Therefore, stable suspension control is performed as much as possible to reliably prevent the occurrence of collision noise. This is because there is a great difference in sensibility between when the collision sound is generated and when the valve is opened after the valve is closed. On the other hand, when the valve is opened, it is required to increase the initial valve opening speed in order to improve the responsiveness of the intake and exhaust valves. Both of these requirements cannot be satisfied by setting only one control target position of the mover.
[0052]
Therefore, even when the valve is opened, the control target position of the mover is set in two steps. In other words, the first control target position z _e1 of the mover set earlier is set to a smaller value close to the valve opening electromagnet, and the second control target position z _e2 set later is opened. A larger value is set so as to increase the distance from the valve electromagnet.
[0053]
In this way, as shown in FIG. 8, the first control target position _ze1 of the movable element is set to be small at the initial stage of valve opening, so that the moving speed of the movable element and the valve body integrated with the movable element is set. Responsiveness can be increased by increasing the first control target position z _e2 of the mover in the latter half of the valve opening, so that stable suspension control is performed and the generation of collision noise is ensured Can be prevented.
[0054]
As the control, as shown in FIG. 8, the movable element to switch from stably moved to the first control target position z _e1 to the second control target position z _e2 is easily and accurately However, as shown in FIG. 9, when the mover moves to the first control target position z _e1 , it switches to the second control target position z _e2 at the same time or before it, and shifts to stable suspension control as soon as possible. You may make it make it.
[0055]
10 and 11 are flowcharts of the operation of the control device 1. FIG. 10 shows a first flow in which the position and speed of the movable part are read every predetermined time, and the speed target function is calculated and the current target value is calculated and output. FIG. A second flow of selectively switching between the valve closing side electromagnet current control unit 9 and the valve opening side electromagnet current control unit 10 by a valve opening / closing command is shown. Both flows are executed with a predetermined time measured by a timer (not shown) built in the control device 1 as a cycle.
[0056]
First, the first flow will be described with reference to FIG.
In step (denoted as S in the figure, the same applies hereinafter) 1, the position signal z and the speed signal v are read from the movable part position sensor 3 and the movable part speed sensor 2.
[0057]
In step 2, the speed target value generator 5 calculates a speed target function r.
In step 3, the current target value i to be applied to the electromagnet is calculated by the cooperation of the comparison unit 4 and the current target value generation unit 6.
[0058]
In step 4, the calculated current target value i is supplied to either the valve closing side electromagnet current control unit 9 or the valve opening side electromagnet current control unit 10 selected by the switch 7.
[0059]
Next, the second flow will be described with reference to FIG.
In step 11, a valve opening / closing command is read from the engine control ECU 8.
In step 12, it is determined whether or not it is a valve opening command. If it is a valve opening command, the switch 7 is switched to connect the valve opening side electromagnet current control unit 10 to the current target value generation unit 6 in step 13.
[0060]
If it is not a valve opening command in the determination of step 12, it is determined whether or not it is a valve closing command in step 14, and if it is a valve closing command, the valve closing side electromagnet current control unit 9 is changed to a current target value generating unit 6 in step 15. The switch 7 is switched so as to be connected to.
[0061]
As described above, the first flow and the second flow can be executed in parallel, but can also be executed in series. In this case, the second flow that does not include time waiting is executed first. It is preferable to do this.
[0062]
FIG. 12 shows a subroutine for calculating the speed target function r in step 2 in the first flow.
In step 21, it is determined whether the gap z between the mover 57 and the electromagnet attracting the mover 57 is larger than the second predetermined value z _s. The first speed target function r ₁ shown in (2) is calculated. Here, when the gap z is larger than the first predetermined value z _s0 , since the actual speed v of the mover is larger than r ₁ , energization is not started according to the equation (8), and the gap z is z _s0. After the following, speed control by energization according to the _first speed target function r ₁ is started.
[0063]
Further, when the determination in step 21 is NO, it is determined in step 23 whether the gap z is substantially equal to or _smaller than the second predetermined value z _s. After calculating the constant c ₁ in the second speed target function r ₂ represented by the equation (3) in step 24 according to the equation (4), the equation (3) or (5) is represented in step 25. A second speed target function r ₂ is calculated.
[0064]
If the determination in step 23 is NO, that is, after the gap z becomes smaller than the second predetermined value z _s , the constant c ₁ calculated in step 26 is used to obtain the expression (3) or (5). The second speed target function r ₂ shown is calculated.
[0065]
Next, control for switching the control target position of the mover according to the present invention to a plurality of stages will be described with reference to FIG.
This control is a control for switching the control target position ze of the mover when the _second speed target function r ₂ is calculated by the equation (3) or (5) in step 25 of FIG.
[0066]
In step 31, the position signal z and the speed signal v are read from the movable part position sensor 3 and the movable part speed sensor 2.
In step 32, it is determined whether the position z and velocity v of the mover from the signal, becomes the first control target position ze ₁ and the first speed target value re ₁ shown respectively.
[0067]
If it is determined that ze ₁ and re ₁ have not been reached, the routine proceeds to step 33, where the control target position ze is set to the first control target position ze ₁ and the speed target value re is set to the first speed target value re ₁ . To do. As a result, in step 25 of FIG. 12, the second speed target function r is obtained from the above equation (3) or (5) using the first control target position ze ₁ and the first speed target value re _{1. 2} is calculated. Then, the current target value i is calculated by the calculated _second speed target function r ₂ in steps 3 and 4 of FIG. 10, and the calculated current target value i is converted into the valve closing side electromagnet current control unit 9. Or it supplies to any one of the valve opening side electromagnet electric current control part 10, and energization control is performed.
[0068]
If it is determined in step 32 that the position z and the speed v of the mover have become approximately ze ₁ and re ₁ , the process proceeds to step 34, where the control target position ze is set to the second control target position ze ₂ , the speed. setting a target value re the second speed target value re _2. As a result, in step 25 of FIG. 12, the second speed target function r is obtained from the equation (3) or (5) using the second control target position ze ₂ and the second speed target value re _{2. 2} is calculated, the current target value i is calculated in steps 3 and 4 of FIG. 10 by the second speed target function r ₂ calculated in the same manner as described above, and the calculated current target value i is closed. The current is supplied to either the side electromagnet current control unit 9 or the valve opening side electromagnet current control unit 10 to perform energization control.
[0069]
The control of the present invention for switching the control target position ze of the mover does not switch the speed target function r in two steps as described above, but has only one speed target function r as described above. It can also be applied by switching to a plurality of stages.
[0070]
As a modification of the present embodiment, it is obvious that instead of the movable part speed sensor 2, a differentiating unit that obtains a speed signal by differentiating the output signal of the movable part position sensor 3 with respect to time may be used.
[0071]
FIG. 14 is a block diagram illustrating a configuration of a second embodiment of the control device for an electromagnetically driven valve according to the present invention. In this embodiment, instead of the movable part speed sensor 2 of the first embodiment, an electromagnet current sensor 16 that detects a current value supplied to the valve closing side electromagnet 11 or the valve opening side electromagnet 12, and a mover speed estimation. A control device 15 including a unit (observer) 17 is used. Other configurations are the same as those of the first embodiment. The electromagnet current sensor 16 may detect the output current of the valve closing side electromagnet current control unit 9 or the valve opening side electromagnet current control unit 10 by a series low resistance, or detect the magnetic flux of the electromagnets 11 and 12 to detect the current. It is also possible to convert to
[0072]
The feature of this embodiment is based on the energizing currents of the electromagnets 11 and 12 detected by the electromagnet current sensor 16 and the position of the movable part detected by the movable part position sensor 3 instead of directly detecting the speed of the movable part. The mover speed estimation unit 17 estimates the speed of the mover.
[0073]
If the mass m of the movable part, the spring constant k associated with the movable part, the viscosity constant c associated with the movable part, and the electromagnetic force are F, the movement of the movable part is
[0074]
[Equation 5]

It is expressed.
[0075]
Here, f (x, i) is a function determined by the shape and material of the magnetic circuit, and can be known in advance by means such as magnetic field analysis. γ is an offset load component of the spring force. Based on these equations, the velocity of the movable portion can be estimated by the mover velocity estimation unit 17 using the following equation from the position x and the current i, instead of being directly detected by the movable portion velocity sensor 2.
[0076]
[Formula 6]

The estimated speed of the mover is input to the comparison unit 5 as in the first embodiment, and the following processing contents are the same as in the first embodiment, and the same effects as in the first embodiment can be obtained. .
[Brief description of the drawings]
FIG. 1 is a conceptual diagram showing a configuration of an electromagnetically driven valve to which the present invention is applied.
FIG. 2 is a block diagram showing the configuration of the first embodiment of the control device for the electromagnetically driven valve according to the present invention.
FIG. 3 is a graph showing a locus of a movable part on a position / velocity phase plane for explaining a method of generating a velocity target function in the embodiment.
FIG. 4 is a block diagram showing a configuration of a speed target value generation unit in the embodiment.
FIG. 5 is a view showing a first example of a change in mover position when the valve is closed in the embodiment;
FIG. 6 is a diagram showing a second example of change in the position of the mover when the valve is closed in the embodiment.
FIG. 7 is a diagram showing a third example of change in the position of the mover when the valve is closed in the embodiment.
FIG. 8 is a diagram showing a first example of a change in mover position when the valve is opened in the embodiment;
FIG. 9 is a diagram showing a second example of a change in mover position when the valve is opened in the embodiment;
FIG. 10 is a flowchart showing a first flow for calculating a speed target function, calculating a current target value, and outputting in the embodiment;
FIG. 11 is a flowchart showing a second flow for selectively switching between the valve closing side electromagnet current control unit and the valve opening side electromagnet current control unit in the embodiment;
FIG. 12 is a flowchart showing a subroutine for calculating a speed target function of the first flow.
FIG. 13 is a flowchart showing a flow of switching control of the control target position of the mover according to the embodiment of the present invention.
FIG. 14 is a block diagram showing the configuration of a second embodiment of the electromagnetically driven valve control device according to the present invention.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Control apparatus 2 Movable part speed sensor 3 Movable part position sensor 4 Comparison part 5 Speed target value generation part 6 Current target value generation part 7 Switch 9 Valve closing side electromagnet control part
10 Valve opening side electromagnet controller
11 Valve closing side electromagnet
12 Valve opening side electromagnet

Claims (5)

An electromagnet, a mover that is driven by the electromagnet against a reaction force of a spring, and a valve body that is driven in conjunction with the mover, and controls the energization of the electromagnet while detecting the position of the mover. And at the time of movement of the mover in at least one direction, after stopping the seating of the valve body, it is a control device for an electromagnetically driven valve that is detached from the valve body and only the mover stops after moving a predetermined amount ,
A control device for an electromagnetically driven valve , wherein a control target position set ahead of the mover is set at a position farther from the electromagnet than a control target position set later when moving in the direction .   The control target position set earlier is set in the vicinity of the mover position at the seating stop position of the valve body, and the control target position set later is set at a position immediately before the collision with the electromagnet. The control device for an electromagnetically driven valve according to claim 1, wherein: Electromagnetically driven valve is an intake and exhaust valves in the engine, during the movement of the direction of the valve body, a control device for an electromagnetically driven valve according to claim 1 or claim 2 characterized in that it is a time of closing the valve . An electromagnet, a mover that is driven by the electromagnet against a reaction force of a spring, and a valve body that is driven in conjunction with the mover, and controls the energization of the electromagnet while detecting the position of the mover. And at the time of movement of the movable part in at least one direction, the control unit for the electromagnetically driven valve that stops the valve body by stopping at a position immediately before the movable element collides with the electromagnet,
During movement of the direction control device of an electromagnetically driven valve and sets the control target position set previously said movable element, close to the electromagnet from the control target position set later position. 5. The electromagnetically driven valve control device according to claim 4 , wherein the electromagnetically driven valve is an intake / exhaust valve in an engine, and when the valve body moves in the direction, the valve is open.

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