JP3894616B2 - Method for determining the lock state of automotive auxiliary equipment - Google Patents

Description

【００２３】
上記の計算式におけるプーリの半径比（Ｒ₁ ／Ｒ₂ ）は定数であるから、スリップ率Ｓは、クランク軸プーリ６とアイドラプーリ１０が同径であると仮定した前述の場合と同様に、変数である２つの回転数の比（Ｗ₁ ／Ｗ₂ ）の値に依存して決まることになる。このようにして求められたスリップ率Ｓから補機トルクの値を求めるための線図は、図４において縦軸にスリップ率Ｓを取ると共に、横軸に負荷トルク（補機トルク）の値をとったときに、縦軸及び横軸間の比例関係を示す傾斜した直線を上下方向に平行移動させたものと同様な形になる。
【００２４】
そこで、回転数Ｗ₁ 及びＷ₂ を常時検出し、その出力信号によって前述のような計算を電子式制御装置内の演算装置によって自動的に行うようにすれば、補機トルクの大きさを絶えずリアルタイムに高精度で検知して、迅速に必要な対応措置を講じることができるようになる。この場合、Ｗ₁ ／Ｗ₂ の値からスリップ率を算出するのを省略して、直接に補機トルクを算出することができることは言うまでもない。
【００２５】
次に、本発明の自動車用補機のロック状態検出システムについて説明する。このロック状態検出システムは、前述の補機トルク検出システムに加えて、エアコンディショナ用の冷媒圧縮機のクラッチをＯＮ／ＯＦＦする手段、演算装置を備えた制御手段、及び、補機類にロック状態等の異常が発生した場合の警告手段を含む。
【００２６】
エアコンディショナ用の冷媒圧縮機或いはパワーステアリング用の油圧ポンプがロック状態となった場合、冷媒圧縮機とプーリを連結しているクラッチ板が滑動したり、ベルト７に対してプーリ２、或いはプーリ３が滑動する。この時の負荷トルクは実験によれば概ね６０Ｎ・ｍ程度である。
【００２７】
図５は、色々な運転状態における各補機毎、及び合計のトルク量を記号を用いて示したものである。即ち、運転状態を示す各記号は次の通りである。
〔１〕…正常な運転状態における最小負荷時；
〔２〕…正常な運転状態における最大負荷時；
〔３〕…エアコンディショナ用の冷媒圧縮機がロックした状態における最小負荷時；
〔４〕…エアコンディショナ用の冷媒圧縮機がロックした状態における最大負荷時；
〔５〕…パワーステアリング用の油圧ポンプがロックした状態における最小負荷時；
〔６〕…パワーステアリング用油圧ポンプがロックした状態における最大負荷時。
【００２８】
また、図５において、各補機の運転状態に付けた記号と、それぞれのトルク量（単位Ｎ・ｍ）は、次の通りである。
Ａ…エアコンディショナの運転状態におけるトルク＝２０；
Ｃ…冷媒圧縮機のロック状態におけるトルク＝６０；
Ｐ…パワーステアリング用油圧ポンプのロック状態におけるトルク＝６０；
Ｓ…パワーステアリングの据え切り状態におけるトルク＝１５；
Ｇ…ヘッドライトＨ／Ｌ及びデフロスタＤ／ＦがＯＮの時のオルタネータの運転状態におけるトルク＝１５；
Ｍ…その他の補機のトルク＝７
【００２９】
図５に示すように、補機類全体の負荷トルク量は、全ての補機が正常に作動している状態においては、最小負荷時〔１〕で７Ｎ・ｍ程度、最大負荷時〔２〕で５２Ｎ・ｍ程度である。今この両極端において考えてみると、冷媒圧縮機がロックした状態の最小負荷時〔３〕、又は油圧ポンプがロックした状態の最小負荷時〔５〕では、補機トルクの大きさはいずれも６７Ｎ・ｍであり、冷媒圧縮機がロックした状態の最大負荷時〔４〕では９２Ｎ・ｍになり、油圧ポンプがロックした状態の最大負荷時〔６〕では９７Ｎ・ｍにもなる。なお、本実施形態における自動車用補機でロックの可能性が大きいものは、エアコンディショナ用の冷媒圧縮機と、パワーステアリング用の油圧ポンプである。
【００３０】
次に、図６のフローチャートに基づいて本発明の自動車用補機のロック状態検出システムの作動について説明する。まず、ステップ１００において、エアコンディショナの圧縮機が作動しているときの第１の補機トルク量Ｘを測定する。そして、ステップ１０１において、第１の補機トルク量Ｘが６０Ｎ・ｍ（第１の所定値）を超えているか否かを判定する。ここで、第１の補機トルク量Ｘが第１の所定値を超えていると判定されると、一応、エアコンディショナ用の冷媒圧縮機がロック状態になったと判定することができるが、更に、以下に示す判定を行なって信頼度を高める。
【００３１】
即ち、Ｘ＞６０Ｎ・ｍのときはステップ１０２においてエアコンディショナ用の冷媒圧縮機に付設されたクラッチを切断し、プーリ２と圧縮機とを切離す。次に、ステップ１０３において、エアコンディショナの圧縮機が負荷とならない状態での第２の補機トルク量Ｙを測定し、ステップ１０４において、ＸとＹとを比較してＸ−Ｙの値、即ち、クラッチ切断による補機トルクの減少量が３０Ｎ・ｍ（第２の所定値）を超えているか否かを判定する。そしてＸ−Ｙの値が第２の所定値を超えている場合には冷媒圧縮機がロック状態と判定し、ステップ１０５において冷媒圧縮機が異常という警報を発する。
【００３２】
一般にエアコンディショナ用の冷媒圧縮機が正常に動作している時は、冷媒圧縮機の消費トルクはたかだか２０Ｎ・ｍ程度であるから、ステップ１０２におけるクラッチの切断によってそれ以上の大きさでトルクが減少すれば冷媒圧縮機がロックしていることが判る。冷媒圧縮機のロック状態においてはクラッチ板が滑動しているか、ベルト７とプーリ２との間に滑動が生じている。
【００３３】
一方、ステップ１０４の判定においてクラッチ切断による補機トルクの減少量（Ｘ−Ｙ）の値が第２の所定値である３０Ｎ・ｍ以下のときは、エアコンディショナ用の冷媒圧縮機はロックしていないと判定することができるので、他の要因の１つであるパワーステアリング用の油圧ポンプがロックしているということになる。このようにして油圧ポンプがロック状態と判定されたときは、ステップ１０６に進んで油圧ポンプが異常という警報を発する。油圧ポンプのロック状態においてはベルト７とプーリ３との間に滑動が生じている。
【００３４】
パワーステアリング用の油圧ポンプが設けられていない自動車においては、図７に示した図６と同様なフローチャートにおいて、ステップ１０４の判定結果がＮＯ、即ちエアコンディショナ用の冷媒圧縮機のクラッチの切断による補機トルクの減少量（Ｘ−Ｙ）が第２の所定値である３０Ｎ・ｍ以下のときは、冷媒圧縮機の他にロックの可能性がある補機がないので正常な運転状態にあると判断され、ステップ１０７に進んで冷媒圧縮機のクラッチを再び接続し、最初のステップ１００に戻って前述の動作を繰返す。なお、図７に示すフローチャートは、ステップ１０７において異なる他は、図６に示すフローチャートと同じ内容であるから、重複部分についての説明は省略する。
【００３５】
図６又は図７のフローチャートに作動が示されている自動車用補機のロック状態検出システムにおいては、第１の補機トルク量Ｘと第２の補機トルク量Ｙとの差の値を第２の所定値と比較することによって、エアコンディショナ用の冷媒圧縮機又はパワーステアリング用の油圧ポンプのいずれがロックしているかを判定しているが、より簡単な方法としては、全ての補機類が正常に作動している状態において測定した第１の補機トルク量の正常値を制御装置のメモリー等に記憶しておき、その値と実測された第２の補機トルク量Ｙとを比較してロック状態を判定することも可能である。
【００３６】
この方法によれば、エアコンディショナ用の冷媒圧縮機をクラッチによって切断した状態で測定された第２の補機トルク量Ｙが、もし第１の補機トルク量の正常値よりも小さい場合には、クラッチによって連動していた冷媒圧縮機がロックしていたと判定することができるし、それと反対に第２の補機トルク量Ｙが第１の補機トルク量の正常値よりも大きい場合には、クラッチによって連動していた冷媒圧縮機以外のものでロックの可能性があるパワーステアリング用の油圧ポンプがロックしたものと推定することができる。
【００３７】
次に、同様にして、本発明の自動車用補機のロック状態判定方法に利用される補機トルク検出システムの第２実施形態について図面に基づいて説明する。
第１実施形態では回転数センサとして電磁誘導式のピックアップ１８を使用したが、第２実施形態として回転数センサに光を使ったものを説明する。図８及び図９において、２２は発光ダイオードのような発光素子を、２３はフォトダイオードのような受光素子を示している。発光素子２２と受光素子２３は、例えば第１実施形態におけるものと同様なオートテンショナー９のアイドラプーリ１０の縁部において、対向するようにアーム１３上に取り付けられる。そのために、発光素子２２と受光素子２３のいずれか一方を支持する突起２４のようなものをアーム１３と一体に形成してもよい。
【００３８】
発光素子２２と受光素子２３の間にはアイドラプーリ１０の縁部に環状に形成された回転スリット２５が介入するように、発光素子２２と受光素子２３が位置決めされる。回転スリット２５は、図９から明らかなように、環状の板２６に光を透過する放射方向の細かな開口２７を円周方向に等間隔に形成したものであって、アイドラプーリ１０のスカート部２８に直接に穿孔形成してもよいが、回転スリット２５をアイドラプーリ１０とは別体のものとして形成して、それをスカート部２８に取り付けてもよい。また、受光素子２３の受光面にはマスクとしての板状の固定スリット２９が固定されており、固定スリット２９には幾つかの開口３０が形成されている。
【００３９】
本発明の方法に利用される補機トルク検出システムの第２実施形態はこのように構成されているので、オートテンショナーのアイドラプーリ１０がベルト７によって駆動されて回転すると、回転スリット２５が共に回転し、発光素子２２の光軸が、回転スリット２５の環状の板２６に形成された開口２７と、固定スリット２９に形成された開口３０に合致した時だけ、発光素子２２の発する光が受光素子２３に到達してパルス電流が受光素子２３から出力される。従って、これは第１実施形態における電磁ピックアップ１８の出力信号と同様に、アイドラプーリ１０の回転数Ｗ₂ を表すものであり、別に計測されるクランク軸２１の回転数Ｗ₁ と共に処理されて、クランク軸プーリ６に対するアイドラプーリ１０のスリップ率Ｓが算出され、図４のような線図からクランク軸２１に作用する補機トルクを知ることができる。
【００４０】
第２実施形態においても、発光素子２２及び受光素子２３はいずれも僅かな回動範囲のみにおいて移動可能なアーム１３上に取り付けられているので、発光素子２２の端子３１及び受光素子２３の端子３２に一端が接続される可撓性のリード線の他端は、いずれもスリップリングのような摺動部分を介することなく直接に対象の端子に接続されるので、この場合もスリップリングを用いることによる信頼性や耐久性の低下を招く恐れがない。
【００４１】
以上の説明では、スリップを含む回転数Ｗ₂ を検出するための回転数センサとして、オートテンショナー９のアイドラプーリ１０に対して電磁ピックアップ１８とか、それに代わる光センサを設ける例を挙げたが、本発明においては、これらの回転数センサをオートテンショナー９に設けることは必須の要件ではなく、ベルト７のガイドとして設けられたアイドラプーリ８のように、実質的に負荷が作用していない他のプーリに回転数センサを設けてもよい。また、車両の回転駆動源は内燃機関に限らないことは言うまでもない。
【００４２】
同様にして、本発明の自動車用補機のロック判定方法に利用される補機トルク検出システムの第３実施形態について図面に基づいて説明する。第３実施形態の構成を図１０（Ａ）から図１０（Ｃ）に示す。図１０（Ａ）は補機トルク検出システムの正面図、図１０（Ｂ）は側面断面図、図１０（Ｃ）は図１０（Ｂ）中のＤ部の拡大斜視図である。
【００４３】
オートテンショナーは固定ハウジング３１、弾性体であるコイルスプリング３２、可動ハウジング３３、可動ハウジング３３の一部であるアーム１３、アイドラプーリ１０から成り、可動ハウジング３３と固定ハウジング３１とはコイルスプリング３２によって連結されており、ベルト７の張力に応じて可動ハウジング３３が変位する。受光部（フォトダイオードアレイ）３４の変位センサが固定ハウジング３１に固定された固定ハウジング３１の一部分をなすステー３５に設置され、それと対向する発光部（発光ダイオード）３６が可動ハウジング３３の一部をなすアーム１３上に設置されている。
【００４４】
次に第３実施形態の補機トルク検出システムの作動について説明する。補機の負荷トルク量に応じて、オートテンショナー可動部である可動ハウジング３３がコイルスプリング３２の付勢力に抗して回転することによって、可動ハウジング３３の一部をなすアーム１３上に取付られた発光部３６が変位する。この発光部３６からの光が受光部３４のスリット３７を通り、受光素子３８に到達する。受光部３４（フォトダイオードアレイ）の検出位置によりオートテンショナーの変位量が分かり、補機の負荷トルク量を検出することができる。
【００４５】
なお、ベルトが劣化して伸びた場合のオートテンショナーの位置と補機トルク量との関係は図１１のようになり、ベルトの伸び量に応じて無負荷状態での位置がずれるだけである。その対策としては、エンジン始動前の無負荷状態においてずれ量が補正されるように、受光部（フォトダイオードアレイ）３４の変位センサと、それに対向する発光部（発光ダイオード）３６との間の相対位置をベルトが伸びる前と同じにしてやればよい。
【００４６】
また、車両、エンジン等の振動によるオートテンショナーの位置の振動は、１ヘルツ程度のローパスフィルタによる電気的なフィルタリングによりＡＣ成分を除去してやればよい。
【００４７】
同様に、補機トルクを検出する検出システムの第４実施形態を図１２（Ａ）及び図１２（Ｂ）に示す。図１２（Ａ）は補機トルク検出システムの正面図、図１２（Ｂ）は側面図である。図中第３実施形態と同じ部分には同一符号を付して説明を省略する。この場合は、対向する一方の部分３９と他方の部分４０との間の変位により補機トルクが検出される。
【００４８】
対向する一方の部分３９として超音波式の変位センサを用いる場合には、他方の部分４０には固体なら何でも良いが、金属、セラミック、プラスチック等を用いるとよい。
【００４９】
対向する一方の部分３９として渦電流式の変位センサを用いる場合には、他方の部分４０には電流を通す物質として、金属を用いるとよい。
【００５０】
また、対向する一方の部分３９として光学式（三角距離式）センサを用いる場合、他方の部分４０としては不透明な固体なら何でもよいが、金属、不透明なセラミック、プラスチック等を用いるとよい。
【００５１】
最後に、本発明の自動車用補機のロック判定方法に利用される補機トルク検出システムの第５実施形態について説明する。第１及び第２実施形態では、いずれも図１に示されたクランク軸２１の回転数Ｗ₁ と、オートテンショナー９のアイドラプーリ１０の回転数Ｗ₂ との回転数比（Ｗ₁ ／Ｗ₂ ）から補機トルクを算出しているが、第５実施形態においても回転数Ｗ₁ としてやはり図１に示されたクランク軸２１の回転数をとるが、回転数Ｗ₂ としては、アイドラプーリ１０の回転数を使用しないで、同じベルト７に係合するプーリ群の中でアイドラプーリ１０に次いでベルト張力の弱い位置に設けられたオルタネータ即ち交流発電機用のプーリ４の回転数を検出して、それを利用する点に特徴がある。
【００５２】
この場合も、２つの回転数の比（Ｗ₁ ／Ｗ₂ ）はスリップ率に対応しており、それによって前述の各実施形態の場合と同様に補機トルクの大きさを知ることができる。しかも、回転数Ｗ₂ はオルタネータの回転数であるから、オルタネータが出力する交流電圧の周波数をカウントすれば回転数Ｗ₂ を直ちに知ることができるので、回転数Ｗ₂ の検出手段が他の実施形態の場合よりも更に簡単になるという利点がある。それ以外の点では前述の各実施形態と同様な効果を奏する。
【００５３】
また、以上の実施形態では、冷媒圧縮機の他にロックの可能性がある補機としてパワーステアリング用の油圧ポンプを挙げているが、それら以外にもロックの可能性があるものとしては、例えばエンジン冷却用のウオーターポンプ等が考えられるので、本発明は、エアコンディショナ用の冷媒圧縮機とパワーステアリング用の油圧ポンプのロック状態のみを対象としている訳ではない。
【図面の簡単な説明】
【図１】自動車用補機類の駆動機構の全体構成を示す正面図である。
【図２】補機トルク検出システムの第１実施形態の要部を示す断面図である。
【図３】図２に示されたアイドラプーリの下面図である。
【図４】スリップ率と負荷トルクの関係を示す線図である。
【図５】補機トルク量と負荷との関係を示す棒グラフである。
【図６】本発明によるロック状態検出システムの作動を示すフローチャートである。
【図７】本発明によるロック状態検出システムの特別の例についての作動を示すフローチャートである。
【図８】補機トルク検出システムの第２実施形態の要部を示す断面図である。
【図９】図８に示された回転数センサの要部の概念的斜視図である。
【図１０】補機トルク検出システムの第３実施形態の構成を示す構成図であり、（Ａ）は補機トルク検出システムの正面図、（Ｂ）は側面断面図、（Ｃ）は（Ｂ）図中のＤ部の拡大斜視図である。
【図１１】ベルトが劣化して伸びた場合のオートテンショナー位置と補機トルク量との関係を示す図である。
【図１２】補機トルク検出システムの第４実施形態の構成を示す構成図であり、（Ａ）は補機トルク検出システムの正面図、（Ｂ）は側面図である。
【符号の説明】
１…内燃機関
２，３，４，５…補機プーリ
６…クランク軸プーリ
７…ベルト
８…アイドラプーリ
９…オートテンショナー
１０…オートテンショナーのアイドラプーリ
１１…円環状内面
１２…磁性体からなる多数の歯
１３…アーム
１８…電磁ピックアップ
１９，２０…リード線
２１…クランク軸
２２…発光素子
２３…受光素子
２５…回転スリット
２９…固定スリット
３１…固定ハウジング
３２…弾性体（コイルスプリング）
３３…可動ハウジング
３４，３９…対向する一方の部分
３６，４０…対向する他方の部分[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a method for detecting a lock state of a refrigerant compressor for an air conditioner that is an auxiliary machine of an automobile engine and a hydraulic pump for power steering.
[0002]
[Prior art]
In an internal combustion engine mounted on a vehicle such as an automobile, its auxiliary equipment, for example, a refrigerant compressor for an air conditioner, a hydraulic pump for power steering, an alternator, a cooling fan for a radiator, etc. are attached to the crankshaft of the engine. Driven simultaneously by a crankshaft pulley through a series of belts.
[0003]
As a conventional method for detecting the lock state of a refrigerant compressor for an air conditioner, the rotation speed of the refrigerant compressor is measured by a pickup type rotation sensor, and the rotation speed is compared with the rotation speed of the engine. There is a method for determining the lock state based on the difference.
[0004]
[Problems to be solved by the invention]
However, the pickup type rotation sensor is used only for detecting the lock state of the refrigerant compressor for the air conditioner. Therefore, when the entire auxiliary machine torque detection system is considered, There is a problem that it is necessary to add an additional dedicated device for a specific purpose of detecting the lock state, which complicates the entire system.
[0005]
The present invention has been created in view of the above-mentioned problems, and an object thereof is an auxiliary machine for an automobile engine, for example, a refrigerant compressor for an air conditioner, a hydraulic pump for power steering. An object of the present invention is to provide a method for detecting the lock state of a refrigerant compressor for an air conditioner and a hydraulic pump for power steering by using a load torque detection system for an alternator, a cooling fan for a radiator, and the like.
[0006]
[Means for Solving the Problems]
The present invention provides, as means for solving the above-mentioned problems, a method for determining a lock state of an auxiliary machine for an automobile described in each claim of the claims.
[0007]
According to the means described in claim 1, first, the first auxiliary machine torque amount when the air conditioner is operating is measured by the auxiliary machine torque detection system. If it is determined that the first auxiliary machine torque amount exceeds the first predetermined value, the refrigerant compressor for the air conditioner is suspected to be locked, so that the refrigerant compressor is driven. In this state, the second accessory torque amount is measured, and the first accessory torque amount is compared with the second accessory torque amount. And, in this comparison, when the difference between the two auxiliary machine torque amounts exceeds the second predetermined value, that is, when the auxiliary machine torque decreases more than the second predetermined value due to the disengagement of the clutch. It can be determined that the refrigerant compressor is in the locked state.
[0008]
According to the means described in claim 2, when the difference between the first auxiliary machine torque amount and the second auxiliary machine torque amount does not exceed the second predetermined value in the comparison as described above, Since the refrigerant compressor for the air conditioner is not in the locked state, it can be determined that another auxiliary device that may be locked is in the locked state.
[0009]
On the other hand, in the means described in claims 3 and 4, the target to be compared with the second auxiliary machine torque amount is not the first auxiliary machine torque amount, but all auxiliary machines operate normally. It is characterized in that the normal value of the first auxiliary machine torque amount memorized at the time of use is used. If the second auxiliary torque amount actually measured with the clutch that drives the refrigerant compressor disengaged is smaller than the normal value of the first auxiliary torque amount stored in the memory or the like of the control device It is clear that the refrigerant compressor engaged by the clutch is locked, and if the second auxiliary torque amount is larger than the normal value of the first auxiliary torque amount, the refrigerant compressor clutch and As an unrelated factor, the lock state of the hydraulic pump for power steering can be estimated.
[0010]
By these means, it is possible to detect general auxiliary machine torque to detect the locked state of automotive auxiliary equipment that can be locked, that is, refrigerant compressors for air conditioners or hydraulic pumps for power steering. Since the system can be used as it is, it becomes possible to eliminate the rotation sensor dedicated to detecting the lock state of the refrigerant compressor for air conditioners that has been used in the past, and the entire system can be simplified. .
[0011]
DETAILED DESCRIPTION OF THE INVENTION
As shown in FIG. 1, in an engine 1 mounted on an automobile, a belt pulley for driving various auxiliary machines, for example, a pulley 2 for a refrigerant compressor of an air conditioner, a pulley for a hydraulic pump of a power steering. 3. Many pulleys for auxiliary machines such as an alternator or pulley 4 for a generator and a pulley 5 for a cooling fan of a radiator are connected to a pulley 6 (generally speaking, a drive shaft) of an engine crankshaft 21 as a power source. Are driven simultaneously via a series of belts 7 by pulleys. In addition, an idler pulley may be used to wind a single belt 7 in a meandering manner on many pulleys. In the example of FIG. 1, the idler pulley 8 is used, and the tension of the belt 7 is constant. An auto tensioner 9 that automatically adjusts so as to become is also provided on the most loose side of the belt 7 with one idler pulley 10.
[0012]
First, a first embodiment of an auxiliary machine torque detection system used in a method for determining a locked state of an auxiliary machine for an automobile according to the present invention will be described with reference to the drawings. The first embodiment shown in FIGS. 2 and 3 shows a mechanism of an auxiliary machine torque detection system using an auto tensioner 9. A large number of teeth 12 made of a magnetic material are provided at equal intervals on the annular inner surface 11 of the idler pulley 10 of the auto tensioner 9. Actually, the entire idler pulley 10 is formed of a material such as magnetic cast iron or steel, and a large number of teeth 12 are cut and formed on the annular inner surface 11 like an internal gear. Alternatively, when the idler pulley 10 is molded by a method such as casting, the process can be simplified if the teeth 12 of the annular inner surface 11 are simultaneously molded by the same mold.
[0013]
The arm 13 of the auto tensioner 9 is supported so that its base portion 14 can be rotated within a limited angular range by a shaft (not shown). The urging means urges the belt 7 in a turning direction that tensions the belt 7. Further, a bearing 16 is provided on a shaft 15 that is integrally attached to the free end of the arm 13, whereby the idler pulley 10 is rotatably supported.
[0014]
An electromagnetic pickup 18 as a rotational speed sensor is attached to the projection 17 formed on the arm 13, and the tip (detection end) of the electromagnetic pickup 18 is a predetermined one with respect to any one of a large number of teeth 12 made of a magnetic material. It protrudes to a position where it can face with a gap. As is well known, the electromagnetic pickup 18 is simply obtained by winding a coil around a permanent magnet or a magnetic core (one end is a detection end) that is magnetically connected thereto. Connect both ends directly to an external fixed terminal by flexible lead wires 19 and 20, or connect one end of the coil to the arm 13 and connect the other end of the coil to a single flexible terminal. Pull out to the outside by lead wire and connect to external fixed terminal. Since the movement (turning) range of the arm 13 is limited to a narrow angle, the tip of the flexible lead wire can be attached without using a sliding mechanism such as a slip ring in the prior art. The output signal can be taken out by connecting directly to the target fixed terminal.
[0015]
Although not shown, the rotation speed (rotation speed) of a shaft driven by the crankshaft 21 with a constant rotation ratio, such as a camshaft (not shown), is not the crankshaft 21 or the crankshaft 21 itself. W ₁ A rotation speed sensor is provided for detecting. In a normal internal combustion engine, the engine speed W ₁ Alternatively, since the rotation speed of a motor that rotates at a constant ratio needs to be measured as one of the factors for operation control, a crankshaft or the like is often provided with a rotation speed sensor. Therefore, even if the rotational speed sensor is provided for other purposes, the output signal can be used for the purpose of the present invention. Rotation speed W ₁ In an internal combustion engine that does not include a means for detecting the rotational speed W of the crankshaft pulley 6 having the same structure as that shown in FIGS. 2 and 3, for example. ₁ The detecting means may be provided.
[0016]
Next, the operation of the first embodiment of the present invention shown in FIGS. 2 and 3 will be described with reference to FIGS. 1 and 6 as well. In FIG. 2, when the crankshaft 21 of the internal combustion engine 1 rotates, the pulley 2 for the refrigerant compressor of the air conditioner engaged with the crankshaft pulley 6 via a series of belts 7, the hydraulic pressure of the power steering The pulley 3 for the pump, the pulley 4 for the generator, the pulley 5 for the cooling fan, the idler pulley 8 and the idler pulley 10 of the auto tensioner 9 are rotationally driven all at once. In order to drive these auxiliary pulleys, The torque (auxiliary torque) acting on the shaft 21 is the rotational speed W of the crankshaft 21 itself. ₁ In addition, since some of the auxiliaries are intermittently operated like a refrigerant compressor connected to the pulley 2, the auxiliaries torque cannot be constant, and the internal combustion engine It can be said that the engine 1 always fluctuates during operation.
[0017]
Therefore, if the fluctuating auxiliary machine torque can be accurately detected at all times in real time, it becomes possible to perform fine control as described above with respect to the operating state of the internal combustion engine 1, but in this embodiment, the crankshaft 21 Rotational speed (rotational speed) W ₁ The rotation speed (rotation speed) W of the pulley 10 that is also one of the idler pulleys is detected by the electromagnetic pickup 18 provided in addition to the auto tensioner 9. ₂ Is detected.
[0018]
Therefore, when the idler pulley 10 of the auto tensioner is rotationally driven from the crankshaft pulley 6 through the belt 7, the magnetic body is positioned immediately before the detection end of the electromagnetic pickup 18 that is fixed to the arm 13 and does not substantially move. Therefore, before and after the passage, the magnetic flux density of the permanent magnet passing through the coil of the electromagnetic pickup 18 is suddenly increased or decreased. As a result, a pulse current having peaks at substantially equal intervals as a voltage waveform is generated in the coil of the electromagnetic pickup 18. This pulse current is the rotational speed W ₂ Is output directly to an external fixed terminal via the lead wires 19 and 20 and the like, and is input to a control device (not shown) provided with an arithmetic unit.
[0019]
In the control device, the rotation number (rotational speed) W of the idler pulley 10 of the auto tensioner is counted by counting the number of peaks per unit time for the pulse current that is the output signal of the electromagnetic pickup 18. ₂ Is detected. If the crankshaft pulley 6 and the idler pulley 10 have the same diameter, the rotational speed W ₂ Is the rotational speed W of the crankshaft pulley 6 ₁ On the other hand, since the amount of slippage between the crankshaft pulley 6 and the belt 7 should be reduced, the rotational speed W ₁ And rotation speed W ₂ Ratio, that is, rotation speed ratio W ₁ / W ₂ The magnitude of the slip amount of the idler pulley 10 relative to the crankshaft pulley 6 can be known from the magnitude of the value of. In this case, almost no load is generated in the auto tensioner 9, and therefore the slip between the belt 7 and the idler pulley 10 can be ignored.
[0020]
Therefore, the detected rotation speed W ₁ And W ₂ Rotational speed ratio W indicating the amount of slip between the crankshaft pulley 6 and the idler pulley 10 by ₁ / W ₂ Is calculated, and the slip ratio is calculated based on that, and the value is applied to a diagram as shown in FIG. 4 to know the magnitude of the auxiliary torque acting on the crankshaft 21 at that time. Can do. It has been confirmed by experiments by the present inventors that the magnitude of the auxiliary machine torque can be detected with extremely high accuracy by such a method.
[0021]
In general, the crankshaft pulley 6 and the idler pulley 10 are not the same diameter, so the above explanation does not occur. In such a case, the speed of acceleration or deceleration caused by the difference between the pulley diameters of the two By taking into account the change, that is, the radius ratio between the crankshaft pulley 6 and the idler pulley 10, the magnitude of the slip amount of the belt 7 can also be known, and the magnitude of the auxiliary machine torque can be calculated based on that. Is possible.
[0022]
That is, the symbol W ₁ , W ₂ , S, R ₁ , R ₂ Each
W ₁ : Number of rotations of the crankshaft 21 and the crankshaft pulley 6
W ₂ : Number of rotations of idler pulley 10 of auto tensioner
S: slip ratio of idler pulley 10 with respect to crankshaft pulley 6
R ₁ : Radius of crankshaft pulley 6
R ₂ : Radius of idler pulley 10 of auto tensioner
In such a case, the slip ratio S generated between the crankshaft pulley 6 and the belt 7 (idler pulley 10) is obtained by the following calculation formula.

[0023]
Pulley radius ratio (R ₁ / R ₂ ) Is a constant, the slip ratio S is the ratio of the two rotational speeds (W) as in the case described above, assuming that the crankshaft pulley 6 and the idler pulley 10 have the same diameter. ₁ / W ₂ ) Depending on the value of). The diagram for obtaining the value of the auxiliary machine torque from the slip rate S thus obtained is the slip ratio S on the vertical axis and the load torque (auxiliary torque) value on the horizontal axis in FIG. When taken, the shape is similar to that obtained by translating an inclined straight line indicating a proportional relationship between the vertical axis and the horizontal axis in the vertical direction.
[0024]
Therefore, rotation speed W ₁ And W ₂ If the calculation as described above is automatically performed by the arithmetic unit in the electronic control device based on the output signal, the magnitude of the auxiliary torque is constantly detected in real time with high accuracy, The necessary response measures can be taken quickly. In this case, W ₁ / W ₂ Needless to say, the auxiliary machine torque can be directly calculated by omitting the calculation of the slip ratio from the above value.
[0025]
Next, the lock state detection system for an automotive auxiliary machine according to the present invention will be described. In addition to the above-mentioned auxiliary machine torque detection system, this lock state detection system locks the means for turning ON / OFF the clutch of the refrigerant compressor for the air conditioner, the control means having an arithmetic unit, and the auxiliary equipment. A warning means is provided when an abnormality such as a condition occurs.
[0026]
When the refrigerant compressor for the air conditioner or the hydraulic pump for the power steering is locked, the clutch plate connecting the refrigerant compressor and the pulley slides, the pulley 2 with respect to the belt 7 or the pulley 3 slides. According to the experiment, the load torque at this time is approximately 60 N · m.
[0027]
FIG. 5 shows the total torque amount for each auxiliary machine in various operating states using symbols. That is, each symbol indicating the operating state is as follows.
[1] ... Minimum load in normal operating condition;
[2] ... at maximum load under normal operating conditions;
[3] At minimum load when the refrigerant compressor for the air conditioner is locked;
[4] ... at maximum load when the refrigerant compressor for the air conditioner is locked;
[5] ... at the minimum load when the hydraulic pump for power steering is locked;
[6] At maximum load when the power steering hydraulic pump is locked.
[0028]
In FIG. 5, symbols attached to the operation states of the auxiliary machines and the respective torque amounts (unit: N · m) are as follows.
A: Torque in the operating state of the air conditioner = 20;
C: Torque in the locked state of the refrigerant compressor = 60;
P: Torque in the locked state of the hydraulic pump for power steering = 60;
S: Torque in the stationary state of the power steering = 15;
G: Torque in the operation state of the alternator when the headlight H / L and the defroster D / F are ON = 15;
M ... Torque of other accessories = 7
[0029]
As shown in FIG. 5, the load torque amount of the entire auxiliary equipment is about 7 N · m at the minimum load [1] and at the maximum load [2] when all the auxiliary machines are operating normally. Is about 52 N · m. Considering these extremes now, the magnitude of the auxiliary torque is 67N at the minimum load [3] with the refrigerant compressor locked or at the minimum load [5] with the hydraulic pump locked. M, 92 N · m at the maximum load [4] with the refrigerant compressor locked, and 97 N · m at the maximum load [6] with the hydraulic pump locked. In addition, what has a high possibility of a lock | rock in the auxiliary machine for motor vehicles in this embodiment is the refrigerant | coolant compressor for air conditioners, and the hydraulic pump for power steering.
[0030]
Next, the operation of the lock state detection system for an automotive auxiliary machine according to the present invention will be described with reference to the flowchart of FIG. First, in step 100, the first auxiliary machine torque amount X when the compressor of the air conditioner is operating is measured. In step 101, it is determined whether or not the first auxiliary machine torque amount X exceeds 60 N · m (first predetermined value). Here, if it is determined that the first auxiliary machine torque amount X exceeds the first predetermined value, it can be determined that the refrigerant compressor for the air conditioner is in a locked state. Further, the following determination is performed to increase the reliability.
[0031]
That is, when X> 60 N · m, the clutch attached to the air conditioner refrigerant compressor is disconnected in step 102, and the pulley 2 and the compressor are disconnected. Next, in step 103, the second auxiliary machine torque amount Y in a state where the compressor of the air conditioner is not loaded is measured, and in step 104, X and Y are compared to determine the value of XY, That is, it is determined whether or not the reduction amount of the auxiliary machine torque due to the clutch disengagement exceeds 30 N · m (second predetermined value). If the value of XY exceeds the second predetermined value, the refrigerant compressor is determined to be in a locked state, and in step 105 an alarm is given that the refrigerant compressor is abnormal.
[0032]
In general, when a refrigerant compressor for an air conditioner is operating normally, the consumed torque of the refrigerant compressor is about 20 N · m at most. If it decreases, it turns out that the refrigerant compressor is locked. In the locked state of the refrigerant compressor, the clutch plate is sliding, or sliding is generated between the belt 7 and the pulley 2.
[0033]
On the other hand, if the value of the reduction amount of the auxiliary machine torque (XY) due to the clutch disengagement is less than 30 N · m, which is the second predetermined value, in step 104, the refrigerant compressor for the air conditioner is locked. Therefore, it can be determined that the hydraulic pump for power steering, which is one of the other factors, is locked. When it is determined in this way that the hydraulic pump is in the locked state, the routine proceeds to step 106, where an alarm is given that the hydraulic pump is abnormal. In the locked state of the hydraulic pump, sliding occurs between the belt 7 and the pulley 3.
[0034]
In an automobile not provided with a hydraulic pump for power steering, in the same flowchart as FIG. 6 shown in FIG. 7, the determination result of step 104 is NO, that is, the clutch of the refrigerant compressor for the air conditioner is disengaged. When the reduction amount (XY) of the auxiliary machine torque is equal to or less than the second predetermined value of 30 N · m, there is no auxiliary machine that may be locked other than the refrigerant compressor, so that the normal operation state is established. The process proceeds to step 107, the clutch of the refrigerant compressor is reconnected, and the process returns to the first step 100 to repeat the above-described operation. The flowchart shown in FIG. 7 has the same contents as the flowchart shown in FIG.
[0035]
In the automotive auxiliary machine lock state detection system whose operation is shown in the flowchart of FIG. 6 or FIG. 7, the difference value between the first auxiliary machine torque amount X and the second auxiliary machine torque amount Y is set to the first value. 2 to determine whether the air conditioner refrigerant compressor or the power steering hydraulic pump is locked. As a simpler method, all auxiliary machines The normal value of the first auxiliary machine torque amount measured in a state where the engine is operating normally is stored in the memory or the like of the control device, and the value and the actually measured second auxiliary machine torque amount Y are stored. It is also possible to determine the lock state by comparison.
[0036]
According to this method, when the second auxiliary machine torque amount Y measured in a state where the refrigerant compressor for the air conditioner is disconnected by the clutch is smaller than the normal value of the first auxiliary machine torque amount. Can be determined that the refrigerant compressor interlocked with the clutch is locked, and conversely, when the second auxiliary torque amount Y is larger than the normal value of the first auxiliary torque amount. It can be presumed that a hydraulic pump for power steering that is locked by a device other than the refrigerant compressor linked by the clutch is locked.
[0037]
Next, in the same manner, a second embodiment of an auxiliary machine torque detection system used in the automotive auxiliary machine lock state determination method of the present invention will be described with reference to the drawings.
In the first embodiment, the electromagnetic induction type pickup 18 is used as the rotation speed sensor. However, as the second embodiment, a description will be given of a light rotation speed sensor using light. 8 and 9, reference numeral 22 denotes a light emitting element such as a light emitting diode, and reference numeral 23 denotes a light receiving element such as a photodiode. The light emitting element 22 and the light receiving element 23 are mounted on the arm 13 so as to face each other at the edge of the idler pulley 10 of the auto tensioner 9 similar to that in the first embodiment, for example. Therefore, a projection 24 that supports either the light emitting element 22 or the light receiving element 23 may be formed integrally with the arm 13.
[0038]
Between the light emitting element 22 and the light receiving element 23, the light emitting element 22 and the light receiving element 23 are positioned so that a rotary slit 25 formed in an annular shape at the edge of the idler pulley 10 intervenes. As is apparent from FIG. 9, the rotary slit 25 is formed by forming fine radial apertures 27 that transmit light on the annular plate 26 at equal intervals in the circumferential direction, and the skirt portion of the idler pulley 10. The rotary slit 25 may be formed as a separate body from the idler pulley 10 and attached to the skirt portion 28. Further, a plate-like fixed slit 29 as a mask is fixed to the light receiving surface of the light receiving element 23, and several openings 30 are formed in the fixed slit 29.
[0039]
Since the second embodiment of the auxiliary torque detection system used in the method of the present invention is configured as described above, when the idler pulley 10 of the auto tensioner is driven by the belt 7 and rotates, the rotation slit 25 rotates together. The light emitted from the light emitting element 22 is received only when the optical axis of the light emitting element 22 matches the opening 27 formed in the annular plate 26 of the rotary slit 25 and the opening 30 formed in the fixed slit 29. A pulse current is output from the light receiving element 23 when reaching 23. Therefore, this is the same as the output signal of the electromagnetic pickup 18 in the first embodiment, and the rotational speed W of the idler pulley 10 is. ₂ The rotation speed W of the crankshaft 21 measured separately ₁ Then, the slip ratio S of the idler pulley 10 with respect to the crankshaft pulley 6 is calculated, and the auxiliary machine torque acting on the crankshaft 21 can be known from the diagram as shown in FIG.
[0040]
Also in the second embodiment, since both the light emitting element 22 and the light receiving element 23 are mounted on the arm 13 that can move only within a slight rotation range, the terminal 31 of the light emitting element 22 and the terminal 32 of the light receiving element 23. Since the other end of the flexible lead wire to which one end is connected is directly connected to the target terminal without going through a sliding part such as a slip ring, a slip ring is used in this case as well. There is no risk of reducing reliability and durability.
[0041]
In the above description, the rotational speed W including slip ₂ As an example of the rotational speed sensor for detecting the above, an example has been described in which an electromagnetic pickup 18 or an optical sensor instead of the electromagnetic pickup 18 is provided for the idler pulley 10 of the auto tensioner 9. In the present invention, these rotational speed sensors are provided as an auto tensioner. 9 is not an essential requirement, and a rotational speed sensor may be provided on another pulley that is not substantially loaded, such as an idler pulley 8 provided as a guide for the belt 7. Needless to say, the rotational drive source of the vehicle is not limited to the internal combustion engine.
[0042]
Similarly, a third embodiment of an accessory torque detection system used in the lock determination method for an automotive accessory according to the present invention will be described with reference to the drawings. The configuration of the third embodiment is shown in FIGS. 10 (A) to 10 (C). 10A is a front view of the auxiliary machine torque detection system, FIG. 10B is a side cross-sectional view, and FIG. 10C is an enlarged perspective view of a portion D in FIG. 10B.
[0043]
The auto tensioner includes a fixed housing 31, a coil spring 32 that is an elastic body, a movable housing 33, an arm 13 that is a part of the movable housing 33, and an idler pulley 10. The movable housing 33 and the fixed housing 31 are connected by a coil spring 32. The movable housing 33 is displaced according to the tension of the belt 7. A displacement sensor of the light receiving portion (photodiode array) 34 is installed on a stay 35 that forms a part of the fixed housing 31 fixed to the fixed housing 31, and a light emitting portion (light emitting diode) 36 that opposes the stay 35 forms a part of the movable housing 33. It is installed on the eggplant arm 13.
[0044]
Next, the operation of the auxiliary torque detection system of the third embodiment will be described. The movable housing 33, which is a movable portion of the auto tensioner, rotates against the urging force of the coil spring 32 according to the load torque amount of the auxiliary machine, and is mounted on the arm 13 forming a part of the movable housing 33. The light emitting unit 36 is displaced. The light from the light emitting unit 36 passes through the slit 37 of the light receiving unit 34 and reaches the light receiving element 38. The amount of displacement of the auto tensioner is known from the detection position of the light receiving unit 34 (photodiode array), and the load torque amount of the auxiliary machine can be detected.
[0045]
The relationship between the position of the auto tensioner and the amount of auxiliary torque when the belt is deteriorated and extended is as shown in FIG. 11, and only the position in the no-load state is shifted according to the amount of extension of the belt. As a countermeasure against this, the relative displacement between the displacement sensor of the light receiving part (photodiode array) 34 and the light emitting part (light emitting diode) 36 facing it is corrected so that the shift amount is corrected in the no-load state before the engine is started. The position should be the same as before the belt was extended.
[0046]
Further, the vibration of the position of the auto tensioner due to the vibration of the vehicle, the engine, etc. may be obtained by removing the AC component by electrical filtering with a low pass filter of about 1 Hz.
[0047]
Similarly, FIG. 12 (A) and FIG. 12 (B) show a fourth embodiment of a detection system for detecting auxiliary machine torque. 12A is a front view of the auxiliary machine torque detection system, and FIG. 12B is a side view. In the figure, the same parts as those of the third embodiment are denoted by the same reference numerals, and description thereof is omitted. In this case, the auxiliary machine torque is detected by the displacement between the one portion 39 and the other portion 40 facing each other.
[0048]
When an ultrasonic displacement sensor is used as one of the opposing portions 39, the other portion 40 may be any solid, but metal, ceramic, plastic, or the like may be used.
[0049]
In the case where an eddy current type displacement sensor is used as one of the opposing portions 39, a metal may be used as the material through which the other portion 40 conducts current.
[0050]
Further, when an optical (triangular distance) sensor is used as one of the opposing portions 39, the other portion 40 may be any opaque solid, but metal, opaque ceramic, plastic, or the like may be used.
[0051]
Finally, a description will be given of a fifth embodiment of the auxiliary torque detection system used in the automotive auxiliary machine lock determination method of the present invention. In both the first and second embodiments, the rotational speed W of the crankshaft 21 shown in FIG. ₁ And the rotation speed W of the idler pulley 10 of the auto tensioner 9 ₂ Rotational speed ratio (W ₁ / W ₂ ), The auxiliary machine torque is calculated from the rotational speed W in the fifth embodiment as well. ₁ The rotation speed of the crankshaft 21 shown in FIG. ₂ As an example of an alternator, that is, an alternator pulley 4 provided at a position where the belt tension is weak next to the idler pulley 10 in the pulley group engaged with the same belt 7 without using the rotational speed of the idler pulley 10. It is characterized in that the number of rotations is detected and used.
[0052]
In this case as well, the ratio of the two rotational speeds (W ₁ / W ₂ ) Corresponds to the slip ratio, whereby the magnitude of the auxiliary machine torque can be known in the same manner as in the above-described embodiments. Moreover, the rotation speed W ₂ Is the speed of the alternator, so if you count the frequency of the AC voltage output by the alternator, the speed W ₂ , So you can know immediately ₂ This has the advantage that the detection means is simpler than in the other embodiments. In other respects, the same effects as those of the above-described embodiments are obtained.
[0053]
Further, in the above embodiment, the hydraulic pump for power steering is cited as an auxiliary machine that can be locked in addition to the refrigerant compressor. Since a water pump for cooling the engine or the like can be considered, the present invention is not intended only for the locked state of the refrigerant compressor for the air conditioner and the hydraulic pump for the power steering.
[Brief description of the drawings]
FIG. 1 is a front view showing an overall configuration of a drive mechanism of auxiliary equipment for automobiles.
FIG. 2 is a cross-sectional view showing a main part of the first embodiment of the auxiliary machine torque detection system.
3 is a bottom view of the idler pulley shown in FIG. 2. FIG.
FIG. 4 is a diagram showing a relationship between a slip ratio and a load torque.
FIG. 5 is a bar graph showing the relationship between the auxiliary machine torque amount and the load.
FIG. 6 is a flowchart showing the operation of the lock state detection system according to the present invention.
FIG. 7 is a flow chart showing the operation of a special example of a lock state detection system according to the present invention.
FIG. 8 is a cross-sectional view showing a main part of a second embodiment of an auxiliary machine torque detection system.
9 is a conceptual perspective view of a main part of the rotational speed sensor shown in FIG.
FIGS. 10A and 10B are configuration diagrams showing a configuration of a third embodiment of an auxiliary machine torque detection system, where FIG. 10A is a front view of the auxiliary machine torque detection system, FIG. 10B is a side sectional view, and FIG. FIG. 4 is an enlarged perspective view of a portion D in the drawing.
FIG. 11 is a diagram showing a relationship between an auto tensioner position and an auxiliary machine torque amount when the belt is deteriorated and extended.
FIGS. 12A and 12B are configuration diagrams showing the configuration of the fourth embodiment of the auxiliary machine torque detection system, where FIG. 12A is a front view of the auxiliary machine torque detection system, and FIG.
[Explanation of symbols]
1. Internal combustion engine
2, 3, 4, 5 ... Auxiliary pulley
6 ... Crankshaft pulley
7 ... Belt
8 ... idler pulley
9 ... Auto tensioner
10 ... Auto tensioner idler pulley
11 ... Annular inner surface
12 ... Many teeth made of magnetic material
13 ... arm
18 ... Electromagnetic pickup
19, 20 ... Lead wire
21 ... Crankshaft
22 ... Light emitting element
23. Light receiving element
25 ... Rotating slit
29 ... Fixed slit
31 ... Fixed housing
32. Elastic body (coil spring)
33 ... Movable housing
34, 39 ... one part facing each other
36, 40 ... the other part facing each other

Claims (4)

A plurality of drive shaft pulleys provided in the traveling engine and driven to rotate by the engine; and at least a refrigerant compressor for an air conditioner that is simultaneously driven to rotate by a single belt wound around the drive shaft pulley. An auxiliary machine lock state detection system for a belt transmission device having an auxiliary machine pulley provided in each auxiliary machine,
A first auxiliary machine torque amount when the air conditioner is operating is measured by an auxiliary machine torque detection system, and when the first auxiliary machine torque amount exceeds a first predetermined value, the air conditioner is measured. The second compressor torque is measured when the clutch of the refrigerant compressor is disengaged and the clutch of the refrigerant compressor is disengaged, and the first auxiliary torque and the second auxiliary torque are measured. A method for determining the lock state of an auxiliary machine for an automobile, wherein the refrigerant compressor is determined to be in a locked state when a difference between the amounts exceeds a second predetermined value. In the comparison between the first auxiliary machine torque amount and the second auxiliary machine torque amount, if the difference between them does not exceed the second predetermined value, the auxiliary machines other than the refrigerant compressor are locked. The method for determining a locked state of an auxiliary machine for an automobile according to claim 1, wherein it is determined that there is a vehicle. A plurality of drive shaft pulleys provided in the traveling engine and driven to rotate by the engine; and at least a refrigerant compressor for an air conditioner that is simultaneously driven to rotate by a single belt wound around the drive shaft pulley. An auxiliary machine lock state detection system for a belt transmission device having an auxiliary machine pulley provided in each auxiliary machine,
The auxiliary torque detection system measures the first auxiliary torque amount when the air conditioner is operating, and the first auxiliary torque amount when all the auxiliary devices are operating normally is measured. The normal value is stored, and when the first auxiliary torque amount exceeds the first predetermined value, the clutch of the refrigerant compressor for the air conditioner is disconnected, and the clutch of the refrigerant compressor is The second auxiliary machine torque amount in the disconnected state is measured, the normal value of the first auxiliary machine torque amount is compared with the second auxiliary machine torque amount, and the second auxiliary machine torque amount is calculated. A method for determining a locked state of an automotive auxiliary machine, wherein the refrigerant compressor is determined to be in a locked state when the first auxiliary machine torque amount is lower than a normal value. In a comparison between the normal value of the first auxiliary machine torque amount and the second auxiliary machine torque amount, when the second auxiliary machine torque amount is higher than the normal value of the first auxiliary machine torque amount 4. The method for determining the locked state of an automotive auxiliary device according to claim 3, wherein it is determined that an auxiliary device other than the refrigerant compressor is in a locked state.

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