JP3684733B2

JP3684733B2 - Compressor control device for vehicle air conditioner

Info

Publication number: JP3684733B2
Application number: JP00403497A
Authority: JP
Inventors: 康彦新美; 義昭高野; 宏木下
Original assignee: Denso Corp
Current assignee: Denso Corp
Priority date: 1997-01-13
Filing date: 1997-01-13
Publication date: 2005-08-17
Anticipated expiration: 2017-01-13
Also published as: JPH10193961A

Description

【発明の実施の形態】
（第１実施形態）
以下、本発明を図に示す第１実施形態について説明する。
図１は、本発明装置の全体システム構成を示すもので、先ず車両用空調装置の冷凍サイクル装置１００について述べると、圧縮機１は電磁クラッチ１ａを介して走行用エンジン２（以下、エンジン２）によりベルト駆動されるようになっている。そして、圧縮機１は、周知の如く冷媒を圧縮して吐出するものであって、圧縮機１から吐出された高温高圧の冷媒ガスは凝縮器３において、図示しない冷却ファンにより送風される冷却空気と熱交換して冷却され、凝縮する。
この凝縮した液冷媒は、レシーバー４に溜められ、ここで冷媒の気液が分離され、液冷媒のみが温度作動式自動膨張弁５において減圧され、気液２相状態となり、次いで蒸発器６において冷媒は空調空気から吸熱して蒸発する。この空調空気は、蒸発器６にて冷却され、冷風となり、車室内へ吹き出し、車室内を冷房する。
蒸発器６は、車両用空調装置の通風路７を形成するダクト８内に設置され、空調用送風機９により送風される送風空気（車室内空気または車室外空気）を冷却する。なお、送風機９は図作成上便宜のため、軸流ファンを図示しているが、実際は遠心ファンである。また、蒸発器６で蒸発したガス冷媒は、圧縮機１に還流して再度圧縮される。
蒸発器６の空気直下流側近傍には、サーミスタ等の温度センサ１０が配置されており、蒸発器６の吹出温度直後の空気温度Ｔｅを検出するようになっている。この温度センサ１０は、蒸発器６の冷却度合いを検出する検出手段としての役割を果たすもので、蒸発器６に冷却度合いは、吹出直後の空気温度Ｔｅの他に、蒸発器フィン表面温度、蒸発器冷媒配管温度等を検出しても良い。
さらに蒸発器６の空気下流側には、通過する空気を加熱する加熱用熱交換器であるヒータコア（図示しない）が配置されている。そして、蒸発器６にて冷却された冷風と、上記ヒータコアとを通過する空気との割合を調整する周知のエアミックスドア（図示しない）が設けられている。なお、上記ヒータコアは、上記エンジン１の冷却水回路中に設けられ、エンジン冷却水を熱源とするものである。１１は、エンジン２の回転数を検出するセンサで、この回転数センサ１１は本実施形態ではエンジン２の回転数と上記圧縮機１との回転数とが一緒なので、エンジン２および圧縮機１の回転数を検出している。
１２は電子制御装置（ＥＣＵ）で、圧縮機１を断続制御（作動停止制御）するため、電磁クラッチ１ａへの通電を断続するものである。この電子制御装置１２には、後述の作動説明おいて詳述する加速判定手段１３、圧縮機１の断続作動の設定温度変更手段１４、蒸発器６の吹出直後の空気温度Ｔｅが設定温度より高いか否かの判定を行う温度判定手段１５等を備えている。
電子制御装置１２には、図示しないイグニッションスイッチがオンされることで、車載バッテリから電源が供給されるようになっている。さらに電子制御装置１２には、入力端子として上記回転数センサ１１および空調操作パネル１６が電気的に接続されている。そして、空調操作パネル１６には、手動操作にて各空調状態を切り換えるスイッチ、レバーが設けられている。
つまり、本実施形態では、各空調状態を手動にて操作設定するマニュアルタイプのものである。そして、上記空調操作パネルには、上記送風機９を駆動するとともに、上記送風機９の送風量を設定する送風機スイッチ１７、周知の吹出モードを変更する吹出モードスイッチ１８、上記圧縮機１を作動停止させるエアコンスイッチ（Ａ／Ｃ）１９、上記エアミックスドアの開度、つまり空調風の温度を調整する温度調節レバー２０が設けられている。また、上記送風機スイッチ１７により、送風機９の送風状態がＯＦＦ、Ｌｏ、Ｍｉｄｉａｍ、Ｈｉが設定可能になる。
そして、本実施形態では上記イグニッションスイッチがオンされた状態で、上記エアコンスイッチ１９がオンされ、さらに送風機スイッチ１７の設定位置がＯＦＦ以外であると、圧縮機１は、温度センサ１０の検出温が後述の作動温度（ＴＥon）より高くなると作動され、後述の停止温度（ＴＥoff ）より低くなると停止される。なお、これら温度センサ１０の検出温と、作動温度（ＴＥon）および停止温度（ＴＥoff ）の判定は、上記温度判定手段にて１５行われる。
次に、上記構成において本実施形態の作動を説明する。なお、本実施形態ではエアコンスイッチがオンされると、上記回転数センサ１１が常時エンジン２（圧縮機１）の回転数を検出するようになっている。
図２は、電子制御装置１２による制御内容を示すフローチャートで、上記エアコンスイッチの投入により制御ルーチンが起動する。
先ず、ステップＳ１０では、上記加速判定手段にて、回転数センサ１１が検出する回転数Ｎｅが５０００ｒｐｍ以上か否かを判定する。ここで、車両を加速させる際には、車両の運転者は図示しないアクセルペダルを踏み込み、これに伴ってエンジン１の回転数が上昇する。つまり、このステップＳ１０では、エンジン１の回転数が５０００ｒｐｍ以上となると、車両を加速させる条件（第１加速条件）としてステップＳ２０に進んで、圧縮機１を電磁クラッチ１ａを介して停止させる。これにより、エンジン２の負荷が低減されて、加速性能が向上する。
一方、エンジン２の回転数が５０００ｒｐｍより低いときには、ステップＳ３０に進む。ステップＳ３０では、このステップＳに進む以前の所定時間Ｔ１（本実施形態では５分）以内に、温度センサ１０の検出温度ＴＥが予め設定された作動温度（ＴＥon）より高くなって圧縮機１を作動（ＯＮ）したのち、予め設定された停止温度（ＴＥoff ）より低くなって圧縮機を停止（ＯＦＦ）したか否かが判定される。
ここで、本実施形態では、上記設定温度変更手段１４により、設定温度である作動温度（ＴＥon）と停止温度（ＴＥoff ）とは、図３に示すようにエンジン２の回転数Ｎｅが高くなるほど、高くなるように設定される。
具体的には、図３に示すように回転数Ｎｅが３０００ｒｐｍまでは、作動温度（ＴＥon）は４℃一定で、停止温度（ＴＥoff ）は３℃一定とする。回転数Ｎｅが３０００ｒｐｍ〜４０００ｒｐｍの間は、作動温度（ＴＥon）と停止温度（ＴＥoff ）とは共に同じ割合で、高くなるように設定される。さらに回転数Ｎｅが４０００ｒｐｍより高くなると、作動温度（ＴＥon）は５℃一定で、停止温度（ＴＥoff ）は４℃一定に設定される。なお、この作動温度（ＴＥon）と停止温度（ＴＥoff ）とは、圧縮機１がハンチングを起こさないように周知のごとくヒステリシスを持たせてある。また、上記停止温度（ＴＥoff ）の最低温度３℃は、蒸発器６がフロストしない最低温度に設定されている。
そして、上記ステップＳ３０では、図３において作動温度（ＴＥon）と停止温度（ＴＥoff ）とが最も低く、作動温度（ＴＥon）４℃、停止温度（ＴＥoff ）３℃に設定されているときに、所定時間Ｔ１以内に圧縮機１が作動（ＯＮ）から停止（ＯＦＦ）となったか否か、もしくは所定時間Ｔ１中に常時圧縮機１が停止していたか否かが判定される。
ここで、このステップＳ３０での機能は、以下のようなものである。
例えば外気温が高い夏場において車室内を急速に冷却するクールダウン時は冷房負荷を大きく、蒸発器６を通過する風量も多いので車室内が十分冷却されるまで、蒸発器６を通過した直後の空気温度は４℃より高く３℃より低くならない。
従って、ステップＳ３０では冷房負荷が所定値より小さいか否かを判定する手段を構成しており、このステップＳ３０での判定結果は、夏場のクールダウン時においてはＮＯとなって、ステップＳ４０に進んで、停止温度（ＴＥoff ）と作動温度（ＴＥon）とを共に最低温度の３℃、４℃とする。これにより、クールダウン時に蒸発器６での冷却能力を確保できる。
また、例えば蒸発器６を通過する空気が外気であって、春や秋等の中間期では、蒸発器６を通過した直後の空気温度は、３℃より低くなって、頻繁に圧縮機１は作動と停止を繰り返す。さらに外気が低い冬季においては、それほど蒸発器６の冷却能力（除湿能力）が必要でなく、圧縮機１は長時間停止状態ということもある。
従って、この場合ステップＳ３０では、所定時間Ｔ１中に常時圧縮機１が停止状態と判定されて、ステップＳ５０に進む。
続いて、ステップＳ５０では、エンジン２の回転数Ｎｅが４０００ｒｐｍ以上か否かを判定する。ここで、車両を加速させる際には、上述したように車両の運転者は図示しないアクセルペダルを踏み込み、これに伴ってエンジン１の回転数が上昇する。そして、上記ステップＳ１０ではエンジン１の回転数が５０００ｒｐｍ以上となると、車両を加速させる第１加速条件としてステップＳ２０に進んで、圧縮機１を電磁クラッチ１ａを介して停止させた。
つまり、このステップＳ５０での機能は、上記第１加速条件より緩く車両を加速させる第２加速条件として、エンジン２の回転数Ｎｅが４０００ｒｐｍ以上か否かを判定している。
ステップＳ５０での判定結果がＮＯの場合、つまり車両をそれほど加速させないときにはステップＳ９０に進む。そして、ステップＳ９０では図３に示す特性図からエンジン２の回転数Ｎｅに応じて作動温度（ＴＥon）と停止温度（ＴＥoff ）とが設定される。
なお、ステップＳ９０では、上記ステップＳ２０の判定結果がＹＥＳで、ステップＳ５０の判定結果がＮＯであるので、エンジン２の回転数Ｎｅは、４０００ｒｐｍより低い。従って、この場合は作動温度（ＴＥon）と停止温度（ＴＥoff ）とは、図３においてエンジン２の回転数Ｎｅが４０００ｒｐｍより低い範囲にて設定される。
一方、ステップＳ５０の判定結果がＹＥＳの場合、つまり上記ステップＳ１０の判定結果がＮＯであったのでエンジン２の回転数Ｎｅが４０００ｒｐｍ以上で５０００ｒｐｍより低いときでは、ステップＳ６０に進む。
ステップＳ６０では、作動温度（ＴＥon）と停止温度（ＴＥoff ）とは図３に基づいて設定されるのであるが、ここで、エンジン２の回転数Ｎｅが４０００ｒｐｍ以上で５０００ｒｐｍより低い。従って、エンジンの回転数Ｎｅが４０００ｒｐｍり低い場合より、作動温度（ＴＥon）と停止温度（ＴＥoff ）は高めに設定され、図３に示すように作動温度（ＴＥon）は５℃で、停止温度（ＴＥoff ）は４℃となる。
これにより、上記第１加速条件より緩く車両を加速させる第２加速条件時には、作動温度（ＴＥon）と停止温度（ＴＥoff ）とがともに高めに設定されるので、圧縮機１が停止しやすくなって、車両の加速性能を向上できるとともに、燃費も向上できる。これに加え、作動温度（ＴＥon）と停止温度（ＴＥoff ）とを若干ながら高めるので、ある程度の冷房能力（除湿能力）を確保できる。
続いて、ステップＳ７０に進み、ステップＳ７０ではエンジン２の回転数Ｎｅが４０００ｒｐｍ以上で５０００ｒｐｍより低い状態が、所定時間Ｔ２（本実施形態では５秒）経過したか否かが判定される。また、ここで所定時間Ｔ２は、停止温度（ＴＥoff ）と作動温度（ＴＥon）とが、それぞれ４℃、５℃となってからの時間である。
そして、ステップＳ７０での判定結果がＹＥＳの場合は、ステップＳ９０に進み、現在のエンジン２の回転数Ｎｅに基づいて図３から停止温度（ＴＥoff ）と作動温度（ＴＥon）とが設定される。
一方、ステップＳ６０にて停止温度（ＴＥoff ）と作動温度（ＴＥon）とが、それぞれ４℃、５℃に設定された直後では、ステップＳ７０での判定結果はＮＯとなり、ステップＳ１００に進む。そして、ステップＳ１００では、現在のエンジン２の回転数Ｎｅが５０００ｒｐｍ以上か否かを判定し、この判定結果がＹＥＳの場合は、ステップＳ２０に進んで、圧縮機２を停止させる。
また、ステップＳ１００の判定結果がＮＯの場合は、ステップＳ１１０に進んで、停止温度（ＴＥoff ）と作動温度（ＴＥon）とをステップＳ６０にて設定された値で、ホールドする。つまり、停止温度（ＴＥoff ）と作動温度（ＴＥon）とは、それぞれ４℃、５℃とし、ステップＳ７０に戻る。
このようにすることで、エンジン２の回転数Ｎｅが、一旦４０００ｒｐｍ以上で５０００ｒｐｍより低くなると、停止温度（ＴＥoff ）と作動温度（ＴＥon）と最高の４℃、５℃とし、この後、所定時間Ｔ２経過しないと、停止温度（ＴＥoff ）と作動温度（ＴＥon）とは変更されないようになる。
つまり、短時間に停止温度（ＴＥoff ）と作動温度（ＴＥon）とが４℃、５℃から、元の３℃、４℃に戻るように変更されると、蒸発器６を通過した直後の空気温度が変動する。これにより、本実施形態では上述したマニュアルタイプのものであるので、車室内に吹き出される空調風の温度も変動し、乗員に不快感を与えるという問題がある。そこで、本実施形態では、停止温度（ＴＥoff ）と作動温度（ＴＥon）とは、所定時間Ｔ２経過するまで４℃、５℃にホールドされるので、上記問題を解決することができる。
また、本実施形態では、回転数センサ１１として、既存のエンジン２の回転数Ｎｅを検出するセンサを用い、さらにタイマー機能を既存の電子制御装置内に組み込めば、システムを複雑化せずに安価に実施することができる。
ところで、本実施形態では以下に述べるような効果を有する。本実施形態では、図３に示すようにエンジン２の回転数Ｎｅが３０００ｒｐｍ以上で、４０００ｒｐｍより低いときには、エンジン２の回転数Ｎｅ、つまり圧縮機１の回転数が高くなるほど、停止温度（ＴＥoff ）と作動温度（ＴＥon）とはリニアに高くなるように設定される。従って、圧縮機１の回転数が高くなるほど、温度センサ１０の検出温に応じて圧縮機１は停止されやすくなる。
ここで、一般的な車両用空調装置の圧縮機１は、図４に示すように実使用での稼働回転数頻度（ここでは４０００ｒｐｍ以下）を考慮し、低中回転域で最高効率となるように設計されている。従って、本実施形態では圧縮機１が、図４に示すように圧縮機効率が低い高回転数になるほど、停止されやすくなるので、効率良く圧縮機１を作動させることができる。
（第２実施形態）
本実施形態は、上記第１実施形態における図３のフローチャートの内容だけが若干異なるものである。図５に本実施形態におけるフローチャートを示す。なお、本実施形態におけるフローチャートは、上記第１実施形態におけるステップＳ３０、４０を無くしたものである。本発明はこのようなものでも良い。なお、本実施形態における説明は、上記第１実施形態にて明らかであるので、説明は省略する。
（第３実施形態）
本実施形態は、上記第１実施形態における図３のフローチャートの内容だけが若干異なるものである。図６に本実施形態におけるフローチャートを示す。なお、本実施形態におけるフローチャートは、上記第１実施形態におけるステップＳ７０、１００、１１０を無くしたものである。本発明はこのようなものでも良い。なお、本実施形態における説明は、上記第１実施形態にて明らかであるので、説明は省略する。
（第４実施形態）
本実施形態は、上記第１実施形態における図３のフローチャートの内容だけが若干異なるものである。図７に本実施形態におけるフローチャートを示す。なお、本実施形態におけるフローチャートは、上記第１実施形態におけるステップＳ３０、４０、７０、１００、１１０を無くしたものである。本発明はこのようなものでも良い。なお、本実施形態における説明は、上記第１実施形態にて明らかであるので、説明は省略する。
（他の実施形態）
上記各実施形態では、車両用空調装置をマニュアルタイプのものとし、特に空調風の温度を温度調整レバー２０にて調整するものであった。しかし、本発明は内気温や、外気温等に基づいて自動的に空調風の温度を調整するものに適用しても良い。
また、上記実施形態では、車両の加速条件としてエンジン２の回転数Ｎｅを用いたが、図示しないアクセルの開度を用いても良い。さらに、エンジン２の回転数Ｎｅと図示しないアクセルの開度との２つを組み合わし、加速条件として、少なくともエンジン２の回転数Ｎｅと、図示しないアクセルの開度とのどちらか一方を用いても良い。さらにエンジン２の回転数の変化率を加速条件としても良い。
また、上記各実施形態では図３に示すような特性図から停止温度（ＴＥoff ）と作動温度（ＴＥon）とを設定したが、本発明はこれに限られるものでは無い。例えば、本発明では図８に示すようにエンジン２の回転数Ｎｅが、３０００〜４０００ｒｐｍの間で、作動温度（ＴＥon）の方が停止温度（ＴＥoff ）より増加温度が大きくなるようにしても良い。また、図９に示すようにエンジン２の回転数Ｎｅに対し作動温度（ＴＥon）を一定とするようにしても良い。さらに、図１０に示すようにエンジン２の回転数Ｎｅに対し作動温度（ＴＥon）を一定とし、エンジン２の回転数Ｎｅが４０００ｒｐｍ以上である停止温度（ＴＥoff ）と作動温度（ＴＥon）とを同じ４℃としても良い。
また、上記各実施形態にて述べた数値は限定されるものでなく、例えばエンジン２の回転数Ｎｅに対する停止温度（ＴＥoff ）と作動温度（ＴＥon）との設定は、車両エンジンの排気量等に応じて可変すれば良い。
また、上記各実施形態では圧縮機１の回転数を検出するためにエンジン２の回転数を検出する回転数センサ１１を使用したが、圧縮機１専用の回転数センサを使用しても良い。
【図面の簡単な説明】
【図１】本発明の第１〜４実施形態における車両用空調装置の全体構成図である。
【図２】上記第１実施形態における圧縮機１の作動を表すフローチャートである。
【図３】上記第１実施形態におけるエンジン２の回転数Ｎｅと設定温度との関係を示す図である。
【図４】本発明の各実施形態における圧縮機の回転数（Ｎｅ）と圧縮機効率との関係を表す図である。
【図５】上記第２実施形態における圧縮機１の作動を表すフローチャートである。
【図６】上記第３実施形態における圧縮機１の作動を表すフローチャートである。
【図７】上記第４実施形態における圧縮機１の作動を表すフローチャートである。
【図８】本発明の他の実施形態におけるエンジン２の回転数Ｎｅと設定温度との関係を示す図である。
【図９】本発明の他の実施形態におけるエンジン２の回転数Ｎｅと設定温度との関係を示す図である。
【図１０】本発明の他の実施形態におけるエンジン２の回転数Ｎｅと設定温度との関係を示す図である。
【符号の説明】
１…圧縮機、１ａ…電磁クラッチ、２…エンジン、６…蒸発器
１１…回転数センサ、１２…電子制御装置。DETAILED DESCRIPTION OF THE INVENTION
(First embodiment)
The first embodiment shown in the drawings will be described below.
FIG. 1 shows the overall system configuration of the apparatus of the present invention. First, a refrigeration cycle apparatus 100 for a vehicle air conditioner will be described. A compressor 1 is connected to a traveling engine 2 (hereinafter referred to as an engine 2) via an electromagnetic clutch 1a. Is driven by a belt. The compressor 1 compresses and discharges the refrigerant as is well known, and the high-temperature and high-pressure refrigerant gas discharged from the compressor 1 is cooled in the condenser 3 by a cooling fan (not shown). It is cooled and condensed by heat exchange.
The condensed liquid refrigerant is stored in the receiver 4, where the gas-liquid of the refrigerant is separated, and only the liquid refrigerant is decompressed in the temperature-actuated automatic expansion valve 5 to be in a gas-liquid two-phase state, and then in the evaporator 6. The refrigerant absorbs heat from the conditioned air and evaporates. This conditioned air is cooled by the evaporator 6 and becomes cold air, blown out into the passenger compartment, and cools the passenger compartment.
The evaporator 6 is installed in a duct 8 that forms the ventilation path 7 of the vehicle air conditioner, and cools the air blown by the air conditioner blower 9 (vehicle interior air or vehicle exterior air). The blower 9 is an axial fan for convenience of drawing, but is actually a centrifugal fan. Further, the gas refrigerant evaporated in the evaporator 6 is returned to the compressor 1 and compressed again.
A temperature sensor 10 such as a thermistor is disposed in the vicinity of the air downstream side of the evaporator 6 so as to detect the air temperature Te immediately after the blowing temperature of the evaporator 6. This temperature sensor 10 serves as a detecting means for detecting the degree of cooling of the evaporator 6, and the degree of cooling of the evaporator 6 is not limited to the air temperature Te immediately after blowing, the evaporator fin surface temperature, the evaporation The refrigerant temperature of the refrigerant pipe may be detected.
Further, a heater core (not shown), which is a heat exchanger for heating that heats the air passing therethrough, is disposed on the air downstream side of the evaporator 6. And the well-known air mix door (not shown) which adjusts the ratio of the cold wind cooled with the evaporator 6 and the air which passes the said heater core is provided. The heater core is provided in the cooling water circuit of the engine 1 and uses engine cooling water as a heat source. 11 is a sensor for detecting the rotational speed of the engine 2. In this embodiment, since the rotational speed of the engine 2 and the rotational speed of the compressor 1 are the same in this embodiment, the rotational speed sensor 11 of the engine 2 and the compressor 1 The rotation speed is detected.
Reference numeral 12 denotes an electronic control unit (ECU) for intermittently energizing the electromagnetic clutch 1a in order to intermittently control (stop operation) the compressor 1. The electronic control unit 12 includes an acceleration determination unit 13, which is described in detail in the description of the operation described later, a set temperature changing unit 14 for intermittent operation of the compressor 1, and an air temperature Te immediately after the evaporator 6 is blown out is higher than the set temperature. Temperature determining means 15 for determining whether or not.
The electronic control device 12 is supplied with power from an in-vehicle battery by turning on an ignition switch (not shown). Further, the rotational speed sensor 11 and the air conditioning operation panel 16 are electrically connected to the electronic control unit 12 as input terminals. The air conditioning operation panel 16 is provided with a switch and a lever for switching each air conditioning state by manual operation.
That is, in this embodiment, it is a manual type that manually sets each air conditioning state. In the air conditioning operation panel, the blower 9 is driven and the blower switch 17 for setting the blown amount of the blower 9, the blowing mode switch 18 for changing a known blowing mode, and the compressor 1 are deactivated. An air conditioner switch (A / C) 19 and a temperature adjusting lever 20 for adjusting the opening of the air mix door, that is, the temperature of the conditioned air are provided. Further, the blower switch 17 enables the blower 9 to be set to OFF, Lo, Midiam, and Hi.
In this embodiment, when the air conditioner switch 19 is turned on with the ignition switch turned on, and the setting position of the blower switch 17 is other than OFF, the compressor 1 detects the temperature detected by the temperature sensor 10. It is activated when it becomes higher than an operating temperature (TEon) described later, and is stopped when it becomes lower than a stopping temperature (TEoff) described later. The detected temperature of the temperature sensor 10 and the determination of the operating temperature (TEon) and the stop temperature (TEoff) are performed 15 times by the temperature determining means.
Next, the operation of this embodiment in the above configuration will be described. In the present embodiment, when the air conditioner switch is turned on, the rotation speed sensor 11 always detects the rotation speed of the engine 2 (compressor 1).
FIG. 2 is a flowchart showing the contents of control by the electronic control unit 12, and the control routine is started when the air conditioner switch is turned on.
First, in step S10, it is determined by the acceleration determination means whether or not the rotation speed Ne detected by the rotation speed sensor 11 is 5000 rpm or more. Here, when accelerating the vehicle, the driver of the vehicle depresses an accelerator pedal (not shown), and the rotational speed of the engine 1 increases accordingly. That is, in step S10, when the rotational speed of the engine 1 reaches 5000 rpm or more, the process proceeds to step S20 as a condition for accelerating the vehicle (first acceleration condition), and the compressor 1 is stopped via the electromagnetic clutch 1a. Thereby, the load of the engine 2 is reduced and acceleration performance is improved.
On the other hand, when the rotational speed of the engine 2 is lower than 5000 rpm, the process proceeds to step S30. In step S30, the detected temperature TE of the temperature sensor 10 becomes higher than the preset operating temperature (TEon) within a predetermined time T1 (5 minutes in the present embodiment) before proceeding to step S, and the compressor 1 is turned on. After the operation (ON), it is determined whether or not the compressor has been stopped (OFF) because the temperature has become lower than a preset stop temperature (TEoff).
Here, in the present embodiment, the operating temperature (TEon) and the stop temperature (TEoff), which are the set temperatures, are set by the set temperature changing means 14 as the engine speed Ne increases as shown in FIG. Set to be higher.
Specifically, as shown in FIG. 3, the operating temperature (TEon) is kept constant at 4 ° C. and the stop temperature (TEoff) is kept constant at 3 ° C. until the rotational speed Ne reaches 3000 rpm. When the rotational speed Ne is between 3000 rpm and 4000 rpm, both the operating temperature (TEon) and the stop temperature (TEoff) are set to be higher at the same rate. Further, when the rotational speed Ne becomes higher than 4000 rpm, the operating temperature (TEon) is set to a constant 5 ° C., and the stop temperature (TEoff) is set to a constant 4 ° C. The operating temperature (TEon) and the stop temperature (TEoff) have hysteresis as is well known so that the compressor 1 does not cause hunting. The minimum temperature 3 ° C. of the stop temperature (TEoff) is set to the minimum temperature at which the evaporator 6 does not frost.
In step S30, when the operating temperature (TEon) and the stop temperature (TEoff) are the lowest in FIG. 3, and the operating temperature (TEon) is set to 4 ° C. and the stop temperature (TEoff) is 3 ° C., a predetermined value is obtained. It is determined whether or not the compressor 1 has been stopped (OFF) from operation (ON) within the time T1, or whether or not the compressor 1 has always been stopped during the predetermined time T1.
Here, the function in step S30 is as follows.
For example, during a cool-down period in which the vehicle interior is rapidly cooled in summer when the outside air temperature is high, the cooling load is large and the amount of air passing through the evaporator 6 is large, so that the vehicle interior immediately after passing through the evaporator 6 is sufficiently cooled. Air temperature is higher than 4 ° C and not lower than 3 ° C.
Accordingly, in step S30, means for determining whether or not the cooling load is smaller than the predetermined value is configured. The determination result in step S30 is NO during the cool-down in summer, and the process proceeds to step S40. Thus, both the stop temperature (TEoff) and the operating temperature (TEon) are set to the minimum temperatures of 3 ° C. and 4 ° C. Thereby, the cooling capacity in the evaporator 6 can be ensured at the time of cool-down.
Further, for example, the air passing through the evaporator 6 is outside air, and in the intermediate period such as spring or autumn, the air temperature immediately after passing through the evaporator 6 becomes lower than 3 ° C. Repeat operation and stop. Further, in the winter season when the outside air is low, the cooling capacity (dehumidification capacity) of the evaporator 6 is not so necessary, and the compressor 1 may be stopped for a long time.
Therefore, in this case, in step S30, it is determined that the compressor 1 is always stopped during the predetermined time T1, and the process proceeds to step S50.
Subsequently, in step S50, it is determined whether or not the rotational speed Ne of the engine 2 is 4000 rpm or more. Here, when accelerating the vehicle, the driver of the vehicle depresses an accelerator pedal (not shown) as described above, and the rotational speed of the engine 1 increases accordingly. In step S10, when the rotational speed of the engine 1 reaches 5000 rpm or more, the process proceeds to step S20 as a first acceleration condition for accelerating the vehicle, and the compressor 1 is stopped via the electromagnetic clutch 1a.
That is, the function in step S50 determines whether the rotational speed Ne of the engine 2 is 4000 rpm or more as a second acceleration condition for accelerating the vehicle more slowly than the first acceleration condition.
If the determination result in step S50 is NO, that is, if the vehicle is not accelerated much, the process proceeds to step S90. In step S90, the operating temperature (TEon) and the stop temperature (TEoff) are set according to the rotational speed Ne of the engine 2 from the characteristic diagram shown in FIG.
In step S90, the determination result in step S20 is YES and the determination result in step S50 is NO. Therefore, the rotational speed Ne of the engine 2 is lower than 4000 rpm. Accordingly, in this case, the operating temperature (TEon) and the stop temperature (TEoff) are set in a range where the rotational speed Ne of the engine 2 is lower than 4000 rpm in FIG.
On the other hand, if the decision result in the step S50 is YES, that is, the decision result in the step S10 is NO, the process proceeds to a step S60 when the rotational speed Ne of the engine 2 is 4000 rpm or higher and lower than 5000 rpm.
In step S60, the operating temperature (TEon) and the stop temperature (TEoff) are set based on FIG. 3, but here, the rotational speed Ne of the engine 2 is 4000 rpm or more and lower than 5000 rpm. Therefore, the operating temperature (TEon) and the stop temperature (TEoff) are set higher than when the engine speed Ne is lower than 4000 rpm, and the operating temperature (TEon) is 5 ° C. as shown in FIG. TEoff) is 4 ° C.
As a result, the operating temperature (TEon) and the stop temperature (TEoff) are both set higher during the second acceleration condition in which the vehicle is accelerated more slowly than the first acceleration condition, so that the compressor 1 is likely to stop. The acceleration performance of the vehicle can be improved, and the fuel consumption can be improved. In addition, since the operating temperature (TEon) and the stop temperature (TEoff) are slightly increased, a certain amount of cooling ability (dehumidifying ability) can be secured.
Subsequently, the process proceeds to step S70. In step S70, it is determined whether or not the state in which the rotational speed Ne of the engine 2 is 4000 rpm or higher and lower than 5000 rpm has elapsed for a predetermined time T2 (5 seconds in the present embodiment). Here, the predetermined time T2 is a time after the stop temperature (TEoff) and the operating temperature (TEon) become 4 ° C. and 5 ° C., respectively.
If the decision result in the step S70 is YES, the process proceeds to a step S90, and the stop temperature (TEoff) and the operating temperature (TEon) are set from FIG. 3 based on the current rotational speed Ne of the engine 2.
On the other hand, immediately after the stop temperature (TEoff) and the operating temperature (TEon) are set to 4 ° C. and 5 ° C., respectively, in step S60, the determination result in step S70 is NO, and the process proceeds to step S100. In step S100, it is determined whether or not the current rotational speed Ne of the engine 2 is 5000 rpm or more. If the determination result is YES, the process proceeds to step S20 and the compressor 2 is stopped.
On the other hand, if the decision result in the step S100 is NO, the process proceeds to a step S110 to hold the stop temperature (TEoff) and the operating temperature (TEon) at the values set in the step S60. That is, the stop temperature (TEoff) and the operating temperature (TEon) are 4 ° C. and 5 ° C., respectively, and the process returns to step S70.
By doing in this way, once the rotational speed Ne of the engine 2 becomes 4000 rpm or more and lower than 5000 rpm, the stop temperature (TEoff) and the operating temperature (TEon) are set to the maximum 4 ° C. and 5 ° C., and thereafter for a predetermined time. If T2 does not elapse, the stop temperature (TEoff) and the operating temperature (TEon) are not changed.
That is, if the stop temperature (TEoff) and the operating temperature (TEon) are changed from 4 ° C. and 5 ° C. back to the original 3 ° C. and 4 ° C. in a short time, the air immediately after passing through the evaporator 6 Temperature fluctuates. Thereby, since it is a manual type thing mentioned above in this embodiment, the temperature of the air-conditioning wind blown out into a vehicle interior also fluctuates, and there is a problem of giving a passenger discomfort. Therefore, in this embodiment, the stop temperature (TEoff) and the operating temperature (TEon) are held at 4 ° C. and 5 ° C. until the predetermined time T2 elapses, so that the above problem can be solved.
In the present embodiment, if a sensor for detecting the rotational speed Ne of the existing engine 2 is used as the rotational speed sensor 11 and a timer function is incorporated in the existing electronic control device, the system is not complicated and inexpensive. Can be implemented.
By the way, this embodiment has the following effects. In this embodiment, as shown in FIG. 3, when the rotational speed Ne of the engine 2 is 3000 rpm or higher and lower than 4000 rpm, the higher the rotational speed Ne of the engine 2, that is, the rotational speed of the compressor 1, the higher the stop temperature (TEoff). The operating temperature (TEon) is set to be linearly high. Therefore, the higher the rotational speed of the compressor 1, the more easily the compressor 1 is stopped according to the temperature detected by the temperature sensor 10.
Here, as shown in FIG. 4, the compressor 1 of a general vehicle air conditioner is considered to have the highest efficiency in a low and medium rotation range in consideration of the operating rotation frequency in actual use (here, 4000 rpm or less). Designed to. Accordingly, in the present embodiment, the compressor 1 is more likely to be stopped as the compressor speed becomes lower as the compressor efficiency becomes lower as shown in FIG. 4, so that the compressor 1 can be operated efficiently.
(Second Embodiment)
This embodiment is slightly different only in the contents of the flowchart of FIG. 3 in the first embodiment. FIG. 5 shows a flowchart in the present embodiment. Note that the flowchart in the present embodiment eliminates steps S30 and S40 in the first embodiment. The present invention may be such. In addition, since the description in this embodiment is clear in the said 1st Embodiment, description is abbreviate | omitted.
(Third embodiment)
This embodiment is slightly different only in the contents of the flowchart of FIG. 3 in the first embodiment. FIG. 6 shows a flowchart in the present embodiment. Note that the flowchart in the present embodiment eliminates steps S70, 100, and 110 in the first embodiment. The present invention may be such. In addition, since the description in this embodiment is clear in the said 1st Embodiment, description is abbreviate | omitted.
(Fourth embodiment)
This embodiment is slightly different only in the contents of the flowchart of FIG. 3 in the first embodiment. FIG. 7 shows a flowchart in the present embodiment. Note that the flowchart in the present embodiment eliminates steps S30, 40, 70, 100, and 110 in the first embodiment. The present invention may be such. In addition, since the description in this embodiment is clear in the said 1st Embodiment, description is abbreviate | omitted.
(Other embodiments)
In each of the above embodiments, the vehicle air conditioner is of the manual type, and in particular, the temperature of the conditioned air is adjusted by the temperature adjustment lever 20. However, the present invention may be applied to an apparatus that automatically adjusts the temperature of the conditioned air based on the inside air temperature, the outside air temperature, or the like.
Moreover, in the said embodiment, although the rotation speed Ne of the engine 2 was used as a vehicle acceleration condition, you may use the opening degree of the accelerator which is not shown in figure. Further, by combining two of the rotational speed Ne of the engine 2 and the opening degree of the accelerator (not shown), at least one of the rotational speed Ne of the engine 2 and the opening degree of the accelerator (not shown) is used as an acceleration condition. Also good. Further, the rate of change of the rotational speed of the engine 2 may be set as the acceleration condition.
In the above embodiments, the stop temperature (TEoff) and the operating temperature (TEon) are set from the characteristic diagram as shown in FIG. 3, but the present invention is not limited to this. For example, in the present invention, as shown in FIG. 8, when the rotational speed Ne of the engine 2 is between 3000 and 4000 rpm, the operating temperature (TEon) may be higher in the increase temperature than the stop temperature (TEoff). . Further, as shown in FIG. 9, the operating temperature (TEon) may be constant with respect to the rotational speed Ne of the engine 2. Further, as shown in FIG. 10, the operating temperature (TEon) is constant with respect to the rotational speed Ne of the engine 2, and the stop temperature (TEoff) and the operating temperature (TEon) at which the rotational speed Ne of the engine 2 is 4000 rpm or more are the same. It may be 4 ° C.
The numerical values described in the above embodiments are not limited. For example, the setting of the stop temperature (TEoff) and the operating temperature (TEon) with respect to the rotational speed Ne of the engine 2 depends on the displacement of the vehicle engine. What is necessary is just to change according to it.
Moreover, in each said embodiment, although the rotation speed sensor 11 which detects the rotation speed of the engine 2 was used in order to detect the rotation speed of the compressor 1, you may use the rotation speed sensor only for the compressor 1. FIG.
[Brief description of the drawings]
FIG. 1 is an overall configuration diagram of a vehicle air conditioner according to first to fourth embodiments of the present invention.
FIG. 2 is a flowchart showing the operation of the compressor 1 in the first embodiment.
FIG. 3 is a diagram showing a relationship between a rotational speed Ne of the engine 2 and a set temperature in the first embodiment.
FIG. 4 is a diagram illustrating a relationship between a compressor rotation speed (Ne) and compressor efficiency in each embodiment of the present invention.
FIG. 5 is a flowchart showing the operation of the compressor 1 in the second embodiment.
FIG. 6 is a flowchart showing the operation of the compressor 1 in the third embodiment.
FIG. 7 is a flowchart showing the operation of the compressor 1 in the fourth embodiment.
FIG. 8 is a diagram showing a relationship between a rotational speed Ne of an engine 2 and a set temperature in another embodiment of the present invention.
FIG. 9 is a diagram showing the relationship between the rotational speed Ne of the engine 2 and the set temperature in another embodiment of the present invention.
FIG. 10 is a diagram showing a relationship between a rotational speed Ne of an engine 2 and a set temperature in another embodiment of the present invention.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 ... Compressor, 1a ... Electromagnetic clutch, 2 ... Engine, 6 ... Evaporator 11 ... Speed sensor, 12 ... Electronic control apparatus.

Claims

A compressor (1) that is driven by a vehicle travel engine (2) and compresses and discharges refrigerant, and an air downstream side of an evaporator (6) of a refrigeration cycle apparatus (100) including the compressor (1). Compressor control means (1a) that operates the compressor (1) when the temperature in the vicinity becomes higher than a predetermined operating temperature (TEon) and stops the compressor (1) when the temperature becomes lower than a predetermined stop temperature (TEoff). 12), a compressor control device for a vehicle air conditioner,
The compressor control means (1a, 12)
The compressor (1) is stopped during a first acceleration condition for accelerating the vehicle, and the stop temperature (TEoff) is set higher during a second acceleration condition for accelerating the vehicle more slowly than the first acceleration condition. A compressor control device for a vehicle air conditioner.

After the stop temperature (TEoff) is set high, the stop temperature (TEoff) is kept high for a predetermined time (T2) regardless of the conditions for accelerating the vehicle. The compressor control device for a vehicle air conditioner according to claim 1.

A cooling load detecting means (S30) for detecting the size of the cooling load in the passenger compartment;
The compression of the vehicle air conditioner according to claim 1 or 2, wherein the stop temperature (TEoff) is set higher when the cooling load detected by the cooling load detection means (S30) is smaller than a predetermined value. Machine control device.

The cooling load is smaller than a predetermined value when the temperature in the vicinity of the downstream side of the evaporator (6) becomes the stop temperature (TEoff) from the operating temperature (TEon) within a predetermined time (T1). The compressor control device for a vehicle air conditioner according to claim 3.

A rotation speed detection means (11) for detecting a physical quantity corresponding to the rotation speed (Ne) of the compressor (1);
The vehicle air conditioner according to any one of claims 1 to 4, wherein the stop temperature (TEoff) is set higher as the physical quantity detected by the rotational speed detection means (11) increases. Compressor control device.

The compressor control means (1a, 12) sets the stop temperature (TEoff) higher and also sets the operating temperature (TEon) higher. The compressor control apparatus of the air conditioner for vehicles described in 2.

The compression of the vehicle air conditioner according to any one of claims 1 to 6, wherein the vehicle air conditioner is configured to adjust the temperature of the conditioned air manually. Machine control device.
BACKGROUND OF THE INVENTION
The present invention relates to a compressor control device for a vehicle air conditioner, and more particularly to a device that improves vehicle acceleration performance and vehicle fuel efficiency.
[Prior art]
Conventionally, a compressor of a vehicle air conditioner is driven by an engine. When such a compressor is driven, a load is applied to the engine, which causes a reduction in engine performance for traveling. In particular, as a condition for determining the state of acceleration of the vehicle, for example, when the engine speed becomes higher than a predetermined value, the operation of the compressor of the vehicle air conditioner is stopped to reduce the load on the engine. Are known to improve the acceleration performance (generally called acceleration cut).
In recent years, for example, low-displacement vehicles have poor acceleration performance due to the performance of the engine itself, compared to large-displacement vehicles, and there is a strong demand for further acceleration capability.
[Problems to be solved by the invention]
Therefore, in order to further improve the acceleration performance as described above, the present inventor stops the compressor even at a moderate acceleration by further reducing the above-described acceleration cut, that is, by further reducing the condition for determining the acceleration state. I examined things.
However, when this is done, the compressor frequently stops, so that there is a problem that the refrigeration cycle of the vehicle air conditioner is stopped and the cooling capacity is remarkably lowered.
[Means for Solving the Problems]
By the way, the refrigerating cycle including the compressor is provided with an evaporator for cooling the passenger compartment. A temperature sensor is installed immediately downstream of the evaporator, and the compressor is stopped when the temperature detected by the temperature sensor is lower than 3 ° C. (stop temperature) as a stop temperature, for example. It is controlled to operate when the temperature is higher than 4 ° C.
Therefore, the inventor of the present invention pays attention to the fact that if the stop temperature is increased during vehicle acceleration, the compressor can be easily stopped, thereby improving the acceleration performance of the vehicle and ensuring a certain cooling capacity. did.
In other words, in the present invention, the compressor is stopped as described above when the vehicle is in the first acceleration condition, and the compressor stop temperature is set under the second acceleration condition, which is an acceleration that is slower than the first condition. The purpose is to improve the acceleration performance of the vehicle and to ensure the cooling capacity by raising
Accordingly, the present invention provides the following aspects of the invention.
The compressor control means (1a, 12)
The compressor (1) is stopped during the first acceleration condition for accelerating the vehicle, and the stop temperature (TEoff) is set higher during the second acceleration condition for accelerating the vehicle more slowly than the first acceleration condition. .
Accordingly, the compressor 1 is stopped under the first acceleration condition for accelerating the vehicle. As a result, the load on the traveling engine is reduced and the acceleration performance is improved. In addition to this, during the second acceleration condition in which the vehicle is accelerated more slowly than the first acceleration condition, the stop temperature is set higher, so that the compressor can be easily stopped and the acceleration performance of the vehicle can be improved. Cooling capacity (dehumidification capacity) can be secured.
In particular, in the invention described in claim 2, the compressor control means (1a, 12) is set high during the predetermined time (T2) regardless of the conditions for accelerating the vehicle after the stop temperature (TEoff) is set high. Further, the present invention is characterized in that a state where the stop temperature (TEoff) is set high is maintained.
Thereby, for example, when the stop temperature is raised in a short time and then returned to the original temperature, the temperature immediately after passing through the evaporator 6 frequently fluctuates, but the stop temperature is temporarily increased. After that, since the state where the stop temperature is raised is maintained until a predetermined time elapses, the above-described problems can be prevented.
In particular, the invention described in claim 3 includes cooling load detection means (S30) for detecting the magnitude of the cooling load in the passenger compartment, and the cooling load detected by the cooling load detection means (S30) is smaller than a predetermined value. In some cases, the stop temperature (TEoff) is set higher.
As a result, the stop temperature is set higher only when the cooling load is smaller than the predetermined value, so that the cooling capacity when the cooling load is larger than the predetermined value can be secured.
In particular, the invention according to claim 5 further includes a rotational speed detection means (11) for detecting a physical quantity corresponding to the rotational speed (Ne) of the compressor (1), and the rotational speed detection means (11) detects the physical quantity. The stopping temperature (TEoff) is set higher as the physical quantity to be increased is larger.
As a result, the compressor of a general vehicle air conditioner is designed so as to have the highest efficiency in the low to medium rotation range in consideration of the operating rotation frequency in actual use as shown in FIG. Paying attention, in the present invention, as the compressor efficiency becomes lower as the compressor speed becomes higher as shown in FIG. 4, the compressor is more easily stopped, so that the compressor can be operated efficiently.