JP4072727B2

JP4072727B2 - DC power supply with charging function

Info

Publication number: JP4072727B2
Application number: JP2003145698A
Authority: JP
Inventors: 卓央荒舘; 岳史武田; 秀一原田; 信宏高野
Original assignee: Hitachi Koki Co Ltd
Current assignee: Koki Holdings Co Ltd
Priority date: 2003-05-23
Filing date: 2003-05-23
Publication date: 2008-04-09
Anticipated expiration: 2023-05-23
Also published as: JP2004350438A

Description

【０００１】
【発明が属する技術分野】
本発明は、着脱可能な電池パックを電源とするコードレス電動工具(以下単に電動工具という)に着脱可能なアダプタを備えたケーブルを介して直流電圧を供給し、かつ電池パックを充電可能な充電機能付き直流電源装置に関するものである。
【０００２】
【従来の技術】
従来、電動工具は電源ケーブルによる作業上の制約は無く、どのような場所においても作業できるというメリットを有しているが、電池パックの容量が低下すると電池パックを充電するか別の充電済み電池パックと交換しなければならないという問題があった。そこで、作業場所と交流電源設置場所が近く作業中の移動が少ない場合には交流を直流に変換する直流電源を用い、作業場所と交流電源設置場所が遠く作業中の移動が多い場合には電池パックを用い、作業状況に合わせて電動工具の電源として電池パックと直流電源を併用していた。
【０００３】
しかし、作業場所に充電器と直流電源を持ち込まなければ効率のよい作業ができないという問題がある。これらの問題を解決ため、電動工具の動作を検出し、電動工具の動作時は充電をせず直流電源を供給し、電動工具の動作が停止している時は電池パックを充電する充電機能付き直流電源装置を特許文献１により提案した。
【０００４】
【特許文献１】
特開２０００−１８４６１４公報
【０００５】
【発明が解決しようとする課題】
特許文献１の充電機能付き直流電源装置において、電池温度勾配に基づき満充電検出を行う場合、電池温度勾配を単純に検出していくだけでは確実な満充電判別を行えないことがある。これは直流電源装置の充電部において充電中の電池パックを冷却ファンにより強制的に冷却するように構成したためであり、これを図１〜図５を用いて説明する。図１〜図５はそれぞれの条件における充電中の電池電圧、電池温度、電池温度勾配（Ａ/Ｄ変換値）、充電電流の推移を示したグラフである。
【０００６】
図１は充電中に電動工具が一切使用されなかったケースを示す。なお、最新の電池温度勾配が電池温度勾配最小値から所定値(以下満充電判別値という)Ｑ２以上上昇したら満充電と判別して充電を終了するものとし、図１は満充電が正確に判別されて充電が停止した状態を示す。
【０００７】
図２は充電中に電池温度勾配が満充電判別値Ｑ２に近い所定値Ｑ１（Ｑ２＞Ｑ１）以上上昇した時点すなわち満充電近傍まで充電された状態で電動工具が使用されたケースを示し、電動工具使用後の充電再開と共に電池温度勾配演算を行い満充電を正確に判別した状態を示す。
【０００８】
図３は充電中に電池温度勾配が前記所定値Ｑ１以上上昇していない時点すなわち満充電近傍まで充電されていない状態で電動工具が使用されたケースを示し、電動工具使用後の充電再開と共に電池温度勾配演算を行ったため、電動工具使用時に電池温度が低下するが充電再開後の相対的な電池温度の上昇から電池温度勾配が急激に上昇して前記満充電判別値Ｑ２以上上昇してしまい、満充電と誤判別し不足充電の状態で充電停止したケースを示す。
【０００９】
図４及び図５は充電中に電動工具が使用され、その後充電が再開した際に電池温度勾配の演算を所定時間行わないようにしたケースを示し、図４は充電中に電池温度勾配が前記所定値Ｑ１以上上昇した時点で電動工具が使用されその後使用が停止して充電が再開された時に電池温度勾配演算を所定時間行わないために満充電の判別が遅れ過充電したケースを示す。
【００１０】
図５は充電中に電池温度勾配が前記所定値Ｑ１以上上昇していない時点で電動工具が使用されその後使用が停止して充電が再開された時に電池温度勾配演算を所定時間行わないために満充電を正確に判別できたケースを示す。
【００１１】
以上のように、充電中に電池温度勾配が前記所定値Ｑ１以上上昇しているすなわち満充電近傍において電動工具が使用され、その後充電を再開した際に、図４に示すように電池温度勾配の演算を所定時間行わないようにすると、その所定時間の分だけ過充電してしまうことになる。
【００１２】
一方、充電中に電池温度勾配が前記所定値Ｑ１以上上昇していないすなわち満充電近傍まで充電されていない時点で電動工具が使用され、その後充電を再開した際に、図３に示すように電池温度勾配演算を連続的に行うと、充電を行っていない時に電池温度が低下することから、電池温度勾配も低下するが、その後の充電再開時において相対的な電池温度の上昇から、電池温度勾配が急激に上昇し、満充電判別値Ｑ２以上上昇してしまい、満充電と誤判別し早切れをおこしてしまう。そこで、図５に示すように、充電再開時に電池温度勾配演算を所定時間行わないようにすれば、上述した電池温度勾配の急激な上昇が無くなり確実な満充電判別が可能となる。
【００１３】
以上示したような充電再開後の電池温度勾配の演算開始を適切に行わないと確実な満充電判別は行えない。
【００１４】
本発明の目的は、上記した従来技術の欠点をなくし、確実な満充電検出及び長寿命化が可能な充電機能付き直流電源装置を提供することである。
【００１５】
【課題を解決するための手段】
かかる目的を達成するため本発明は、着脱可能な電池パックを電源とするコードレス電動工具に着脱可能なアダプタを備えたケーブルを介して直流電圧を供給し、コードレス電動工具不使用時に電池パックを充電するものであって、電池温度を検出する電池温度検出手段と、電池温度検出手段の出力に基づいて電池温度を記憶する電池温度記憶手段と、電池温度検出手段及び電池温度記憶手段の出力に基づいて電池温度勾配を演算する電池温度勾配演算手段と、電池温度勾配演算手段の出力に基づいて電池温度勾配を記憶する電池温度勾配記憶手段とを有し、最新の電池温度勾配が前記電池温度勾配記憶手段の中の最小値より満充電判別値以上上昇した時に満充電と判別して充電を停止する充電機能付き直流電源装置であって、電池パックの充電中にコードレス電動工具が使用されその後コードレス電動工具の使用が停止されて電池パックの充電が再開された際、電池パックが充電停止する際の充電状態に応じて満充電検出動作を充電再開後直ちに行うか、充電再開から所定時間経過後に行うかを選択決定するようにした充電機能付き直流電源装置を提供している。
【００１６】
前記充電停止する際の電池パックの充電状態を、最新の電池温度が満充電判別電池温度値より小さい満充電近傍値以上上昇しているか否かにより判別し、上昇していない時、電池温度勾配の演算を所定時間行わないようにするのが好ましい。
【００１７】
また電池温度でなく電池電圧をベースにすなわち最新の電池温度勾配が第一所定値以上上昇し、その後第一所定値より小さい第二所定値以下になったら満充電と検出する場合、電池パックが充電停止する際の電池電圧勾配が第一所定値以上上昇していない時、充電再開後電池電圧勾配の演算を所定時間行わないようにするのが好ましい。
【００１８】
また電池パックの残容量を検出する電池残容量検出手段を設け、電池パックの充電中にコードレス電動工具が使用されその後コードレス電動工具の使用が停止されて電池パックの充電が再開された際、前記電池残容量検出手段が所定値以上の残容量があると検出した場合、電池温度勾配の演算を連続的に行うようにするのが好ましい。
【００１９】
【発明の実施の形態】
以下本発明の一実施形態を示した図面を参照して説明する。図６は本発明充電機能付き直流電源装置の一実施形態を示す斜視図である。
【００２０】
１はＡＣコード組、２は充電機能付き直流電源装置本体(以下単に電源装置本体という)、３はアダプタ組であり、一端に電動工具４に接続するアダプタプラグ、他端に電源装置本体２に接続する出力ケーブルとを有する。アダプタプラグは、上部が電池パック５の挿入部と同じ形状をしており、電池パック５と同様に電動工具４に着脱可能となっている。
【００２１】
図７は充電機能付き直流電源装置の一実施形態を示すブロック図である。ＡＣコード組１はＡＣ１００Ｖの商用交流電源に接続される。アダプタ組３は複数の電動工具４に対し、各々の定格電圧に対応する電圧を出力させるための出力電圧設定手段３ａを備えている。電動工具４はＤＣモータ４ａ及び直列に接続された電源スイッチ４ｂを内蔵し、電源スイッチ４ｂがオンされた時、アダプタ組３を介して、電源装置本体２から直流電源が供給される。電動工具４に装着可能な電池パック５は、充電可能な蓄電池５ａ及び蓄電池５ａの近傍または接触されて取り付けられる温度素子５ｂ（例えばサーミスタ等）及びセル数判別素子５ｃ（例えばセル数に対応した抵抗値を持つ抵抗等）から構成される。
【００２２】
１０は種々の駆動電圧の電動工具４に対応する所定の駆動電圧及び電池電圧が異なる種々の電池パック５を充電可能な如く所定の充電電流を出力可能なスイッチング電源で、第一整流平滑回路１１、高周波トランス１２、第二整流平滑回路１３、スイッチング素子１４、スイッチング制御回路１５から構成され、スイッチング制御回路１５はスイッチング素子１４の駆動パルス幅を変えて第二整流平滑回路１３の出力電圧及び出力電流を調整する。
【００２３】
電源出力制御手段２０は、電源スイッチ４ｂのオン時に電動工具４の駆動電圧を制御し、電源スイッチ４ｂのオフ時で電池パック５が充電可能な場合に充電電流を制御する電圧・電流制御回路２１、駆動電圧及び充電電流の値を設定する電圧・電流設定回路２２から構成される。電動工具４が駆動している時は、電圧検出回路４２の信号に基づきスイッチング制御回路１５に帰還をかけスイッチング素子１４のスイッチングデューティを制御し、同時に出力電流検出回路４１からの信号に基づきアダプタ組３のケーブルにおける電圧降下分を補正する機能を有する。また電源スイッチ４ｂのオフ時で電池パック５が充電可能な場合は、出力電流検出回路４１からの信号に基づきスイッチング制御回路１５に帰還をかけ、スイッチング素子１４のスイッチングデューティを制御し、電池パック５への充電電流を電池状態検出手段５０の出力に基づいて制御する。
【００２４】
電源出力切り換え手段３０は、電源スイッチ４ｂのオン時に電源出力を電動工具４に供給可能にする電源出力スイッチ回路３１、電動工具４の不使用時に電池パック５への充電を可能にする充電出力スイッチ回路３２から構成される。充電出力スイッチ回路３２は、例えば上記した如くまた特願２００１−１１１０２３で提案した如く、リレー回路から構成される。
【００２５】
電源出力検出手段４０は、電源スイッチ４ｂのオン時に電動工具４に供給される電流または電源スイッチ４ｂのオフ時に電池パック５に供給される充電電流を検出する出力電流検出回路４１、第二整流平滑回路１３の出力電圧を検出する電圧検出回路４２、電源スイッチ４ｂがオンされたことを検出し、その瞬間に充電不許可信号及び電動工具４への電源供給を許可する信号を出力するトリガ検出回路４３、アダプタ組３の出力電圧設定手段３ａの設定電圧を検出する出力電圧設定検出回路４４等から構成される。
【００２６】
電池状態検出手段５０は、蓄電池５ａの電池電圧を検出する電池電圧検出回路５１、電池パック５内の温度素子５ｂの特性に応じて電池温度を検出する電池温度検出回路５２及びセル数判別素子５ｃの抵抗値等に応じてセル数を判別するセル数判別回路５３から構成される。
【００２７】
本発明制御手段を構成するマイコン６０は、電源出力検出手段４０の出力及び電池状態検出手段５０の出力に基づいて、電動工具４の駆動電圧の設定、電動工具４不使用時における電池パック５の充電電流の設定を行うと共に、電動工具４の未使用すなわち電源スイッチ４ｂのオフ及び電池状態検出手段５０の出力に基づき充電可能か否かを判別し、電池パック５が充電可能な時はトリガ検出回路４３を介して充電出力スイッチ回路３２に充電許可信号を出力する等の機能及び、電池温度Ｔｉｎ、電池電圧Ｖｉｎ、電池温度の最小値Ｔｍｉｎ、電池温度勾配ｄＴ／ｄｔ、電池電圧勾配の最小値ｄＴ／ｄｔ（ｍｉｎ）、電池電圧勾配ΔＶ、電池電圧勾配の最小値ΔＶｍｉｎ等を記憶するＲＡＭ、最新の電池温度と所定サンプリング前の電池温度から電池温度勾配を、又、最新の電池電圧と所定サンプリング前の電池電圧から電池電圧勾配を演算する機能を有する。
【００２８】
例えばＬＥＤ等から構成される表示回路７０は、マイコン６０の出力に基づいて、電動工具４が使用中、電動工具４が使用可能か否かの表示、または電池パック５が充電中であること等を表示する。補助電源回路８０は、マイコン６０等の電源及び電源出力制御手段２０、電源出力検出手段４０及び電池状態検出手段５０等へ基準電圧Ｖｃｃを供給する。
【００２９】
次に図７のブロック図、図８〜図１１のフローチャートを参照して本発明充電機能付き電源装置の動作を説明する。ＡＣコード組１をＡＣ１００Ｖの商用交流電源に接続すると、補助電源回路８０が起動し、マイコン６０及び電源出力制御手段２０等に基準電圧Ｖｃｃを供給する。マイコン６０は記憶手段であるＲＡＭ内の充電完了フラグ、充電中フラグ、電源スイッチ４ｂがオンされたことを示すトリガ検出フラグ、電動工具使用後に充電が再開された時の電池温度勾配の演算を連続的に行うためのｄＴ/ｄｔ連続フラグ、電池電圧検出による満充電判別用のΔＶフラグ、電池パック５が電源装置本体２の電池パック挿入口に挿入されたことを示す電池パックフラグ及び負荷電流零カウンタをリセットすると共に電源出力切り換え手段３０の充電出力スイッチ回路３２をオフさせる信号を出力してイニシャルセットを行う（ステップ７０１）。続いて、マイコン６０はスイッチング電源１０のスイッチング制御回路１５にスイッチング電源１０が起動する信号を出力し（ステップ７０２）、電動工具４の電源スイッチ４ｂがオンした時は、電源出力検出手段４０のトリガ検出回路４３が電源出力切り換え手段３０の電源出力スイッチ回路３１をオンさせ、電動工具４の定格電圧に対応する所定の駆動電圧を供給する。
【００３０】
マイコン６０は、電池状態検出手段５０の電池電圧検出回路５１及び電池温度検出回路５２の出力に基づいて、電池パック５が電源装置本体２に挿入されているか否かを判別し（ステップ７０３）、電池パック５が挿入されていると判別した時は、電池パックフラグがセットされているか否かを判別する（ステップ７０５）。ステップ７０５において電池パックフラグがセットされていない場合は電池パックフラグをセットし（ステップ７０６）、電池電圧検出回路５１より充電開始前の電池電圧Ｖ０を検出し（ステップ７０７）、電池パック５内の抵抗値５ｃに応じてセル数判別回路５３からセル数ｎを判別する（ステップ７０８）。次に、ステップ７０７及びステップ７０８において検出した充電開始前の電池電圧Ｖ０及びセル数ｎよりセル当たりの電池電圧を演算し、セル当たりの電池電圧が１．４０Ｖ以上であるか否かを判別する（ステップ７０９）。ステップ７０９において、セル当たりの電池電圧が１．４０Ｖ以上であれば、電池パック５は満充電近傍（電池残容量が多い）であると判別し、電動工具使用後、充電を再開した時にｄＴ／ｄｔを連続的に演算するために、ｄＴ／ｄｔ連続フラグをセットする（ステップ７１０）。ステップ７０９において、セル当たりの電池電圧が１．４０Ｖ以上でなければ電池残容量が多くないと判別しステップ７１１にジャンプする。
【００３１】
ステップ７０３において電池パック５が挿入されていない時は、ＲＡＭ内の充電完了フラグ、充電中フラグ、電池パックフラグ、ｄＴ/ｄｔ連続フラグ、トリガ検出フラグ、ΔＶフラグ及び負荷電流零カウンタをリセットする（ステップ７０４）。続いて、電源スイッチ４ｂがオフされたかを判別するため、出力電流検出回路４１の出力に基づいて、負荷電流が零か否かを判別する（ステップ７１１）。
【００３２】
負荷電流が零の場合、電池パック５が電源装置本体２に挿入されているか否かを判別し（ステップ７１２）、電池パック５が電源装置本体２に挿入されてない場合は再度ステップ７０３に戻る。
【００３３】
ステップ７１２において電池パック５が挿入されている時は、電池パック５が充電完了しているか否かを判別し（ステップ７１３）、充電完了の時は再度ステップ７０３に戻る。
【００３４】
ステップ７１３において電池パック５が充電完了状態でない場合は、電池パック５が充電中であるか否かを判別し（ステップ７１４）、充電中でない場合は、電池パック５が充電すべきでない高温であるか否かの判別を、電池温度検出回路５２の出力に基づいて行い(ステップ７１５)、電池パック５が高温の時は再度ステップ７０３に戻る。
【００３５】
ステップ７１５において電池パック５が高温でない時は、引き続きトリガ検出回路４３の出力に基づいて、電源スイッチ４ｂがオンされたか否かを監視し(ステップ７１６)、ステップ７１６において電源スイッチ４ｂがオンされていない場合は所定の充電電流に制御すべく、電圧・電流設定回路２２に信号を出力し充電電流を設定する（ステップ７１７）。次いで、トリガ検出回路４３及び充電出力スイッチ回路３２に充電許可信号を出力し（ステップ７１９）、トリガ検出回路４３を介して電源出力スイッチ回路３１をオフさせると同時に、充電出力スイッチ回路３２をオンさせて充電を開始し、充電中フラグをセットし(ステップ７２０)、ステップ７０３に戻る。
【００３６】
ステップ７１１において負荷電流が零でない場合は、負荷電流零カウンタをクリアし（ステップ７２１）、引き続きトリガ検出回路４３の出力に基づいて、電源スイッチ４ｂがオンされたか否かを監視する(ステップ７２２)。ステップ７２２において電源スイッチ４ｂがオンされている場合は、トリガ検出フラグをセットし（ステップ７２３）、次いで、充電中フラグがあるか否かを判別し（ステップ７２４）、充電中フラグがある場合は、ステップ７１６にジャンプする。充電中フラグがない場合はステップ７１２に戻る。
【００３７】
ステップ７２２において、電源スイッチ４ｂがオンされてない場合はステップ７３０にジャンプして電池パック５の満充電近傍判別及び満充電判別処理に必要なデータ処理を行う。まず充電中における電池パック５の最新の電池温度Ｔinを電池温度検出回路５２よりＲＡＭに取込む（ステップ７３０）。また、演算した最新の電池温度勾配Ｔinのデータを比較することにより、電池温度の最小値Ｔ（min）を演算し記憶する（ステップ７３１）。引き続き、電池パック５の最新の電池電圧Ｖｉｎを電池電圧検出回路５１よりＲＡＭに取込む（ステップ７３２）。
【００３８】
さらに、電池電圧検出回路５１より所定サンプリング幅の最新の電池電圧勾配ΔＶを演算し（ステップ７３３）、演算した電池電圧勾配ΔＶのデータを比較することにより、所定サンプリング幅の電池電圧勾配の最小値ΔＶminを演算し記憶する（ステップ７３４）。
【００３９】
次に、ｄＴ/ｄｔ連続フラグが有るか否かを判別する（ステップ７３５）。ステップ７３５において、ｄＴ/ｄｔ連続フラグが有る場合はステップ７３９にジャンプする。ｄＴ/ｄｔ連続フラグが無い場合は、トリガ検出フラグが有るか否かを判別する（ステップ７３６）。ステップ７３６において、トリガ検出フラグが無い場合はステップ７３９にジャンプする。トリガ検出フラグが有る場合は、充電再開後所定時間Ｕ経過したか否かを判別する（ステップ７３７）。ステップ７３７において、充電再開後所定時間Ｕ経過していない場合は、電池温度勾配による満充電判別を行わないようにするため、ステップ７４４にジャンプする。充電再開後所定時間Ｕ経過している場合は、トリガ検出フラグをクリアする（ステップ７３８）。
【００４０】
次いで、電池温度検出回路５２がサンプリングした充電中の電池温度データから所定サンプリング幅の最新の電池温度勾配ｄＴ／ｄｔを演算し（ステップ７３９）、演算した最新の電池温度勾配ｄＴ／ｄｔのデータを比較することにより、所定サンプリング幅の電池温度勾配ｄＴ／ｄｔの最小値ｄＴ／ｄｔ（min）を演算し記憶する（ステップ７４０）。
【００４１】
次に、最新の電池温度勾配ｄＴ／ｄｔが、電池温度勾配最小値ｄＴ／ｄｔ（min）から前記所定値Ｑ１以上上昇したか否かの判別を行い（ステップ７４１）、所定値Ｑ１以上上昇した場合、電池パック５が満充電近傍と判別し、この場合の充電完了までの時間が、満充電近傍なので短かくなっていると判断し、ｄＴ/ｄｔ連続フラグをセットし（ステップ７４３）、ステップ７４４に進む。ステップ７４１において、最新の電池温度勾配ｄＴ／ｄｔが、電池温度勾配最小値ｄＴ／ｄｔ（min）から前記所定値Ｑ１以上上昇していない場合は、ステップ７４２に進み最新の電池温度勾配ｄＴ／ｄｔが、電池温度勾配最小値ｄＴ／ｄｔ（min）から満充電判別値Ｑ２（Ｑ２＞Ｑ１）以上上昇したか否かの判別を行い、満充電判別値Ｑ２以上上昇した場合は満充電と判別し、充電中フラグをリセットする（ステップ７２７）と共に充電完了フラグをセットし（ステップ７２８）、充電出力スイッチ回路３２をオフして（ステップ７２９）充電を停止し、再びステップ７０３に戻る。
【００４２】
ステップ７４２において、最新の電池温度勾配値ｄＴ／ｄｔが電池温度勾配最小値ｄＴ／ｄｔ（min）から満充電判別値Ｑ２以上上昇していない場合は、最新の電池電圧勾配ΔＶが、電池電圧勾配最小値ΔＶminから予め設定した所定値Ｒ１以上上昇したか否かの判別を行い（ステップ７４４）、所定値Ｒ１以上上昇した場合、電池パック２は満充電近傍と判別し、ＲＡＭのΔＶＦｌａｇを１にセットし（ステップ７４６）、この場合の充電完了までの時間が満充電近傍なので短かくなっていると判断し、ｄＴ/ｄｔ連続フラグをセットし（ステップ７４７）、その後ステップ７４８の処理を行う。
【００４３】
ステップ７４４において、最新の電池電圧勾配ΔＶが、電池電圧勾配最小値ΔＶminから所定値Ｒ１以上上昇していない場合は、最新の電池温度Ｔｉｎが、電池温度最小値Ｔｍｉｎから予め設定した所定値Ｐ１以上上昇したか否かの判別を行い（ステップ７４５）、所定値Ｐ１以上上昇した場合は、充電完了までの時間が満充電近傍なので短かくなっていると判断し、ｄＴ/ｄｔ連続フラグをセットし（ステップ７４７）、その後ステップ７４８の処理を行う。
【００４４】
ステップ７４５において、最新の電池温度Ｔｉｎが、電池温度最小値Ｔｍｉｎから所定値Ｐ１以上上昇していない場合は、最新の電池温度Ｔｉｎが、電池温度最小値Ｔｍｉｎから予め設定した所定値Ｐ２（Ｐ２＞Ｐ１）以上上昇したか否かの判別を行い（ステップ７４８）、Ｐ２以上上昇している場合は、満充電と判別し（図１２参照）、ステップ７２７以降の処理を行い充電を終了する。ステップ７４８において、最新の電池温度Ｔｉｎが、電池温度最小値Ｔｍｉｎから所定値Ｐ２以上上昇していない場合は、ΔＶフラグがセットされているか否かを判別し（ステップ７４９）、セットされていない場合はステップ７０３に戻る。ステップ７４９においてΔＶフラグがセットされている場合は、最新の電池電圧勾配ΔＶが所定値Ｒ２（Ｒ１＞Ｒ２）以下になったか否かの判別を行い（ステップ７５０）、所定値Ｒ２以下の場合は満充電と判別し（図１３参照）、ステップ７２７以降の処理を行い充電を終了する。ステップ７５０において、最新の電池電圧勾配ΔＶが所定値Ｒ２以下でない場合はステップ７０３に戻る。
【００４５】
ステップ７１４において、電池パック５が充電中の場合、すなわちここでは、充電中に電源スイッチ４ｂが一度オンされ、その後電源スイッチ４ｂがオフされた時、負荷電流零カウンタをスタートし（ステップ７２５）、次いで負荷電流零の状態が連続してすなわち電動工具４の連続不使用時間が所定時間経過したか否かを判別、すなわち連続で電源スイッチ４ｂがオフされているか否かを判別し（ステップ７２６）、所定時間経過した時は、電池パック５の充電を再開すべく、ステップ７１６にスキップする。なおこの所定時間は、例えば満充電判別のための電池電圧や電池温度のサンプリング時間または電動工具４の実際の使用形態を考慮して設定するのが望ましく、一例を挙げれば１分である。
【００４６】
ステップ７２６において、負荷電流零の状態が連続で所定時間経過していない場合は、引き続きトリガ検出回路４３及び充電出力スイッチ回路３２に充電不許可信号を出力し（ステップ７５１）、次いで電池パック５が電源装置本体２に挿入されているか否かを判別し（ステップ７５２）、電池パック５が電源装置本体２に挿入されていない場合はステップ７０３に戻り、電池パック５が挿入されている時は、充電中に電源スイッチ４ｂが一度オンされ、充電を行っていない状態でも連続的に満充電判別をすべく、満充電近傍判別及び満充電判別処理に必要なデータ処理を行う。
【００４７】
まず充電中における電池パック５の最新の電池温度Ｔinを電池温度検出回路５２よりＲＡＭに取込む（ステップ７５３）。また、演算した最新の電池温度勾配Ｔinのデータを比較することにより、電池温度の最小値Ｔ（min）を演算し記憶する（ステップ７５４）。
【００４８】
電池温度検出回路５２がサンプリングした充電中の電池温度データから所定サンプリング幅の最新の電池温度勾配ｄＴ／ｄｔを演算し（ステップ７５５）、最新の電池温度勾配ｄＴ／ｄｔのデータを比較することにより、所定サンプリング幅の電池温度勾配ｄＴ／ｄｔの最小値ｄＴ／ｄｔ（min）を演算し記憶する（ステップ７５６）。
【００４９】
次に、最新の電池温度勾配ｄＴ／ｄｔが、電池温度勾配最小値ｄＴ／ｄｔ（min）から所定値Ｑ１以上上昇したか否かの判別を行い（ステップ７５７）、所定値Ｑ１以上上昇した場合は、電池パック２は満充電近傍と判別し、この場合の充電完了までの時間が満充電近傍なので短かくなっていると判断し、ｄＴ/ｄｔ連続フラグをセットし（ステップ７５９）、その後ステップ７６０の処理を行う。ステップ７５７において、最新の電池温度勾配ｄＴ／ｄｔが、電池温度勾配最小値ｄＴ／ｄｔ（min）から所定値Ｑ１以上上昇していない場合は、最新の電池温度Ｔｉｎが、電池温度最小値Ｔｍｉｎから所定値Ｐ１以上上昇したか否かの判別を行い（ステップ７５８）、所定値Ｐ１以上上昇した場合は、電池パック２が満充電近傍と判別し、充電完了までの時間が短かくなっていると判断し、ｄＴ/ｄｔ連続フラグをセットし（ステップ７５９）、その後ステップ７６０の処理を行う。ステップ７５８において、最新の電池温度Ｔｉｎが、電池温度最小値Ｔｍｉｎから所定値Ｐ１以上上昇していない場合は、最新の電池温度Ｔｉｎが、電池温度最小値Ｔｍｉｎから所定値Ｐ２以上上昇したか否かの判別を行い（ステップ７６０）、Ｐ２以上上昇の場合は満充電と判別し、ステップ７２７以降の処理を行い充電を終了する。
【００５０】
ステップ７６０において、最新の電池温度Ｔｉｎが、電池温度最小値Ｔｍｉｎから所定値Ｐ２以上上昇していない場合は、最新の電池温度勾配ｄＴ／ｄｔが、電池温度勾配最小値ｄＴ／ｄｔ（min）から満充電判別値Ｑ２以上上昇したか否かの判別を行い（ステップ７６１）、満充電判別値Ｑ２以上上昇した場合は、満充電と判別し、ステップ７２７以降の処理を行い充電を終了する。
【００５１】
ステップ７６１において、最新の電池温度勾配ｄＴ／ｄｔが、電池温度勾配最小値ｄＴ／ｄｔ（min）から満充電判別値Ｑ２以上上昇していない場合はステップ７０３に戻る。
【００５２】
【発明の効果】
以上のように本発明によれば、電動工具使用後に充電を再開する時、電池温度又は電池温度勾配又は電池電圧から満充電間際であると判別されていない場合は、充電再開後の電池温度勾配の演算を所定時間行わないようにすることにより、より確実な満充電検出が可能となる。
【図面の簡単な説明】
【図１】本発明直流電源装置の充電制御説明用グラフ。
【図２】本発明直流電源装置の充電制御説明用グラフ。
【図３】本発明直流電源装置の充電制御説明用グラフ。
【図４】本発明直流電源装置の充電制御説明用グラフ。
【図５】本発明直流電源装置の充電制御説明用グラフ。
【図６】本発明直流電源装置の一実施形態を示す斜視図。
【図７】本発明直流電源装置の一実施形態を示すブロック図
【図８】本発明直流電源装置の動作説明用フローチャート。
【図９】本発明直流電源装置の動作説明用フローチャート。
【図１０】本発明直流電源装置の動作説明用フローチャート。
【図１１】本発明直流電源装置の動作説明用フローチャート。
【図１２】本発明直流電源装置の充電制御説明用グラフ。
【図１３】本発明直流電源装置の充電制御説明用グラフ。
【符号の説明】
２は電源装置本体、３はアダプタ組、４は電動工具、５は電池パック、１０はスイッチング電源、２０は電源出力制御手段、３０は電源出力切り換え手段、４０は電源出力検出手段、４３はトリガ検出回路、５０は電池状態検出回路、５２は電池温度検出手段、６０はマイコンである。[0001]
[Technical field to which the invention belongs]
The present invention provides a charging function capable of supplying a DC voltage via a cable having a detachable adapter to a cordless power tool (hereinafter simply referred to as a power tool) using a detachable battery pack as a power source and charging the battery pack. The present invention relates to a direct current power supply device.
[0002]
[Prior art]
Conventionally, power tools have the advantage of being able to work in any location without any power cable restrictions, but when the capacity of the battery pack decreases, the battery pack is charged or another charged battery There was a problem that it had to be replaced with a pack. Therefore, a DC power source that converts AC to DC is used when the work location is close to the AC power supply installation location and there is little movement during work, and a battery is used when the work location is far from the AC power supply installation location and there is much movement during work. A battery pack and a DC power source were used together as a power source for the electric tool in accordance with the work situation.
[0003]
However, there is a problem that efficient work cannot be performed unless a charger and a DC power supply are brought into the work place. In order to solve these problems, the function of the power tool is detected. When the power tool is operating, it is supplied with DC power without being charged. When the power tool is stopped, the battery pack is charged. A direct-current power supply device was proposed in Japanese Patent Application Laid-Open No. H10-228707.
[0004]
[Patent Document 1]
JP 2000-184614 A
[0005]
[Problems to be solved by the invention]
In the DC power supply with a charging function disclosed in Patent Document 1, when full charge detection is performed based on a battery temperature gradient, it may not be possible to reliably determine full charge by simply detecting the battery temperature gradient. This is because the battery pack being charged is forcibly cooled by the cooling fan in the charging unit of the DC power supply device, and this will be described with reference to FIGS. 1 to 5 are graphs showing changes in battery voltage, battery temperature, battery temperature gradient (A / D conversion value), and charging current during charging under the respective conditions.
[0006]
FIG. 1 shows a case where no power tool is used during charging. When the latest battery temperature gradient rises from the minimum value of the battery temperature gradient by a predetermined value (hereinafter referred to as full charge determination value) Q2 or more, it is determined that the battery is fully charged and charging is terminated. FIG. In this state, charging is stopped.
[0007]
FIG. 2 shows a case where the electric power tool is used at the time when the battery temperature gradient rises by more than a predetermined value Q1 (Q2> Q1) close to the full charge discriminating value Q2 during charging, that is, the battery is charged to the vicinity of full charge The state where the battery temperature gradient calculation is performed simultaneously with the resumption of charging after using the tool and the full charge is accurately determined is shown.
[0008]
FIG. 3 shows a case where the power tool is used at the time when the battery temperature gradient does not rise above the predetermined value Q1 during charging, that is, the battery is not charged to near full charge. Since the temperature gradient calculation is performed, the battery temperature decreases when the power tool is used, but the battery temperature gradient rapidly increases from the relative increase in battery temperature after resumption of charging, and increases above the full charge determination value Q2, A case in which charging is erroneously determined as full charging and charging is stopped due to insufficient charging is shown.
[0009]
4 and 5 show a case in which the power tool is used during charging and the calculation of the battery temperature gradient is not performed for a predetermined time when the charging is restarted after that. FIG. When the electric tool is used at the time when it rises by a predetermined value Q1 or more and then the use is stopped and the charging is resumed, the battery temperature gradient calculation is not performed for a predetermined time.
[0010]
FIG. 5 shows that the battery temperature gradient calculation is not performed for a predetermined time when the power tool is used at the time when the battery temperature gradient does not rise above the predetermined value Q1 during charging, and then the use is stopped and charging is resumed. The case where charging was correctly identified is shown.
[0011]
As described above, when the battery temperature gradient is increased by more than the predetermined value Q1 during charging, that is, when the electric tool is used in the vicinity of the full charge and then the charging is resumed, as shown in FIG. If the calculation is not performed for a predetermined time, the battery is overcharged for the predetermined time.
[0012]
On the other hand, when the electric power tool is used when the battery temperature gradient does not increase by more than the predetermined value Q1 during charging, that is, when the battery is not charged to near full charge, and when charging is resumed thereafter, the battery as shown in FIG. If the temperature gradient calculation is performed continuously, the battery temperature decreases when the battery is not being charged, so the battery temperature gradient also decreases. Suddenly rises and rises by more than the full charge discriminating value Q2. Therefore, as shown in FIG. 5, if the battery temperature gradient calculation is not performed for a predetermined time when charging is resumed, the above-described rapid increase in the battery temperature gradient is eliminated, and reliable full charge determination becomes possible.
[0013]
If the calculation of the battery temperature gradient after the resumption of charging as described above is not properly performed, the full charge determination cannot be performed reliably.
[0014]
An object of the present invention is to provide a DC power supply device with a charging function that eliminates the above-mentioned drawbacks of the prior art and enables reliable full charge detection and long life.
[0015]
[Means for Solving the Problems]
  In order to achieve such an object, the present invention provides a cordless power tool that supplies a DC voltage via a cable having a detachable adapter to a cordless power tool that uses a detachable battery pack as a power source.BadA battery pack for charging a battery pack during use, a battery temperature detecting means for detecting a battery temperature, a battery temperature storing means for storing a battery temperature based on an output of the battery temperature detecting means, a battery temperature detecting means, and a battery temperature A battery temperature gradient calculating means for calculating a battery temperature gradient based on the output of the storage means; and a battery temperature gradient storing means for storing the battery temperature gradient based on the output of the battery temperature gradient calculating means. A DC power supply device with a charging function that determines a full charge and stops charging when the gradient rises more than a full charge determination value from a minimum value in the battery temperature gradient storage means, the cordless electric power supply during charging of the battery pack When the tool is used and then the use of the cordless power tool is stopped and charging of the battery pack is resumed, the full charge detection operation is performed according to the state of charge when the battery pack stops charging. Whether performed immediately after charging restarts provides a charging function DC power supply device so as to select and determine whether to perform the charging resumed after a predetermined time has elapsed.
[0016]
The state of charge of the battery pack when the charging is stopped is determined by whether or not the latest battery temperature has risen by a value near the full charge that is smaller than the full charge determination battery temperature value. It is preferable not to perform the calculation ofYes.
[0017]
If the battery pack is detected based on the battery voltage instead of the battery temperature, that is, when the latest battery temperature gradient rises above the first predetermined value and then falls below the second predetermined value smaller than the first predetermined value, When the battery voltage gradient at the time of stopping charging is not increased by the first predetermined value or more, it is preferable not to perform the calculation of the battery voltage gradient after the resumption of charging for a predetermined time.
[0018]
The battery remaining capacity detecting means for detecting the remaining capacity of the battery pack is provided, and when the cordless power tool is used during charging of the battery pack, and then the use of the cordless power tool is stopped and the charging of the battery pack is resumed, When the battery remaining capacity detection means detects that there is a remaining capacity equal to or greater than a predetermined value, it is preferable to continuously calculate the battery temperature gradient.
[0019]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, an embodiment of the present invention will be described with reference to the drawings. FIG. 6 is a perspective view showing an embodiment of a DC power supply device with a charging function according to the present invention.
[0020]
1 is an AC cord set, 2 is a DC power supply main body with a charging function (hereinafter simply referred to as a power supply main body), 3 is an adapter set, one end is an adapter plug connected to the electric tool 4, and the other end is connected to the power supply main body 2 And an output cable to be connected. The upper part of the adapter plug has the same shape as the insertion part of the battery pack 5 and can be attached to and detached from the electric tool 4 in the same manner as the battery pack 5.
[0021]
FIG. 7 is a block diagram showing an embodiment of a DC power supply device with a charging function. The AC cord set 1 is connected to an AC 100V commercial AC power source. The adapter set 3 includes output voltage setting means 3a for outputting a voltage corresponding to each rated voltage to the plurality of power tools 4. The electric power tool 4 includes a DC motor 4a and a power switch 4b connected in series. When the power switch 4b is turned on, DC power is supplied from the power supply device body 2 via the adapter set 3. The battery pack 5 that can be attached to the electric tool 4 includes a rechargeable storage battery 5a, a temperature element 5b (for example, a thermistor) that is attached in the vicinity of or in contact with the storage battery 5a, and a cell number determination element 5c (for example, a resistance corresponding to the number of cells). A resistor having a value).
[0022]
Reference numeral 10 denotes a switching power source capable of outputting a predetermined charging current so that various battery packs 5 having different predetermined driving voltages and battery voltages corresponding to the electric tools 4 having various driving voltages can be charged. , A high-frequency transformer 12, a second rectifying / smoothing circuit 13, a switching element 14, and a switching control circuit 15. The switching control circuit 15 changes the drive pulse width of the switching element 14 and outputs the output voltage and output of the second rectifying / smoothing circuit 13. Adjust the current.
[0023]
The power output control means 20 controls the drive voltage of the electric tool 4 when the power switch 4b is turned on, and controls the charging current when the battery pack 5 can be charged when the power switch 4b is turned off. And a voltage / current setting circuit 22 for setting values of the driving voltage and the charging current. When the power tool 4 is driven, the switching control circuit 15 is fed back based on the signal from the voltage detection circuit 42 to control the switching duty of the switching element 14, and at the same time, the adapter assembly is set based on the signal from the output current detection circuit 41. 3 has a function of correcting a voltage drop in the cable 3. Further, when the battery pack 5 can be charged when the power switch 4b is turned off, feedback is given to the switching control circuit 15 based on a signal from the output current detection circuit 41 to control the switching duty of the switching element 14, and the battery pack 5 The charging current is controlled based on the output of the battery state detecting means 50.
[0024]
  The power output switching means 30 includes a power output switch circuit 31 that enables the power output to be supplied to the power tool 4 when the power switch 4b is turned on.BadThe battery pack 5 includes a charge output switch circuit 32 that enables charging of the battery pack 5 when in use. The charge output switch circuit 32 includes a relay circuit, for example, as described above and as proposed in Japanese Patent Application No. 2001-111023.
[0025]
The power output detection means 40 includes an output current detection circuit 41 for detecting a current supplied to the electric tool 4 when the power switch 4b is turned on or a charging current supplied to the battery pack 5 when the power switch 4b is turned off. A voltage detection circuit 42 that detects the output voltage of the circuit 13, a trigger detection circuit that detects that the power switch 4 b is turned on and outputs a charging non-permission signal and a signal that permits power supply to the power tool 4 at that moment. 43, an output voltage setting detection circuit 44 for detecting the set voltage of the output voltage setting means 3a of the adapter set 3 and the like.
[0026]
The battery state detection means 50 includes a battery voltage detection circuit 51 that detects the battery voltage of the storage battery 5a, a battery temperature detection circuit 52 that detects the battery temperature according to the characteristics of the temperature element 5b in the battery pack 5, and a cell number determination element 5c. The cell number discriminating circuit 53 discriminates the number of cells according to the resistance value of the cell.
[0027]
  The microcomputer 60 constituting the control means of the present invention sets the drive voltage of the electric tool 4 based on the output of the power output detection means 40 and the output of the battery state detection means 50, and sets the electric tool 4.BadWhile setting the charging current of the battery pack 5 at the time of use, it is determined whether or not charging is possible based on the unused state of the electric tool 4, that is, the power switch 4b is turned off and the output of the battery state detecting means 50. When charging is possible, a function of outputting a charge permission signal to the charge output switch circuit 32 via the trigger detection circuit 43, and the like, battery temperature Tin, battery voltage Vin, battery temperature minimum value Tmin, battery temperature gradient dT / dt RAM for storing battery voltage gradient minimum value dT / dt (min), battery voltage gradient ΔV, battery voltage gradient minimum value ΔVmin, etc., battery temperature gradient from latest battery temperature and battery temperature before predetermined sampling, The battery voltage gradient is calculated from the latest battery voltage and the battery voltage before the predetermined sampling.
[0028]
  For example, the display circuit 70 constituted by LEDs or the like is based on the output of the microcomputer 60 to indicate whether or not the electric power tool 4 is in use, the electric power tool 4 is usable, or that the battery pack 5 is being charged. Is displayed. The auxiliary power circuit 80 includes a power source for the microcomputer 60 and the like, a power source output control unit 20, a power source output detection unit 40, a battery state detection unit 50, and the like.WhatA reference voltage Vcc is supplied.
[0029]
Next, the operation of the power supply device with a charging function according to the present invention will be described with reference to the block diagram of FIG. 7 and the flowcharts of FIGS. When the AC cord set 1 is connected to a commercial AC power supply of AC100V, the auxiliary power supply circuit 80 is activated to supply the reference voltage Vcc to the microcomputer 60, the power supply output control means 20, and the like. The microcomputer 60 continuously calculates a charging completion flag in the RAM as a storage means, a charging flag, a trigger detection flag indicating that the power switch 4b is turned on, and a battery temperature gradient when charging is resumed after using the power tool. DT / dt continuous flag to perform automatically, a ΔV flag for full charge determination by battery voltage detection, a battery pack flag indicating that the battery pack 5 has been inserted into the battery pack insertion port of the power supply body 2, and zero load current The counter is reset and a signal for turning off the charging output switch circuit 32 of the power output switching means 30 is output to perform initial setting (step 701). Subsequently, the microcomputer 60 outputs a signal for starting the switching power supply 10 to the switching control circuit 15 of the switching power supply 10 (step 702), and when the power switch 4b of the power tool 4 is turned on, the trigger of the power supply output detecting means 40 is triggered. The detection circuit 43 turns on the power output switch circuit 31 of the power output switching means 30 and supplies a predetermined drive voltage corresponding to the rated voltage of the electric tool 4.
[0030]
  The microcomputer 60 determines whether or not the battery pack 5 is inserted in the power supply main body 2 based on the outputs of the battery voltage detection circuit 51 and the battery temperature detection circuit 52 of the battery state detection means 50 (step 703). When it is determined that the battery pack 5 is inserted, it is determined whether or not the battery pack flag is set (step 705). If the battery pack flag is not set in step 705, the battery pack flag is set (step 706),Battery voltage detection circuit 51Then, the battery voltage V0 before the start of charging is detected (step 707), and the cell number n is determined from the cell number determination circuit 53 according to the resistance value 5c in the battery pack 5 (step 708). Next, the battery voltage per cell is calculated from the battery voltage V0 before the start of charging detected in step 707 and step 708 and the number n of cells, and it is determined whether or not the battery voltage per cell is 1.40V or more. (Step 709). In step 709, if the battery voltage per cell is 1.40 V or more, it is determined that the battery pack 5 is near full charge (the remaining battery capacity is large), and dT / when charging is resumed after using the power tool. In order to continuously calculate dt, a dT / dt continuous flag is set (step 710). In step 709, if the battery voltage per cell is not 1.40V or more, it is determined that the remaining battery capacity is not large, and the process jumps to step 711.
[0031]
When the battery pack 5 is not inserted in step 703, the charge completion flag, the charging flag, the battery pack flag, the dT / dt continuous flag, the trigger detection flag, the ΔV flag, and the zero load current counter in the RAM are reset ( Step 704). Subsequently, in order to determine whether or not the power switch 4b is turned off, it is determined whether or not the load current is zero based on the output of the output current detection circuit 41 (step 711).
[0032]
If the load current is zero, it is determined whether or not the battery pack 5 is inserted in the power supply main body 2 (step 712). If the battery pack 5 is not inserted in the power supply main body 2, the process returns to step 703 again. .
[0033]
When the battery pack 5 is inserted in step 712, it is determined whether or not the battery pack 5 is fully charged (step 713), and when charging is completed, the process returns to step 703 again.
[0034]
If the battery pack 5 is not fully charged in step 713, it is determined whether or not the battery pack 5 is being charged (step 714). If not, the battery pack 5 is at a high temperature that should not be charged. Is determined based on the output of the battery temperature detection circuit 52 (step 715). When the battery pack 5 is hot, the process returns to step 703 again.
[0035]
When the battery pack 5 is not at a high temperature in step 715, whether or not the power switch 4b is turned on is continuously monitored based on the output of the trigger detection circuit 43 (step 716), and the power switch 4b is turned on in step 716. If not, a signal is output to the voltage / current setting circuit 22 to set the charging current so as to control to a predetermined charging current (step 717). Next, a charge permission signal is output to the trigger detection circuit 43 and the charge output switch circuit 32 (step 719), the power output switch circuit 31 is turned off via the trigger detection circuit 43, and at the same time the charge output switch circuit 32 is turned on. The charging is started, the charging flag is set (step 720), and the process returns to step 703.
[0036]
If the load current is not zero in step 711, the zero load current counter is cleared (step 721), and it is continuously monitored whether or not the power switch 4b is turned on based on the output of the trigger detection circuit 43 (step 722). . If the power switch 4b is turned on in step 722, a trigger detection flag is set (step 723), and then it is determined whether or not there is a charging flag (step 724). , Jump to step 716. If there is no charging flag, the process returns to step 712.
[0037]
In step 722, if the power switch 4b is not turned on, the process jumps to step 730 to perform data processing necessary for determining whether the battery pack 5 is near full charge and full charge. First, the latest battery temperature Tin of the battery pack 5 during charging is taken into the RAM from the battery temperature detection circuit 52 (step 730). Further, by comparing data of the latest battery temperature gradient Tin calculated, a minimum value T (min) of the battery temperature is calculated and stored (step 731). Subsequently, the latest battery voltage Vin of the battery pack 5 is taken into the RAM from the battery voltage detection circuit 51 (step 732).
[0038]
Further, the battery voltage detection circuit 51 calculates the latest battery voltage gradient ΔV having a predetermined sampling width (step 733), and compares the calculated battery voltage gradient ΔV with the minimum value of the battery voltage gradient having a predetermined sampling width. ΔVmin is calculated and stored (step 734).
[0039]
Next, it is determined whether or not there is a dT / dt continuous flag (step 735). If there is a dT / dt continuous flag in step 735, the process jumps to step 739. If there is no dT / dt continuous flag, it is determined whether or not there is a trigger detection flag (step 736). If there is no trigger detection flag in step 736, the process jumps to step 739. If there is a trigger detection flag, it is determined whether or not a predetermined time U has elapsed after resuming charging (step 737). In step 737, if the predetermined time U has not elapsed since the resumption of charging, the routine jumps to step 744 so as not to perform full charge determination based on the battery temperature gradient. If the predetermined time U has elapsed after resuming charging, the trigger detection flag is cleared (step 738).
[0040]
Next, the latest battery temperature gradient dT / dt having a predetermined sampling width is calculated from the battery temperature data during charging sampled by the battery temperature detection circuit 52 (step 739), and the calculated latest battery temperature gradient dT / dt data is calculated. By comparison, the minimum value dT / dt (min) of the battery temperature gradient dT / dt having a predetermined sampling width is calculated and stored (step 740).
[0041]
Next, it is determined whether or not the latest battery temperature gradient dT / dt has increased from the battery temperature gradient minimum value dT / dt (min) by the predetermined value Q1 or more (step 741), and has increased by a predetermined value Q1 or more. In this case, it is determined that the battery pack 5 is in the vicinity of full charge. In this case, it is determined that the time until completion of charging is short because it is close to full charge, and the dT / dt continuous flag is set (step 743). Proceed to 744. In step 741, if the latest battery temperature gradient dT / dt has not risen by more than the predetermined value Q1 from the battery temperature gradient minimum value dT / dt (min), the process proceeds to step 742 and the latest battery temperature gradient dT / dt. Is increased from the battery temperature gradient minimum value dT / dt (min) by a full charge determination value Q2 (Q2> Q1) or more, and if it has increased by a full charge determination value Q2 or more, it is determined to be full charge. The charging flag is reset (step 727) and the charging completion flag is set (step 728), the charging output switch circuit 32 is turned off (step 729), the charging is stopped, and the process returns to step 703 again.
[0042]
In step 742, when the latest battery temperature gradient value dT / dt has not risen from the battery temperature gradient minimum value dT / dt (min) by the full charge determination value Q2 or more, the latest battery voltage gradient ΔV is the battery voltage gradient. It is determined whether or not the predetermined value R1 has increased from the minimum value ΔVmin (step 744). If it has increased by the predetermined value R1 or more, the battery pack 2 is determined to be near full charge, and the ΔVFlag of the RAM is set to 1. Set (step 746), it is determined that the time until the completion of charging in this case is near full charge, so that it is short, a dT / dt continuous flag is set (step 747), and then the processing of step 748 is performed.
[0043]
In step 744, if the latest battery voltage gradient ΔV has not risen from the battery voltage gradient minimum value ΔVmin by a predetermined value R1 or more, the latest battery temperature Tin is the predetermined value P1 or more set in advance from the battery temperature minimum value Tmin. It is determined whether or not it has risen (step 745). If it has risen by a predetermined value P1 or more, it is judged that the time until the completion of charging is short because it is near full charge, and the dT / dt continuous flag is set. (Step 747), and then the process of step 748 is performed.
[0044]
In step 745, if the latest battery temperature Tin has not risen from the battery temperature minimum value Tmin by a predetermined value P1 or more, the latest battery temperature Tin is set to a predetermined value P2 (P2> preset from the battery temperature minimum value Tmin). P1) It is determined whether or not it has risen (step 748). If it has risen by P2 or more, it is determined that the battery is fully charged (see FIG. 12), and the processing after step 727 is performed to complete the charging. In step 748, if the latest battery temperature Tin has not risen from the battery temperature minimum value Tmin by a predetermined value P2 or more, it is determined whether or not the ΔV flag is set (step 749). Returns to step 703. If the ΔV flag is set in step 749, it is determined whether or not the latest battery voltage gradient ΔV is equal to or smaller than a predetermined value R2 (R1> R2) (step 750). It is determined that the battery is fully charged (see FIG. 13), and the processing after step 727 is performed to complete the charging. In step 750, if the latest battery voltage gradient ΔV is not less than or equal to the predetermined value R2, the process returns to step 703.
[0045]
  In step 714, when the battery pack 5 is being charged, that is, here, when the power switch 4b is turned on once during charging and then the power switch 4b is turned off, a zero load current counter is started (step 725), Next, the load current zero state continues, that is, the power tool 4 continues.BadIt is determined whether or not the usage time has elapsed, that is, whether or not the power switch 4b is continuously turned off (step 726). When the predetermined time has elapsed, charging of the battery pack 5 should be resumed. , Skip to step 716. The predetermined time is desirably set in consideration of, for example, the sampling time of the battery voltage and battery temperature for full charge determination or the actual usage pattern of the electric tool 4, and is one minute as an example.
[0046]
In step 726, when the load current is zero and the predetermined time has not elapsed, the charging non-permission signal is continuously output to the trigger detection circuit 43 and the charge output switch circuit 32 (step 751). It is determined whether or not the battery pack 5 is inserted (step 752). If the battery pack 5 is not inserted in the power supply apparatus body 2, the process returns to step 703, and when the battery pack 5 is inserted, The power switch 4b is turned on once during charging, and data processing necessary for full charge determination and full charge determination processing is performed in order to continuously determine full charge even when charging is not being performed.
[0047]
First, the latest battery temperature Tin of the battery pack 5 during charging is taken into the RAM from the battery temperature detection circuit 52 (step 753). Further, the latest battery temperature gradient Tin calculated is compared to calculate and store the minimum battery temperature value T (min) (step 754).
[0048]
By calculating the latest battery temperature gradient dT / dt having a predetermined sampling width from the battery temperature data during charging sampled by the battery temperature detection circuit 52 (step 755) and comparing the data of the latest battery temperature gradient dT / dt. Then, the minimum value dT / dt (min) of the battery temperature gradient dT / dt having a predetermined sampling width is calculated and stored (step 756).
[0049]
Next, it is determined whether or not the latest battery temperature gradient dT / dt has increased by a predetermined value Q1 or more from the battery temperature gradient minimum value dT / dt (min) (step 757). Determines that the battery pack 2 is in the vicinity of full charge, and in this case, it is determined that the time until completion of charging is short because it is close to full charge, and the dT / dt continuous flag is set (step 759). The process of 760 is performed. In step 757, when the latest battery temperature gradient dT / dt has not risen from the battery temperature gradient minimum value dT / dt (min) by a predetermined value Q1 or more, the latest battery temperature Tin is calculated from the battery temperature minimum value Tmin. It is determined whether or not it has risen by a predetermined value P1 or more (step 758). If it has risen by a predetermined value P1 or more, it is determined that the battery pack 2 is in the vicinity of full charge, and the time until charging is completed is short. Judgment is made, the dT / dt continuous flag is set (step 759), and then the processing of step 760 is performed. In step 758, if the latest battery temperature Tin has not risen from the battery temperature minimum value Tmin by a predetermined value P1 or more, whether or not the latest battery temperature Tin has risen from the battery temperature minimum value Tmin by a predetermined value P2 or more. (Step 760), if it is increased by P2 or more, it is determined that the battery is fully charged.
[0050]
In step 760, if the latest battery temperature Tin has not risen from the battery temperature minimum value Tmin by a predetermined value P2 or more, the latest battery temperature gradient dT / dt is determined from the battery temperature gradient minimum value dT / dt (min). It is determined whether or not the full charge determination value Q2 or more has been increased (step 761). If the full charge determination value Q2 or more has been increased, it is determined that the battery has been fully charged, the processing from step 727 is performed, and the charging is terminated.
[0051]
In step 761, when the latest battery temperature gradient dT / dt has not risen from the battery temperature gradient minimum value dT / dt (min) by the full charge determination value Q2 or more, the process returns to step 703.
[0052]
【The invention's effect】
As described above, according to the present invention, when charging is resumed after using the electric tool, if it is not determined that the battery is fully charged from the battery temperature, the battery temperature gradient, or the battery voltage, the battery temperature gradient after the resumption of charging is performed. By not performing this calculation for a predetermined time, it is possible to detect full charge more reliably.
[Brief description of the drawings]
FIG. 1 is a graph for explaining charging control of a DC power supply device of the present invention.
FIG. 2 is a graph for explaining charge control of the DC power supply device of the present invention.
FIG. 3 is a graph for explaining charging control of the DC power supply device of the present invention.
FIG. 4 is a graph for explaining charging control of the DC power supply device of the present invention.
FIG. 5 is a graph for explaining charging control of the DC power supply device of the present invention.
FIG. 6 is a perspective view showing an embodiment of the DC power supply device of the present invention.
FIG. 7 is a block diagram showing an embodiment of the DC power supply device of the present invention.
FIG. 8 is a flowchart for explaining the operation of the DC power supply device of the present invention.
FIG. 9 is a flowchart for explaining the operation of the DC power supply device of the present invention.
FIG. 10 is a flowchart for explaining the operation of the DC power supply device of the present invention.
FIG. 11 is a flowchart for explaining the operation of the DC power supply device of the present invention.
FIG. 12 is a graph for explaining charging control of the DC power supply device of the present invention.
FIG. 13 is a graph for explaining charge control of the DC power supply device of the present invention.
[Explanation of symbols]
2 is a power supply unit body, 3 is an adapter set, 4 is an electric tool, 5 is a battery pack, 10 is a switching power supply, 20 is a power output control means, 30 is a power output switching means, 40 is a power output detection means, 43 is a trigger A detection circuit, 50 is a battery state detection circuit, 52 is a battery temperature detection means, and 60 is a microcomputer.

Claims

DC voltage is supplied via a cable equipped with a detachable adapter to a cordless power tool that uses a detachable battery pack as a power source, and the battery pack is charged when the cordless power tool is not used, and the battery temperature is detected. Battery temperature detecting means, battery temperature storing means for storing the battery temperature based on the output of the battery temperature detecting means, and battery temperature gradient for calculating the battery temperature gradient based on the outputs of the battery temperature detecting means and the battery temperature storing means A battery temperature gradient storage means for storing the battery temperature gradient based on the output of the battery temperature gradient calculation means, the latest battery temperature gradient being fully charged from the minimum value in the battery temperature gradient storage means; It is a DC power supply device with a charging function that determines that it is fully charged when it rises above the discrimination value and stops charging,
When the cordless power tool is used while the battery pack is being charged, and then the use of the cordless power tool is stopped and the charging of the battery pack is resumed, the full charge detection operation is performed according to the charging state when the battery pack stops charging. A direct current power supply device with a charging function, wherein the selection is made immediately after resuming charging or after a predetermined time has elapsed since resuming charging.

DC voltage is supplied via a cable equipped with a detachable adapter to a cordless power tool that uses a detachable battery pack as a power source, and the battery pack is charged when the cordless power tool is not used, and the battery temperature is detected. Battery temperature detecting means, battery temperature storing means for storing the battery temperature based on the output of the battery temperature detecting means, and battery temperature gradient for calculating the battery temperature gradient based on the outputs of the battery temperature detecting means and the battery temperature storing means A battery temperature gradient storage means for storing the battery temperature gradient based on the output of the battery temperature gradient calculation means, the latest battery temperature gradient being fully charged from the minimum value in the battery temperature gradient storage means; It is a DC power supply device with a charging function that determines that it is fully charged when it rises above the discrimination value and stops charging,
When the cordless power tool is used while the battery pack is being charged, and then the use of the cordless power tool is stopped and the battery pack is recharged, the latest battery temperature is greater than or equal to the full charge value that is less than the full charge determination battery temperature value. A DC power supply device with a charging function, wherein the battery temperature gradient is not calculated for a predetermined time when it is not rising.

DC voltage is supplied via a cable equipped with a detachable adapter to a cordless power tool that uses a detachable battery pack as a power source, and the battery pack is charged when the cordless power tool is not used, and the battery voltage is detected. Battery voltage detection means, battery voltage storage means for storing the battery voltage based on the output of the battery voltage detection means, and battery voltage gradient for calculating the battery voltage gradient based on the outputs of the battery voltage detection means and the battery voltage storage means And a battery voltage gradient storage means for storing the battery voltage gradient based on the output of the battery voltage gradient calculation means, and the latest battery voltage gradient rises by a first predetermined value or more, and then the first predetermined value. It is a DC power supply device with a charging function that determines that it is fully charged when it is less than a second predetermined value that is smaller, and stops charging,
When the cordless power tool is used while the battery pack is being charged, and then the use of the cordless power tool is stopped and the battery pack is recharged, when the latest battery voltage gradient does not rise above the first predetermined value, the battery A DC power supply device with a charging function, wherein a voltage gradient is not calculated for a predetermined time.

DC voltage is supplied via a cable equipped with a detachable adapter to a cordless power tool that uses a detachable battery pack as a power source, and the battery pack is charged when the cordless power tool is not used, and the battery temperature is detected. Battery temperature detecting means, battery temperature storing means for storing the battery temperature based on the output of the battery temperature detecting means, and battery temperature gradient for calculating the battery temperature gradient based on the outputs of the battery temperature detecting means and the battery temperature storing means A battery temperature gradient storage means for storing the battery temperature gradient based on the output of the battery temperature gradient calculation means, the latest battery temperature gradient being fully charged from the minimum value in the battery temperature gradient storage means; It is a DC power supply device with a charging function that determines that it is fully charged when it rises above the discrimination value and stops charging,
A battery voltage detecting means for detecting the battery voltage and a battery remaining capacity detecting means for detecting the remaining battery capacity from the output of the battery voltage detecting means at the start of charging are provided, and the cordless electric tool is used after the battery pack is charged. When the use of the cordless power tool is stopped and the charging of the battery pack is resumed, the battery temperature gradient is continuously calculated when the remaining battery capacity detecting means detects that there is a remaining capacity exceeding a predetermined value. charging function DC power supply it said.