JP2004350438A

JP2004350438A - Dc power supply device with charging function

Info

Publication number: JP2004350438A
Application number: JP2003145698A
Authority: JP
Inventors: Takahisa Aradate; 卓央荒舘; Takeshi Takeda; 岳史武田; Shuichi Harada; 秀一原田; Nobuhiro Takano; 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: 2004-12-09
Anticipated expiration: 2023-05-23
Also published as: JP4072727B2

Abstract

【課題】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。
【解決手段】電池温度を検出する電池温度検出手段の出力に基づいて電池温度を記憶し、新たに検出した電池温度及び記憶電池温度から電池温度勾配を演算し、電池温度勾配が満充電判別値以上上昇した時に満充電として充電を停止する充電機能付き直流電源装置において、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。
【選択図】図７An object of the present invention is to provide a DC power supply device with a charging function capable of reliably detecting full charge and extending the life.
A battery temperature is stored based on an output of a battery temperature detecting means for detecting a battery temperature, and a battery temperature gradient is calculated from a newly detected battery temperature and a stored battery temperature. In a DC power supply with a charging function that stops charging as a full charge when the battery pack rises above, 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 charging of the battery pack is restarted. According to the state of charge when the charging of the battery pack is stopped, whether to perform the full charge detection operation immediately after the restart of charging or after a predetermined time has elapsed from the restart of charging is selectively determined.
[Selection diagram] FIG.

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未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。したことを特徴とする充電機能付き直流電源装置。
【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の未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未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等の基準電圧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）、電圧検出回路４２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７２４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の連続未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 OF THE INVENTION
The present invention provides a charging function capable of supplying a DC voltage to a cordless power tool (hereinafter simply referred to as a power tool) using a removable battery pack as a power supply via a cable having a removable adapter and charging the battery pack. The present invention relates to a direct current power supply device with a tag.
[0002]
[Prior art]
Conventionally, power tools have the advantage of being able to work in any place without any restrictions on the operation by the power cable, but when the capacity of the battery pack decreases, the battery pack can be charged or another charged battery can be used. There was a problem that it had to be replaced with a pack. Therefore, use a DC power supply that converts AC to DC when the work place and the AC power supply installation place are close and there is little movement during work. A battery pack and a DC power supply were used together as a power supply for the power tool according to the work situation using a pack.
[0003]
However, there is a problem that efficient work cannot be performed unless a charger and a DC power supply are brought to the work place. To solve these problems, it has a charging function that detects the operation of the power tool, supplies DC power without charging when the power tool is operating, and charges the battery pack when the operation of the power tool is stopped A direct-current power supply device was proposed in Japanese Patent Application Laid-Open No. H11-163,837.
[0004]
[Patent Document 1]
JP 2000-184614 A
[0005]
[Problems to be solved by the invention]
In the DC power supply device with a charging function disclosed in Patent Literature 1, when full charge detection is performed based on a battery temperature gradient, reliable detection of full charge may not be performed by simply detecting the battery temperature gradient. This is because the battery pack being charged in the charging section of the DC power supply device is forcibly cooled by the cooling fan, 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 each condition.
[0006]
FIG. 1 shows a case where no power tool was 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 a full charge determination value) Q2 or more, it is determined that the battery is fully charged and the charging is terminated. This indicates that charging has been stopped.
[0007]
FIG. 2 shows a case in which the power tool is used when the battery temperature gradient rises by a predetermined value Q1 (Q2> Q1) close to the full charge determination value Q2 (Q2> Q1), that is, when the battery is charged to near full charge. This shows a state in which the battery temperature gradient calculation is performed together with the restart of charging after the use of the tool, and the full charge is accurately determined.
[0008]
FIG. 3 shows a case where the power tool is used when the battery temperature gradient does not increase by the predetermined value Q1 or more during charging, that is, when the battery is not charged up to near full charge. Since the temperature gradient calculation was performed, the battery temperature decreases when the power tool is used, but the battery temperature gradient sharply increases due to the relative increase in the battery temperature after the restart of charging, and the full charge determination value Q2 or more increases. This shows a case where charging is erroneously determined to be full and charging is stopped in a state of insufficient charging.
[0009]
FIGS. 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. This shows a case where the power tool is used at the time when the power tool rises by the predetermined value Q1 or more, and then the use is stopped and the charging is restarted.
[0010]
FIG. 5 shows a state in which the power tool is used when the battery temperature gradient does not rise by the predetermined value Q1 or more during charging, and then the battery temperature gradient calculation is not performed for a predetermined time when the use is stopped and charging is restarted. This shows the case where charging was correctly determined.
[0011]
As described above, when the battery temperature gradient rises by the predetermined value Q1 or more during charging, that is, when the power tool is used in the vicinity of the full charge, and then the charging is restarted, 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 power tool is used at the time when the battery temperature gradient does not rise by the predetermined value Q1 or more during charging, that is, when the battery is not charged to near the full charge, and when the charging is resumed thereafter, as shown in FIG. If the temperature gradient calculation is performed continuously, the battery temperature decreases when the battery is not charged, and the battery temperature gradient also decreases. Rapidly rises and rises above the full charge determination value Q2, and is erroneously determined to be full charge, causing early disconnection. Therefore, as shown in FIG. 5, if the battery temperature gradient calculation is not performed for a predetermined time at the time of resuming charging, the above-mentioned rapid rise of the battery temperature gradient is eliminated and reliable full charge determination can be performed.
[0013]
If the calculation of the battery temperature gradient after the restart of charging as described above is not properly performed, it is impossible to reliably determine whether the battery is fully charged.
[0014]
SUMMARY OF THE INVENTION It is an object of the present invention to provide a DC power supply device with a charging function that eliminates the above-mentioned disadvantages of the prior art and that can reliably detect a full charge and extend the life.
[0015]
[Means for Solving the Problems]
In order to achieve this object, the present invention provides a cordless power tool powered by a detachable battery pack, supplying a DC voltage through a cable having a detachable adapter, and charging the battery pack when the cordless power tool is not used. 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, and a battery temperature detecting means based on an output of the battery temperature detecting means and a battery temperature storing means. Battery temperature gradient calculating means for calculating the battery temperature gradient by using a battery temperature gradient calculating means for storing the battery temperature gradient based on the output of the battery temperature gradient calculating means. A DC power supply with a charging function, which determines that the battery is fully charged and stops charging when the charge exceeds a full charge determination value from a minimum value in the storage means. When the cordless power tool is used during powering and then the use of the cordless power tool is stopped and charging of the battery pack is restarted, the full charge detection operation is resumed according to the charging state when the battery pack stops charging. A direct-current power supply device with a charging function is provided which selectively determines whether to perform the charging immediately or after a predetermined time has elapsed from the restart of charging.
[0016]
The state of charge of the battery pack when the charging is stopped is determined based on whether or not the latest battery temperature has increased by a value close to full charge that is smaller than a full charge determination battery temperature value. Is preferably not performed for a predetermined time. A DC power supply with a charging function.
[0017]
When the battery pack is detected as being fully charged when the latest battery temperature gradient rises by a first predetermined value or more and then becomes a second predetermined value or less that is smaller than the first predetermined value based on the battery voltage instead of the battery temperature, the battery pack When the battery voltage gradient at the time of stopping charging has not risen by the first predetermined value or more, it is preferable that the calculation of the battery voltage gradient after charging restart is not performed for a predetermined time.
[0018]
Further, a 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 charging of the battery pack is restarted, When the remaining battery charge detecting means detects that the remaining battery charge is equal to or more than a predetermined value, it is preferable to continuously calculate the battery temperature gradient.
[0019]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, an embodiment of the present invention will be described with reference to the drawings. FIG. 6 is a perspective view showing one embodiment of the DC power supply device with a charging function of 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, an adapter plug connected to the power tool 4 at one end, and a power supply main body 2 at the other end. And an output cable to be connected. The upper portion of the adapter plug has the same shape as the insertion portion of the battery pack 5, and is detachable from the electric tool 4 like the battery pack 5.
[0021]
FIG. 7 is a block diagram showing an embodiment of a DC power supply device with a charging function. AC cord set 1 is connected to a commercial AC power supply of AC100V. The adapter set 3 is provided with output voltage setting means 3a for outputting a voltage corresponding to each rated voltage to the plurality of power tools 4. The power tool 4 has a built-in 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 main body 2 via the adapter set 3. The battery pack 5 that can be mounted on the electric tool 4 includes a rechargeable storage battery 5a, a temperature element 5b (for example, a thermistor, etc.) and a cell number discriminating element 5c (for example, a resistor corresponding to the number of cells). Etc.).
[0022]
Reference numeral 10 denotes a switching power supply capable of outputting a predetermined charging current so as to charge various battery packs 5 having different predetermined driving voltages and battery voltages corresponding to the power tool 4 having various driving voltages. , 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 driving pulse width of the switching element 14 to change 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 the values of the driving voltage and the charging current. When the power tool 4 is being driven, the switching control circuit 15 is fed back based on the signal of the voltage detection circuit 42 to control the switching duty of the switching element 14, and at the same time, the adapter assembly is controlled based on the signal from the output current detection circuit 41. 3 has a function of correcting a voltage drop in the cable. When the battery pack 5 can be charged when the power switch 4b is turned off, the switching control circuit 15 is fed back 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 is charged. 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 for supplying power output to the power tool 4 when the power switch 4b is turned on, and a charge output switch for charging the battery pack 5 when the power tool 4 is not used. It is composed of a circuit 32. The charge output switch circuit 32 is configured by 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 power 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 for detecting an output voltage of the circuit 13, a trigger detection circuit for detecting that the power switch 4b is turned on, and outputting a charging non-permission signal and a signal for permitting power supply to the electric 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 detecting means 50 includes a battery voltage detecting circuit 51 for detecting a battery voltage of the storage battery 5a, a battery temperature detecting circuit 52 for detecting a battery temperature according to characteristics of a temperature element 5b in the battery pack 5, and a cell number determining element 5c. And a cell number discriminating circuit 53 for discriminating the number of cells according to the resistance value or the like.
[0027]
The microcomputer 60 constituting the control means of the present invention sets the drive voltage of the power 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 battery pack 5 when the power tool 4 is not used. In addition to setting the charging current, it is determined whether or not charging is possible based on whether the power tool 4 is not used, that is, the power switch 4b is turned off and the output of the battery state detecting means 50. When the battery pack 5 is chargeable, a trigger is detected. A function of outputting a charge permission signal to the charge output switch circuit 32 via the circuit 43, a battery temperature Tin, a battery voltage Vin, a minimum battery temperature value Tmin, a battery temperature gradient dT / dt, and a minimum battery voltage gradient value. RAM for storing dT / dt (min), battery voltage gradient ΔV, minimum value of battery voltage gradient ΔVmin, etc., whether the latest battery temperature and the battery temperature before predetermined sampling It has the function of calculating the battery temperature gradient from the latest battery voltage and the battery voltage gradient from the latest battery voltage and the battery voltage before predetermined sampling.
[0028]
For example, the display circuit 70 including an LED or the like displays, based on the output of the microcomputer 60, whether the power tool 4 is in use, whether the power tool 4 is usable, or that the battery pack 5 is being charged. Is displayed. The auxiliary power supply circuit 80 supplies a power supply such as the microcomputer 60 and a reference voltage Vcc such as the power supply output control means 20, the power supply output detection means 40, and the battery state detection means 50.
[0029]
Next, the operation of the power supply device with a charging function of 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 100 VAC, the auxiliary power supply circuit 80 is activated and supplies the reference voltage Vcc to the microcomputer 60, the power supply output control means 20, and the like. The microcomputer 60 continuously calculates the charging completion flag, the charging flag, the trigger detection flag indicating that the power switch 4b is turned on in the RAM serving as the storage means, and the battery temperature gradient when the charging is restarted after using the power tool. DT / dt continuous flag, a ΔV flag for full charge determination by detecting battery voltage, a battery pack flag indicating that the battery pack 5 has been inserted into the battery pack insertion opening of the power supply main body 2, and a load current of zero. The counter is reset and a signal for turning off the charge output switch circuit 32 of the power supply output switching means 30 is output to perform an initial set (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). When the power switch 4b of the power tool 4 is turned on, the trigger of the power output detection 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 power tool 4.
[0030]
The microcomputer 60 determines whether or not the battery pack 5 is inserted into 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), and the battery voltage V0 before the start of charging is detected by the voltage detection circuit 42 (step 707). The cell number determination circuit 53 determines the cell number n according to the value 5c (step 708). Next, the battery voltage per cell is calculated from the battery voltage V0 and the number of cells n before the start of charging detected in steps 707 and 708, and it is determined whether 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 in the vicinity of full charge (the remaining battery capacity is large). In order to continuously calculate dt, a dT / dt continuation flag is set (step 710). In step 709, unless the battery voltage per cell is 1.40 V or more, it is determined that the remaining battery capacity is not large, and the process jumps to step 711.
[0031]
If the battery pack 5 is not inserted in step 703, the charging completion flag, charging flag, battery pack flag, dT / dt continuous flag, trigger detection flag, ΔV flag, and zero load current counter in the RAM are reset ( Step 704). Subsequently, in order to determine whether the power switch 4b has been 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 into the power supply main body 2 (step 712). If the battery pack 5 is not inserted into the power supply main body 2, the process returns to step 703 again. .
[0033]
When the battery pack 5 is inserted in the step 712, it is determined whether or not the charging of the battery pack 5 is completed (step 713). When the charging is completed, the process returns to the step 703 again.
[0034]
If the battery pack 5 is not in the charging completed state 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. The determination as to whether or not the battery pack 5 is performed is made based on the output of the battery temperature detection circuit 52 (step 715). When the temperature of the battery pack 5 is high, the process returns to step 703 again.
[0035]
When the temperature of the battery pack 5 is not high 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 control the charging current so as to set the 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), and 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. To start charging, set a charging flag (step 720), and return to step 703.
[0036]
If the load current is not zero in step 711, the load current zero counter is cleared (step 721), and based on the output of the trigger detection circuit 43, it is monitored whether the power switch 4b is turned on (step 722). . If the power switch 4b is turned on in step 722, a trigger detection flag is set (step 723). 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]
If the power switch 4b is not turned on in step 722, the process jumps to step 730 to perform data processing necessary for the near-full charge determination of the battery pack 5 and the full charge determination processing. First, the latest battery temperature Tin of the battery pack 5 during charging is loaded into the RAM from the battery temperature detection circuit 52 (step 730). Further, by comparing the latest data of the calculated battery temperature gradient Tin, the 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 loaded into the RAM from the battery voltage detection circuit 51 (step 732).
[0038]
Further, the latest battery voltage gradient ΔV of a predetermined sampling width is calculated by the battery voltage detection circuit 51 (step 733), and the calculated data of the battery voltage gradient ΔV is compared with the minimum value of the battery voltage gradient of the 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 after the restart of charging, the process jumps to step 744 to prevent the full charge determination based on the battery temperature gradient from being performed. If the predetermined time U has elapsed after the restart of charging, the trigger detection flag is cleared (step 738).
[0040]
Next, the latest battery temperature gradient dT / dt of 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 data of the latest battery temperature gradient dT / dt is calculated. By comparison, the minimum value dT / dt (min) of the battery temperature gradient dT / dt with 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 risen from the minimum battery temperature gradient dT / dt (min) by the predetermined value Q1 or more (step 741). In this case, it is determined that the battery pack 5 is near full charge, the time until the completion of charging in this case is near full charge, it is determined to be short, 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 from the minimum battery temperature gradient value dT / dt (min) by the predetermined value Q1 or more, the process proceeds to step 742, and the latest battery temperature gradient dT / dt. Is higher than the battery temperature gradient minimum value dT / dt (min) by a full charge determination value Q2 (Q2> Q1) or more, and if it is higher than the full charge determination value Q2, it is determined that the battery is fully charged. The charging flag is reset (step 727), 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, if the latest battery temperature gradient value dT / dt has not risen from the minimum battery temperature gradient value dT / dt (min) by the full charge determination value Q2 or more, the latest battery voltage gradient ΔV becomes the battery voltage gradient It is determined whether or not the value has risen from the minimum value ΔVmin by a predetermined value R1 or more (step 744). When the battery pack 2 has risen by more than the predetermined value R1, it is determined that the battery pack 2 is near full charge, and ΔVFlag of the RAM is set to 1. It is set (step 746), and it is determined that the time until the completion of charging in this case is short because it is near full charge, and the dT / dt continuous flag is set (step 747). Thereafter, the process of step 748 is performed.
[0043]
In step 744, when the latest battery voltage gradient ΔV has not risen from the minimum battery voltage gradient value ΔVmin by a predetermined value R1 or more, the latest battery temperature Tin is changed from the minimum battery temperature value Tmin to a predetermined value P1 or more. It is determined whether or not the charge has risen (step 745). If the charge has risen by the predetermined value P1 or more, it is determined that the time until the completion of charging is short because the time until the completion of charging is near full charge, and the dT / dt continuous flag is set. (Step 747) Then, the process of Step 748 is performed.
[0044]
In step 745, if the latest battery temperature Tin has not risen from the minimum battery temperature value Tmin by a predetermined value P1 or more, the latest battery temperature Tin is changed from the minimum battery temperature value Tmin to a predetermined value P2 (P2>). It is determined whether or not P1) or more has risen (step 748). If it has risen or more than P2, it is determined that the battery is fully charged (see FIG. 12), and the processing of step 727 and subsequent steps is performed to terminate charging. In step 748, if the latest battery temperature Tin has not risen from the minimum battery temperature value Tmin by a predetermined value P2 or more, it is determined whether or not the ΔV flag has been 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 has become equal to or less than a predetermined value R2 (R1> R2) (step 750). It is determined that the battery is fully charged (see FIG. 13), and the processes after step 727 are performed to terminate the charging. In step 750, when the latest battery voltage gradient ΔV is not equal to or smaller than the predetermined value R2, the process returns to step 703.
[0045]
In step 724, when the battery pack 5 is being charged, that is, in this case, when the power switch 4b is turned on once during charging and then the power switch 4b is turned off, a load current zero counter is started (step 725). Next, it is determined whether the state of zero load current is continuous, that is, whether or not the continuous unused time of the power tool 4 has passed a predetermined time, that is, whether the power switch 4b is continuously turned off is determined (step 726). If the predetermined time has elapsed, the process skips to step 716 in order to restart charging of the battery pack 5. The predetermined time is desirably set in consideration of, for example, a sampling time of a battery voltage and a battery temperature for full charge determination or an actual use form of the power tool 4, and is, for example, one minute.
[0046]
In step 726, if the state of zero load current has not continued for a predetermined period of time, a charge disapproval 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 into the power supply main body 2 (step 752). If the battery pack 5 is not inserted into the power supply main body 2, the process returns to step 703. During charging, the power switch 4b is turned on once, and data processing necessary for near-full-charge determination and full-charge determination processing is performed so as to continuously determine full charge even when charging is not performed.
[0047]
First, the latest battery temperature Tin of the battery pack 5 during charging is loaded into the RAM from the battery temperature detection circuit 52 (step 753). Further, by comparing the latest data of the calculated battery temperature gradient Tin, the minimum value T (min) of the battery temperature is calculated and stored (step 754).
[0048]
The latest battery temperature gradient dT / dt of a predetermined sampling width is calculated from the battery temperature data during charging sampled by the battery temperature detection circuit 52 (step 755), and the data of the latest battery temperature gradient dT / dt is compared. 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 minimum battery temperature gradient dT / dt (min) (step 757). Determines that the battery pack 2 is near full charge, determines that the time until the completion of charging in this case is short since full charge is near, and sets the dT / dt continuous flag (step 759). 760 is performed. In step 757, if the latest battery temperature gradient dT / dt has not risen from the minimum battery temperature gradient dT / dt (min) by a predetermined value Q1 or more, the latest battery temperature Tin is increased from the minimum battery temperature Tmin. It is determined whether or not the battery pack 2 has risen by the predetermined value P1 or more (step 758). If the battery pack 2 has risen by the predetermined value P1 or more, it is determined that the battery pack 2 is near full charge, and it is determined that the time until the completion of charging is short. Judgment is made and the dT / dt continuous flag is set (step 759), and then the process 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, it is determined whether the latest battery temperature Tin has risen from the battery temperature minimum value Tmin by a predetermined value P2 or more. Is determined (step 760). If the charge is higher than P2, it is determined that the battery is fully charged.
[0050]
In step 760, if the latest battery temperature Tin has not risen from the minimum battery temperature value Tmin by a predetermined value P2 or more, the latest battery temperature gradient dT / dt is calculated from the minimum battery temperature gradient value dT / dt (min). It is determined whether or not the value has risen to the full charge determination value Q2 or more (step 761). If the value has risen to the full charge determination value Q2 or more, it is determined that the battery is fully charged, and the process of step 727 and subsequent steps is performed to finish charging.
[0051]
In step 761, if the latest battery temperature gradient dT / dt has not risen from the minimum battery temperature gradient 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 use of the power tool, if it is not determined that the battery is just before full charge from the battery temperature or the battery temperature gradient or the battery voltage, the battery temperature gradient after the restart of charging is resumed. Is not performed for a predetermined time, it is possible to detect the full charge more reliably.
[Brief description of the drawings]
FIG. 1 is a graph for explaining charging control of a DC power supply device according to 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 charge control of the DC power supply device of the present invention.
FIG. 4 is a graph for explaining charge control of the DC power supply device of the present invention.
FIG. 5 is a graph for explaining charge 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 charge 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 main body, 3 is an adapter set, 4 is a power 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, and 43 is a trigger. A detecting circuit, 50 is a battery state detecting circuit, 52 is a battery temperature detecting means, and 60 is a microcomputer.

Claims

A DC voltage is supplied to a cordless power tool powered by a detachable battery pack via a cable equipped with a detachable adapter, and the battery pack is charged when the cordless power tool is not used, and the battery temperature is detected. Battery temperature detecting means, a battery temperature storing means for storing a battery temperature based on the output of the battery temperature detecting means, and a battery temperature gradient for calculating a 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, wherein the latest battery temperature gradient is more fully charged than the minimum value in the battery temperature gradient storage means. A DC power supply with a charging function that stops charging by determining that the battery is fully charged when the value exceeds a determination value,
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 charging of the battery pack is restarted, a full charge detection operation is performed according to the state of charge when the battery pack stops charging. A DC power supply device with a charging function, wherein whether to perform the charging immediately after the restart of charging or after a predetermined time has elapsed from the restart of charging is determined.

A DC voltage is supplied to a cordless power tool powered by a detachable battery pack via a cable equipped with a detachable adapter, and the battery pack is charged when the cordless power tool is not used, and the battery temperature is detected. Battery temperature detecting means, a battery temperature storing means for storing a battery temperature based on the output of the battery temperature detecting means, and a battery temperature gradient for calculating a 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, wherein the latest battery temperature gradient is more fully charged than the minimum value in the battery temperature gradient storage means. A DC power supply with a charging function that stops charging by determining that the battery is fully charged when the value exceeds a determination value,
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 charging of the battery pack is resumed, the latest battery temperature is equal to or greater than the near full charge value that is smaller than the battery temperature value for full charge determination A DC power supply with a charging function, wherein calculation of a battery temperature gradient is not performed for a predetermined time when the temperature is not rising.

A DC voltage is supplied to a cordless power tool powered by a detachable battery pack via a cable with a detachable adapter, and the battery pack is charged when the cordless power tool is not used, and the battery voltage is detected. Battery voltage detecting means, a battery voltage storing means for storing the battery voltage based on the output of the battery voltage detecting means, and a battery voltage gradient for calculating the battery voltage gradient based on the outputs of the battery voltage detecting means and the battery voltage storing means. Computing means, and battery voltage gradient storage means for storing the battery voltage gradient based on the output of the battery voltage gradient computing means, wherein the latest battery voltage gradient rises by a first predetermined value or more, and thereafter, the first predetermined value A DC power supply device with a charging function that stops charging by determining that the battery is fully charged when the voltage falls below a second predetermined value that is smaller than the second predetermined value.
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 charging of the battery pack is restarted, when the latest battery voltage gradient has not risen by more than the first predetermined value, the battery A DC power supply with a charging function, wherein calculation of a voltage gradient is not performed for a predetermined time.

Battery voltage detecting means for detecting the battery voltage, and battery remaining capacity detecting means for detecting the remaining capacity of the battery from the output of the battery voltage detecting means at the start of charging, the cordless power tool is used during charging of the battery pack, When the use of the cordless power tool is stopped and charging of the battery pack is restarted, when the remaining battery charge detecting means detects that there is remaining charge equal to or greater than a predetermined value, the battery temperature gradient is continuously calculated. The DC power supply device with a charging function according to claim 1 or 2, wherein