JP2004344283A

JP2004344283A - Electric wheelchair

Info

Publication number: JP2004344283A
Application number: JP2003143128A
Authority: JP
Inventors: Yutaka Yoshida; 吉田　　裕
Original assignee: Aisin Seiki Co Ltd
Current assignee: Aisin Corp
Priority date: 2003-05-21
Filing date: 2003-05-21
Publication date: 2004-12-09
Anticipated expiration: 2023-05-21
Also published as: JP4217960B2

Abstract

PROBLEM TO BE SOLVED: To provide an electric wheelchair which can favorably correspond with size variation in a cross section of a body frame when an electric driving unit is fixed to the body frame. SOLUTION: The electric wheelchair includes a first clamping part 40 having a first clamping surface 41, a second clamping part 45 having a second clamping surface 46 and a tightening member 6 which tightens the first clamping part 40 and the second clamping part 45 while a frame part 16 for mounting the electric driving unit is supported between the first clamping part 40 and the second clamping part 45. The first clamping part 40 has a first inclined plane 51 and the second clamping part 45 has a second inclined plane 52. A supporting interval A between the first clamping surface 41 and the second clamping surface 46 can be adjustable by relative displacement of the first inclined plane 51 and the second inclined plane 52 along an inclination direction. COPYRIGHT: (C)2005,JPO&NCIPI

Description

【０００１】
【発明の属する技術分野】
本発明は電動ユニットを搭載する電動車椅子に関する。
【０００２】
【従来の技術】
電動電動車椅子は、一般的には、使用者を着座させる着座部と使用者の背を受ける背もたれ部とをもつ車体フレームと、車体フレームに配設された駆動車輪と、駆動車輪を回転させる電動ユニットとを有する。そして、特許文献１によれば、電動ユニット搭載用のフレーム部の横断面を示す断面において第１挟持面をもつ第１挟持部と、第１挟持部の第１挟持面に対面する第２挟持面をもつ第２挟持部とを有する電動ユニット固定機構をもつものが開示されている。
【０００３】
このものによれば、電動ユニットを車体フレームに固定する際に、第１挟持部の第１挟持面と第２挟持部の第２挟持面とにより、車体フレームのフレーム部分の外周面を挟持することにしている。
【０００４】
【特許文献１】特開平９−２６２２６０号公報の図９
【０００５】
【発明が解決しようとする課題】
上記した特許文献１に係る技術によれば、前述したように、電動ユニットを車体フレームに固定する際に、電動ユニット固定機構の第１挟持部の第１挟持面と第２挟持部の第２挟持面とにより、フレームのフレーム部分の外周面を挟持することにしている。しかしながら特許文献１に係る技術によれば、フレーム部分の横断面サイズが変更されたときに、対処することは容易ではない。
【０００６】
本発明は上記した実情に鑑みてなされたものであり、車体フレームに電動ユニットを固定する際において、車体フレームの横断面サイズが変動するときであっても、良好に対処することができる電動車椅子を提供することを課題とするにある。
【０００７】
【課題を解決するための手段】
本発明に係る電動車椅子は、使用者を着座させるための着座部と電動ユニット搭載用のフレーム部とをもつ車体フレームと、車体フレームの電動ユニット搭載用のフレーム部に配置され駆動モータをもつ電動ユニットと、車体フレームまたは電動ユニットに回転可能に配設された駆動車輪と、電動ユニットを車体フレームの電動ユニット搭載用のフレーム部に固定する電動ユニット固定機構とを具備する電動車椅子において、電動ユニット固定機構は、
電動ユニット搭載用のフレーム部の横断面を示す断面において第１挟持面をもつ第１挟持部と、第１挟持部の第１挟持面に対面すると共に電動ユニット搭載用のフレーム部を第１挟持部の第１挟持面とで挟持する第２挟持面をもつ第２挟持部と、第１挟持部及び第２挟持部の間に電動ユニット搭載用のフレーム部を挟持した状態で第１挟持部及び第２挟持部を締結する締結部材とを有しており、
第１挟持部は第１傾斜面を有しており、第２挟持部は第１傾斜面と対面する第２傾斜面を有しており、第１傾斜面及び第２傾斜面を第１傾斜面及び第２傾斜面の傾斜方向に沿って相対変位させることにより、第１挟持部の第１挟持面と第２挟持部の第２挟持面との間の挟持間隔は、調整可能とされていることを特徴とするものである。
【０００８】
本発明に係る電動車椅子によれば、電動ユニットの駆動モータが駆動すれば、駆動車輪が回転し、電動車椅子が走行する。
【０００９】
本発明に係る電動車椅子によれば、電動ユニット搭載用のフレーム部の横断面を示す断面において、第１挟持部の第１挟持面及び第２挟持部の第２挟持面で電動ユニット搭載用のフレーム部を挟持する。このように第１挟持部の第１挟持面と第２挟持部の第２挟持面との間に電動ユニット搭載用のフレーム部を挟持した状態で、第１挟持部及び第２挟持部を締結部材で互いに締結する。
【００１０】
ここで、第１挟持部は第１傾斜面を有しており、第２挟持部は第１傾斜面と対面する第２傾斜面を有する。第１傾斜面及び第２傾斜面を第１傾斜面及び第２傾斜面の傾斜方向に沿って相対変位させることにより、第１挟持部と第２挟持部との間の挟持間隔は調整可能とされている。このため電動ユニット搭載用のフレーム部の横断面を示す断面において、電動ユニット搭載用のフレーム部の横断面サイズが変更されたとしても、第１傾斜面及び第２傾斜面を、第１傾斜面及び第２傾斜面の傾斜方向に沿って相対変位させれば、第１挟持部の第１挟持面と第２挟持部の第２挟持面との間における挟持間隔を調整できる。この結果、電動ユニット搭載用のフレーム部の横断面を示す断面において、電動ユニット搭載用のフレーム部の横断面サイズの変化に対応することができる。
【００１１】
【発明の実施の形態】
本発明に係る電動車椅子によれば、第１挟持部は第１傾斜面を有しており、第２挟持部は第１傾斜面と対面する第２傾斜面を有する。第１傾斜面及び第２傾斜面の傾斜の程度としては、適宜設定することができる。第１傾斜面及び第２傾斜面を第１傾斜面及び第２傾斜面の傾斜方向に相対変位させることにより、第１挟持部の第１挟持面と第２挟持部の第２挟持面との間の挟持間隔は、調整可能とされている。
【００１２】
本発明に係る電動車椅子の好ましい形態によれば、電動ユニット搭載用のフレーム部はこれの軸直角方向に沿った方向において貫通する取付孔をもち、電動ユニットは、取付孔に対面すると共に第１挟持部と第２挟持部とを繋ぐ方向に延びる長孔をもつ形態を採用することができる。この場合、電動ユニット搭載用のフレーム部の取付孔及び電動ユニットの長孔に挿通したボルト部材にナット部材を螺着させることができる。これにより電動ユニット搭載用のフレーム部の横断面サイズが変更されるときであっても、電動ユニット搭載用のフレーム部に対する電動ユニットの取付性を高めることができる。
【００１３】
また、車体フレームの電動ユニット搭載用のフレーム部に電動ユニットが固定され、電動ユニットに駆動車輪が取り付けられている形態を採用できる。
【００１４】
【実施例】
以下、本発明の一実施例について図１〜図５を参照して具体的に説明する。本実施例は、手動走行型の電動車椅子の車体フレーム１をベースとし、手動走行型の車椅子の車体フレーム１に電動ユニット３を後付けで搭載した電動車椅子を対象とする。図１に示すように、電動車椅子は、骨格を構成する車体フレーム１と、車体フレーム１に回転可能に配設され外周面２ｃをもつ駆動車輪２と、駆動車輪２を回転させる駆動源である電動ユニット３とをもつ。車体フレーム１は、使用者を着座させる着座部１０と、使用者の背を受ける背もたれ部１１とをもつ。更に車体フレーム１は、着座部１０に着座している使用者のひじをかける肘アームレスト１２と、車体フレーム１の後側に設けられ着座部１０に着座している使用者を介護する介護者が操作できるグリップ状の操作部１５と、着座部１０の下側に位置して上下方向にのびる電動ユニット搭載用のフレーム部１６と、電動ユニット３に給電するバッテリー１７と、着座部１０に着座している使用者の脚を載せるフットレスト１９とをもつ。なお図１は駆動車輪２を略記している。
【００１５】
車椅子の電動化にあたり、車体フレーム１の前側に操作用フレーム部１ｅを取付け、着座部１０に着座する使用者が操作する電動操作レバー１４ａをもつ電動操作部１４を操作用フレーム部１ｅに取り付けている。駆動車輪２は、車幅方向において車体フレーム１の左右に位置しており、車軸２１を介して回転可能に設けられている。駆動車輪２は、車体フレーム１の車軸２１に挿通された状態に車体フレーム１に固定された電動ユニット３により回転駆動される。車体フレーム１の前側には補助車輪１８が設けられている。電動ユニット搭載用のフレーム部１６は、車幅方向において車体フレーム１の左右に設けられており、従って電動ユニット３も車幅方向において車体フレーム１の左右に設けられている。
【００１６】
図２は電動ユニット３の付近を示す。電動ユニット３は、取付具３０ｗで分割ケースを接続して形成され伝達ギヤ類を内蔵したケース３０と、ケース３０に固定された駆動モータ３２とをもつ。ケース３０の横軸型の軸孔３０ｘには、駆動車輪２の車軸２１が横軸型に挿通されている。駆動モータ３２が駆動すると、ケース３０内の伝達ギヤ類を介して車軸２１が回転し、ひいては駆動車輪２が回転し、電動車椅子が走行する。本実施例によれば、駆動車輪２は直接的に車体フレーム１に取り付けられているのではなく、後述するように、車体フレーム１の電動ユニット搭載用のフレーム部１６に電動ユニット３が着脱可能に取り付けられており、この電動ユニット３に駆動車輪２が取り付けられているものである。
【００１７】
図２に示すように、電動ユニット３を車体フレーム１の電動ユニット搭載用のフレーム部１６に固定するための電動ユニット固定機構４が設けられている。図３は、電動ユニット搭載用のフレーム部１６の横断面を示すと共に、電動ユニット固定機構４の横断面を示す。図３に示すように、電動ユニット固定機構４は、電動ユニット３のケース３０に設けられた金属製の第１挟持部４０と、第１挟持部４０に対面する金属製の第２挟持部４５と、締結部材６とを有する。締結部材６は、第１挟持部４０及び第２挟持部４５の間に電動ユニット搭載用のフレーム部１６の外周面１６ａを挟持した状態で、第１挟持部４０及び第２挟持部４５を締結するものである。なお、締結部材６は、電動車椅子の前後方向（前進後退方向）に沿ってのびている。
【００１８】
図３に示すように、第１挟持部４０は電動ユニット３のケース３０と一体的に形成されており、横断面で直状をなす平坦状の第１挟持面４１と、第１挟持面４１に交差する平坦状の第１交差面４２とを有する。第２挟持部４５は電動ユニット３のケース３０の第１挟持部４０に分離可能に設けられており、ケース３０の第１挟持部４０に対して着脱可能とされている。従って、第２挟持部４５は第１挟持部４０に対して着脱可能とされている。第２挟持部４５は、横断面で直状をなす平坦状の第２挟持面４６と、第２挟持面４６に交差する平坦状の第２交差面４７とを有する。図３に示すように、第１挟持面４１及び第２挟持面４６は互いに平行またはほぼ平行とされており、互いに対向しており、この結果、電動ユニット搭載用のフレーム部１６の外周面１６ａを挟持する挟持間隔Ａ（図４参照）を形成する。
【００１９】
図３に示すように、第１挟持部４０は、横断面で直線状に傾斜する第１傾斜面５１を有する。第２挟持部４５は、第１傾斜面５１と対面すると共に横断面で直線状に傾斜する第２傾斜面５２を有する。第１傾斜面５１及び第２傾斜面５２は、後述の締結孔５６の軸芯Ｓ１の軸直角方向に対して角度θ１傾斜している。
【００２０】
締結部材６が本締結される前の状態において、第１傾斜面５１及び第２傾斜面５２が第１傾斜面５１及び第２傾斜面５２の傾斜方向（図４に示す矢印Ｗ１，Ｗ２方向）に相対変位すれば、第１挟持部４０の第１挟持面４１と第２挟持部４５の第２挟持面４６との間の挟持間隔Ａの大きさを調整することができる。しかも挟持間隔Ａの大きさの調整は無段階である。
【００２１】
第１挟持部４０の第１傾斜面５１には、雌螺子５５をもつ締結孔５６が開口して形成されている。なお、締結孔５６の軸芯Ｓ１は、第１挟持部４０の第１挟持面４１と第２挟持部４５の第２挟持面４６とを繋ぐ方向と平行に沿っている。本実施例によれば、締結孔５６の軸芯Ｓ１は、電動車椅子の前後方向（前進後退方向）に沿ってのびている。第２挟持部４５の第２傾斜面５２には、締結孔５６に対面する挿通孔４８が貫通して形成されている。挿通孔４８は内周壁４８ｋをもち、第１挟持部４０の第１挟持面４１と第２挟持部４５の第２挟持面４６とを繋ぐ方向（矢印Ｗ４方向）と交差する方向（矢印Ｅ方向）に沿って延設された長孔状とされている。従って、挿通孔４８の長軸方向（矢印Ｅ方向）に沿って、第２挟持部４５は第１挟持部４０に対して相対移動可能とされている。
【００２２】
図３に示すように、締結部材６は、締結孔５６の雌螺子５５に螺合可能な雄螺子６１をもつ雄螺子部材６２と、雄螺子部材６２の他端部に設けられ雄螺子部材６２よりも径大な頭部６３とを有する。締結部材６の雄螺子部材６２は挿通孔４８に挿通可能とされている。
【００２３】
さて、電動ユニット３を車体フレームの電動ユニット搭載用のフレーム部１６に搭載するときについて説明する。即ち、図３，図４は、電動ユニット搭載用のフレーム部１６の横断面を示す。図３，図４から理解できるように、第１挟持部４０の第１挟持面４１及び第２挟持部４５の第２挟持面４６とで電動ユニット搭載用のフレーム部１６の外周面１６ａを挟むように、第１挟持部４０及び第２挟持部４５を配置する。この状態において、第２挟持部４５の挿通孔４８に挿通した締結部材６の雄螺子部材６２の雄螺子６１を、第２挟持部４５の締結孔５６の雌螺子５５に螺着させ、締結部材６を締結する。これにより図４に示すように、第１挟持部４０の第１挟持面４１及び第２挟持部４５の第２挟持面４６とで、電動ユニット搭載用のフレーム部１６の外周面１６ａは挟持される。
【００２４】
ところで、車体フレーム１の型番が異なると、電動ユニット搭載用のフレーム部１６の外径サイズＷ３（横断面サイズ）が変わることが多い。また電動ユニット搭載用のフレーム部１６の外径サイズＷ３は、製造工程における公差内でばらつくことがある。このようなときであっても、本実施例によれば、前述したように第１挟持部４０は第１傾斜面５１を有しており、第２挟持部４５は第１傾斜面５１と対面するように同じ方向に傾斜した第２傾斜面５２を有する。そして、第１傾斜面５１に対して第２傾斜面５２を第１傾斜面５１及び第２傾斜面５２の傾斜方向（図３及び図４に示す矢印Ｗ１，Ｗ２方向）に沿って滑らせて相対変位させれば、前述したように、第１挟持部４０の第１挟持面４１と第２挟持部４５の第２挟持面４６との間の挟持間隔Ａ（図４参照）を無段階で調整することができる。
【００２５】
このため、電動ユニット搭載用のフレーム部１６の外径サイズＷ３の大きさが変動したとしても、電動ユニット搭載用のフレーム部１６を第１挟持部４０の第１挟持面４１と第２挟持部４５の第２挟持面４６とで電動ユニット搭載用のフレーム部１６の外周面１６ａを良好に挟持することができる。即ち、電動ユニット搭載用のフレーム部１６の外径サイズＷ３の変動に対応することができる。
【００２６】
本実施例によれば、図５に示すように、電動ユニット搭載用のフレーム部１６はその中間部に角柱形状とされた取付ボス部１６０をもつ。この取付ボス部１６０は、電動ユニット搭載用のフレーム部１６の軸直角方向に沿って貫通する取付孔１６２をもつ。取付孔１６２は、電動ユニット３を手動式車椅子に取り付ける前において、手動式車椅子の車輪の車軸を挿通する車軸挿通孔として機能していたものである。本実施例によれば、手動式車椅子のときの車輪の車軸は、フレーム１の取付孔１６２から取り外されている。手動式車椅子に電動ユニット３を取り付けた本実施例に係る電動車椅子によれば、駆動車輪２の回転中心である車軸２１は、フレーム１に固定された電動ユニット３の軸孔３０ｘに挿通されているため、駆動車輪２の車軸２１の軸芯は、手動式車椅子の場合における車輪の軸芯よりもＬ分、後方にオフセットされている（図２参照）。
【００２７】
本実施例によれば、図５に示すように、手動式車椅子に取り付ける電動ユニット３は、外方に向けて（矢印Ｗ４方向）延設されている取付鍔部３５をもつ。取付鍔部３５は、電動車椅子の前方に向けて電動ユニット３のケース３０から突出しており、電動ユニット搭載用のフレーム部１６の取付孔１６２に対面する。更に、取付鍔部３５に長孔３６が貫通孔状に形成されている。長孔３６の長軸３６ｍは、電動ユニット３の第１挟持部４０の第１挟持面４１と第２挟持部４５の第２挟持面４６とを繋ぐ方向（矢印Ｗ４方向；挟持間隔Ａの間隔幅；電動車椅子の前後方向）に沿って延びている。
【００２８】
そして、電動ユニット３を車体フレーム１の電動ユニット搭載用のフレーム部１６に搭載するときには、図５から理解できるように、電動ユニット搭載用のフレーム部１６の取付ボス部１６０の平坦な取付面１６３に電動ユニット３の取付鍔部３５をあてがうと共に、取付ボス部１６０の取付孔１６２及び電動ユニット３の長孔３６にボルト部材８を挿通し、そのボルト部材８の雄螺子８ａにナット部材８５の雌螺子８５ａを螺着させる。この結果、手動式車椅子の車軸挿通孔として機能していた取付孔１６２をボルト挿通孔として利用し、取付孔１６２に挿通したボルト部材８及びナット部材８５により、電動ユニット３の取付鍔部３５を電動ユニット搭載用のフレーム部１６の取付ボス部１６０に固定する。この状態では、図２に示すように、電動ユニット３の大半は、手動式車椅子の車軸挿通孔として機能していた取付孔１６２の後方に配置される。
【００２９】
このとき電動ユニット搭載用のフレーム部１６の外径サイズＷ３の大きさが変更されたとしても、ボルト部材８に対して取付鍔部３５の長孔３６を矢印Ｗ４方向に相対変位させることができる。故に、電動ユニット３の取付鍔部３５をボルト部材８及びナット部材８５により電動ユニット搭載用のフレーム部１６に固定するときにおいて、電動ユニット搭載用のフレーム部１６の外径サイズＷ３の変動に良好に対応することができる。なお図２から理解できるように、締結部材６及びボルト部材８は互いに接近していると共に、締結部材６及び締結孔５６の延設方向とボルト部材８の延設方向とは互いに交差する方向とされている。
【００３０】
図１において、駆動車輪２の車軸２１は車体フレーム１の取付孔１６２に対してオフセットして配置されている。このような本実施例によれば、車体フレーム１の着座部１０に使用者が着座するときには、車体フレーム１及び使用者を含む重量負荷Ｆ１は、車軸２１を中心とするモーメントとして作用する。また、駆動モータ３２をもつ電動ユニット３の重量負荷Ｆ２は、車軸２１を中心とする逆向きのモーメントとして作用する。電動ユニット３はこのモーメントＦ１，Ｆ２の影響で車軸２１を中心として空転してしまうおそれがあり、電動ユニット３はこのモーメントに対向する必要がある。ここで、電動ユニット固定機構４の第１挟持部４０の第１挟持面４１、第２挟持部４５の第２挟持面４６は、このモーメントＦ１，Ｆ２に対向するトルク受け面として機能することができ、電動ユニット３の回り止めを図ることができる。またボルト部材８及びナット部材８５もこのモーメントＦ１，Ｆ２に対向するトルク受けとして機能することができ、電動ユニット３の回り止めを図ることができる。
【００３１】
（他の実施例）
図６は本発明の他の実施例を示す。本実施例においても、第２挟持部４５は電動ユニット３のケース３０に対して分割されている。但し、第２挟持部４５は、締結孔５６の軸芯Ｓ１の回りで、つまり、締結部材６の軸芯の回りで回転可能とされている。第２挟持部４５は、締結孔５６の軸芯Ｓ１に対して第２挟持面４６と反対側に第２挟持部４５ｘをもつ。図６に示すように第２挟持部４５ｘは平坦な第２挟持面４６ｘをもつ。第２挟持面４６ｘは、締結孔５６の軸芯Ｓ１に対して第２挟持面４６と反対側に形成されており、第２挟持面４６とほぼ平行または平行とされている。
【００３２】
本実施例においても、図６から理解できるように、第１傾斜面５１に対して第２傾斜面５２を第１傾斜面５１及び第２傾斜面５２の傾斜方向（矢印Ｗ１，Ｗ２方向）に沿って滑らせて相対変位させれば、前述したように、第１挟持部４０の第１挟持面４１と第２挟持部４５の第２挟持面４６との間の挟持間隔Ａを無段階で調整することができる。このため、電動ユニット搭載用のフレーム部１６の外径サイズＷ３の大きさが変更されたとしても、その変動に対応することができる。
【００３３】
更に、電動ユニット搭載用のフレーム部１６の外径サイズＷ３が更に変更されたときには、第２挟持部４５を、締結孔５６の軸芯Ｓ１つまり締結部材６の軸芯の回りで１８０度回転させれば、第２挟持部４５ｘの第２挟持面４６ｘと第１挟持部４０の第１挟持面４１とで電動ユニット搭載用のフレーム部１６の外周面１６ａをこれの横断面方向において挟持することも可能である。このため、電動ユニット搭載用のフレーム部１６の外径サイズＷ３がかなり変更されるときであっても、適用性を高めることができる。その他、本発明は上記しかつ図面に示す実施例のみに限定されるものではなく、要旨を逸脱しない範囲内で適宜変更して実施できるものである。
【００３４】
【発明の効果】
本発明によれば、第１挟持部は第１傾斜面を有しており、第２挟持部は第１傾斜面と対面する第２傾斜面を有する。第１傾斜面及び第２傾斜面を第１傾斜面及び第２傾斜面の傾斜方向に相対変位させることにより、第１挟持部と第２挟持部との間の挟持間隔は調整可能とされている。このため電動ユニット搭載用のフレーム部の横断面を示す断面において、電動ユニット搭載用のフレーム部の外径サイズ等の横断面サイズが変更されたとしても、第１傾斜面及び第２傾斜面を、第１傾斜面及び第２傾斜面の傾斜方向に沿って相対変位させれば、第１挟持部の第１挟持面と第２挟持部の第２挟持面との間における挟持間隔を調整できる。この結果、電動ユニット搭載用のフレーム部の横断面を示す断面において、電動ユニット搭載用のフレーム部のサイズの変化に対応することができる。
【図面の簡単な説明】
【図１】電動車椅子を模式的に示す側面図である。
【図２】電動ユニット固定機構により電動ユニットを搭載している状態を示す側面図である。
【図３】電動ユニット固定機構の第１挟持部及び第２挟持部により車体フレームの電動ユニット搭載用のフレーム部を挟持する前の状態を示す断面図である。
【図４】電動ユニット固定機構の第１挟持部及び第２挟持部により車体フレームの電動ユニット搭載用のフレーム部を挟持した後の状態を示す断面図である。
【図５】電動ユニットの取付鍔部を車体フレームの電動ユニット搭載用のフレーム部に取り付ける前の状態を示す斜視図である。
【図６】他の実施例に係り、電動ユニット固定機構の第１挟持部及び第２挟持部により車体フレームの電動ユニット搭載用のフレーム部を挟持した後の状態を示す断面図である。
【符号の説明】
図中、１は車体フレーム、１０は着座部、１１は背もたれ部、１６は電動ユニット搭載用のフレーム部、２は駆動車輪、３は電動ユニット、３０はケース、３２は駆動モータ、４は電動ユニット固定機構、４０は第１挟持部、４１は第１挟持面、４５は第２挟持部、４６は第２挟持面、５１は第１傾斜面、５２は第２傾斜面、５６は締結孔、６は締結部材、６２は雄螺子部材を示す。[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an electric wheelchair equipped with an electric unit.
[0002]
[Prior art]
An electric electric wheelchair is generally a vehicle body frame having a seating portion for seating a user and a backrest portion for receiving the back of the user, a drive wheel disposed on the vehicle body frame, and an electric motor for rotating the drive wheel. Unit. And according to patent document 1, in the cross section which shows the cross section of the frame part for electric unit mounting, the 1st clamping part which has a 1st clamping surface, and the 2nd clamping which faces the 1st clamping surface of a 1st clamping part What has the electric unit fixing mechanism which has the 2nd clamping part with a surface is disclosed.
[0003]
According to this, when the electric unit is fixed to the vehicle body frame, the outer peripheral surface of the frame portion of the vehicle body frame is clamped by the first clamping surface of the first clamping unit and the second clamping surface of the second clamping unit. I have decided.
[0004]
[Patent Document 1] FIG. 9 of JP-A-9-262260
[0005]
[Problems to be solved by the invention]
According to the technique according to Patent Document 1 described above, as described above, when the electric unit is fixed to the vehicle body frame, the first holding surface of the first holding portion and the second holding portion of the second holding portion of the electric unit fixing mechanism. The outer peripheral surface of the frame portion of the frame is held by the holding surface. However, according to the technique according to Patent Document 1, it is not easy to cope with a change in the cross-sectional size of the frame portion.
[0006]
The present invention has been made in view of the above-described situation, and when the electric unit is fixed to the vehicle body frame, the electric wheelchair that can cope well even when the cross-sectional size of the vehicle body frame varies. It is in the subject to provide.
[0007]
[Means for Solving the Problems]
An electric wheelchair according to the present invention includes a vehicle body frame having a seating portion for seating a user and a frame portion for mounting the electric unit, and an electric motor having a drive motor disposed on the frame portion for mounting the electric unit on the vehicle body frame. An electric wheelchair comprising: a unit; a drive wheel rotatably disposed on the body frame or the electric unit; and an electric unit fixing mechanism that fixes the electric unit to a frame portion for mounting the electric unit on the body frame. The fixing mechanism is
A first sandwiching portion having a first sandwiching surface in a cross section showing a cross section of the frame portion for mounting the electric unit, and a first sandwiching frame portion for mounting the electric unit while facing the first sandwiching surface of the first sandwiching portion A second clamping part having a second clamping surface that is clamped by the first clamping surface of the part, and a first clamping part with a frame part for mounting the electric unit sandwiched between the first clamping part and the second clamping part And a fastening member for fastening the second clamping part,
The first clamping portion has a first inclined surface, the second clamping portion has a second inclined surface facing the first inclined surface, and the first inclined surface and the second inclined surface are inclined to the first. By relatively displacing the surface and the second inclined surface along the inclination direction, the holding interval between the first holding surface of the first holding portion and the second holding surface of the second holding portion can be adjusted. It is characterized by being.
[0008]
According to the electric wheelchair according to the present invention, when the drive motor of the electric unit is driven, the drive wheel rotates and the electric wheelchair runs.
[0009]
According to the electric wheelchair according to the present invention, in the cross section showing the cross section of the frame portion for mounting the electric unit, the electric unit mounting on the first holding surface of the first holding portion and the second holding surface of the second holding portion. Hold the frame part. In this manner, the first clamping part and the second clamping part are fastened with the frame unit for mounting the electric unit sandwiched between the first clamping surface of the first clamping part and the second clamping surface of the second clamping part. Fasten together with members.
[0010]
Here, the 1st clamping part has a 1st inclined surface, and the 2nd clamping part has a 2nd inclined surface facing a 1st inclined surface. By relatively displacing the first inclined surface and the second inclined surface along the inclination direction of the first inclined surface and the second inclined surface, the holding interval between the first holding portion and the second holding portion can be adjusted. Has been. Therefore, in the cross section showing the cross section of the frame portion for mounting the electric unit, even if the cross section size of the frame portion for mounting the electric unit is changed, the first inclined surface and the second inclined surface are changed to the first inclined surface. And if it carries out relative displacement along the inclination direction of a 2nd inclined surface, the clamping space | interval between the 1st clamping surface of a 1st clamping part and the 2nd clamping surface of a 2nd clamping part can be adjusted. As a result, in the cross section showing the cross section of the frame portion for mounting the electric unit, it is possible to cope with the change in the cross sectional size of the frame portion for mounting the electric unit.
[0011]
DETAILED DESCRIPTION OF THE INVENTION
According to the electric wheelchair according to the present invention, the first holding portion has the first inclined surface, and the second holding portion has the second inclined surface facing the first inclined surface. The degree of inclination of the first inclined surface and the second inclined surface can be appropriately set. By relatively displacing the first inclined surface and the second inclined surface in the inclination direction of the first inclined surface and the second inclined surface, the first holding surface of the first holding portion and the second holding surface of the second holding portion The clamping interval between them is adjustable.
[0012]
According to a preferred embodiment of the electric wheelchair according to the present invention, the frame portion for mounting the electric unit has an attachment hole penetrating in a direction along the direction perpendicular to the axis thereof, and the electric unit faces the attachment hole and is first. A form having a long hole extending in a direction connecting the sandwiching portion and the second sandwiching portion can be employed. In this case, the nut member can be screwed onto the bolt member inserted through the mounting hole of the frame portion for mounting the electric unit and the long hole of the electric unit. Thereby, even when the cross-sectional size of the frame portion for mounting the electric unit is changed, the attachment property of the electric unit to the frame portion for mounting the electric unit can be improved.
[0013]
Further, it is possible to adopt a form in which the electric unit is fixed to the frame portion of the body frame for mounting the electric unit, and the driving wheel is attached to the electric unit.
[0014]
【Example】
Hereinafter, an embodiment of the present invention will be described in detail with reference to FIGS. The present embodiment is directed to an electric wheelchair based on a body frame 1 of a manually-running electric wheelchair and an electric unit 3 mounted on the body frame 1 of the manually-running wheelchair. As shown in FIG. 1, the electric wheelchair is a vehicle body frame 1 that constitutes a skeleton, a drive wheel 2 that is rotatably disposed on the vehicle body frame 1 and has an outer peripheral surface 2 c, and a drive source that rotates the drive wheel 2. It has an electric unit 3. The vehicle body frame 1 has a seating portion 10 on which a user is seated and a backrest portion 11 that receives the back of the user. Further, the body frame 1 is provided by an elbow armrest 12 for putting an elbow of a user seated on the seat portion 10 and a caregiver who cares for a user seated on the seat portion 10 provided on the rear side of the body frame 1. It is seated on the seating part 10, a grip-like operation part 15 that can be operated, a frame part 16 for mounting the electric unit located below the seating part 10 and extending in the vertical direction, a battery 17 that feeds power to the electric unit 3, and the seating part 10. And a footrest 19 on which the user's legs are placed. In FIG. 1, the drive wheel 2 is abbreviated.
[0015]
When the wheelchair is electrified, an operation frame portion 1e is attached to the front side of the body frame 1, and an electric operation portion 14 having an electric operation lever 14a operated by a user seated on the seat portion 10 is attached to the operation frame portion 1e. Yes. The drive wheels 2 are positioned on the left and right sides of the vehicle body frame 1 in the vehicle width direction, and are rotatably provided via the axles 21. The drive wheel 2 is rotationally driven by the electric unit 3 fixed to the vehicle body frame 1 while being inserted through the axle 21 of the vehicle body frame 1. Auxiliary wheels 18 are provided on the front side of the body frame 1. The frame portions 16 for mounting the electric unit are provided on the left and right sides of the vehicle body frame 1 in the vehicle width direction. Therefore, the electric unit 3 is also provided on the left and right sides of the vehicle body frame 1 in the vehicle width direction.
[0016]
FIG. 2 shows the vicinity of the electric unit 3. The electric unit 3 includes a case 30 that is formed by connecting divided cases with a fixture 30 w and that incorporates transmission gears, and a drive motor 32 that is fixed to the case 30. The axle 21 of the drive wheel 2 is inserted into the horizontal shaft through the horizontal shaft type shaft hole 30x of the case 30. When the drive motor 32 is driven, the axle 21 is rotated via the transmission gears in the case 30, and the drive wheel 2 is rotated, so that the electric wheelchair runs. According to the present embodiment, the drive wheel 2 is not directly attached to the vehicle body frame 1, but the electric unit 3 can be attached to and detached from the frame portion 16 for mounting the electric unit of the vehicle body frame 1 as will be described later. The drive wheel 2 is attached to the electric unit 3.
[0017]
As shown in FIG. 2, an electric unit fixing mechanism 4 for fixing the electric unit 3 to the frame unit 16 for mounting the electric unit of the vehicle body frame 1 is provided. FIG. 3 shows a cross section of the frame unit 16 for mounting the electric unit and also shows a cross section of the electric unit fixing mechanism 4. As shown in FIG. 3, the electric unit fixing mechanism 4 includes a metal first holding part 40 provided in the case 30 of the electric unit 3 and a metal second holding part 45 facing the first holding part 40. And a fastening member 6. The fastening member 6 fastens the first clamping part 40 and the second clamping part 45 in a state where the outer peripheral surface 16a of the frame part 16 for mounting the electric unit is sandwiched between the first clamping part 40 and the second clamping part 45. To do. The fastening member 6 extends along the front-rear direction (forward and backward direction) of the electric wheelchair.
[0018]
As shown in FIG. 3, the first clamping portion 40 is formed integrally with the case 30 of the electric unit 3, and includes a flat first clamping surface 41 and a first clamping surface 41 that are straight in cross section. And a flat first intersecting surface 42 that intersects with. The second clamping unit 45 is detachably provided on the first clamping unit 40 of the case 30 of the electric unit 3 and is detachable from the first clamping unit 40 of the case 30. Therefore, the second clamping part 45 is detachable from the first clamping part 40. The second sandwiching portion 45 has a flat second sandwiching surface 46 that is straight in cross section and a flat second intersecting surface 47 that intersects the second sandwiching surface 46. As shown in FIG. 3, the first clamping surface 41 and the second clamping surface 46 are parallel or substantially parallel to each other and face each other. As a result, the outer peripheral surface 16a of the frame unit 16 for mounting the electric unit. A clamping interval A (see FIG. 4) is formed.
[0019]
As shown in FIG. 3, the 1st clamping part 40 has the 1st inclined surface 51 which inclines linearly with a cross section. The 2nd clamping part 45 has the 2nd inclined surface 52 which inclines linearly with a cross section while facing the 1st inclined surface 51. As shown in FIG. The first inclined surface 51 and the second inclined surface 52 are inclined at an angle θ1 with respect to a direction perpendicular to the axis of an axis S1 of a fastening hole 56 described later.
[0020]
In the state before the fastening member 6 is fully fastened, the first inclined surface 51 and the second inclined surface 52 are inclined directions of the first inclined surface 51 and the second inclined surface 52 (the directions of arrows W1 and W2 shown in FIG. 4). If the relative displacement is performed, the size of the clamping interval A between the first clamping surface 41 of the first clamping unit 40 and the second clamping surface 46 of the second clamping unit 45 can be adjusted. Moreover, the adjustment of the size of the clamping interval A is stepless.
[0021]
A fastening hole 56 having a female screw 55 is formed in the first inclined surface 51 of the first clamping unit 40 so as to open. The axis S1 of the fastening hole 56 is parallel to the direction connecting the first clamping surface 41 of the first clamping unit 40 and the second clamping surface 46 of the second clamping unit 45. According to the present embodiment, the axis S1 of the fastening hole 56 extends along the front-rear direction (forward and backward direction) of the electric wheelchair. An insertion hole 48 that faces the fastening hole 56 is formed through the second inclined surface 52 of the second clamping part 45. The insertion hole 48 has an inner peripheral wall 48k, and intersects the direction (arrow W4 direction) that connects the first clamping surface 41 of the first clamping part 40 and the second clamping surface 46 of the second clamping part 45 (arrow E direction). ) Along the long hole. Therefore, the second clamping part 45 is movable relative to the first clamping part 40 along the long axis direction (arrow E direction) of the insertion hole 48.
[0022]
As shown in FIG. 3, the fastening member 6 includes a male screw member 62 having a male screw 61 that can be screwed into the female screw 55 of the fastening hole 56, and a male screw member 62 provided at the other end of the male screw member 62. And a head 63 having a larger diameter. The male screw member 62 of the fastening member 6 can be inserted into the insertion hole 48.
[0023]
Now, the case where the electric unit 3 is mounted on the frame unit 16 for mounting the electric unit of the vehicle body frame will be described. 3 and 4 show a cross section of the frame unit 16 for mounting the electric unit. As can be understood from FIGS. 3 and 4, the outer peripheral surface 16 a of the frame unit 16 for mounting the electric unit is sandwiched between the first clamping surface 41 of the first clamping unit 40 and the second clamping surface 46 of the second clamping unit 45. Thus, the 1st clamping part 40 and the 2nd clamping part 45 are arrange | positioned. In this state, the male screw 61 of the male screw member 62 of the fastening member 6 inserted through the insertion hole 48 of the second clamping part 45 is screwed to the female screw 55 of the fastening hole 56 of the second clamping part 45, and the fastening member 6 is concluded. As a result, as shown in FIG. 4, the outer peripheral surface 16 a of the frame unit 16 for mounting the electric unit is sandwiched between the first clamping surface 41 of the first clamping unit 40 and the second clamping surface 46 of the second clamping unit 45. The
[0024]
By the way, when the model number of the vehicle body frame 1 is different, the outer diameter size W3 (transverse section size) of the frame unit 16 for mounting the electric unit often changes. Further, the outer diameter size W3 of the frame portion 16 for mounting the electric unit may vary within a tolerance in the manufacturing process. Even in such a case, according to the present embodiment, as described above, the first sandwiching portion 40 has the first inclined surface 51, and the second sandwiching portion 45 faces the first inclined surface 51. As described above, the second inclined surface 52 is inclined in the same direction. Then, the second inclined surface 52 is slid with respect to the first inclined surface 51 along the inclination directions of the first inclined surface 51 and the second inclined surface 52 (the directions of arrows W1 and W2 shown in FIGS. 3 and 4). If relative displacement is performed, as described above, the clamping interval A (see FIG. 4) between the first clamping surface 41 of the first clamping unit 40 and the second clamping surface 46 of the second clamping unit 45 is stepless. Can be adjusted.
[0025]
For this reason, even if the outer diameter size W3 of the frame unit 16 for mounting the electric unit varies, the frame unit 16 for mounting the electric unit is connected to the first clamping surface 41 and the second clamping unit of the first clamping unit 40. The outer peripheral surface 16a of the frame portion 16 for mounting the electric unit can be favorably clamped by the 45 second clamping surfaces 46. That is, it is possible to cope with a change in the outer diameter size W3 of the frame portion 16 for mounting the electric unit.
[0026]
According to the present embodiment, as shown in FIG. 5, the frame unit 16 for mounting the electric unit has a mounting boss portion 160 having a prismatic shape at an intermediate portion thereof. The mounting boss 160 has a mounting hole 162 penetrating along the direction perpendicular to the axis of the frame unit 16 for mounting the electric unit. The attachment hole 162 functions as an axle insertion hole for inserting the wheel axle of the manual wheelchair before attaching the electric unit 3 to the manual wheelchair. According to the present embodiment, the wheel axle of the manual wheelchair is removed from the mounting hole 162 of the frame 1. According to the electric wheelchair according to this embodiment in which the electric unit 3 is attached to the manual wheelchair, the axle 21 that is the rotation center of the drive wheel 2 is inserted into the shaft hole 30x of the electric unit 3 fixed to the frame 1. Therefore, the axis of the axle 21 of the drive wheel 2 is offset backward by L from the axis of the wheel in the case of a manual wheelchair (see FIG. 2).
[0027]
According to the present embodiment, as shown in FIG. 5, the electric unit 3 attached to the manual wheelchair has the attachment collar portion 35 extending outward (in the direction of arrow W 4). The attachment flange 35 protrudes from the case 30 of the electric unit 3 toward the front of the electric wheelchair, and faces the attachment hole 162 of the frame unit 16 for mounting the electric unit. Further, a long hole 36 is formed in the attachment flange 35 in the shape of a through hole. The long axis 36m of the long hole 36 is a direction connecting the first clamping surface 41 of the first clamping unit 40 of the electric unit 3 and the second clamping surface 46 of the second clamping unit 45 (arrow W4 direction; interval of the clamping interval A). It extends along the width (front and rear direction of the electric wheelchair).
[0028]
When the electric unit 3 is mounted on the frame unit 16 for mounting the electric unit of the vehicle body frame 1, as can be understood from FIG. 5, the flat mounting surface 163 of the mounting boss 160 of the frame unit 16 for mounting the electric unit. The bolt member 8 is inserted into the mounting hole 162 of the mounting boss 160 and the elongated hole 36 of the electric unit 3, and the nut member 85 is inserted into the male screw 8 a of the bolt member 8. The female screw 85a is screwed. As a result, the mounting hole 162 that functioned as the axle insertion hole of the manual wheelchair is used as the bolt insertion hole, and the mounting flange portion 35 of the electric unit 3 is removed by the bolt member 8 and the nut member 85 inserted through the mounting hole 162. It fixes to the attachment boss part 160 of the frame part 16 for mounting the electric unit. In this state, as shown in FIG. 2, most of the electric unit 3 is disposed behind the attachment hole 162 functioning as an axle insertion hole of the manual wheelchair.
[0029]
At this time, even if the size of the outer diameter size W3 of the frame portion 16 for mounting the electric unit is changed, the long hole 36 of the mounting flange portion 35 can be displaced relative to the bolt member 8 in the direction of the arrow W4. . Therefore, when the mounting flange portion 35 of the electric unit 3 is fixed to the frame portion 16 for mounting the electric unit by the bolt member 8 and the nut member 85, the outer diameter size W3 of the frame portion 16 for mounting the electric unit is good. It can correspond to. As can be understood from FIG. 2, the fastening member 6 and the bolt member 8 are close to each other, and the extending direction of the fastening member 6 and the fastening hole 56 and the extending direction of the bolt member 8 intersect each other. Has been.
[0030]
In FIG. 1, the axle 21 of the drive wheel 2 is arranged offset with respect to the mounting hole 162 of the body frame 1. According to this embodiment, when the user is seated on the seating portion 10 of the vehicle body frame 1, the weight load F 1 including the vehicle body frame 1 and the user acts as a moment around the axle 21. Further, the weight load F 2 of the electric unit 3 having the drive motor 32 acts as a reverse moment about the axle 21. The electric unit 3 may run idle about the axle 21 due to the effects of the moments F1 and F2, and the electric unit 3 needs to face this moment. Here, the first clamping surface 41 of the first clamping unit 40 of the electric unit fixing mechanism 4 and the second clamping surface 46 of the second clamping unit 45 can function as torque receiving surfaces facing the moments F1 and F2. The electric unit 3 can be prevented from rotating. Further, the bolt member 8 and the nut member 85 can also function as torque receivers facing the moments F1 and F2, and can prevent the electric unit 3 from rotating.
[0031]
(Other examples)
FIG. 6 shows another embodiment of the present invention. Also in the present embodiment, the second holding part 45 is divided with respect to the case 30 of the electric unit 3. However, the second clamping portion 45 is rotatable around the axis S1 of the fastening hole 56, that is, around the axis of the fastening member 6. The second clamping part 45 has a second clamping part 45 x on the opposite side of the second clamping surface 46 with respect to the axis S 1 of the fastening hole 56. As shown in FIG. 6, the second clamping part 45x has a flat second clamping surface 46x. The second clamping surface 46x is formed on the side opposite to the second clamping surface 46 with respect to the axis S1 of the fastening hole 56, and is substantially parallel or parallel to the second clamping surface 46.
[0032]
Also in the present embodiment, as can be understood from FIG. 6, the second inclined surface 52 is set to be inclined with respect to the first inclined surface 51 (in the directions of the arrows W 1 and W 2). If it is slid along and relatively displaced, the clamping interval A between the first clamping surface 41 of the first clamping unit 40 and the second clamping surface 46 of the second clamping unit 45 is steplessly set as described above. Can be adjusted. For this reason, even if the size of the outer diameter size W3 of the frame portion 16 for mounting the electric unit is changed, it is possible to cope with the change.
[0033]
Further, when the outer diameter size W3 of the frame portion 16 for mounting the electric unit is further changed, the second clamping portion 45 is rotated 180 degrees around the axis S1 of the fastening hole 56, that is, the axis of the fastening member 6. Then, the outer peripheral surface 16a of the frame unit 16 for mounting the electric unit is clamped in the cross-sectional direction between the second clamping surface 46x of the second clamping unit 45x and the first clamping surface 41 of the first clamping unit 40. Is also possible. For this reason, even when the outer diameter size W3 of the frame portion 16 for mounting the electric unit is considerably changed, the applicability can be improved. In addition, the present invention is not limited to only the embodiments described above and shown in the drawings, and can be implemented with appropriate modifications within a range not departing from the gist.
[0034]
【The invention's effect】
According to this invention, the 1st clamping part has a 1st inclined surface, and the 2nd clamping part has a 2nd inclined surface facing a 1st inclined surface. By relatively displacing the first inclined surface and the second inclined surface in the inclination direction of the first inclined surface and the second inclined surface, the holding interval between the first holding portion and the second holding portion can be adjusted. Yes. For this reason, in the cross section showing the cross section of the frame portion for mounting the electric unit, even if the cross section size such as the outer diameter size of the frame portion for mounting the electric unit is changed, the first inclined surface and the second inclined surface are changed. If the relative displacement is performed along the inclination direction of the first inclined surface and the second inclined surface, the holding interval between the first holding surface of the first holding portion and the second holding surface of the second holding portion can be adjusted. . As a result, it is possible to cope with a change in the size of the frame portion for mounting the electric unit in the cross section showing the cross section of the frame portion for mounting the electric unit.
[Brief description of the drawings]
FIG. 1 is a side view schematically showing an electric wheelchair.
FIG. 2 is a side view showing a state where the electric unit is mounted by the electric unit fixing mechanism.
FIG. 3 is a cross-sectional view illustrating a state before the electric unit mounting frame portion of the vehicle body frame is clamped by the first clamping portion and the second clamping portion of the electric unit fixing mechanism.
FIG. 4 is a cross-sectional view showing a state after the frame unit for mounting the electric unit of the vehicle body frame is clamped by the first clamping unit and the second clamping unit of the electric unit fixing mechanism.
FIG. 5 is a perspective view showing a state before the mounting flange portion of the electric unit is attached to the frame portion for mounting the electric unit of the vehicle body frame.
FIG. 6 is a cross-sectional view showing a state after the frame unit for mounting the electric unit of the vehicle body frame is clamped by the first clamping unit and the second clamping unit of the electric unit fixing mechanism according to another embodiment.
[Explanation of symbols]
In the figure, 1 is a body frame, 10 is a seating part, 11 is a backrest part, 16 is a frame part for mounting an electric unit, 2 is a driving wheel, 3 is an electric unit, 30 is a case, 32 is a driving motor, and 4 is electric Unit fixing mechanism, 40 is a first clamping portion, 41 is a first clamping surface, 45 is a second clamping portion, 46 is a second clamping surface, 51 is a first inclined surface, 52 is a second inclined surface, and 56 is a fastening hole , 6 is a fastening member, and 62 is a male screw member.

Claims

A vehicle body frame having a seat part for seating a user and a frame part for mounting the electric unit;
An electric unit having a drive motor disposed in a frame portion for mounting the electric unit of the vehicle body frame;
A drive wheel rotatably disposed on the body frame or the electric unit;
In the electric wheelchair comprising the electric unit fixing mechanism for fixing the electric unit to the frame portion for mounting the electric unit of the body frame,
The electric unit fixing mechanism is
A first clamping part having a first clamping surface in a cross section showing a cross section of the frame part for mounting the electric unit, and the frame part for mounting the electric unit while facing the first clamping surface of the first clamping part A second clamping part having a second clamping surface that clamps the first clamping part with the first clamping surface of the first clamping part, a first clamping surface of the first clamping part, and a second clamping surface of the second clamping part A fastening member that fastens the first clamping part and the second clamping part in a state where the frame part for mounting the electric unit is sandwiched therebetween,
The first clamping part has a first inclined surface, and the second clamping part has a second inclined surface facing the first inclined surface,
The first sandwiching surface and the second sandwiching surface of the first sandwiching portion are obtained by relatively displacing the first sloped surface and the second sloped surface along the tilting direction of the first sloped surface and the second sloped surface. The electric wheelchair characterized in that the holding interval between the second holding surface of the part is adjustable.

In Claim 1, the frame portion for mounting the electric unit has a mounting hole penetrating in a direction along a direction perpendicular to the axis thereof,
The electric unit has a long hole facing the mounting hole and extending in a direction connecting the first clamping surface of the first clamping part and the second clamping surface of the second clamping part,
An electric wheelchair, wherein a nut member is screwed to a bolt member inserted through the mounting hole of the frame portion for mounting the electric unit and the elongated hole of the electric unit.

The electric wheelchair according to claim 1 or 2, wherein the electric unit is fixed to a frame portion for mounting the electric unit of the vehicle body frame, and the driving wheel is attached to the electric unit.