JP4311025B2

JP4311025B2 - Transport vehicle

Info

Publication number: JP4311025B2
Application number: JP2003013569A
Authority: JP
Inventors: 英幸己野
Original assignee: Toyota Industries Corp
Current assignee: Toyota Industries Corp
Priority date: 2003-01-22
Filing date: 2003-01-22
Publication date: 2009-08-12
Anticipated expiration: 2023-01-22
Also published as: JP2004224161A

Description

【０００１】
【発明の属する技術分野】
本発明は、例えば工場内の走行路に設けられた誘導部材に沿って走行する搬送車に関する。
【０００２】
【従来の技術】
従来、荷物を積載した搬送車や荷物を積載した台車を牽引する搬送車が、工場内や倉庫内等にて用いられている。
これらの搬送車は、床面に敷設あるいは床内部に埋設された誘導部材（光学誘導式のテープ、磁気誘導式のテープまたは電線等）に沿って、予め設定された走行ルートを走行する。
従来、２個または１個の駆動輪と４個の従動輪とを備え、駆動輪を搬送車のほぼ中心に配置し、２個の従動輪を搬送車の前端近傍に配置し、２個の従動輪を搬送車の後端近傍に配置し、進行方向側の２個の従動輪を走行ルートに沿って操舵制御し、進行方向と反対側の従動輪を進行方向に固定する搬送車が提案されている（例えば特許文献１や特許文献２等）。
【０００３】
【特許文献１】
特開平１０−６９８０号公報
【特許文献２】
特開平１１−７３２２３号公報
【０００４】
【発明が解決しようとする課題】
従来の搬送車は、ほぼ中心に駆動輪が設けられ、水平面内で旋回（操舵）可能な４個の従動輪が搬送車の四隅に設けられている。このため、４個の従動輪及び駆動輪が全て接地しており、走行路の凹凸等によっては駆動輪が接地しない可能性がある。この場合、駆動輪が必ず接地するようにするためには、駆動輪にサスペンション機構を設ける必要がある。
また、従来の搬送車は、進行方向側の２個の従動輪を走行ルートに沿って操舵制御するとともに、進行方向と反対側の２個の従動輪を進行方向に固定させている。このため、進行方向（前進及び後進）に合わせて操舵制御する従動輪と、進行方向に固定する従動輪とを切り替える必要があり、４個の従動輪の制御機構が複雑である。
本発明は、このような点に鑑みて創案されたものであり、駆動輪を確実に接地させることが可能であり、よりシンプルな機構で直進性と旋回性をより向上することができる搬送車を提供することを課題とする。
【０００５】
【課題を解決するための手段】
上記課題を解決するための手段として、請求項１に記載の搬送車は、本体フレーム部に、駆動輪と、当該駆動輪の前後に水平面内で自在に旋回可能な前従動輪と後従動輪とを備えた搬送車であって、前記駆動輪が床面に当接し、前記前従動輪または後従動輪の一方が前記床面に当接した場合に、前記前従動輪または後従動輪の他方が前記床面より所定距離だけ浮き上がるように、前記駆動輪が、前記前従動輪の下端部と前記後従動輪の下端部とを結んだ直線よりも下方に突出するように設けられており、前記前従動輪と前記後従動輪は操舵制御する機構を有することなく自在に旋回可能であるとともに、進行方向に対して左右に配置されて各々独立して回転可能な少なくとも２個の駆動輪を備えている。
また、請求項２に記載の搬送車は、請求項１に記載の搬送車であって、前記駆動輪と前記前従動輪と前記後従動輪のそれぞれは、サスペンション機構を有することなく、前記本体フレーム部に取付けられている。
【０００６】
また、請求項３に記載の搬送車は、請求項１または２に記載の搬送車であって、少なくとも２個の駆動輪を有し、各駆動輪を各々駆動する少なくとも２個の電動モータと、各電動モータを各々一方向に可変速で回転駆動させる電力を供給し、且つ各電動モータの回転速度の差で搬送車を旋回制御する制御手段と、走行路に設けられ走行ルートを示す誘導部材を検出する第１検出手段と、前記走行路に設けられ走行速度に関する情報を示す走行制御部材を検出する第２検出手段と、前進指示操作手段と後進指示操作手段とを含む進行方向指示手段とを備える。
そして、第１検出手段として前進用第１検出手段と後進用第１検出手段とを備え、第２検出手段として前進用第２検出手段と後進用第２検出手段とを備える。
更に、前進用第１検出手段と制御手段とを接続するとともに後進用第１検出手段と制御手段とを開放、あるいは前進用第１検出手段と制御手段とを開放するとともに後進用第１検出手段と制御手段とを接続可能な第１切替手段と、前進用第２検出手段と制御手段とを接続するとともに後進用第２検出手段と制御手段とを開放、あるいは前進用第２検出手段と制御手段とを開放するとともに後進用第２検出手段と制御手段とを接続可能な第２切替手段と、電動モータの回転方向が切り替わるように電動モータと制御手段との配線を前進方向または後進方向に切り替えるモータ切替手段とを備える。
【０００７】
【発明の実施の形態】
以下に本発明の実施の形態を図面を用いて説明する。図１は、本発明の搬送車１の一実施の形態の概略外観図を示している。
●［全体構成（図１）］
図１を用いて、本実施の形態の搬送車１の全体構成について説明する。図１（Ａ）は搬送車１の側面図を示しており、図１（Ｂ）は搬送車１の底面図（裏側）を示している。ここで、Ｘ軸及びＹ軸は水平方向を示し、Ｘ軸が進行方向を示し（図１に示す例では、右方向が前進方向を示し、左方向が後進方向を示している）、Ｚ軸は垂直方向を示している。
【０００８】
搬送車１には、本体フレーム部１０に、２個の駆動輪２０ａ及び２０ｂと、当該駆動輪２０ａ及び２０ｂの前後に２個の従動輪３０ｆ（この場合、前従動輪）及び３０ｒ（この場合、後従動輪）とが設けられている。各駆動輪２０ａ及び２０ｂは、進行方向（Ｘ軸方向）に対して本体フレーム部１０のほぼ中心に、所定の間隔（距離Ｌｗ）を設けて配置されている。本実施の形態における搬送車１は、２個の駆動輪２０ａ及び２０ｂの回転差を用いて搬送車１を旋回させるため、距離Ｌｗがある程度大きい方が直進安定性が向上する。このため、各駆動輪２０ａ及び２０ｂは、本体フレーム部１０のＹ軸方向の幅の内部に収まる間隔、且つ適切な間隔（距離Ｌｗ）で配置されている。
なお、本実施の形態における搬送車１は、駆動輪の回転差を用いて旋回するため、少なくとも２個の駆動輪を備えている。
【０００９】
各駆動輪２０ａ及び２０ｂには、各々を回転駆動する電動モータ２３ａ及び２３ｂが設けられている。電動モータ２３ａは、伝達部材２２ａ（チェーン、ベルト等）を介して駆動輪２０ａに固定されたホイール２１ａを回転させる。同様に、電動モータ２３ｂは、伝達部材２２ｂを介して駆動輪２０ｂに固定されたホイール２１ｂを回転させる。各駆動輪２０ａ及び２０ｂは各々独立して回転することが可能となるように、シャフト２５に組み付けられている。
なお、本実施の形態における搬送車１では、電動モータにて駆動輪２０ａ及び２０ｂを駆動しているが、駆動方法は電動モータに限定されるものではない。
【００１０】
また、一方の従動輪（例えば３０ｆ）は、進行方向に対して本体フレーム部１０の前端近傍に設けられている。例えば右側が進行方向の場合は、従動輪３０ｆが本体フレーム部１０の前端近傍に設けられている。そして、他方の従動輪（例えば３０ｒ）は、進行方向に対して本体フレーム部１０の後端近傍に設けられている。例えば右側が進行方向の場合は、従動輪３０ｒが本体フレーム部１０の後端近傍に設けられている。
なお、従動輪は、駆動輪を挟んで前後に設けられていればよく、前端あるいは後端に限定するものではない。また、従動輪３０ｆ（前従動輪）及び従動輪３０ｒ（後従動輪）は、各々１個であることが好ましいが、各々２個以上であってもよい。
また、各従動輪３０ｆ及び３０ｒは、床面等に敷設された走行ルートを示す誘導部材をできるだけ踏まないように、Ｙ軸方向の中心からやや離れた位置に設けられている。
【００１１】
各従動輪３０ｆ及び３０ｒは、支持部材３１ｆ及び３１ｒにて本体フレーム部１０に接続されており、搬送車１の旋回に応じて任意の方向に向かうように水平方向に回転自在に設けられている。
また、各従動輪３０ｆ及び３０ｒは、各駆動輪２０ａ及び２０ｂが床面等に接地し且つ一方の従動輪が当該床面等に接地した場合に、他方の従動輪が当該床面等から所定距離Ｌｖだけ浮くように設けられている。これにより、搬送車１と床面とは、２個の駆動輪（２０ａ及び２０ｂ）と一方の従動輪（３０ｆまたは３０ｒ）の３点で接地し、２個の駆動輪２０ａ及び２０ｂは必ず床面と接地する。このため、駆動輪２０ａ及び２０ｂの双方の駆動力を確実に床面に伝えることができ、直進性及び旋回性をより向上させることができる。
【００１２】
次に、駆動輪２０ａ及び２０ｂを駆動する電動モータ２３ａ及び２３ｂを制御する制御手段４０について説明する。
制御手段４０は、本体フレーム部１０のほぼ中心に載置されている。制御手段４０は、各電動モータ２３ａ及び２３ｂを各々一方向に可変速で回転駆動する電力を各々供給可能であり、各電動モータ２３ａ及び２３ｂの回転速度の差で搬送車１を旋回可能である。ただし、一方向に可変速で回転駆動するため、前進と後進を切り替えることができないが、前進と後進を切り替える方法については後述する。
電源５０（バッテリ等）は、本体フレーム部１０に設けられた電源収容部１０ａに収められている。電源５０は重量が大きいため、駆動輪２０ａ及び２０ｂの両側にほぼ均等な距離で配置されている。
【００１３】
搬送車１の走行ルートには、走行ルートを示す誘導部材が走行路に設けられている（床面等に敷設あるいは床内部に埋設されている）。搬送車１は、誘導部材を検出して走行ルートに沿って走行する。また、走行ルート中には、走行速度に関する情報を示す走行制御部材が必要に応じて設けられている。搬送車１は、走行制御部材を検出して走行速度を変更したり（低速あるいは高速等）停止したりする。
本体フレーム部１０の前端及び後端には、誘導部材を検出する走行ルート検出センサ６１ｆ及び６１ｒ（第１検出手段）と、走行制御部材を検出する走行速度検出センサ６２ｆ及び６２ｒ（第２検出手段）が、ブラケット６０ｆ、６０ｒ、６３ｆ、６３ｒを介して設けられている。
【００１４】
走行ルート検出センサ６１ｆ及び走行速度検出センサ６２ｆは、搬送車１が当該センサの方向に進行している場合（本実施の形態では前進方向）に用いられる。また、走行ルート検出センサ６１ｒ及び走行速度検出センサ６２ｒは当該センサの方向に進行している場合（本実施の形態では後進方向）に用いられる。つまり、搬送車１は、進行方向の前端に、当該進行方向に対応する走行ルート検出センサ及び走行速度検出センサを備えている。
なお、走行速度検出センサ６２ｆの間隔Ｌｆと、走行速度検出センサ６２ｒの間隔Ｌｒは、前進の場合と後進の場合で異なる走行制御部材を検出できるように、異なる間隔で設けられている。
【００１５】
また、図示しないが、搬送車１は前進指示操作手段（前進ボタン等）と後進指示操作手段（後進ボタン等）を含む進行方向指示手段を備えている。進行方向指示手段は、有線にて搬送車１に設けてもよいし、無線にて搬送車１とは分離できるようにしてもよい。また、進行方向指示手段には、停止指示操作手段（停止ボタン）等、他の指示を行う操作手段を備えていてもよい。
また進行方向指示手段の操作は、搬送車１が走行路の実質直線である部分で走行又は停車中に操作することが望ましい。そうすれば進行方向が変わった際に、第１の検出手段が確実に誘導部材を検出できる。
【００１６】
●［搬送車の姿勢（図２）］
図２（Ａ）及び（Ｂ）は、搬送車１が従動輪３０ｆの方向に進行する場合における姿勢の模式図を示している。この場合、床面から所定距離Ｌｖだけ浮く従動輪は、図２（Ａ）に示すように従動輪３０ｆ（前従動輪）である場合と、図２（Ｂ）に示すように従動輪３０ｒ（後従動輪）である場合の２通りがある。本実施の形態における搬送車１では、２個の駆動輪２０ａ及び２０ｂと、一方の従動輪（３０ｆまたは３０ｒのどちらか）が床面に接地する。
このように、２個の駆動輪２０ａ及び２０ｂが確実に床面に接地するため、直進性をより向上させることができるとともに、駆動輪の回転差で旋回させる搬送車１では旋回性をより向上させることができる。
【００１７】
前後の従動輪両方に荷重がかかっている場合では、従動輪に発生する首振り現象（進行方向、旋回方向に関係なく種々の方向を向く現象）にて、蛇行が発生しやすく、走行安定性が低下する。しかし、本実施の形態における搬送車１では、搬送車１の荷重は、図２に示すとおり、接地面Mｆ部分と接地面Ｍｒ部分のどちらか一方と接地面Ｍｄ部分にかかる。つまり接地面Mｆ部分と接地面Ｍｒ部分の他方には荷重はかからない。従って、首振り現象が発生する従動輪の接地している数が少ないので蛇行が発生しにくく、走行安定性が向上する。
さらに搬送車１にかかる荷重の重心がほぼ中央から進行方向と逆側にある場合や、搬送車１を牽引車として利用する場合、図２（Ａ）に示すとおり、進行方向と逆側の従動輪（図２（Ａ）では従動輪３０ｒ）が接地する。つまり駆動輪より進行方向に対して後ろ側の従動輪が接地するので、首振り現象の影響がさらに小さくなり、走行安定性がさらに向上する。
【００１８】
なお、従動輪と床面との所定距離Ｌｖは、搬送車１のサイズ、ホイールベース、及び床面の凹凸状態等に応じて適切な距離に設定する。本実施の形態における搬送車１では、本体フレーム部１０の長さＬｂが１［ｍ］程度の長さの搬送車１を工場内の床面で使用し、所定距離Ｌｖを約１［ｍｍ］〜２［ｍｍ］に設定した。この所定距離Ｌｖは、種々の寸法に設定することが可能である。
【００１９】
以上に説明したように、本実施の形態における搬送車１では、駆動輪２０ａ及び２０ｂを確実に床面に接地させることが可能であり、床面に確実に駆動力を伝達できる。また、従動輪を操舵制御したり進行方向に固定する機構を必要とせず、水平面内で自在に旋回可能な従動輪を設けるだけでよく、駆動輪にサスペンション機構等を設ける必要もない。このように、よりシンプルな機構で搬送車１の直進性及び旋回性をより向上させることができる。
また本実施の形態では、従動輪は駆動輪を挟んで前後に各々１個である。つまり、図２（Ａ）または図２（Ｂ）に示すとおり、２個の駆動輪と１個の従動輪の３輪支持である。従って、従動輪が駆動輪を挟んで前後に各々２個以上の場合に比べて、駆動輪２０ａおよび２０ｂをより確実に接地させることが可能である。
また、（電動モータを含む）駆動輪、従動輪、第１及び第２検出手段、制御手段等の各構成要素が各々分離されているので、種々のサイズあるいは形状の本体フレーム部に設けることが可能であり、種々のサイズあるいは形状の搬送車１を構成することが可能である。
【００２０】
●［回路構成（図３）］
次に、図３を用いて、搬送車１の回路構成について説明する。図３（Ａ）は、図１（Ａ）及び（Ｂ）に示す前進及び後進が可能な搬送車１の回路構成の例を示している。図３（Ｂ）は、図１（Ａ）及び（Ｂ）に示す搬送車１から本体フレーム部１０の後端に設けられた走行ルート検出センサ６１ｒ及び走行速度検出センサ６２ｒを省略し、前進のみが可能な搬送車１の回路構成の例を示している。
図３（Ａ）を用いて、前進及び後進が可能な搬送車１の回路構成について説明する。
制御手段４０は、電動モータ２３ａを一方向に可変速で回転駆動させる電力を供給可能な端子ＭＲ＋と端子ＭＲ−と、電動モータ２３ｂを一方向に可変速で回転駆動させる電力を供給可能な端子ＭＬ＋と端子ＭＬ−とを備えている。
【００２１】
進行方向指示手段４０ｃの前進指示操作手段４０ｆが操作されると、第１切替手段７１が走行ルート検出センサ６１ｆ（前進用第１検出手段）と制御手段４０の走行ルート検出センサ入力ＳＣとを接続して走行ルート検出センサ６１ｒ（後進用第１検出手段）と制御手段４０とを開放する。また、第２切替手段７２が走行速度検出センサ６２ｆ（前進用第２検出手段）と制御手段４０の走行速度検出センサ入力ＳＲ（右側入力）及びＳＬ（左側入力）とを接続して走行速度検出センサ６２ｒ（後進用第２検出手段）と制御手段４０とを開放する。このように、前進用第１検出手段と前進用第２検出手段を制御手段４０に接続し、後進用第１検出手段と後進用第２検出手段を制御手段４０から開放する。
【００２２】
更に、モータ切替手段７３が電動モータ２３ａの＋端子を制御手段４０の端子ＭＲ＋と接続して電動モータ２３ａの−端子を制御手段４０の端子ＭＲ−に接続する。同様に、モータ切替手段７３が電動モータ２３ｂの＋端子を制御手段４０の端子ＭＬ＋と接続して電動モータ２３ｂの−端子を制御手段４０の端子ＭＬ−に接続する。このように、モータを前進方向に回転させるように各モータと制御手段４０とを接続する。
この接続により、制御手段４０は電動モータ２３ａ及び２３ｂを可変速で一方向に回転駆動することで搬送車１を可変速で前進、前進方向での旋回、及び停止をさせることができる。また、前進方向側の走行ルート検出センサ６１ｆと走行速度検出センサ６２ｆを用いることで、より安定的に走行ルートに沿って前進させることができる。
【００２３】
進行方向指示手段４０ｃの後進指示操作手段４０ｒが操作されると、第１切替手段７１が走行ルート検出センサ６１ｒ（後進用第１検出手段）と制御手段４０の走行ルート検出センサ入力ＳＣとを接続して走行ルート検出センサ６１ｆ（前進用第１検出手段）と制御手段４０とを開放する。また、第２切替手段７２が走行速度検出センサ６２ｒ（後進用第２検出手段）と制御手段４０の走行速度検出センサ入力ＳＲ及びＳＬとを接続して走行速度検出センサ６２ｆ（前進用第２検出手段）と制御手段４０とを開放する。このように、後進用第１検出手段と後進用第２検出手段を制御手段４０に接続し、前進用第１検出手段と前進用第２検出手段を制御手段４０から開放する。
【００２４】
更に、モータ切替手段７３が電動モータ２３ａの−端子を制御手段４０の端子ＭＲ＋と接続して電動モータ２３ａの＋端子を制御手段４０の端子ＭＲ−に接続する。同様に、モータ切替手段７３が電動モータ２３ｂの−端子を制御手段４０の端子ＭＬ＋と接続して電動モータ２３ｂの＋端子を制御手段４０の端子ＭＬ−に接続する。このように、モータを後進方向に回転させるように各モータと制御手段４０とを接続する。
この接続により、制御手段４０は電動モータ２３ａ及び２３ｂを可変速で一方向に回転駆動することで搬送車１を可変速で後進、後進方向での旋回、及び停止をさせることができる。また、後進方向側の走行ルート検出センサ６１ｒと走行速度検出センサ６２ｒを用いることで、より安定的に走行ルートに沿って後進させることができる。
【００２５】
以上に説明したように、第１切替手段７１、第２切替手段７２、モータ切替手段７３を用いて前進と後進の切り替えを行うことにより、制御手段４０は、前進及び後進の双方の制御を行う必要がなく、前進のみの制御を行うことができればよい。このため、前進及び後進が可能な制御手段４０と、前進のみが可能な制御手段４０とを同一の制御手段４０で実現することができ、制御手段４０の汎用性が増す。
また、走行ルート検出センサ６１ｆ，６１ｒ、走行速度検出センサ６２ｆ，６２ｒは駆動輪２０ａ，２０ｂから前後に同じ距離だけ離れて配置されている。従って前進と後進で走行路に対する搬送車１の挙動が同じとなり、制御手段４０の汎用性がさらに増す。
【００２６】
次に、図３（Ｂ）を用いて、前進のみが可能な搬送車１の回路構成について説明する。以下、図３（Ａ）との相違点について説明する。
図３（Ｂ）に示す回路構成では、図３（Ａ）に対して、後進指示操作手段４０ｒと走行ルート検出センサ６１ｒと走行速度検出センサ６２ｒと第１切替手段７１と第２切替手段７２とモータ切替手段７３とが省略されている（制御手段４０の端子ＭＲ＋等の各端子と電動モータ等との接続は配線等にて接続し、切替手段を省略している）。
このように、前進のみが可能な搬送車１を構成する場合は、制御手段４０と走行ルート検出センサ６１ｆと走行速度検出センサ６２ｆと電動モータ２３ａ及び２３ｂを用いて構成すればよい。
【００２７】
また、前進及び後進が可能な搬送車１を構成する場合は、前進のみが可能な搬送車１に対して、後進指示操作手段４０ｒと走行ルート検出センサ６１ｒと走行速度検出センサ６２ｒと第１切替手段７１と第２切替手段７２とモータ切替手段７３とを追加すればよい。つまり、制御手段４０は、どちらの場合（前進及び後進可能な場合と、前進のみが可能な場合）も同一の前進のみが可能な制御手段４０を用いることができ、後進制御機能を追加する必要がない。
このため、前進のみが可能な搬送車１から前進及び後進が可能な搬送車１への変更、あるいは前進及び後進が可能な搬送車１から前進のみが可能な搬送車１への変更が容易である。
【００２８】
●［使用例（図４）］
次に、本実施の形態で説明した搬送車１の使用例について、図４（Ａ）及び（Ｂ）に示す模式図にて説明する。
図４（Ａ）は、搬送車１に荷台ユニット９０を設け、当該荷台ユニット９０に荷物Ｎを積載した様子を示している。この場合、前進及び後進可能な搬送車１を用いた場合、走行路に設けられた走行ルートを示す誘導部材に沿って、前進あるいは後進しながら荷物Ｎを搬送することができる。
また、図４（Ｂ）は、搬送車１に連結ユニット８２を設け、連結ユニット８２を介して荷物Ｎを積載した台車８０を牽引する様子を示している。この場合、前進のみが可能な搬送車１を用いた場合、走行路に設けられた走行ルートを示す誘導部材に沿って、前進しながら荷物Ｎを積載した台車８０を牽引することができる。
【００２９】
本発明の搬送車１は、本実施の形態で説明した構成、接続、外観、動作等に限定されず、本発明の要旨を変更しない範囲で種々の変更、追加、削除が可能である。
例えば、本実施の形態では駆動輪の左右の回転差を用いて旋回する構成としたが駆動輪又は駆動ユニット自体を旋回させて搬送台車を旋回する構成としても良い。この場合も駆動輪の前従動輪または後従動輪の一方が接地した時に他方が所定距離だけ浮き上がる構成であればよい。
搬送車１の回路構成は、図３（Ａ）及び（Ｂ）に示す回路構成に限定されるものではない。また、搬送車１の使用方法は、図４（Ａ）及び（Ｂ）に示す使用方法に限定されるものではない。
また、本実施の形態の説明に用いた数値は一例であり、この数値に限定されるものではない。
【００３０】
【発明の効果】
以上説明したように、請求項１または２に記載の搬送車を用いれば、駆動輪を確実に接地させることが可能であり、よりシンプルな機構で直進性と旋回性をより向上させることができる搬送車を提供できる。
【図面の簡単な説明】
【図１】本発明の搬送車１の一実施の形態の概略外観図を説明する図である。
【図２】本発明の搬送車１の姿勢を説明する図である。
【図３】本発明の搬送車１の回路構成の例を説明する図である。
【図４】本発明の搬送車１の使用例を説明する図である。
【符号の説明】
１搬送車
１０本体フレーム部
２０ａ、２０ｂ駆動輪
２３ａ、２３ｂ電動モータ
３０ｆ従動輪（前従動輪）
３０ｒ従動輪（後従動輪）
４０制御手段
４０ｃ進行方向指示手段
４０ｆ前進指示操作手段
４０ｒ後進指示操作手段
５０電源
６１ｆ走行ルート検出センサ（前進用第１検出手段）
６１ｒ走行ルート検出センサ（後進用第１検出手段）
６２ｆ走行速度検出センサ（前進用第２検出手段）
６２ｒ走行速度検出センサ（後進用第２検出手段）
７１第１切替手段
７２第２切替手段
７３モータ切替手段[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a transport vehicle that travels along a guide member provided on a travel path in a factory, for example.
[0002]
[Prior art]
2. Description of the Related Art Conventionally, a transport vehicle that loads a load or a transport vehicle that pulls a cart loaded with a load is used in a factory, a warehouse, or the like.
These transport vehicles travel along a preset travel route along a guide member (optical guide tape, magnetic guide tape, electric wire, or the like) laid on the floor surface or embedded in the floor.
Conventionally, two or one driving wheel and four driven wheels are provided, the driving wheel is arranged almost at the center of the carrier vehicle, the two driven wheels are arranged near the front end of the carrier vehicle, Proposed a transport vehicle that places the driven wheel near the rear end of the transport vehicle, controls the two driven wheels on the traveling direction side along the traveling route, and fixes the driven wheel on the opposite side to the traveling direction in the traveling direction. (For example, Patent Document 1 and Patent Document 2).
[0003]
[Patent Document 1]
Japanese Patent Laid-Open No. 10-6980 [Patent Document 2]
Japanese Patent Laid-Open No. 11-73223 [0004]
[Problems to be solved by the invention]
A conventional transport vehicle is provided with a drive wheel substantially at the center, and four driven wheels that can turn (steer) in a horizontal plane are provided at four corners of the transport vehicle. For this reason, all of the four driven wheels and the drive wheel are grounded, and the drive wheel may not be grounded depending on the unevenness of the traveling path. In this case, it is necessary to provide a suspension mechanism for the drive wheel in order to ensure that the drive wheel is grounded.
Further, the conventional transport vehicle controls steering of two driven wheels on the traveling direction side along the traveling route, and fixes the two driven wheels on the opposite side to the traveling direction in the traveling direction. For this reason, it is necessary to switch between a driven wheel for steering control in accordance with the traveling direction (forward and reverse) and a driven wheel fixed in the traveling direction, and the control mechanism for the four driven wheels is complicated.
The present invention was devised in view of the above points, and is capable of reliably grounding a driving wheel, and can further improve straightness and turning performance with a simpler mechanism. It is an issue to provide.
[0005]
[Means for Solving the Problems]
As means for solving the above-mentioned problems, the transport vehicle according to claim 1 includes a main body frame portion, a driving wheel, and a front driven wheel and a rear driven wheel that can freely turn in a horizontal plane before and after the driving wheel. When the driving wheel contacts the floor surface and one of the front driven wheel or the rear driven wheel contacts the floor surface, the front driven wheel or the rear driven wheel The driving wheel is provided so as to protrude below a straight line connecting the lower end of the front driven wheel and the lower end of the rear driven wheel so that the other is lifted from the floor by a predetermined distance. The front driven wheel and the rear driven wheel can freely turn without having a steering control mechanism, and are arranged on the left and right with respect to the traveling direction, and can be rotated independently of each other. It has.
Further, the transport vehicle according to claim 2 is the transport vehicle according to claim 1, wherein each of the driving wheel, the front driven wheel, and the rear driven wheel does not have a suspension mechanism, and the main body. Installed on the frame.
[0006]
Further, a transport vehicle according to claim 3 is the transport vehicle according to claim 1 or 2, wherein the transport vehicle has at least two drive wheels, and each of the drive wheels drives at least two electric motors. A control means for supplying electric power for rotating each electric motor to rotate in one direction at a variable speed, and for controlling the turning of the conveyance vehicle by a difference in rotational speed between the electric motors; A traveling direction instruction means including a first detection means for detecting a member, a second detection means for detecting a traveling control member provided on the traveling path and indicating information relating to traveling speed, a forward instruction operating means, and a reverse instruction operating means. With.
The first detection means includes a forward first detection means and the reverse first detection means, and the second detection means includes a forward second detection means and a reverse second detection means.
Further, the first forward detection means and the control means are connected and the first reverse detection means and the control means are opened, or the first forward detection means and the control means are opened and the first reverse detection means. The first switching means that can be connected to the control means, the second forward detection means and the control means are connected, and the second reverse detection means and the control means are opened, or the second forward detection means and the control are controlled. The second switching means capable of connecting the second reverse detection means and the control means, and the wiring between the electric motor and the control means in the forward direction or the reverse direction so that the rotation direction of the electric motor is switched. Motor switching means for switching.
[0007]
DETAILED DESCRIPTION OF THE INVENTION
Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 shows a schematic external view of an embodiment of a transport vehicle 1 of the present invention.
● [Overall structure (Fig. 1)]
The overall configuration of the transport vehicle 1 according to the present embodiment will be described with reference to FIG. FIG. 1 (A) shows a side view of the transport vehicle 1, and FIG. 1 (B) shows a bottom view (back side) of the transport vehicle 1. Here, the X axis and the Y axis indicate the horizontal direction, the X axis indicates the traveling direction (in the example shown in FIG. 1, the right direction indicates the forward direction, the left direction indicates the reverse direction), and the Z axis Indicates the vertical direction.
[0008]
In the transport vehicle 1, the main body frame portion 10, two driving wheels 20a and 20b, and two driven wheels 30f (in this case, front driven wheels) and 30r (in this case) before and after the driving wheels 20a and 20b are provided. , Rear driven wheel). The drive wheels 20a and 20b are arranged at a predetermined interval (distance Lw) at substantially the center of the main body frame portion 10 with respect to the traveling direction (X-axis direction). Since the transport vehicle 1 in the present embodiment turns the transport vehicle 1 using the rotational difference between the two drive wheels 20a and 20b, the straight travel stability is improved when the distance Lw is somewhat large. For this reason, each drive wheel 20a and 20b is arrange | positioned by the space | interval which fits in the inside of the width | variety of the Y-axis direction of the main body frame part 10, and the suitable space | interval (distance Lw).
In addition, since the conveyance vehicle 1 in this Embodiment turns using the rotation difference of a drive wheel, it is provided with the at least 2 drive wheel.
[0009]
The drive wheels 20a and 20b are provided with electric motors 23a and 23b that respectively rotate. The electric motor 23a rotates a wheel 21a fixed to the drive wheel 20a via a transmission member 22a (chain, belt, etc.). Similarly, the electric motor 23b rotates the wheel 21b fixed to the drive wheel 20b via the transmission member 22b. The drive wheels 20a and 20b are assembled to the shaft 25 so as to be able to rotate independently.
In the transport vehicle 1 in the present embodiment, the driving wheels 20a and 20b are driven by the electric motor, but the driving method is not limited to the electric motor.
[0010]
One driven wheel (for example, 30f) is provided in the vicinity of the front end of the main body frame portion 10 in the traveling direction. For example, when the right side is the traveling direction, the driven wheel 30 f is provided near the front end of the main body frame portion 10. The other driven wheel (for example, 30r) is provided in the vicinity of the rear end of the main body frame portion 10 in the traveling direction. For example, when the right side is the traveling direction, the driven wheel 30 r is provided in the vicinity of the rear end of the main body frame portion 10.
The driven wheel is not limited to the front end or the rear end as long as the driven wheel is provided on the front and rear sides of the drive wheel. The number of the driven wheels 30f (front driven wheels) and the driven wheels 30r (rear driven wheels) is preferably one each, but may be two or more each.
Each driven wheel 30f and 30r is provided at a position slightly away from the center in the Y-axis direction so as not to step on the guide member indicating the travel route laid on the floor or the like as much as possible.
[0011]
The driven wheels 30f and 30r are connected to the main body frame portion 10 by support members 31f and 31r, and are provided so as to be rotatable in the horizontal direction so as to be directed in an arbitrary direction in accordance with the turning of the transport vehicle 1. .
Further, each driven wheel 30f and 30r is configured so that when each driving wheel 20a and 20b is grounded to the floor surface and one driven wheel is grounded to the floor surface or the like, the other driven wheel is predetermined from the floor surface or the like. It is provided so as to float by the distance Lv. Thereby, the conveyance vehicle 1 and the floor surface are grounded at three points of the two driving wheels (20a and 20b) and one driven wheel (30f or 30r), and the two driving wheels 20a and 20b are always connected to the floor. Make contact with the surface. For this reason, the driving force of both the driving wheels 20a and 20b can be reliably transmitted to the floor surface, and the straightness and turning performance can be further improved.
[0012]
Next, the control means 40 for controlling the electric motors 23a and 23b that drive the drive wheels 20a and 20b will be described.
The control means 40 is placed substantially at the center of the main body frame portion 10. The control means 40 can respectively supply electric power for rotationally driving the electric motors 23a and 23b in one direction at variable speeds, and can turn the transport vehicle 1 by the difference in rotational speed between the electric motors 23a and 23b. . However, since it is rotationally driven in one direction at a variable speed, forward and reverse cannot be switched, but a method for switching forward and reverse will be described later.
The power source 50 (battery or the like) is accommodated in a power source accommodating portion 10 a provided in the main body frame portion 10. Since the power supply 50 is heavy, the power supply 50 is disposed at substantially equal distances on both sides of the drive wheels 20a and 20b.
[0013]
In the travel route of the transport vehicle 1, a guide member indicating the travel route is provided in the travel route (laid on the floor surface or embedded in the floor). The transport vehicle 1 travels along the travel route by detecting the guide member. Further, a travel control member that indicates information related to the travel speed is provided in the travel route as necessary. The transport vehicle 1 detects the travel control member, changes the travel speed (such as low speed or high speed), and stops.
Traveling route detection sensors 61f and 61r (first detection means) for detecting a guiding member and traveling speed detection sensors 62f and 62r (second detection means) for detecting a traveling control member are provided at the front end and the rear end of the main body frame portion 10, respectively. ) Is provided via brackets 60f, 60r, 63f, 63r.
[0014]
The travel route detection sensor 61f and the travel speed detection sensor 62f are used when the transport vehicle 1 travels in the direction of the sensor (the forward direction in the present embodiment). In addition, the travel route detection sensor 61r and the travel speed detection sensor 62r are used when traveling in the direction of the sensors (in the present embodiment, the reverse direction). That is, the transport vehicle 1 includes a travel route detection sensor and a travel speed detection sensor corresponding to the travel direction at the front end in the travel direction.
The interval Lf between the traveling speed detection sensors 62f and the interval Lr between the traveling speed detection sensors 62r are provided at different intervals so that different traveling control members can be detected in the forward and reverse directions.
[0015]
Although not shown, the transport vehicle 1 includes a traveling direction instruction means including a forward instruction operation means (forward button, etc.) and a reverse instruction operation means (reverse button, etc.). The traveling direction instruction means may be provided on the transport vehicle 1 by wire, or may be separated from the transport vehicle 1 by radio. Further, the advancing direction instruction means may be provided with operation means for giving other instructions such as a stop instruction operation means (stop button).
Further, it is desirable to operate the traveling direction instruction means while the transport vehicle 1 is traveling or stopped at a portion that is a substantially straight line of the traveling path. If it does so, when the advancing direction changes, the 1st detection means can detect a guidance member reliably.
[0016]
● [Conveyor posture (Fig. 2)]
FIGS. 2A and 2B are schematic diagrams of postures when the transport vehicle 1 travels in the direction of the driven wheel 30f. In this case, the driven wheel that floats by a predetermined distance Lv from the floor surface is a driven wheel 30f (front driven wheel) as shown in FIG. 2A, and a driven wheel 30r (as shown in FIG. 2B). There are two types of rear driven wheels). In the transport vehicle 1 in the present embodiment, two drive wheels 20a and 20b and one driven wheel (either 30f or 30r) are grounded to the floor surface.
As described above, since the two drive wheels 20a and 20b are surely grounded to the floor surface, the straight traveling performance can be further improved, and the turnability is further improved in the transport vehicle 1 that turns by the rotational difference of the drive wheels. Can be made.
[0017]
When a load is applied to both the front and rear driven wheels, meandering is likely to occur due to the swinging phenomenon that occurs on the driven wheels (phenomenon that faces in various directions regardless of the traveling direction and turning direction), and driving stability Decreases. However, in the transport vehicle 1 in the present embodiment, the load of the transport vehicle 1 is applied to one of the ground contact surface Mf portion, the ground contact surface Mr portion, and the ground contact surface Md portion as shown in FIG. That is, no load is applied to the other of the ground contact surface Mf portion and the ground contact surface Mr portion. Accordingly, since the number of driven wheels on which the swing phenomenon occurs is small, meandering is unlikely to occur, and running stability is improved.
Further, when the center of gravity of the load applied to the transport vehicle 1 is substantially opposite to the traveling direction from the center, or when the transport vehicle 1 is used as a towing vehicle, as shown in FIG. The driving wheel (the driven wheel 30r in FIG. 2A) is grounded. That is, since the driven wheel on the rear side with respect to the traveling direction from the driving wheel is grounded, the influence of the swinging phenomenon is further reduced, and the running stability is further improved.
[0018]
The predetermined distance Lv between the driven wheel and the floor surface is set to an appropriate distance according to the size of the transport vehicle 1, the wheel base, the uneven state of the floor surface, and the like. In the transport vehicle 1 in the present embodiment, the transport vehicle 1 having a length Lb of the main body frame portion 10 of about 1 [m] is used on the floor in the factory, and the predetermined distance Lv is about 1 [mm]. It was set to ˜2 [mm]. The predetermined distance Lv can be set to various dimensions.
[0019]
As described above, in the transport vehicle 1 in the present embodiment, the drive wheels 20a and 20b can be reliably grounded to the floor surface, and the driving force can be reliably transmitted to the floor surface. Further, it is not necessary to provide a mechanism for steering-controlling the driven wheel or fixing the driven wheel in the traveling direction, it is only necessary to provide a driven wheel that can freely turn in a horizontal plane, and it is not necessary to provide a suspension mechanism or the like on the drive wheel. Thus, the straight traveling property and turning property of the transport vehicle 1 can be further improved with a simpler mechanism.
In the present embodiment, the number of driven wheels is one each on the front and rear sides across the drive wheel. That is, as shown in FIG. 2 (A) or FIG. 2 (B), it is a three-wheel support of two drive wheels and one driven wheel. Therefore, the drive wheels 20a and 20b can be more reliably grounded as compared with the case where there are two or more driven wheels before and after the drive wheel.
In addition, since the components such as the drive wheel (including the electric motor), the driven wheel, the first and second detection means, and the control means are separated from each other, they can be provided on the body frame portion of various sizes or shapes. It is possible, and it is possible to constitute the conveyance vehicles 1 of various sizes or shapes.
[0020]
● [Circuit configuration (Fig. 3)]
Next, the circuit configuration of the transport vehicle 1 will be described with reference to FIG. FIG. 3A shows an example of a circuit configuration of the transport vehicle 1 capable of moving forward and backward shown in FIGS. 1A and 1B. 3B omits the travel route detection sensor 61r and the travel speed detection sensor 62r provided at the rear end of the main body frame 10 from the transport vehicle 1 shown in FIGS. 1A and 1B, and only forwards. The example of the circuit structure of the conveyance vehicle 1 which can do is shown.
A circuit configuration of the transport vehicle 1 that can move forward and backward will be described with reference to FIG.
The control means 40 has a terminal MR + and a terminal MR− that can supply electric power for rotating the electric motor 23a in one direction at a variable speed, and a terminal that can supply electric power for rotating the electric motor 23b in one direction at a variable speed. ML + and a terminal ML− are provided.
[0021]
When the forward direction operation means 40f of the travel direction instruction means 40c is operated, the first switching means 71 connects the travel route detection sensor 61f (first detection means for forward movement) and the travel route detection sensor input SC of the control means 40. Then, the travel route detection sensor 61r (first reverse detection means) and the control means 40 are opened. Further, the second switching means 72 connects the travel speed detection sensor 62f (second advance detection means) and the travel speed detection sensor inputs SR (right input) and SL (left input) of the control means 40 to detect the travel speed. The sensor 62r (second reverse detection means) and the control means 40 are opened. Thus, the first forward detection means and the second forward detection means are connected to the control means 40, and the first reverse detection means and the second reverse detection means are released from the control means 40.
[0022]
Further, the motor switching means 73 connects the + terminal of the electric motor 23 a to the terminal MR + of the control means 40 and connects the − terminal of the electric motor 23 a to the terminal MR− of the control means 40. Similarly, the motor switching unit 73 connects the + terminal of the electric motor 23 b to the terminal ML + of the control unit 40 and connects the − terminal of the electric motor 23 b to the terminal ML− of the control unit 40. Thus, each motor and the control means 40 are connected to rotate the motor in the forward direction.
By this connection, the control means 40 can rotate the electric motors 23a and 23b in one direction at a variable speed to move the transport vehicle 1 forward at a variable speed, turn in the forward direction, and stop. Further, by using the traveling route detection sensor 61f and the traveling speed detection sensor 62f on the forward direction side, it is possible to move forward along the traveling route more stably.
[0023]
When the reverse direction instruction operation means 40r is operated, the first switching means 71 connects the travel route detection sensor 61r (first reverse detection means) and the travel route detection sensor input SC of the control means 40. Then, the travel route detection sensor 61f (first detection means for forward movement) and the control means 40 are opened. The second switching means 72 connects the travel speed detection sensor 62r (second reverse detection means) and the travel speed detection sensor inputs SR and SL of the control means 40 to connect the travel speed detection sensor 62f (second forward detection). Means) and the control means 40 are opened. In this way, the first reverse detection means and the second reverse detection means are connected to the control means 40, and the first forward detection means and the second forward detection means are released from the control means 40.
[0024]
Further, the motor switching means 73 connects the negative terminal of the electric motor 23 a to the terminal MR + of the control means 40 and connects the positive terminal of the electric motor 23 a to the terminal MR− of the control means 40. Similarly, the motor switching unit 73 connects the-terminal of the electric motor 23b to the terminal ML + of the control unit 40 and connects the + terminal of the electric motor 23b to the terminal ML- of the control unit 40. Thus, each motor and the control means 40 are connected so as to rotate the motor in the reverse direction.
With this connection, the control means 40 can rotate the electric motors 23a and 23b in one direction at a variable speed to turn the transport vehicle 1 backward at a variable speed, turn in the reverse direction, and stop. Further, by using the travel route detection sensor 61r and the travel speed detection sensor 62r on the reverse direction side, the vehicle can be moved backward along the travel route more stably.
[0025]
As described above, the control means 40 controls both forward and reverse by switching between forward and reverse using the first switching means 71, the second switching means 72, and the motor switching means 73. It is not necessary and it is only necessary to be able to control only forward movement. For this reason, the control means 40 capable of moving forward and backward and the control means 40 capable of only moving forward can be realized by the same control means 40, and the versatility of the control means 40 is increased.
In addition, the travel route detection sensors 61f and 61r and the travel speed detection sensors 62f and 62r are arranged at the same distance from the drive wheels 20a and 20b in the front-rear direction. Accordingly, the behavior of the transport vehicle 1 with respect to the travel path is the same in forward and reverse travel, and the versatility of the control means 40 is further increased.
[0026]
Next, a circuit configuration of the transport vehicle 1 that can only move forward will be described with reference to FIG. Hereinafter, differences from FIG. 3A will be described.
In the circuit configuration shown in FIG. 3 (B), as compared with FIG. 3 (A), the reverse instruction operation means 40r, the travel route detection sensor 61r, the travel speed detection sensor 62r, the first switching means 71, the second switching means 72, The motor switching means 73 is omitted (the connection between each terminal such as the terminal MR + of the control means 40 and the electric motor is connected by wiring or the like, and the switching means is omitted).
In this way, when the transport vehicle 1 that can only move forward is configured, it may be configured using the control means 40, the travel route detection sensor 61f, the travel speed detection sensor 62f, and the electric motors 23a and 23b.
[0027]
In the case where the transport vehicle 1 capable of moving forward and backward is configured, the reverse switching operation means 40r, the travel route detection sensor 61r, the travel speed detection sensor 62r, and the first switching are performed for the transport vehicle 1 capable of traveling only forward. A means 71, a second switching means 72, and a motor switching means 73 may be added. That is, the control means 40 can use the control means 40 capable of only the same forward movement in any case (when forward and backward movement is possible and when only forward movement is possible), and it is necessary to add a backward control function. There is no.
For this reason, it is easy to change from a transport vehicle 1 that can only move forward to a transport vehicle 1 that can move forward and backward, or from a transport vehicle 1 that can move forward and backward to a transport vehicle 1 that can only move forward. is there.
[0028]
● [Usage example (Fig. 4)]
Next, a usage example of the transport vehicle 1 described in the present embodiment will be described with reference to schematic diagrams shown in FIGS.
FIG. 4A shows a state in which the carrier unit 90 is provided in the transport vehicle 1 and the luggage N is loaded on the carrier unit 90. In this case, when the transport vehicle 1 capable of moving forward and backward is used, the load N can be transported while moving forward or backward along a guide member indicating a travel route provided on the travel path.
FIG. 4B shows a state in which a connecting unit 82 is provided in the transport vehicle 1 and the cart 80 loaded with the luggage N is pulled through the connecting unit 82. In this case, when the transport vehicle 1 that can only move forward is used, the cart 80 loaded with the luggage N can be pulled along the guide member indicating the travel route provided on the travel path.
[0029]
The transport vehicle 1 of the present invention is not limited to the configuration, connection, appearance, operation, and the like described in the present embodiment, and various changes, additions, and deletions can be made without departing from the scope of the present invention.
For example, although the present embodiment is configured to turn using the left and right rotational difference of the drive wheel, the drive wheel or the drive unit itself may be turned to turn the transport carriage. In this case as well, any configuration may be employed as long as one of the front driven wheel and the rear driven wheel of the driving wheel comes into contact with the other, and the other is lifted by a predetermined distance.
The circuit configuration of the transport vehicle 1 is not limited to the circuit configuration shown in FIGS. Moreover, the usage method of the conveyance vehicle 1 is not limited to the usage method shown to FIG. 4 (A) and (B).
The numerical values used in the description of the present embodiment are examples, and are not limited to these numerical values.
[0030]
【The invention's effect】
As described above, if the transport vehicle according to claim 1 or 2 is used, it is possible to reliably ground the drive wheel, and it is possible to further improve the straightness and turning performance with a simpler mechanism. A transport vehicle can be provided.
[Brief description of the drawings]
FIG. 1 is a diagram illustrating a schematic external view of an embodiment of a transport vehicle according to the present invention.
FIG. 2 is a diagram illustrating the posture of the transport vehicle 1 of the present invention.
FIG. 3 is a diagram illustrating an example of a circuit configuration of the transport vehicle 1 of the present invention.
FIG. 4 is a diagram illustrating an example of use of the transport vehicle 1 of the present invention.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Carrier vehicle 10 Main body frame part 20a, 20b Drive wheel 23a, 23b Electric motor 30f A driven wheel (front driven wheel)
30r driven wheel (rear driven wheel)
40 control means 40c traveling direction instruction means 40f forward instruction operation means 40r reverse instruction operation means 50 power supply 61f travel route detection sensor (first detection means for forward movement)
61r Travel route detection sensor (first detecting means for reverse travel)
62f Traveling speed detection sensor (second forward detection means)
62r Traveling speed detection sensor (second reverse detection means)
71 First switching means 72 Second switching means 73 Motor switching means

Claims

A main body frame portion is provided with a drive wheel and a front driven wheel and a rear driven wheel that can freely turn in a horizontal plane before and after the drive wheel,
When the driving wheel is in contact with the floor surface and one of the front driven wheel or the rear driven wheel is in contact with the floor surface, the other of the front driven wheel or the rear driven wheel is lifted by a predetermined distance from the floor surface. As described above, the drive wheel is provided so as to protrude downward from a straight line connecting the lower end portion of the front driven wheel and the lower end portion of the rear driven wheel,
The front driven wheel and the rear driven wheel can freely turn without having a steering control mechanism, and are arranged at left and right with respect to the advancing direction and have at least two drive wheels that can rotate independently. Have
A transport vehicle characterized by that.

The transport vehicle according to claim 1,
Each of the driving wheel, the front driven wheel, and the rear driven wheel is attached to the main body frame portion without having a suspension mechanism.
A transport vehicle characterized by that.

The transport vehicle according to claim 1 or 2,
Having at least two drive wheels,
At least two electric motors each driving each drive wheel;
Control means for supplying electric power for driving each electric motor to rotate in one direction at a variable speed, and for controlling the turning of the conveyance vehicle by the difference in rotational speed between the electric motors;
First detecting means for detecting a guide member provided on the travel path and indicating the travel route;
Second detection means for detecting a travel control member that is provided on the travel path and that indicates information related to travel speed;
A transport vehicle including a forward direction operation means and a forward direction instruction means including a reverse direction operation means;
A first detection means for forward movement and a first detection means for backward movement as the first detection means;
A second detection means for forward movement and a second detection means for backward movement as the second detection means;
The first forward detection means and the control means are connected and the first reverse detection means and the control means are opened, or the first forward detection means and the control means are opened and the first reverse detection means and the control are opened. First switching means connectable to the means;
The second forward detection means and the control means are connected and the second reverse detection means and the control means are opened, or the second forward detection means and the control means are opened and the second reverse detection means and the control are opened. Second switching means connectable to the means;
Motor switching means for switching the wiring between the electric motor and the control means to the forward direction or the reverse direction so that the rotation direction of the electric motor is switched.
A transport vehicle characterized by that.