PROBLEM TO BE SOLVED: To provide a convenient drug administration device capable of reducing cost incidental to manufacturing and usage and of facilitating attachment/detachment of a shaft included in the driving part.SOLUTION: A first housing 10 holds a driving part 11 that has a rotatable shaft 13 in which a first threaded part 15 is formed. A second housing 20 includes: a medical fluid storage part 40 for storing a medical fluid a medical fluid administration part 50 which administers a medical fluid in a state fluidly communicated with the medical fluid storage part and introduced into a living body a delivery piston 52 which delivers the medical fluid from the medical fluid storage part to the medical fluid administration part with reciprocation and a bearing part 81 which has a second threaded part 82 freely engageable with the shaft and which converts rotation of the shaft to the reciprocation of the delivery piston. The bearing part is provided with an opening 91 for accepting the shaft into the second threaded part and, when the first housing and the second housing are assembled, the shaft is engaged with the second threaded part in a range equal to or over a semicircle in the circumferential direction.COPYRIGHT: (C)2015,JPO&INPIT【課題】製造コストや使用に伴うコストの低減を図ることができ、かつ、駆動部が備えるシャフトの着脱を簡便かつ容易に行うことが可能な利便性に優れる薬液投与装置を提供する。【解決手段】 第1のハウジング10は、第1のネジ部15が形成された回転可能なシャフト13を備える駆動部11を保持しており、第2のハウジング20は、薬液を貯蔵する薬液貯蔵部40と、薬液貯蔵部に流体連通され生体内に導入された状態で薬液を投与する薬液投与部50と、往復動に伴い薬液貯蔵部から薬液投与部へ薬液を送出する送出ピストン52と、シャフトが係脱自在な第2のネジ部82が形成されシャフトの回転を送出ピストンの往復動に変換する軸受部81と、を保持しており、軸受部は、第2のネジ部内へシャフトを受容するための開口部91を有しており、第1のハウジングと第2のハウジングが組み付けられた際に、シャフトと第2のネジ部は周方向の半周以上の範囲で係合する。【選択図】図7
