LIFTING DEVICE

To provide a lifting device for lifting/lowering a conveyance object by using a motor in which an overload state can be accurately detected in an early stage after starting the supporting and lifting of the conveyance object and the upward movement can be stopped urgently.SOLUTION: A lifting device 1 includes a motor 41 including a brake, a power source part outputting a frequency variable AC current to the motor 41 as a driving power source, a support tool 30, which supports the conveyance object and is moved up/down by the rotation of the motor 41, and a control part, which can control the power source part and the brake and urgently stop the rotation of the motor 41. When starting the rise of the support tool 30, the power source part increases the frequency of the driving power source gradually. The control part starts to monitor motor torque at the time when the frequency of the driving power source is stabilized to be a predetermined value and urgently stops the rotation of the motor 41 when it is detected that the motor torque exceeds a threshold.SELECTED DRAWING: Figure 1 【課題】モータによって搬送対象物を昇降させる昇降装置において、搬送対象物を支持して上昇を開始した後、早期に、過荷重状態を正確に検出し、上昇運動を緊急停止させることができる昇降装置を提供する。【解決手段】昇降装置１は、ブレーキを備えたモータ４１と、モータ４１に周波数可変の交流を駆動電源として出力する電源部と、搬送対象物を支持し、モータ４１の回転によって昇降される支持具３０と、電源部およびブレーキを制御し、モータ４１の回転を緊急停止させることができる制御部とを有する。支持具３０の上昇の開始時に、電源部は、駆動電源の周波数を徐々に増大させ、制御部は、駆動電源の周波数が所定値に安定した時点で、モータトルクの監視を開始し、モータトルクが閾値を超えたのを検出すると、モータ４１の回転を緊急停止させる。【選択図】図１