| 摘要 |
PROBLEM TO BE SOLVED: To relieve the impact caused when an opening/closing body during the lowering by its own weight is reversely raised by operating a hydraulic pressure switch. SOLUTION: This opening/closing device comprises the opening/closing body 10 delivered from a storage part for closing by its own weight, the hydraulic pressure switch 61 which outputs a hydraulic pressure sensing signal when receiving a hydraulic pressure, a drive source 41 which opens the opening/closing body 10, a restraint releasing means for unopenably restraining or releasing the opening/closing body 10, and a control circuit 80. The control circuit 80 restrains the opening/closing body 10 for a predetermined time by the restraint releasing means under the condition that there is the hydraulic pressure sensing signal after the start of a closing operation by the self-weight of the opening/closing body 10, and then releases the opening/closing body 10 by the restraint releasing means, and opens the opening/closing body 10 by driving the drive source. COPYRIGHT: (C)2009,JPO&INPIT
|
