fact that the locking sheet 205 is not at the right position i e the notch 2051 is not at the proper position therefore the blocking sheet 20611 can not rotate into the range of the locking sensor 31 within the specific time at this time the control portion may send a warning instruction due to the timeout of the locking operation thus the administrator may immediately knows that an abnormal situation occurs on the oil port furthermore referring to fig7 in order to monitor illegal destruction of the electrically controlled locking apparatus 2 an opening closing state sensor 33 is provided between the cover 203 and the housing 202 the opening closing state sensor 33 can monitor the opening and closing states of the cover 203 of the electrically controlled locking apparatus the opening closing state sensor 33 includes a supporting plate 331 and a self returning pressing sheet 332 mounted on a surface facing the cover 203 of the supporting plate 331 the self returning pressing sheet 332 is rotatably provided on the supporting plate 331 via a rotating shaft 333 and has one end extending towards the cover and forming a pressing end 3321 and the other end forming a detecting end 3322 the rotating shaft 333 is located between the pressing end 3321 and the detecting end 3322 a detecting sensor 334 is provided in a stroke of the detecting end 3322 rotating around the rotating shaft 333 the self returning pressing sheet 332 realizes the self returning function via a torsion spring 335 coaxially provided relative to the self returning pressing sheet 332 when the cover 203 is opened the self returning pressing sheet 332 is.