| 摘要 |
<p>PROBLEM TO BE SOLVED: To provide a failure determination device of an electromagnetic valve capable of detecting deformation of a diaphragm supporting a valve body, and capable of accurately detecting the state where the valve body and a valve seat are not completely brought into close contact by holding a foreign matter between the valve body and a flow passage hole.SOLUTION: An electromagnetic valve 100 includes a piezoelectric sensor 130 for detecting deformation of a diaphragm 110. A failure determination device includes: an information storage part for storing a signal value of an output signal of the piezoelectric sensor at the time of normal closing operation of the electromagnetic valve 100 as a reference value; and a control part for comparing a signal value of an output signal of the piezoelectric sensor detected at the time of closing operation of the electromagnetic valve with the reference value, and determining failure of the electromagnetic valve according to whether the difference between the signal value and the reference value is a threshold value or more.</p> |
