Patent ID: 7836784

Claim:
A motor-operated valve diagnosing device for diagnosing a motor-operated valve which comprises a valve element driving part for opening and closing a valve element using a rotational driving force of a worm to which a rotational driving force is applied, and a spring cartridge which expands and contracts in proportion to a reaction force exerted thereon from the valve element side of said valve element driving part in an axial direction of said worm, said motor-operated valve diagnosing device comprising a spring compression mechanism operable for compressing the spring cartridge externally and measuring a compression force thereon simultaneously with measuring an amount of compression thereof, or a worm displacement measuring means for measuring displacement of said worm, wherein said spring compression mechanism or said worm displacement measuring means is attachable to the valve element driving part via an adapter, and wherein said spring compression mechanism has a unitary structure including a base attachable to the adapter; a pusher assembled to said base for reciprocating movement in an axial direction thereof; a compressing means for pressing said pusher in an axial direction thereof to compress said spring cartridge via said pusher; a compression force measuring means for measuring an axial force on said pusher as a compression force on said spring cartridge; and a compression amount measuring means for measuring an axial displacement of said pusher as an amount of compression of said spring cartridge.