Valve seat machining device, and valve seat machining method using said valve seat machining device

A valve seat processing machine configured to process a valve seat in a valve device including a valve body portion that forms a fluid flow passage and a valve drive portion that is detachably provided on the valve body portion and which opens and closes the flow passage by reciprocally driving a valve element relative to the valve seat in the valve body portion, the valve seat processing machine comprising:

• a base portion configured to be attached to the valve body portion;
• a main body portion provided on the base portion, the main body portion being movable relative to the base portion in two different axial directions;
• a support portion provided on the main body portion, the support portion being movable relative to the main body portion;
• a main spindle provided on the support portion, the main spindle being rotatable about a spindle axis;
• and
• a tool holder provided on the main spindle, the tool holder being configured to hold a tool for processing the valve seat, wherein:
• the main body portion includes a plurality of flanges including a plurality of screw holes penetrating the flanges and lifting bolts received in the screw holes formed in the flanges, respectively,
• the lifting bolts are capable of being screwed into the screw holes until the lifting bolts engage the base portion and a gap is formed between the main body portion and the base portion from a state where the main body portion and the base portion are in contact,
• the base portion includes a plurality of bolt insertion holes capable of being aligned with a plurality of bolt holes provided in the valve body portion, the bolt insertion holes being arranged at an equal pitch on a common circumference,
• the base portion is capable of being attached to the valve body portion in various attachment positions within a plane orthogonal to the axial direction of the main spindle, and
• the main spindle is adjustable, relative to the base portion, by selectively screwing the lifting bolts in the screw holes formed in the flanges to tilt the main body portion relative to the base portion.