Precision boring bar and numerical control boring machine using the precision boring bar

A precision boring bar for processing different shapes of holes, comprising:

• a bar body, two ends of the bar body respectively having a connection portion and a blade seat portion, the bar body having an inner chamber therein to communicate with the connection portion and the blade seat portion, the inner chamber being filled with a fluid medium which is not compressed;
• an active diaphragm assembly, the active diaphragm assembly being disposed at the connection portion of the bar body, the active diaphragm assembly being composed of at least one layer of diaphragm, the active diaphragm assembly comprising a central guide block to connect the diaphragm, the guide block having a connecting interface on an outside thereof;
• and
• a passive diaphragm assembly, the passive diaphragm assembly being disposed at the blade seat portion of the bar body, the passive diaphragm assembly being composed of at least one layer of diaphragm, the passive diaphragm assembly comprising a central guide block to connect the diaphragm, the guide block comprising a blade seat on an outside thereof, the blade seat being adapted to lock a blade, wherein when the active diaphragm assembly is activated, the blade on the passive diaphragm assembly is driven synchronously for micro feed.