PCB ENTRY-BOARD COME AND GO INCESSANT PRESENT STATE PREVENTION SMALL-HOLL DRILL EQUIPMENT TYPE DIRLL-SPINDLE HOUSING

摘要

A spindle housing of a small diameter drilling device is provided to prevent fine lifting phenomenon of an entry board due to outside air entering through a recess and air outlet of a bush after drilling work. A drill spindle housing(200) has a number of external air induction path(221) introducing external air from an outer periphery of a cover body(220) to a bush. The open air inlet of the semicircular shape is formed into the outer circumference of the bush body portion A number of vertical external discharge hole connecting the external air inlet from the extension bottom surface forming the stepped projection downward are formed. A drill chip is discharged in boring by the drill through an inlet pipe(210) to outside. External air is fed into the bush through a hose connected to the external air induction path.