basics of drill machine
TRANSCRIPT
Muhammad ZaroonUniversity of Central Punjab (UCP) Lahore
Mechanical Engineering
a machine for making holes with removal of chips. Drilling machines are used for drilling, boring, countersinking, reaming, and tapping.
Vertical drilling machines are the most widely used in metalworking
Drill machine (Introduction)
Drill Machine (Drill bit)
Cutting Diameter is the largest diameter measured across the top off the land behind the point.
Drill Bit (ELEMENTS)
Back Tapper The diameter reduces towardsthe shank to provide the clearanceAnd prevent the Friction and Heat
FLUTES AND TYPES
parabolic Conventional chip breaker
Provide greater space for the
chips to .
In industry most of the drills have
this type of construction.
Process where long chips are produce , tight flute radii helps to breakdown of chips
The axial length from the outer corners of the cutting lips to the extreme back end of the flutes
To form the cutting edge on the pointTo allow the chip to escapeTo cause the chip to curlTo permit the cutting fluid to reach the
cutting edges
Why we Create FLUTES
The part of drill body between the flutes is called Land.Increase land increase Tensional StrengthDecrease Land Chip width increases
HELIX ANGLEThe helix or rake angle is the angle formed by the leading edge of the land with a plane having the axis of the drill.
TYPESHELIX ANGLE
HIGH SPIRAL degree
REGULAR SPIRALdegree
SLOW SPIRALdegree
34 to 38 28 to 32 12 to 22
Fast spiral Drills Slow spiral Drills•Greater lifting power for chips•Used for deeper holes•Weaker in strength
•Lesser lifting Power for chips•Generally for shallow holes•Stronger in Strength
Effect of helix angle on performance ??