Drill Presses Session 8. Shop Tools and Techniques2 Drilling Machines Probably first mechanical...
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Transcript of Drill Presses Session 8. Shop Tools and Techniques2 Drilling Machines Probably first mechanical...
Shop Tools and Techniques 2
Drilling Machines
• Probably first mechanical device developed
• Principle of rotating tool to make hole
• One of most common and useful machines in industry
• Come in several types and sizes• From hand-fed to computer-controlled
Shop Tools and Techniques 3
Drill Press
• Drilling machine• Spindle
• Turns drill to advance into work (hand or automatically)
• Work table• Holds workpiece rigidly in place as hole drilled
• Used primarily to produce holes in metal• Other operations: tapping, reaming, boring,
counterboring, countersinking, spot-facing
Shop Tools and Techniques 4
Standard Operations
• Drilling• Operation of producing hole by
removing metal from solid massusing twist drill
• Countersinking• Operation of producing tapered
or cone-shaped enlargementto end of hole
Shop Tools and Techniques 5
Standard Operations
• Reaming• Operation of sizing and producing
smooth, round hole from previously drilled or bored hole
• Boring• Truing and enlarging hole by
means of single-point cutting tool
Shop Tools and Techniques 6
Standard Operations
• Tapping• Cutting internal threads in
hole with cutting tool called tap
• Counterboring• Enlarging top of previously
drilled hole to given depthto provide square shoulder for head of bolt or capscrew
Shop Tools and Techniques 7
Standard Operations
• Spot-Facing• Smoothing and squaring surface
around hole to provide seat for head of cap screw or nut
• Boring bar fitted with double-edged cuttingtool
• Pilot section on endto fit into existing hole
Shop Tools and Techniques 8
Principal Types of Drilling Machines• Wide variety of drill presses
• Size of drill press may be designated in different ways by different companies
• Some state size as distance from center of spindle to column of machine
• Others state size by diameter of largest circular piece that can be drilled in center
Shop Tools and Techniques 9
Sensitive Drill Press Parts• Hand feed lever
• Controls downfeedpressure
• Feel the pressure
• Manufactured in bench and floor model
• Four main parts• Base, column, table
and drilling head
Shop Tools and Techniques 10
Sensitive Drill Press Parts• Base
• Provides stability for machine• Cast iron with holes to be bolted to table or
bench• Slots or ribs in base allow work-holding
device or workpiece to be fastened• Column
• Accurate cylindrical post that fits in base• Table may be adjusted any point (base to
head)• Drill press head mounted near top
Shop Tools and Techniques 11
Sensitive Drill Press Parts• Table
• Round or rectangle shaped• Used to support workpiece to be machined• Surface 90º to column (move around)
• Drilling Head• Mechanism used to revolve cutting tool• Spindle: round shaft holds cutting tool• Quill: houses spindle
Shop Tools and Techniques 15
Upright Drilling Machine• Larger and heavier
• Differences from sensitive-type drill• Equipped with gearbox for variety of speeds• Spindle may be advanced by: hand lever,
handwheel, and automatically by feed mechanism
• Table raised or lowered by mechanism• Some have reservoir in base for coolant
storage
Shop Tools and Techniques 18
Radial Drill
• Sometimes called radial-arm drill• Advantages of this machine
• Larger and heavier work may be machined• Drilling head raised or lowered• Drilling head moves rapidly to any desired
location while workpiece remains clamped• More power• Head may swivel so holes can be drilled on
angle
Shop Tools and Techniques 21
Radial Drill Parts
• Base• Heavy, box-type, ribbed cast iron or welded
steel• Used to bolt machine to floor and provide
coolant reservoir• Table may be bolted to base for small work
• Column• Upright cylindrical member fitter to base• Supports radial arm at right angles
Shop Tools and Techniques 22
Radial Drill Parts
• Radial arm• Attached to column• May be raised and lowered by means of
power-driven elevating screw• Supports drive motor and drilling head
• Drilling head• Mounted on arm and moved along length of
arm by traverse handwheel• Drill spindle may be raised or lowered