Bachelor of Technology Mechanical

Lecture # 3

Workshop Technology

University of Gujrat

By: Jahangir Rana

Drills and Drilling Processes

Types of Drilling Machine

1. Sensitive Drilling Machine2. Heavy Duty Drill Machine3. Gang Drill Machine4. Radial Drill Machine5. Multiple-drill-head Machine6. Tape-controlled Drill Machine

What is Sensitive Drilling Machine?

Sensitive Drilling Machine

Sensitive Drilling Machine Is a belt driven general purpose machine to produce a range of small size holes. These drill presses are made on pedestal model , bench model, and multiple model spindle units.These machine do not have automatic feed mechanism, so the cutting tool must be fed by hand using the hand feed lever.

Heavy Duty Drill Machine

A heavy duty drilling machine is a large, heavier machine than the sensitive or the standard upright drill press. It is a gear train drive and power feeds. It is a powerful machine for drilling, tapping, and machining large holes. The gear drive permits a wide range of spindle speeds, which vary from 60 to 1000 revolution per minute.

Gang Drill Machine

The multiple spindle, or Gang, drilling machine consists of large base supporting a long table. The back of the bas is designed so that several spindles may be mounted on it. Each spindle is driven by its individual direct connecting motor.

Radial Drill MachineThe radial drill is a precision machine that is designed so that the entire mechanism may be adjust to bring the spindle into the required position over the wok, which is fastened securely to the stationary base. The large arm of the machine is raised or lowered by a motor driven mechanism, which operates on a long, stationary, elevating screw. The arm is automatically clamped on the vertical column when elevating mechanism is stopped.

Multiple-drill-head Machine

The multiple drilling head machine may have any number of spindle from 4 to 48, or more, all driven from the one spindle driven gear in one head. Multiple head are specially design for mass production operations such as drilling, reaming, or tapping many holes at one time in a specific unit of work such as an automobile engines block. There may be two or more dill heads on one machine, each with many spindles.

Tape-controlled Drill Machine

A tape controlled drill machine is a numerically controlled machine tool, which automatically performs most of the operations a skilled operator would do manually. The work piece is clamped into position on a fixture mounted on the table. Tape on which instruction have been punched controls the motors that drive the table feed screws and positions. The tape also control the movement for feeding the drill spindle the required distance into the work piece, withdrawing it, and turning the coolant on and off at the desired time.

Drill ViseA drill vise is a working holding tool in which the work piece may be seated square and parallel and held securely while the drilling and other operations are performed . Because it can be turned over on three sides, several hole can be drilled without removing the work.

Drill JigsA drill jig is a work holding tool, which locates the work piece in proper position and holds it securely. The drill and other cutting tools are guided by hardened steel drill bushing so that the holes drilled in all of the parts are in the same exact location. Drill jigs are production tools used in the mass production of parts.

Types of Drill Bits

1. Twist Drill2. Flat Drill3. Oil Hole Drill

Twist Drill Cutting Edges

Assignment1.Flat Drill2.Oil Hole Drill3.Masonry Drill