Manufacturing Science : Types And Detail About DRILLING MACHINE

DRILLING MACHINE

Drilling is an operation of making a circular hole by removing a volume of metal from the job by cutting tool called drill. A drill is a rotary end-cutting tool with one or more cutting lips and usually one or more flutes for the passage of chips and the admission of cutting fluid. A drilling machine is a machine tool designed for drilling holes in metals. It is one of the most important and versatile machine tools in a workshop. Besides drilling round holes, many other operations can also be performed on the drilling machine such as counter- boring, countersinking, honing, reaming, lapping, sanding etc.

This machine consists of following parts

1. Base

2. Pillar

3. Main drive

4. Drill spindle

5. Feed handle

6. Work table

TYPES OF DRILLING MACHINE

Drilling machines are classified on the basis of their constructional features, or the type

of work they can handle. The various types of drilling machines are:

(1) Portable drilling machine

A portable drilling machine is a small compact unit and used for drilling holes in worpieces

in any position, which cannot be drilled in a standard drilling machine. It may be used for

drilling small diameter holes in large castings or weldments at that place itself where they

are lying. Portable drilling machines are fitted with small electric motors, which may be

driven by both A.C. and D.C. power supply. These drilling machines operate at fairly high

speeds and accommodate drills up to 12 mm in diameter.

(2) Sensitive drilling machine

It is a small machine used for drilling small holes in light jobs. In this drilling machine, the workpiece is mounted on the table and drill is fed into the work by purely hand control. High rotating speed of the drill and hand feed are the major features of sensitive drilling machine. As the operator senses the drilling action in the workpiece, at any instant, it is called sensitive drilling machine. A sensitive drilling machine consists of a horizontal table, a vertical column, a head supporting the motor and driving mechanism, and a vertical spindle.Drills of diameter from 1.5 to 15.5 mm can be rotated in the spindle of sensitive drilling machine.

      (a) Bench mounting

      (b) Floor mounting

(3) Upright drilling machine

      (a) Round column section

      (b) Box column section machine

(4) Radial drilling machine

      (a) Plain

      (b) Semi-universal

      (c) Universal

(5) Gang drilling machine

(6) Multiple spindle drilling machine

(7) Automatic drilling machine

(8) Deep hole drilling machine

      (a) Vertical

      (b) Horizontal

TYPES OF DRILLS

A drill is a multi point cutting tool used to produce or enlarge a hole in the workpiece. It usually consists of two cutting edges set an angle with the axis. Broadly there are three

types of drills:

1. Flat drill,

2. Straight-fluted drill, and

3. Twist drill