In this content, you can learn about introduction of drilling machines and it's type with diagram of drilling machines. 


             DRILLING


          The machining process of producing cylindrical holes with the use of a multipoint tool called ' Drill' in a workpiece is called" Drilling". The primary cutting motion involved in drilling is a rotary motion generally given to the drill and feed motion is translation imparted to the drill.



                  Drilling operation can be performed on Drilling machines, Boring machines , Centres Lathes, Semi automatic and automatic Lathes etc. To produce a hole where none previously existed a drilling machine is used.


 


The working principle of drilling in the given figure. The drilling tool called drill rotating about its axis is fed axially into the workpiece which is held on the table of the drilling machine.


 The simultaneous rotation and feed motion of the drill helps to cut off chips from the workpiece. The action under the web of the drill is a combination of chisel action and metal being forced away by extrusion.


 

          Drilling operation can be performed on various types of drilling machines as listed below:-


(1) Portable Drilling Machines


(2) Bench Type Drilling Machines


(3) Sensitive Drilling Machines


(4) Upright Drilling Machines


(5) Radial Drilling Machines


(6) Multiple Spindle Drilling Machines


(7) Deep Hole Drilling Machines


(8) Gang Drilling Machines


Types of Drilling Machines in detail:-


(1) Portable Drilling Machines:-


These are used for operations on big jobs which are difficult to brought under a regular drilling machine & these may also be used for drilling small diameter holes in large castings  at that place itself where they are lying.







(2) Bench Type Drilling Machines:-


These are the simplest type drilling machines used to drill holes upto 12.5 mm i.e. they can hold drills  upto 12.5 mm diameter.




(3) Sensitive Drilling Machines:-


Sensitive drilling machines  are same as bench drilling machine with differences that it is smaller, provided with more accurate spindles and bearings and operates at higher speeds upto 30,000 rpm. 


(4) Upright Drilling Machines:-


Upright drilling machines or presses are provided with a power feed and are similar to the sensitive type drilling machine with heavier construction and are suited to wide range of work. 


(5) Radial Drilling Machines:-


The radial drilling machine is heavy duty machine used primarily for drilling parts too large or heavy to move under a stationary drill spindle.


(6) Multiple Spindle Drilling Machines:-


Multiple drilling machine is used to drill a number of parallel holes simultaneously in a workpiece. These are generally used in automobile or aircraft industries for drilling small component. 


(7) Deep Hole Drilling Machines:-


These are used for drilling long holes in connecting rods, rifle barrels and long spindles.





(8) Gang Drilling Machines:-


These are series of single spindle drilling heads on a long table used in mass production purposes.


Diagram of other drilling machines:-






Conclusion:-


You have learnt about introduction of drilling machines and it's type with it's diagram.