MACHINES USED IN TOOLING CONVENTIONAL MACHINES

 

MACHINES USED IN TOOLING CONVENTIONAL MACHINES

1)      LATHE

It is a machine tool where the excess material is removed in a round piece by a single point tool when the job is revolving around its own axis. It is a most versatile machine. All cylindrical parts are pre tooled in this machine. First facing is done and then center drilling and counter sinking at the each end of the stock is done to turn the job between centers. For guide bushes, it needs to be bored inside, so jobs are held in the check, the material removing is very fast. Due to its wide usage it is known as 'Mother of machines'

 

2)       MILLING

Milling is a process of removing excess material by feeding a work piece against a rotating multipoint cutter. It is widely used machine tool both for Tool Room and production work. In this machine we can perform 64 operations like slotting indexing, ball milling, helical milling, etc.

 

3)      DRILLING

This machine produces holes or enlarging holes in a work piece by forcing a rotating tool called drill. All holes, pinholes are done in this machine.

 

4)      GRINDING MACHINE

It is a machine tool in which less amount of material is removed to impart highly accurate with good surface finished jobs. Here an abrasive wheel is used for the removal of excess stock kept while pre tooling. There are different types of grinding machines like surface grinding, cylindrical grinding machines. For flat surfaces surface grinding is used and for round jobs cylindrical grinding machines are used. All cylindrical and flat jobs are ground after heat treatment to the required size and shape.

 

2)      NON-CONVENTIONAL OR SPECIAL PURPOSE         MACHINES

1)      CNC MILLING:

It is the most advanced milling machine. Here the parameter and co-ordinates are strictly controlled by computer system to achieve good accuracy and finish. Any  kind of intricate profiles can be done.

Since the machine cost is more and the cost of manufacturing is also the same parts that is produced are accurate with respective to pitches, profile and contours etc.

 

2)      EDM AND EDNC MACHINES:

Electro discharge machining and Electro discharge numerical Control Machining is a process of metal removing by means of electric discharge between a shaped electrode and electrode conductive work piece (core and cavity in this tool) in the presence of a dielectric fluid. In simple words an electric arc is used to erode. The work-piece, which takes a shape opposite to that of the electrode.

The gap between electrode and job is raised until dielectric barrier is ruptured, which usually occurs at a distance of 0.03mm or less at about 70V. Technically, the dielectric is ionized to form a column or path between the work piece and tool so that a surge of current takes place as spark is produced. Thus a minute part of work is vaporized and tiny particles are cooled into spheres and are swept away by the machining gap through the flushing of dielectric fluid.

 

Utility of EDM process

1)    Completely finishing the profiles before heat treatment could have resulted in distortion during the heat treatment process.

2)    Moreover, surface finish obtained by this process is very good, as there is no cutting force acting on the work, by this, error due to elastic deformation is eliminated.

3)    Accuracy of the profile up to 0.02mm can be achieved.

4)    Except polishing, no other finishing operation is required.

 

3)      WIRE EDM

As the name indicates a wire of less than 0.2mm diameter brass coated is used to cut the material. The process is employed where high accuracy is required to produce through slots, holes and intricate profiles. NC program for the required profile is fed into the control of the machine and according to this program the worktable moves against the wire to cut the profile.