PPT: Computer Numerical Control | Manufacturing Engineering - Mechanical Engineering PDF Download

 Page 1


2
? 15th century - machining metal.
? 18th century - industrialization, production-type machine 
tools.
? 20th century - tool metal – HSS
? Automated production equipment -
? Screw machines
? Transfer lines
? Assembly lines
? Programmable automation -
? NC
? PLC
? Robots
Historical Development
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2
? 15th century - machining metal.
? 18th century - industrialization, production-type machine 
tools.
? 20th century - tool metal – HSS
? Automated production equipment -
? Screw machines
? Transfer lines
? Assembly lines
? Programmable automation -
? NC
? PLC
? Robots
Historical Development What is Numerical control?
3
? Numerical Control is a system in which actions are 
controlled by the direct insertion of numerical data at 
some point.
? In other words Programmable automation in which the 
mechanical actions of a ‘machine tool’ are controlled 
by a program.
Page 3


2
? 15th century - machining metal.
? 18th century - industrialization, production-type machine 
tools.
? 20th century - tool metal – HSS
? Automated production equipment -
? Screw machines
? Transfer lines
? Assembly lines
? Programmable automation -
? NC
? PLC
? Robots
Historical Development What is Numerical control?
3
? Numerical Control is a system in which actions are 
controlled by the direct insertion of numerical data at 
some point.
? In other words Programmable automation in which the 
mechanical actions of a ‘machine tool’ are controlled 
by a program.
4
Components of NC Machines
MCU
Machine
Tool
CLU
DPU
? MCU – Machine Controlled unit
? It consists of some electronic hardware that reads the 
NC programme, interprets it and conversely translates 
it for mechanical actions of the machine tool.
? Machine Tool
? Machine tool is the main components of a numerical 
control system, which executes the operations.
? CLU – Control loops unit
DPU – Data Processing unit
? Units which control the input data and execute the 
required operations.
Page 4


2
? 15th century - machining metal.
? 18th century - industrialization, production-type machine 
tools.
? 20th century - tool metal – HSS
? Automated production equipment -
? Screw machines
? Transfer lines
? Assembly lines
? Programmable automation -
? NC
? PLC
? Robots
Historical Development What is Numerical control?
3
? Numerical Control is a system in which actions are 
controlled by the direct insertion of numerical data at 
some point.
? In other words Programmable automation in which the 
mechanical actions of a ‘machine tool’ are controlled 
by a program.
4
Components of NC Machines
MCU
Machine
Tool
CLU
DPU
? MCU – Machine Controlled unit
? It consists of some electronic hardware that reads the 
NC programme, interprets it and conversely translates 
it for mechanical actions of the machine tool.
? Machine Tool
? Machine tool is the main components of a numerical 
control system, which executes the operations.
? CLU – Control loops unit
DPU – Data Processing unit
? Units which control the input data and execute the 
required operations.
5
? Preparatory functions : Which unit, which interpolator, absolute 
or incremental programming, which circular interpolation plane, 
cutter compensation, etc.
? Coordinates : Three translational, and three rotational axes.
? Machining parameters : Feed, and speed.
? Tool control : Tool diameter, next tool number, tool change.
? Cycle functions : Drill cycle, ream cycle, bore cycle, mill cycle, 
clearance plane.
? Coolant control : Coolant on/off, flood, mist.
? Miscellaneous control : Spindle on/off, tape rewind, spindle 
rotation direction, pallet change, clamps control, etc.
? Interpolators : Linear, circular interpolation
Basic Requirement of NC Control
Page 5


2
? 15th century - machining metal.
? 18th century - industrialization, production-type machine 
tools.
? 20th century - tool metal – HSS
? Automated production equipment -
? Screw machines
? Transfer lines
? Assembly lines
? Programmable automation -
? NC
? PLC
? Robots
Historical Development What is Numerical control?
3
? Numerical Control is a system in which actions are 
controlled by the direct insertion of numerical data at 
some point.
? In other words Programmable automation in which the 
mechanical actions of a ‘machine tool’ are controlled 
by a program.
4
Components of NC Machines
MCU
Machine
Tool
CLU
DPU
? MCU – Machine Controlled unit
? It consists of some electronic hardware that reads the 
NC programme, interprets it and conversely translates 
it for mechanical actions of the machine tool.
? Machine Tool
? Machine tool is the main components of a numerical 
control system, which executes the operations.
? CLU – Control loops unit
DPU – Data Processing unit
? Units which control the input data and execute the 
required operations.
5
? Preparatory functions : Which unit, which interpolator, absolute 
or incremental programming, which circular interpolation plane, 
cutter compensation, etc.
? Coordinates : Three translational, and three rotational axes.
? Machining parameters : Feed, and speed.
? Tool control : Tool diameter, next tool number, tool change.
? Cycle functions : Drill cycle, ream cycle, bore cycle, mill cycle, 
clearance plane.
? Coolant control : Coolant on/off, flood, mist.
? Miscellaneous control : Spindle on/off, tape rewind, spindle 
rotation direction, pallet change, clamps control, etc.
? Interpolators : Linear, circular interpolation
Basic Requirement of NC Control
6
? Convectional Numerical Control (NC)
? Direct Numerical Control (DNC)
? Computer Numerical Control (CNC)
Types of Numerical Control