Control of machine tools with the help of computers is called the CNC machining process. This process is used in the manufacturing sector and this can control tools like grinders, routers, lathes and mills. The CNC, in other words is, Computer Numerical Control. Under this system tools are able to operate through numerical control. A program is specially customized for a specific object and the machines are then programmed with the G-code, which is the language for CNC machining. This code can control the coordination, speed rate, speeds and location. Velocity and positioning of different objects can be controlled with CNC machining. This machining is used for the manufacture of plastic and metal parts.
Components of CNC
Basically, any CNC machine tool consists of the following components which are essential.
* Part Program
These are coded instruction in a series which are a requirement to produce parts. This part program is able to control the movement of the tool and an on and off control for functions like coolant and spindle rotation. These instructions which are coded consist of symbols, numerical and letters.
* Machine Control Unit (MCU)
This MCU is the most important part of CNC machining. Made of electronics components, this is able to interpret after reading the program instructions, after which, this is able to convert them in to the mechanical actions of the specific machine tools. The control unit, thus, is the required link between the machine tool and the program. This operates the machine in accordance to the given instructions. The functions are,
1. Reading the instructions which are coded
2. Decoding these instructions.
3. Implementing interpolations (helical, circular, linear) generating commands for motion of the axis.
4. Feeding these axis commands to the amplifier circuits to enable driving of the mechanisms of the axis.
5. Receiving the signals of the feedback of the speed and position for every drive axis.
6. Implementing the controls of the auxiliary functions like tool change, spindle on and off and coolant.
* Machine Tool
The actual operations for machining are carried out by the machine tool. This can be any tool like drilling machine, milling machine, lathe or any other. This is the part which is controlled in the CNC. These machines also have the control console or the control panel that contains the switches and dials which the operator uses to run the machine. You also have displays where the required information is displayed.
*Program Input Device
This is for entering the part program in the CNC machine. The three common input devices used are magnetic tape reader, punch tape reader and computer via the RS-232-C communication.
* Drive System
This system consists of drive motors, ball lead-screws and amplifier circuits. The MCU feeds the signals for control of the position and speed of every axis to the circuits of the amplifier. These signals are then augmented to drive the motors which turn the ball lead-screws in order to position the table of the machine.
*Feed Back System
The measuring system is the feedback system. Making use of transducers of speed and position, this can monitor constantly the position of the tool which is cutting, at any instant. Using the difference between the feed back signals and reference signals, the MCU is able to generate the signals for controlling and correction any errors in the speed and position.
CNC Machines are apt due to its many advantages
There are multiple benefits for the manufacturers when opting for these CNC machines. Some of them are saving on the time factor besides the cost. These machines can be handled by only one worker so there is no requirement of employing many. The consistence and accuracy is looked into by these machines so there are no tensions.