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Sistem Pengaturan Manufaktur - 02 11

TE090565 Sistem Pengaturan Manufaktur

Prinsip dan Komponen Mesin Numerical Control

Ir. Jos Pramudijanto, M.Eng.Jurusan Teknik Elektro FTI ITS

Telp. 5947302 Fax.5931237Email: [email protected]

Sistem Pengaturan Manufaktur - 02

Objektif:History of NC TechnologyType of NCLevel of CNCThe component of NC system


What the letters stand for

NC Numerical ControlCNC Computer Numerical ControlDNC Direct or Distributed Numerical

Control

NC, CNC, and DNC


Comparison of NC, CNC and DNC Technology

What they have in CommonAll are considered necessary elements of Computer Aided Manufacture (like graphics and solid modeling in CAD)All use coded numerical information to automatically direct the operation of machine tools or processes.Common physical elements are machine tools, drive systems and controllers.

How they differTechnology to interpret the coded information is hardware for NC and software for CNC and DNCNC and CNC are clearly stand alone and so is Distributed NC. Direct Numerical Control involves supervisory control, and so does Distributed NC in the for of a network communicating with stand alone machine tools.


Direct Numerical Control


In 1952 Parsons Co. and M.I.T made the first three-axes NC machine tool in the world.In 1955, the first industry NC machine tool was made by Bendix, U.S.A.From 1952 to present, NC machine tool has experienced five generations according to the development of NC system.

History of NC Technology


The NC machine tool is now machining an turbine

The Five Coordinate NC Systems


First: In 1955,NC was made of electron tubes. Large volume and high power consumption.Second: In 1959, it was made of transistors. Printed circuit board was widely used.Third: In 1965, small scale integrated circuit was used. Small volume and low power consumption. Improved reliability.NC functions were realized by hardware, so called “hard NC”



Fourth: In 1970, most hardware circuit was replaced by micro computer. Some functions were realized by software. Low price and power consumption, high reliability and multiple functions.Fifth: In 1974, micro processor was used as the core. Much more lower price, smaller volume.



Open loop CNC systemNo position detector. Signal is single-direction (NC ⇒ Feeding), so system has good stability.

Types of CNC

motor

Application Parts

phase A phaseBphaseC

F,nCNCInter-polation command

Pulse frequency &

pulseconversion

Pulse round

distri-bute switch

Power amplify


Semi-closed loop NC Semi-closed loop NC’s position detector is shown in figure: driver equipment (always servo) , samples the revolving angle but not detect the real position of movement parts directly.

Position Control Adjuster

Speed Control Adjuster &

Driver

Detect & Feedback Unit

Position Control Unit Speed Control Unit

++

- -

Motor

Application PartsCNC inter-polation command

Position Feed-back

Speed Feed-back

Types of NC


Full closed loop NCFull closed loop CNC’s position detector(raster) is shown as dashed in figure, detects the real position of movement parts directly

Types of NC

Position Control Adjuster

Speed Control Adjuster &

Driver

Detect & Feedback Unit

Position Control Unit Speed Control Unit

++

- -

Motor

Application PartsCNC inter-polation command

Position Feed-back

Speed Feedback


Open loop control, Single chip CNC, displays by LED or small single-color LCD, no more than 100KB RAM, step motor driver, Coordinated axis is 2 or 2,5, motion speed lower<6m/min, precision 0,01mm. Cost is cheap. Classic system: Dafang, Siemens 802S etc.Used in lathe mainly.

Economy level of CNC


Semi-closed loop control, 8-32bits CPU, 9 inch single color LCD, no graphic color display, about 150KB RAM, DNC function, analog DC brush or DC brushless servo driver, Coordinated axis are 3 to 4, highest speed 6-16m/min; position precision is 0,005-0,01mm.Classic system: Fanuc 0, Siemens 810,802C series etc.Used in cheap lathe, milling machine and machining center.

Popular level of NC


Full closed loop control, 32-64bits CPU, colorful or TFT LCD, graphic display, RAM is higher than 150KB, DNC and ether net function, extended digital profile modeling function, good user interface, digital AC brushless servo driver, linkage axis are more than 4, highest speed is more than 16m/min; position precision is more than 0,005mm. Classic system: Fanuc 160i,Siemens840 series,MAZAKA640 etc. Used in advanced,high precision machining center.

Advanced level of NC


I/O circuit of machine

Measure

equipment

Spindle

drive motor

Feed drive

motor

Spindle

Servo unit

Feed servo unit CNC

Unit

Control panel PLC

CNC system Machine

1. Main

movement

framework

2. Feed drive

framework

3. Accessorial

control

framework

Key board

I/O device

The component of NC system


The Control panel of NC system

Component: button station, state light, key array (has the same function as computer key) and monitor.A tool to communicate CNC unit for operatorA peculiar parts of NC machine.

BACK

CTR

L

INS

CR

TAB

ALT0SHI

→ ZEND

←WHO

ME

↓ TPgD

↑ OPgU

J

RST E

65“ 4

32？ 1

98: 7

YX< >

VU[ ]

SRP Q

NMK L

IHF G

DCA BESC

14''

彩色

显示器

空运行 Z 轴锁定 MST 锁定

任选程序段

机床锁定

快进+JOG -JOG 主轴正转主轴停主轴反转

急停

超程解除

循环驱动进给保持冷却液开/关刀松/刀紧

主轴修调

16010

进给修调

160

50403020

100

电源

关开自动

方式选择

回零

手摇点动步进

单段

驱动器

NC机床

电源

X Y Z A

主轴超程

报警

− +

手摇脉冲发生器

2010 0 90增量倍率

1000

10 100

1

坐标轴选择

Z

Y

X


Control Panel of Turning CJK6132


Control Panel of Milling XK714


The Communication of NC system

Besides exchanging information with I/O device, modern NC system has the ability to exchange information with communication manner in common. They are the basic technology of achieving the integration of CAD/CAM, FMS and CIMS. The manner adopted as follows:

Serial communication (RS-232 etc)The special interface and criterion of autocontrol (DNC mode, MAP protocol etc)Network technology (internet, LAN etc)


Communication Unit


The CNC unit NC systemComponent: computer system, position control panel, PLC interface panel, communication interface panel, special function module and corresponding control software.Function: According to the input part program, output control order to the executive parts (servo unit, drive device and PLC, etc) to achieve the control of movement track and I/O of machine. All the work are organized by the hardware and software inside CNC unit. CNC unit is the kernel of CNC system


The Component of CNC unit

I/O device

Computer board

Display card

Function module m

Function module 1Electron disk

Multi function card Position control board n

Position control board 1

PLC module

Spindle control module

I/O of machine

Control panel

servo unit 1

servo unit n

Function drive 1

Function drive m

… ………

System B

US

The part of computer

CNC unit CNC system

The part of interface


The data transform in NC machining

decode

cutter compensation

Interpolation PLCcontrol

Feed servo system

Cutting movement,I/O circuit of machine

PositioncontrolPart program

Shape movement


Servo Drive SystemServo unit and drive motor

Spindle servo unit and spindle drive motor Feed servo unit and feed drive motor

Measure equipmentMeasure equipment of position and feed, used to achieve the closed loop control of feed servo system

Function: Ensure to track the order from CNC unit sensitively and exactly:

feed order: to achieve the movement of parts shape (speed and position control)Spindel order: to achieve the movement of parts cutting (speed control)


AC Servo Drive Unit or Spindle


HNC-21/22 Century star panel


Vertical Lathe


VMC750E Machining Center

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