【正文】 ly in respect to the specialized
ponents that make up the CNC system. The CNC system can be further divided into three
subsystemscontroldriveand feedback. All of these subsystems must work together to form a plete
CNC system. 數(shù)控機床不同于一個手動機床只有在尊重專業(yè)的組件構(gòu)成的數(shù)控系統(tǒng)。數(shù)控系統(tǒng)可以進一步
分為三個子系統(tǒng):控制、驅(qū)動,和反饋。所有這些子系統(tǒng)必須共同努力,形成一個完整的數(shù)控系
統(tǒng)。 1. control system 1。控制系統(tǒng) The centerpiece of the CNC system is the control. Technically the control is called the machine control
unitMCUbut the most mon names used in recent years are controllercontrol unitor just plain
control. This is the puter that stores and reads the program and tells the other ponents what to
do. 數(shù)控系統(tǒng)控制的核心。技術(shù)控制稱為機控制單元(MCU),但近年來最常用的名字是控制器,控
制單元,或者就是簡單的控制。這是計算機存儲和讀取程序,告訴其他組件該做什么。 2. Drive system. 2。驅(qū)動系統(tǒng)。 The drive system is prised of screws and motors that will finally turn the part program into motion.
The first ponent of typical drive system is a highprecision lead screw called a ball screw.
Eliminating backlash in a ball screw is very important for two reasons. Firsthighprecision positioning
can not be achieved if the table is free to move slightly when it is supposed to be stationary. Second
materials can be climbcut safely if the backlash has been eliminated. Climb cutting is usually the most
desirable method for machining on a CNC machine. 螺絲和汽車的傳動系統(tǒng)是由部分程序,最終將變成運動。第一個組件的典型的驅(qū)動系統(tǒng)是一
種高精度絲杠稱為滾珠絲桿()。消除反應(yīng)在滾珠螺桿是非常重要的兩個原因。首先,
不能實現(xiàn)高精度定位如果表是免費的移動略當它應(yīng)該是固定的。第二,材料可以安全地同向
如果反彈已經(jīng)消除。爬上切割通常是最可取的方法在數(shù)控加工機器。 Drive motors are the second specialized ponent in the drive system. The turning of the motor will turn
the ball screw to directly cause the machining table to move. Several types of electric motors are used on
CNC control systemsand hydraulic motors are also occasionally used. 驅(qū)動電機驅(qū)動系統(tǒng)中的第二專業(yè)組件。電動機的轉(zhuǎn)動將滾珠螺桿直接導致加工表。幾種類型
的電機是用在數(shù)控控制系統(tǒng)和液壓馬達也偶爾使用。 The simplest type of electric motor used in CNC positioning systems is the stepper motorsometimes
called a stepping motor. A stepper motors rotates a fixed number of degrees when it receives an
electrical pulse and then stops until another pulse is received. The stepping characteristic makes stepper
motors easy to control. 最簡單的類型的電動機用于數(shù)控定位系統(tǒng)是步進電機(有時稱為步進電機)。步進電機旋轉(zhuǎn)固
定數(shù)量的度當它收到一個電脈沖,然后停止,直到接收到一個脈沖。步進特性使步進電機容易
控制。 It is more mon to use servomotors in CNC systems today. Servomotors operated in a smooth 
continuous motion—not like the discrete movements of the stepper motors. This smooth motion leads to
highly desirable machining characteristicsbut they are also difficult to control. Specialized hardware
controls and feedback systems are needed to control and drive these motors. Alternating currentAC
servomotors are currently the standard choice for industrial CNC machine tools. 這是今天使用伺服電機在數(shù)控系統(tǒng)中更為普遍。伺服電機運行在一個光滑、連續(xù)的活動,如
離散運動的步進電機。這光滑的運動導致高度理想的加工特點,但他們也難以控制。需要專
門的硬件控制和反饋系統(tǒng)控制和驅(qū)動這些汽車。交流電伺服電機目前工業(yè)數(shù)控機床的標準選
擇。 3. Feedback System 3。反饋系統(tǒng) The function of a feedback system is to provide the control with information about the status of the motion
control systemwhich is described in Figure . 反饋系統(tǒng)的功能是為控制提供運動控制系統(tǒng)的狀態(tài)信息,。 The control can pare the desired condition to the actual condition and make corrections. The most obvious information to be fed back to the control on a CNC machine 控制可以比較所需的條件的實際條件和改正。最明顯的信息反饋給控制數(shù)控機器上 tool is the position of the table and the velocity of the motors. Other information may also be fed back that is not directly related to motion controlsuch as the temperature of the motor and the load on the
spindle—this information protects the machine from damage. 工具的位置表和汽車的速度。其他信息也可以反饋,不是直接關(guān)系到運動控制,如電動機的溫
度和負載spindlethis信息保護機器免受損壞。 There are two main types of control systemsopenloop and closedloop. An openloop system does not
have any device to determine if the instructions were carried out. For examplein an openloop system
the control could give instructions to turn the motor 10 revolutions. Howeverno information can e
back to the control to tell it if it actually turned。All the control knows is that it delivered the instructions.
Openloop control is not used for critical systemsbut it is a good choice for inexpensive motion control
systems in which accuracy and reliability are not critical. 主要有兩種類型的控制系統(tǒng):開環(huán)和閉環(huán)。一個開環(huán)系統(tǒng)沒有任何設(shè)備來確定指令進行。例
如,在一個開環(huán)系統(tǒng),控制可以給指令將電動機10革命。然而,任何信息可以回到控制告訴它,
。開環(huán)控制不用于關(guān)鍵系統(tǒng),但這是一個不
錯的選擇廉價的運動控制系統(tǒng)的精度和可靠性并不是最關(guān)鍵的。 Closedloop feedback uses external sensors to verify that certain conditions have been met. Of course
position and velocity feedback is of primary importance to an accurate CNC system. Feedback is the only
way to ensure that the machine is behaving the way the control intended it to behave. 閉環(huán)反饋使用外部傳感器驗證某些條件已經(jīng)滿足。當然,位置和速度反饋是最重要的一個精
確的數(shù)控系統(tǒng)。反饋是唯一的辦法,以確保機器的行為控制計劃的行為方式。