【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(jī)床不同于一個(gè)手動(dòng)機(jī)床只有在尊重專(zhuān)業(yè)的組件構(gòu)成的數(shù)控系統(tǒng)。數(shù)控系統(tǒng)可以進(jìn)一步
分為三個(gè)子系統(tǒng):控制、驅(qū)動(dòng),和反饋。所有這些子系統(tǒng)必須共同努力,形成一個(gè)完整的數(shù)控系
統(tǒng)。 1. control system 1?？刂葡到y(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(chēng)為機(jī)控制單元(MCU),但近年來(lái)最常用的名字是控制器,控
制單元,或者就是簡(jiǎn)單的控制。這是計(jì)算機(jī)存儲(chǔ)和讀取程序,告訴其他組件該做什么。 2. Drive system. 2。驅(qū)動(dòng)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(chē)的傳動(dòng)系統(tǒng)是由部分程序,最終將變成運(yùn)動(dòng)。第一個(gè)組件的典型的驅(qū)動(dòng)系統(tǒng)是一
種高精度絲杠稱(chēng)為滾珠絲桿()。消除反應(yīng)在滾珠螺桿是非常重要的兩個(gè)原因。首先,
不能實(shí)現(xiàn)高精度定位如果表是免費(fèi)的移動(dòng)略當(dāng)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(jī)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(dòng)電機(jī)驅(qū)動(dòng)系統(tǒng)中的第二專(zhuān)業(yè)組件。電動(dòng)機(jī)的轉(zhuǎn)動(dòng)將滾珠螺桿直接導(dǎo)致加工表。幾種類(lèi)型
的電機(jī)是用在數(shù)控控制系統(tǒng)和液壓馬達(dá)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(jiǎn)單的類(lèi)型的電動(dòng)機(jī)用于數(shù)控定位系統(tǒng)是步進(jìn)電機(jī)(有時(shí)稱(chēng)為步進(jìn)電機(jī))。步進(jìn)電機(jī)旋轉(zhuǎn)固
定數(shù)量的度當(dāng)它收到一個(gè)電脈沖,然后停止,直到接收到一個(gè)脈沖。步進(jìn)特性使步進(jìn)電機(jī)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(jī)在數(shù)控系統(tǒng)中更為普遍。伺服電機(jī)運(yùn)行在一個(gè)光滑、連續(xù)的活動(dòng),如
離散運(yùn)動(dòng)的步進(jìn)電機(jī)。這光滑的運(yùn)動(dòng)導(dǎo)致高度理想的加工特點(diǎn),但他們也難以控制。需要專(zhuān)
門(mén)的硬件控制和反饋系統(tǒng)控制和驅(qū)動(dòng)這些汽車(chē)。交流電伺服電機(jī)目前工業(yè)數(shù)控機(jī)床的標(biāo)準(zhǔn)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(yùn)動(dòng)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(shí)際條件和改正。最明顯的信息反饋給控制數(shù)控機(jī)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(chē)的速度。其他信息也可以反饋,不是直接關(guān)系到運(yùn)動(dòng)控制,如電動(dòng)機(jī)的溫
度和負(fù)載spindlethis信息保護(hù)機(jī)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(lèi)型的控制系統(tǒng):開(kāi)環(huán)和閉環(huán)。一個(gè)開(kāi)環(huán)系統(tǒng)沒(méi)有任何設(shè)備來(lái)確定指令進(jìn)行。例
如,在一個(gè)開(kāi)環(huán)系統(tǒng),控制可以給指令將電動(dòng)機(jī)10革命。然而,任何信息可以回到控制告訴它,
。開(kāi)環(huán)控制不用于關(guān)鍵系統(tǒng),但這是一個(gè)不
錯(cuò)的選擇廉價(jià)的運(yùn)動(dòng)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(yàn)證某些條件已經(jīng)滿足。當(dāng)然,位置和速度反饋是最重要的一個(gè)精
確的數(shù)控系統(tǒng)。反饋是唯一的辦法,以確保機(jī)器的行為控制計(jì)劃的行為方式。