【正文】
。在此次設(shè)計(jì)過(guò)程中,筆者對(duì)數(shù)控系統(tǒng)、主軸單元、變速箱、齒輪齒條和絲杠導(dǎo)軌等都按照樣本上的經(jīng)驗(yàn)公式得出,不僅大大縮短了設(shè)計(jì)時(shí)間,同時(shí)使設(shè)計(jì)的可靠性更高。運(yùn)動(dòng)的實(shí)際值可進(jìn)行連續(xù)比較,即使最小的偏差也可以得到糾正,因此提高了X軸的運(yùn)動(dòng)精度。數(shù)控系統(tǒng)采用的是西門子840D,因?yàn)榇讼到y(tǒng)提供了龍門軸的同步功能。主軸箱的左右移動(dòng)為Y軸,為了保證Y軸的傳動(dòng)精度,并使絲杠只受水平軸向力,故采用伺服電動(dòng)機(jī)與滾珠絲杠直聯(lián)方式。當(dāng)然,為了保護(hù)Z軸進(jìn)給機(jī)構(gòu)的精度,還在滑臺(tái)上裝有兩個(gè)平衡油缸。筆者在設(shè)計(jì)中特別注意Z軸的安全問(wèn)題。主軸箱的上下垂直運(yùn)動(dòng)Z軸采用滾珠絲杠副傳動(dòng)。軸2上兩個(gè)斜齒輪的螺旋線的方向相反??紤]到安全系數(shù),每根導(dǎo)軌安裝3個(gè)滑塊。因?yàn)闈L動(dòng)導(dǎo)軌副的摩擦系數(shù)小,非常適合龍門框架移動(dòng)的動(dòng)靜剛度要求。這樣設(shè)計(jì)使機(jī)床的整體進(jìn)給性能得以協(xié)調(diào),各軸的進(jìn)給速度和進(jìn)給力得到了最佳匹配?;_(tái)的設(shè)計(jì)是在龍門架和主軸箱的幾何尺寸確定后,按照主軸的中心盡量貼近橫梁上的導(dǎo)軌面為原則,并把Z軸驅(qū)動(dòng)安裝位置設(shè)計(jì)在滑臺(tái)上,有效地減輕了滑臺(tái)的重量。主軸單元采用4支承結(jié)構(gòu),前面三組角接觸球軸承用來(lái)承受切削力,主軸尾部一個(gè)深溝球軸承用來(lái)卸荷,使主軸不受到滑移齒輪產(chǎn)生的附加力矩的影響。 截面設(shè)計(jì),其抗扭抗彎能力更強(qiáng)。床身的基本壁厚由以下公式初定:C=1/4(2L+B+H)式中:L. B. H 分別為床身的長(zhǎng)、寬、高尺寸,單位為m。筆者把導(dǎo)軌面設(shè)計(jì)在床身的兩下側(cè),主要是考慮力的傳遞方向與卸荷問(wèn)題。床身的上平面即工作臺(tái)面設(shè)計(jì)有9條T形槽,為方便床身工作臺(tái)面和T形槽的精刨加工,槽完全貫通。現(xiàn)把設(shè)計(jì)過(guò)程中的重點(diǎn)闡述如下:床身是本次設(shè)計(jì)工作的基礎(chǔ),床身的尺寸設(shè)計(jì)影響著對(duì)整機(jī)的設(shè)計(jì),而且設(shè)計(jì)的合理性直接影響到整機(jī)的剛度。該龍門銑床的主要設(shè)計(jì)參數(shù)如下:工作臺(tái)面積為1800mmX4000mm,X軸行程為4000mm,Y軸行程為2000mm,Z軸行程為750mm,各軸快速進(jìn)給為10m/min。筆者獨(dú)立設(shè)計(jì)的移動(dòng)式數(shù)控龍門銑床(圖1),現(xiàn)已作為專機(jī)投入生產(chǎn)應(yīng)用,能滿足大型鑄件、鋼件的鏜、銑、鉆等多工序加工;配上直角銑頭,還可對(duì)工件的個(gè)側(cè)面進(jìn)行加工。(2)機(jī)床的動(dòng)態(tài)響應(yīng)好。移動(dòng)式龍門銑床的最大優(yōu)點(diǎn)是:(1)機(jī)床占地面積小。燕山大學(xué)本科生畢業(yè)設(shè)計(jì)(論文) 附錄3外文文獻(xiàn)Design of Movable Gantry CNC Milling MachineZHANG JianAbstract: this paper describes the nc milling roller, the overall design and analyses the bilateralsupermodulus gear pair of driving mechanism of the main points of design,installationguidesurface of the X axis is introduced in this paperKeywords: mobile nc milling designThis machine is mainly used for metal parts of the plane and inclined plane work. It has enough rigidity, Milling head adopts milling head in Taiwan, Milling head with flexible, Spindle motor is frequency conversion motor. It can undertake stepless speed, Ensure accuracy of machine tools and machining precision has good stability, This machine is of high efficiency and exercise,For convenience, make the drive more reliable and convenient in maintenance, less consumption, beautiful modelling, etc, widely used in mechanical manufacturing industry.This paper described the mobile CNC milling refers to longmen framework Vertical milling movement. The biggest advantage of milling roller is (1) Machine cover an area o