【導(dǎo)讀】長期以來，山藥都是靠傳統(tǒng)的人力收獲，山藥的根莖較長，深入地下，難以采收，如果收獲技術(shù)不夠成熟，根莖破損率就會很高。設(shè)計(jì)的準(zhǔn)確性和可靠性。本設(shè)計(jì)利用三維設(shè)計(jì)軟件，對農(nóng)業(yè)機(jī)械進(jìn)行產(chǎn)品設(shè)計(jì)。本文設(shè)計(jì)了一種山藥收獲裝置，結(jié)構(gòu)簡單合理，能夠完成山藥的機(jī)械化收獲作業(yè)。不僅極大地提高山藥收獲效率，而且對深土農(nóng)作物的規(guī)?；N植起到了推廣作用。動方式、工作方式，論述了裝置在收獲過程中的的工作原理。山藥對當(dāng)?shù)貧夂蛞蟛粐?yán)，但喜溫暖濕潤，忌積水，怕干旱。特別是近幾年，山藥的種植面積和種植規(guī)模不斷上升。因此，山藥生產(chǎn)和收。我國大部分地區(qū)收獲山藥的方法是：從山。心拔出山藥的根莖。一定要小心精細(xì)鏟土，避免山藥根莖的損傷和折斷。由于山藥一般在下層土壤延伸，最深可延伸到地下70～100cm處，靠人力收獲相。為此，山藥收獲的機(jī)械化問題就亟待解決。化，能夠同時(shí)實(shí)現(xiàn)收獲山藥和溝內(nèi)填土的兩項(xiàng)功能，除了采收山藥外，

　　

【正文】 NFLUENCE THE TRANSLATION GUIDE WEAR OVER THE MACHINING ACCURACY ON THE MACHINE TOOL . Ivona PETRE, University Valahia from Targoviste Lecturer dr. eng. Carmen POPA, University Valahia from Targoviste Lecturer dr. eng. Dumitru DUMITRU, University Valahia from Targoviste Eng. Ciprian MANESCU, University Valahia from Targoviste Abstract: The wear of machine tools guides influences favorably to vibrations. As a result of guides wear, the initial trajectory of cutting tools motion will be modified, the generating dimensional accuracy discrepancies and deviations of geometrical shape of the work pieces. As it has already been known, the wear of mobile and rigid guides is determined by many parameters (pressure, velocity, friction length, lubrication, material). The choice of one or another analytic model and/or the experimental model of the wear is depending by the working conditions, assuming that the coupling material is present work’s goal is to establish an analytic model of calculus showing the influence of the translation guides wear over the machining accuracy on machinetools. Keywords: accuracy, machinetools, surface. As it has already been known the accuracy of machining each piece depends on a multitude of factors connected to the technological system (the machine tool, the clamping device, the cutting tool etc) [1, 2, 3]. In the present work, the author’s goal is to establish the size and influence only of the wear of the bed the slide guide over the machining accuracy on machinetools with use on lather. The size of the guide and (longitudinal) slide wear are important to be known because the change of the slide trajectory due to the wear that occurs in time conditions the 華北水利水電大學(xué)畢業(yè)設(shè)計(jì)（論文） dimensional deviations and the quality of the machined parts surface. In order to establish the wear size of the system bedslide, three distinct situations are being analyzed: 1 – the bed guide only is being worn 2 – the slide guide only is being worn 3 – both guides (bedslide) are being worn 2. Analytic models establishing the error produced by the bedslides wear. In order to establish the quantitative influence of the wear process over the machining accuracy on a lathe, the following assumptions are made [2]: the curve of the worn profile of the rigid guide U(x) is considered known at a certain moment assessed by the number of the stress cycles。 the wear on the current stress cycles is neglected pared to the wear produced by all the previous cycles。 the mobile guide wear U1(l) is so produced that the profile of this guide follows continuously the rigid guide profile。 based on this assumption it is admitted that the contact is always of the type according to the appropriate distribution of the normal and tangential stress。 the mobile guide is set on the rigid one during the displacement so that normal line to the contact surface of the two profiles is unique。 the wear is a continuous process and is characterized by the thickness of the worn layer, considered as a continuous function onto the guide length and in time. Based on these assumptions the wear of the bed and slide guide is established for the 3situation shown in the first part of the work. Case 1: the bed guide is being only () 華北水利水電大學(xué)畢業(yè)設(shè)計(jì)（論文） . Settlement scheme of the mobile slide on a bedguide Taking a point A (xo, Uxo) situated at the middle of the mobile slide. The wear of the bed guide in the considered point is Uxo and the function of the bed guide wear Ux. The deviation of the point A is considered ? 1 = AC . In order to establish, the coordinates of the point C the normal at the bed guide profile in the point A is considered a straight line with the slope m that can be determined based on the wear function Ux. nmxy ?? （ 1） XMUm 39。/1?? （ 2） where： XUUn a n d nXUU XXXX 39。139。1 ????? Being the conditions to limit, the coordinates of the point C will be y c = 0 and x c = U x U 39。x + x . The deviation in this case considered: admXXAcAc UUyyxx ????????? 2221 )39。(1)()( （ 3） Case 2: the slide guide only is being worn according to a linear variation law (). Considering the point B(0,b) situated at the half of the slide with the length l. After a certain period of functioning, as a result of the slide wear, the point B will be displaced in the point B’. In this situation the deviation of the point will be: ? 2 = BB39。 In order to make the calculation of this deviation 2 cases can be distinguished: 華北水利水電大學(xué)畢業(yè)設(shè)計(jì)（論文） a) the point A is not worn U A = 0 。 b) the point A is worn by a size that can be established (measured) U A ≠ 0 Fig. 2. Assessment scheme of the mobile slide geometry changes Staring from the equation of the straight line that goes through the points AO’ and following the some argument as in case 1, the deviation of the point B’ will be: when 2/c o s20 222 ??????? baU A when 2/c o s)(239。0 22 ???????? AA UbaU The size of the angle α depends on the size of the accuracy deviation imposed to the slide: 1CUMACMtg ??? The angle α can be known if the wear of the point C, Us and α α adm are measured(known). The allowable size of the angle α adm is a size that can be established from the accuracy conditions imposed by the machine tool on which the slide is installed where: lAiAAlAtg ppira ???? （ 5） where: Ai – the initial deviation that can be accepted as being the maximum allowable deviation prescribed within the accuracy parameters of the machinetool。 華北水利水電大學(xué)畢業(yè)設(shè)計(jì)（論文） App – the accuracy d