【正文】 s mitment to GT principles and support for the personnel i。附錄BThe potential of group technology for . manufacturingNancy Lea Hyer*Group Technology (GT) is an innovative approach to batch production which seeks to rationalize a variety of aspects of the conversion process by recognizing and exploiting the underlying sameness which exists among ponent parts, end items, raw materials and so forth. The majority of GT applications, however, focus on identifying and capitalizing on ponent part similarities. The central theme of GT when applied to this class of items is the formation of part families based on design or manufacturing similarities (or both).Although the basic principles of GT were described and applied overseas as early as 1950, it is only in the past ten years that any significant and sustained . interest in GT has surfaced. In an effort, first, to determine the status of GT use in the . and, second, to provide some insights as to the desirability of GT for . manufacturers, data was collected on twenty . firms known to use this innovation. A fifteen page questionnaire was employed to gather information on (1) the characteristics of these firms which use GT, (2) the ways in which GT has been applied at these panies and (3) the costs and benefits of these GT programs. The results of this survey, described below, provide an overview of GT practices in a sample of . firms and indicate the potential usefulness of this innovation for a broad spectrum of . manufacturers.The survey responses indicate that GT is a multifaceted tool which can be applied to a variety of problems in a variety of industrial settings. GT has been adopted by both large and small installations involved in the manufacture of metal items produced in small to medium quantity lots. Although no applications were identified outside metal working, the range of metalworking industries in which GT had been implemented is quite broad. Universally, GT was adopted in response to a particular problem or set of problems. Frequently, the need to curb excessive lead times motivated firms to introduce GT.In terms of implementing and using GT there were a number of interesting findings. First, the survey results confirm that GT is more than cellular manufacturing. In fact, the most popular application of GT was in manufacturing engineering, particularly as an aid in rationalizing the process planning function. Seventyfive percent of the firms had used GT in manufacturing engineering, while fiftyfive percent had set up one or more production cells and an equal number had applied GT to product design. A second interesting finding was that, for the majority of firms, informal procedures for identifying and grouping similar items (. by visual inspection or informed judgement) proved inadequate for pursuing GT applications. Consequently, eightyfive percent of the respondents noted that formal classification and coding schemes had been used to aid in identifying and exploiting item similarities. The survey also yielded interesting results with respect to the problems encountered in implementing GT. The firms reported that regardless of the type of application (., product design, manufacturing engineering or cellular manufacturing), human resistance to change was the most serious impediment to successfully introducing GT. This obstacle could be surmounted, in most instances, by GT education and by involving those affected by GT as early in the implementation process as possible. A number of other problems specific to the type of GT application were also noted. With regard to the relative ease of implementing GT in various areas, the respondents generally agreed that establishing cells is fraught with more difficulties than are GT applications in manufacturing engineering or product design.With respect to costs and benefits, 85% of the firms reported that the actual benefits from GT met or exceeded their anticipated benefits. Specific savings frequently mentioned included reduced lead times and easier preparation of process plans. Costs for planning the GT program and for purchasing additional puter hardware and software were the most monly cited GTrelated expenses. In terms of prerequisites for success in implementing GT, the overwhelming majority of respondents agreed that two elements are essential. The first is GT education for all those (managers, supervisors and line personnel) who are affected by the changes that acpany GT39。 第二個(gè)重要因素是最高管理層的承諾，對成組技術(shù)（GT）應(yīng)用的原則和支持介入指揮學(xué)習(xí)成組技術(shù)（GT）努力人員。在對于運(yùn)用成組技術(shù)成功的先決條件，絕大多少受訪者一至認(rèn)為，兩個(gè)因素是至關(guān)重要的。具體包括，經(jīng)常提到的減少儲(chǔ)蓄周轉(zhuǎn)時(shí)間，更容易編寫進(jìn)程計(jì)劃。關(guān)于相對容易實(shí)施成組技術(shù)（GT）的各個(gè)領(lǐng)域，受訪者普遍認(rèn)為，建立細(xì)胞比應(yīng)用在制造工程或產(chǎn)品設(shè)計(jì)充滿了更多的困難。有個(gè)公司報(bào)道說，不管什么類型的應(yīng)用程序（即產(chǎn)品設(shè)計(jì)，制造工程或單元制造），人力抵抗變革是最嚴(yán)重的障礙對于介紹成組技術(shù)，在大多數(shù)情況下，這個(gè)障礙可以戰(zhàn)勝，盡早和盡可能的通過對成組技術(shù)的教育和引進(jìn)一些成組技術(shù)介入的生產(chǎn)實(shí)例。因此，應(yīng)答者的百分之八十五注意到，正式分類和編碼方案在辨認(rèn)和利用被用于援助項(xiàng)目相似性。企業(yè)的百分之七十五在制造業(yè)工程學(xué)使用了GT，而百分之五十五設(shè)定了一個(gè)或更多生產(chǎn)細(xì)胞，并且一個(gè)相應(yīng)的數(shù)字應(yīng)用了GT于產(chǎn)品設(shè)計(jì)。首先，調(diào)查結(jié)果證實(shí)成組技術(shù)是多樣花的制造技術(shù)。通常，需要遏制向企業(yè)過分的過早的介紹成組技術(shù)。雖然沒有被廣泛應(yīng)用到金屬加工和各種金屬加工工業(yè)中外（這些行業(yè)的成組技術(shù)已經(jīng)應(yīng)用很廣泛了）。它可以適應(yīng)在不同環(huán)境下的各種各樣的問題。這次調(diào)查的結(jié)果如下所述，概述了成組技術(shù)在美國應(yīng)用的范例并說明了應(yīng)用這一創(chuàng)新技術(shù)的范圍廣泛的美國制造商的潛在發(fā)展實(shí)力。數(shù)據(jù)收集了20個(gè)應(yīng)用了這一先進(jìn)技術(shù)了公司。雖然成組技術(shù)的基本原理早在1950年就被描述和提出，然而只是在過去10年里對成組技術(shù)重大和持續(xù)的興趣才在美國浮出水面。它旨在認(rèn)識和理順各個(gè)方面的轉(zhuǎn)換過程，利用各組成部分之間存在著的相同點(diǎn)，如工作原理、原材料等等。在此向他們表示感謝。并帶領(lǐng)我們親自參觀了泰克液壓件廠，在那里我們參觀了泵體的整個(gè)加工工藝流程，獲得了很大的幫助。尤其在編寫格式上老師更是認(rèn)真檢查，嚴(yán)格要求，使論文的格式得到很大的完善。致 謝本設(shè)計(jì)在導(dǎo)師魏家鵬的悉心指導(dǎo)和嚴(yán)格要求下業(yè)以完成。本設(shè)計(jì)也存在不足之處，由于數(shù)控程序的生成掌握的不好，因此采用了手動(dòng)編程的辦法，編程中有錯(cuò)誤也是在所難免；由于實(shí)踐經(jīng)驗(yàn)少，對機(jī)床的了解不夠，在設(shè)計(jì)中可能造成一些與實(shí)際有偏差的地方。內(nèi)容涉及到工程材料、熱處理、尺寸公差和加工精度、加工工藝、刀具的選擇、數(shù)控編程等。本設(shè)計(jì)通過對齒輪泵泵體的加工，應(yīng)用了數(shù)控機(jī)床和普通機(jī)床交替加工的方法。因此數(shù)控加工將是未來制造業(yè)的主要部分。 程序結(jié)束（5） 粗銑半精銑齒輪孔底端面N10 G92 X0 Y0 Z0 建立工件坐標(biāo)系N20 G90 G00 X28 Y50 Z150 快速移動(dòng)動(dòng)刀具加工孔1起始點(diǎn)上方150mmN30 G43 H08 Z15 S160 M03 建立刀具長度補(bǔ)償，主軸以160r/minN40 G41 G01 X18 Y40 D05 F130 建立刀具半徑補(bǔ)償N50 G03 X0 Y0 I52 J50 粗銑孔1的底端面N60 G03 X0 Y0 I52 J50 半精銑孔1的底端