2379 成品軸承自動清洗生產(chǎn)線上料裝置設(shè)計

2379 成品軸承自動清洗生產(chǎn)線上料裝置設(shè)計,成品,軸承,自動,清洗,生產(chǎn)線,裝置,設(shè)計 3.1.2 Effects of pre-strain and rake angle in machining copperIn the previous section, the machining of annealed metals by a 6° rake angle tool was considered. Both pre-strain and an increased rake angle result in reduced specific cutting forces and reduced cutting temperatures, but have little effect on the stressses on the tool. These generalizations may be illustrated by the cutting of copper, a metal sufficiently soft (as also is aluminium) to allow machining by tools of rake angle up to around 40°. Figure 3.6 shows examples of specific forces and shear plane angles measured in turning annealed and heavily cold-worked copper at feeds in the range 0.15 to 0.2 mm, with high speed steel tools of rake angle from 6° to 35°. Specific forces vary over a sixfold range at the lowest cutting speed, with shear plane angles from 8° to 32°. The left panel of Figure 3.7 shows that the estimated tool contact stresses change little with rake angle, although they are clearly larger for the annealed than the pre-strained material. The right-hand panel shows that the temperature rises are halved on changing from a 6° to 35° rake angle tool. These observations, that tool stresses are determined bythe material being cut and do not vary much with the cutting conditions, while temperatures depend strongly on both the material being cut and the cutting conditions, is a continuing theme that will be developed for metal alloys in the following sections.3.1.3 Machining copper and aluminium alloysIt is often found that alloys of metals machine with larger shear plane angles and hence lower specific forces than the elemental metals themselves. Sometimes a strong reason is a lower value of the strain hardening parameter Dk/kmax, at other times the chip/tool friction (as indicated by the friction coefficient) is less; and at others again it is not at all obvious why this should be so. But even when the specific forces are lower, the tool contact stress can be higher. In this section, examples of machining two copper and one aluminium alloy are taken to illustrate this.Figure 3.8 records the behaviours of a CuNi and a CuZn alloy. The CuNi alloy, with 80%Ni, might better be considered as a Ni alloy. However, it machines at a higher shear plane angle at a given cutting speed than either copper or nickel, despite its strain-hardening characteristic being similar to or more severe than either of these (Appendix 4.1). The CuZn alloy (an a-brass) is a well-known very easy material to machine. Its shear plane angle is twice as large as that of Cu, despite having a similar strain-hardening characteristic (Appendix 4.1 again) and an apparently higher friction interaction with the tool (as judged by the relative sizes of its specific thrust and cutting forces). (Figure 3.8 describes the machining of an annealed brass. After cold-working, even higher shear plane angles, and lower specific forces are obtained.) These two examples are ones where the reason for the easier machining of the alloys compared with the elemental metals is not obvious from their room temperature, low strain rate mechanical behaviours. Figure 3.9 shows machining data for an aluminium alloy. In this case the variation of behaviour with rake angle is shown. At a rake angle and speed comparable to that shown in Figure 3.3, the shear plane angle is five times as large and the specific cutting force is half as large for the alloy as for pure Al. In this case both the strain-hardening and friction factors are less for the alloy than for pure Al.For both the copper and aluminium alloy examples, the primary shear plane shear stress and the average rake contact stresses are similar to, or slightly larger than, those for theelemental metals. Figure 3.8 shows only the values of k, but (sn)av may be calculated to be ≈ 0.6k. Figure 3.9 shows both k and (sn)av. It also shows that, in this case, the estimated rake face temperature does not change as the rake angle is reduced. This is different fromthe observations recorded in Figure 3.7: perhaps the maximum temperature is limited bymelting of the aluminium alloy? The choice in Figure 3.9 of showing how machining parameters vary with rake angle has been made to introduce the observation that, in this case, at a rake angle of around 35° the thrust force passes through zero. Consequently, such a high rake angle is appropriate for machining thin walled structures, for which thrust forces might cause distortions in the finished part.However, the main point of this section, to be carried forward to Section 3.2 on tool materials, is that the range of values estimated for k follows the range expected from Figure 3.1 and the estimated values of (sn)av range from 0.5 to 1.0k. This is summarized in Table 3.4 which also contains data for the other alloy systems to be considered next.3.1.4 Machining austenitic steels and temperature resistant nickel andtitanium alloysThe austenitic steels, NiCr, and Ti alloys are at the opposite extreme of severity to the aluminium and copper alloys. Although their specific forces are in the same range and their shear plane angles are higher, the tool stresses and temperatures (for a given speed and feed) that they generate are significantly higher. Figure 3.10 presents observations for two austenitic steels, a NiCr and a Ti alloy. One of the austenitic steels (the 18Cr8Ni material) is a common stainless steel. The 18Mn5Cr material, which also contains 0.47C, is an extremly difficult to machine creep and abrasion resistant material. The NiCr alloy is a commercial Inconel alloy, X750. In all cases the feed was 0.2 mm except for the Ti alloy, for which it was 0.1 mm. The rake angle was 6° except for the NiCr alloy, for which it was 0°. Specific cutting forces are in the range 2 to 4 GPa. Thrust forces are mainly between 1 and 2 GPa. Shear plane angles are mainly greater than 25°. In most cases, the chip formation is not steady but serrated. The values shown in Figure 3.10 are average values. Figure 3.11 shows stresses and temperatures estimated from these. The larger stresses and temperatures are clear.3.1.5 Machining carbon and low alloy steelsCarbon and alloy steels span the range of machinability between aluminium and copper alloys on the one hand and austentic steels and temperature resistant alloys on the other. There are two aspects to this. The wide range of materials’ yield stresses that can be achieved by alloying iron with carbon and small amounts of other metals, results in their spanning the range as far as tool stressing is concerned. Their intermediate thermal conductivities and diffusivities result in their spanning the range with respect to temperature rise per unit feed and also cutting speed.Figure 3.12 shows typical specific force and shear plane angle variations with cutting speed measured in turning steel bars that have received no particular heat treatment other than the hot rolling process used to manufacture them. At cutting speeds around 100 m/min the specific forces of 2 to 3 GPa are smaller than those for pure iron (Figure 3.3), but as speed increases, the differences between the steels and pure iron reduce. In the same way as for many other alloy systems, the shear plane angles of the ferrous alloys are larger than for the machining of pure iron. In the hot rolled condition, steels (other than the austenitic steels considered in the previous section) have a structure of ferrite and pearlite (or, at high carbon levels, pearlite and cementite). For equal coarsenesses of pearlite, the steels’ hardness increases with carbon content. The left panel of Figure 3.13 shows how the estimated k and (sn)av values from the data of Figure 3.12 increase with carbon content. Additional results have been included, for the machining of a 0.13C and a 0.4C steel. An increase of both k and (sn)av with %C is clear. The right panel of the figure likewise shows that the increasing carbon content gives rise to increasing temperatures for a given cutting speed. This comes from the increasing shear stress levels.This completes this brief survey of the stresses and temperatures generated by different alloy groups in machining. Tool stresses are mainly controlled by the metal being machined and vary little with cutting conditions (although the tool rake face area over which they act changes with speed and, obviously, also with feed). Temperatures, on the other hand, depend not only on the material being machined (both through stress levels and thermal properties) but also on the speeds and feeds used.3.1.6 Machining with built-up edge formationIn the previous section, data were presented mainly for cutting speeds greater than 100 m/min. This is because, at slightly lower cutting speeds, at the feeds considered, those steels machine with a built-up edge (BUE). In Chapter 2, photographs were shown of BUE formation. Figure 3.14 shows, for a 0.15C steel, what changes in specific force and shear plane angle are typically associated with this. In this example, the largest BUE occurred at a cutting speed close to 25 m/min. There, the specific forces passed through a minimum and the shear plane angle through a maximum. Qualitatively, this may be explained by the BUE increasing the effective rake angle of the cutting tool. Built-up edge formation occurs at some low speed or other for almost all metal alloys. It offers a way of relieving the large strains (small shear plane angles) that can occur at low speeds, but at the expense of worsening the cut surface finish. For those alloys that do show BUE formation, the cutting speed at which the BUE is largest reduces as the feed increases. Figure 3.15 gathers data for three ferrous alloys and one Ni-Cr creep resistant alloy (Nimonic 80). One definition of high speed machining is machining at speeds above those of built-up-edge formation. These are the conditions mostly focused on in this book.3.1.7 SummarySection 3.1 mentioned the variety of specific forces and shear plane angles that are commonly observed in machining aluminium, copper, ferrous, nickel and titanium alloys. It has sought to establish that the average contact stresses that a tool must withstand depend mainly on the material being machined, through the level of that material’s shear flow stress and hardly at all on the cutting speed and feed nor on the tool rake angle. Table 3.4 lists the range of these stresses. Peak contact stresses may be two to three times as large as the average values recorded in the table. In contrast, the temperatures that a tool must withstand do depend on cutting speed and feed and rake angle, and on the work material’s 96 Work and tool materials Fig. 3.17 Machining characterisitcs of a low alloy (?) and a semi-free-cutting low alloy (o) steel (f = 0.25 mm, α = 6o) thermal properties: diffusivity, conductivity and heat capacity. By both thermal and stress severity criteria, the easiest metals to machine are alumimium alloys and copper alloys.The most difficult to machine are austenitic steels, nickel heat resistant alloys and titanium alloys. Ferritic and pearlitic steels lie between these extremes, with stresses and temperatures increasing with carbon content and hardness. Beyond that, this section has been mainly descriptive, particularly with respect to reporting what shear plane angles have been measured for the different alloys. This remains the main task of predictive mechanics. The next section, on tool material properties, complements this one, in describing the properties of tool materials that influence and enable the tools to withstand the machininggenerated stresses and temperature .中原工學(xué)院畢業(yè)設(shè)計開題報告01 本課題所涉及的內(nèi)容及其研究的綜述1.1 自動化生產(chǎn)線簡介自動生產(chǎn)線是由工件傳送系統(tǒng)和控制系統(tǒng)，將一組自動機床和輔助設(shè)備按照工藝順序聯(lián)結(jié)起來，自動完成產(chǎn)品全部或部分制造過程的生產(chǎn)系統(tǒng)，簡稱自動線。在大批、大量生產(chǎn)中采用自動線能提高勞動生產(chǎn)率，穩(wěn)定和提高產(chǎn)品質(zhì)量，改善勞動條件，縮減生產(chǎn)占地面積，降低生產(chǎn)成本，縮短生產(chǎn)周期，保證生產(chǎn)均衡性，有顯著的經(jīng)濟效益。從二十世紀(jì)20年代開始，隨著汽車、滾動軸承、小型電動機和縫紉機等工業(yè)發(fā)展，機械制造中開始出現(xiàn)自動線，最早出現(xiàn)的是組合機床自動線。在此之前，首先是在汽車工業(yè)中出現(xiàn)了流水生產(chǎn)線和半自動生產(chǎn)線，隨后發(fā)展成為自動線。第二次世界大戰(zhàn)后，在工業(yè)發(fā)達(dá)國家的機械制造業(yè)中，自動線的數(shù)目出現(xiàn)了急劇增。機械制造業(yè)中有鑄造、鍛造、沖壓、熱處理、焊接、切削加工和機械裝配等自動線，也有包括不同性質(zhì)的工序，如毛坯制造、加工、裝配、檢驗和包裝等的綜合自動線。自動線中設(shè)備的聯(lián)結(jié)方式有剛性聯(lián)接和柔性聯(lián)接兩種。在剛性聯(lián)接自動線中，工序之間沒有儲料裝置，工件的加工和傳送過程有嚴(yán)格的節(jié)奏性。當(dāng)某一臺設(shè)備發(fā)生故障而停歇時，會引起全線停工。因此，對剛性聯(lián)接自動線中各種設(shè)備的工作可靠性要求高。在柔性聯(lián)接自動線中，各工序(或工段)之間設(shè)有儲料裝置，各工序節(jié)拍不必嚴(yán)格一致，某一臺設(shè)備短暫停歇時，可以由儲料裝置在一定時間內(nèi)起調(diào)劑平衡的作用，因而不會影響其他設(shè)備正常工作。綜合自動線、裝配自動線和較長的組合機床自動線常采用柔性聯(lián)接。切削加工自動線在機械制造業(yè)中發(fā)展最快、應(yīng)用最廣。主要有：用于加工箱體、殼體、雜類等零件的組合機床自動線；用于加工軸類、盤環(huán)類等零件的，由通用、專門化或?qū)Ｓ米詣訖C床組成的自動線；旋轉(zhuǎn)體加工自動線；用于加工工序簡單小型零件的轉(zhuǎn)子自動線等。自動線的工件傳送系統(tǒng)一般包括機床上下料裝置、傳送裝置和儲料裝置。在旋轉(zhuǎn)體加工自動線中，傳送裝置包括重力輸送式或強制輸送式的料槽或料道，提升、轉(zhuǎn)位和分配裝置等。有時采用機械手完成傳送裝置的某些功能。在組合機床自動線中當(dāng)工件有合適的輸送基面時，采用直接輸送方式，其傳送裝置有各種步進式輸送裝置、轉(zhuǎn)位裝置和翻轉(zhuǎn)裝置中原工學(xué)院畢業(yè)設(shè)計開題報告1等對于外形不規(guī)則、無合適的輸送基面的工件，通常裝在隨行夾具上定位和輸送，這種情況下要增設(shè)隨行夾具的返回裝置。自動線的控制系統(tǒng)主要用于保證線內(nèi)的機床、工件傳送系統(tǒng)，以及輔助設(shè)備按照規(guī)定的工作循環(huán)和聯(lián)鎖要求正常工作，并設(shè)有故障尋檢裝置和信號裝置。為適應(yīng)自動線的調(diào)試和正常運行的要求，控制系統(tǒng)有三種工作狀態(tài)：調(diào)整、半自動和自動。在調(diào)整狀態(tài)時可手動操作和調(diào)整，實現(xiàn)單臺設(shè)備的各個動作；在半自動狀態(tài)時可實現(xiàn)單臺設(shè)備的單循環(huán)工作；在自動狀態(tài)時自動線能連續(xù)工作。控制系統(tǒng)有“預(yù)?！笨刂茩C能，自動線在正常工作情況下需要停車時，能在完成一個工作循環(huán)、各機床的有關(guān)運動部件都回到原始位置后才停車。自動線的其他輔助設(shè)備是根據(jù)工藝需要和自動化程度設(shè)置的，如有清洗機工件自動檢驗裝置、自動換刀裝置、自動捧屑系統(tǒng)和集中冷卻系統(tǒng)等。為提高自動線的生產(chǎn)率，必須保證自動線的工作可靠性。影響自動線工作可靠性的主要因素是加工質(zhì)量的穩(wěn)定性和設(shè)備工作可靠性。自動線的發(fā)展方向主要是提高生產(chǎn)率和增大多用性、靈活性。為適應(yīng)多品種生產(chǎn)的需要，將發(fā)展能快速調(diào)整的可調(diào)自動線?，F(xiàn)代生產(chǎn)和科學(xué)技術(shù)的發(fā)展，對自動化技 術(shù)提出越來越高的要求，同時也為自動化技術(shù)的革新提供了必要條件。數(shù)字控制機床、工業(yè)機器人和電子計算機等技術(shù)的發(fā)展，以及成組技術(shù)的應(yīng)用，將使自動線的靈活性更大，可實現(xiàn)多品種、中小批量生產(chǎn)的自動化。多品種可調(diào)自動線，降低了自動線生產(chǎn)的經(jīng)濟批量，因而在機械制造業(yè)中的應(yīng)用越來越廣泛，并向更高度自動化的柔性制造系統(tǒng)發(fā)展。1.2 自動上料在機械生產(chǎn)中的作用在自動化加工、裝配生產(chǎn)線中，能自動完成將工件向加工或裝配機械供給并上料的裝置，稱為自動上料裝置。是自動化生產(chǎn)先線中一個重要環(huán)節(jié)。統(tǒng)計表明，在工件的加工裝配過程中，工件的供給、上料、下料及搬運等工作所需費用約占全部費用的 1/3 以上，所需的工時約占全部工時的 2/3 以上，而且絕大多數(shù)的事故都發(fā)生在這些工序中，尤其是成批大量生產(chǎn)的場合，當(dāng)要求生產(chǎn)效率很高而且機動工時很短時，上下料是一項重復(fù)而繁重的作業(yè)。所以，為了提高生產(chǎn)率、減輕作業(yè)者的勞動強度，保證安全生產(chǎn)，實現(xiàn)上下料自動化是很有必要的。自動上料裝置通常由工料器、分路機構(gòu)、合路機構(gòu)、上料機構(gòu)及輸送機構(gòu)等所組成。其中，供料器、隔離機構(gòu)及上料機構(gòu)是其最基本的三個組成部分，中原工學(xué)院畢業(yè)設(shè)計開題報告2各機構(gòu)之間的連接通常使用料道或其它輸送機構(gòu)。在實際應(yīng)用中，上述各機構(gòu)往往不是彼此獨立的，有事一個機構(gòu)既能將工件隔離又能將其分路，既能將能工件隔離又能上料。在當(dāng)今工業(yè)發(fā)達(dá)國家，自動上料裝置在各類制造業(yè)中比比皆是，上產(chǎn)過程的自動化不僅大大提高了生產(chǎn)率，把人們從繁重的勞動中解脫出來;而且對提高產(chǎn)品質(zhì)量，降低成本、促進產(chǎn)業(yè)結(jié)構(gòu)的合理化起到了積極的 作用。隨著電子技術(shù)的發(fā)展，現(xiàn)在自動上料裝置中已經(jīng)越來越多的采用傳感器等電子設(shè)備，這樣不僅能提高精度，而且能減小設(shè)備的大小，降低成本，這已是未來的發(fā)展趨勢。1.3 本課題涉及內(nèi)容1.軸承清洗方式 壓緊外套，內(nèi)套旋轉(zhuǎn)使軸承處于共作狀態(tài)下清洗。2.圓柱滾子軸承 N308E生產(chǎn)類型：大批大量參考文獻：[1] 黃大宇 梅瑛主編. 機械設(shè)計課程設(shè)計.吉林大學(xué)出版社,2007[2] 徐灝主編. 機械設(shè)計手冊[第二版].北京：機械工業(yè)出版社,2000[3] 彭文生等主編.機械設(shè)計.北京：高等教育出版社，2002[4] 黃玉美等主編.機械制造裝備設(shè)計. 高等教育出版社，2006[5] 劉德忠 費仁元主編.裝配自動化. 高等教育出版社，2003中原工學(xué)院畢業(yè)設(shè)計開題報告32 本課題有待解決的主要關(guān)鍵問題工件的上料通常是指將定向羊列好的工件裝入加工機械夾具中作業(yè)，是自動化上料裝置中最為復(fù)雜的一環(huán)。工件的上料通常是指將定向羊列好的工件裝入加工機械夾具中作業(yè)，是自動化上料裝置中最為復(fù)雜的一環(huán)。上料機構(gòu)的設(shè)計，關(guān)鍵在于根據(jù)工件的形狀、重量、特性及要實現(xiàn)的動作等選擇最適當(dāng)?shù)纳狭戏椒?。該課題全稱為成品軸承自動生產(chǎn)線自動上料裝置設(shè)計。即針對特定的清洗方式設(shè)計上料裝置。由于清洗方式及設(shè)計要求的限制，解決節(jié)能這個問題的思路在于尋求合適的機構(gòu) 或組合機構(gòu)來來實現(xiàn)軸承的送料、定位、及停歇。送料與定位易于完成，問題核心在于清洗，因此必須擁有足夠長的清洗時間，即停歇時間。中原工學(xué)院畢業(yè)設(shè)計開題報告4中原工學(xué)院畢業(yè)設(shè)計開題報告53 對課題要求及預(yù)期目標(biāo)的可行性分析 (包括解決關(guān)鍵問題技術(shù)和所需條件兩方面)1.該方案采用組合機構(gòu)，如圖 3-1 所示該機構(gòu)的傳動比等于凸輪的啟停之比與不完全齒輪啟停之比的成積。因此容易獲得較大的停歇時間。如圖 3-1 所示：圖 3-1 不完全齒輪-凸輪組合機構(gòu)示意圖 2.送料方式送料機構(gòu)如圖 3-2 所示。當(dāng)軸承到達(dá) A 位置時，凸輪 1 動作，將軸承推向 B 位置，在 B 位置經(jīng)清洗后再由凸輪 2 推向 C 位置，由輸送帶帶走。兩凸輪相對運動的原則為：當(dāng)凸輪 2 推動軸承至輸送帶回到起始位置時，凸輪 1 剛好準(zhǔn)備運動。圖 3-2 送料機構(gòu)示意圖中原工學(xué)院畢業(yè)設(shè)計開題報告63.為了使得兩凸輪能夠按照以上要求以上動作，兩凸輪間應(yīng)有一定的連接，如下圖 3-3 示：圖 3-3 傳功機構(gòu)示意圖4.該機構(gòu)的傳動比等于凸輪的啟停之比與不完全齒輪啟停之比的成積。因此容易獲得較大的停歇時間。中原工學(xué)院畢業(yè)設(shè)計開題報告74 完成本課題的工作計劃及進度安排3.08――3.23 課題調(diào)研、實習(xí)、開題報告、譯文3.24――4.05 總體方案論證4.06――6.04 總體結(jié)構(gòu)設(shè)計及具體零部件設(shè)計6.05――6.12 評閱6.13――6.15 答辯6.16——6.19 修改5 指導(dǎo)教師審閱意見指導(dǎo)教師(簽字)：　　　　　　 年 月 日中原工學(xué)院畢業(yè)設(shè)計開題報告86 指導(dǎo)小組意見指導(dǎo)小組組長(簽字)：　　 　　　年 月 日說明：1. 本報告前 4 項內(nèi)容由承擔(dān)畢業(yè)論文(設(shè)計)課題任務(wù)的學(xué)生獨立撰寫；2. 本報告必須在第八學(xué)期開學(xué)兩周內(nèi)交指導(dǎo)教師審閱并提出修改意見；3. 學(xué)生須在小組內(nèi)進行報告，并進行討論；4.本報告作為指導(dǎo)教師、畢業(yè)論文(設(shè)計)指導(dǎo)小組審查學(xué)生能否承擔(dān)該畢業(yè)設(shè)計(論文)課題和是否按時完成進度的檢查依據(jù)，并接受學(xué)校的抽查。