連桿生產(chǎn)線連桿體鉆兩孔夾具設(shè)計(jì)【含CAD圖紙+PDF圖】
喜歡這套資料就充值下載吧。資源目錄里展示的都可在線預(yù)覽哦。下載后都有,請放心下載,文件全都包含在內(nèi),【有疑問咨詢QQ:414951605 或 1304139763】
中國地質(zhì)大學(xué)長城學(xué)院畢業(yè)設(shè)計(jì)外文資料翻譯譯文從生態(tài)加工技術(shù)對攻絲的研究摘 要 這項(xiàng)研究是關(guān)于攻螺紋(扭矩,攻絲,磨損,工作硬度等)的加工特性。在生態(tài)加工技術(shù)操作下,涂有TiN的MMC(鋁合金金屬復(fù)合材料)攻螺絲形成的攻絲得到了調(diào)查,并與沒有涂層的特性進(jìn)行了比較。下面的結(jié)果就是從這份研究中得到的:1.TiN涂層攻絲的刀具壽命是沒有攻絲的四倍;2.有TiN涂層的攻絲形成的螺紋比沒有的加工硬化要低。關(guān)鍵詞:攻絲; 攻螺絲; 螺紋; 生態(tài)加工; 鉆孔1引言螺栓、螺釘機(jī)械連接中的螺紋是機(jī)械部件的最重要緊固系統(tǒng)之一。螺紋制造有很多種方法,特別攻螺絲是用來生產(chǎn)內(nèi)螺紋的有效的技術(shù)。最近,每年都強(qiáng)調(diào)增加生產(chǎn)力。據(jù)說現(xiàn)在的車間里,最重要和最嚴(yán)重的問題是提高生產(chǎn)力。怎樣改善孔加工(鉆/鉸孔和攻絲)已成為一個(gè)嚴(yán)重的問題。傳統(tǒng)的刀具材料限制了生產(chǎn)力的提高,如高速鋼刀具加工鋁合金金屬復(fù)合材料(MMC)時(shí)刀具壽命很短由于碳化硅粒子的腐蝕天性。因此,刀具的磨損和破壞阻礙了生產(chǎn)力的提高。為了實(shí)現(xiàn)理想的生產(chǎn)力,攻絲已經(jīng)吸引了車間工程師的注意。在這項(xiàng)研究中,用攻絲加工MMC,利用攻絲(扭矩,攻絲磨損,工作硬度等)的切割特點(diǎn), 有TiN涂層和沒有涂層的都進(jìn)行了調(diào)查。 2. 實(shí)驗(yàn)方法2.1實(shí)驗(yàn)裝置攻絲試驗(yàn)在辛辛那提5NC-MC (5HP)進(jìn)行。該(鉆孔和攻絲) 儀器和數(shù)據(jù)采集系統(tǒng)如圖2.1。切削力(推力和扭矩)測定使用三個(gè)類型9273 壓電電力測功器和相應(yīng)的場所用5007電荷放大器放大。得到的信號,然后傳遞到A / D轉(zhuǎn)換器AZI-16-12 ,連接到個(gè)人電腦。切削力測量安裝如圖2.2。2.2工件,鉆及塔在本實(shí)驗(yàn)中使用的工件是鋁合金(2618 MMC)的增強(qiáng),15碳化硅顆粒。形成無槽絲錐的螺紋是M10如圖2.3和兩種類型的攻絲被用來在調(diào)查過程中。攻絲的形狀類似于螺釘?shù)男螤睿∕10,孔距1.5),無論有沒有氮化鈦涂層。定位孔的直徑9.3mm,用于所有試驗(yàn)和聚晶金剛石攻絲鉆孔(高速鋼硬質(zhì)合金碳化鎢和聚晶金剛石鉆孔)用在所有測試。本實(shí)驗(yàn)中用的鉆頭如圖2.4。圖2.1 竊聽器和數(shù)據(jù)采集儀器 圖2.2 Schmatic圖的竊聽系統(tǒng) 圖2.3 水龍頭用于這項(xiàng)工作2.3儀表和檢測方法的線程線程的估計(jì)是用螺紋規(guī)來衡量。結(jié)果被分為A等和B等 1 。硬鋁合金 2 螺紋深度是攻絲直徑的1.4倍。甲等-質(zhì)量:直徑通過整個(gè)螺紋測量。乙等-質(zhì)量:直徑至少15毫米。圖2.5是顯示的直徑指標(biāo)(M101.5 ISO 6H)。2.4實(shí)驗(yàn)特性攻絲試驗(yàn)時(shí),切削速度(攻絲的轉(zhuǎn)速)是215 rpm和進(jìn)給速度0.1mm/rev (322.5mm/min)。冷卻油(氯和硫免費(fèi)熱切割石油)手動供應(yīng)。3.實(shí)驗(yàn)結(jié)果與討論 在M10攻絲操作的推力和扭矩信號顯示在圖3.1 。結(jié)果表明,隨著螺紋扣數(shù)的形成,扭矩增大,離開孔時(shí)減小。然而,可以看到幾乎沒有推力的增加。圖2.4 形狀的聚晶金剛石鉆頭 圖2.5 螺紋規(guī)3.1轉(zhuǎn)矩比較圖3.2顯示是先前所提到的有TiN涂層和沒有涂層的第1孔和第8孔攻絲的扭矩信號。圖2.1 參數(shù)確定圖3.1 圖切削力信號根據(jù)竊聽測試扭矩 圖3.2 比較扭矩信號(第1洞和第8洞)與扭矩在攻絲操作的初始階段顯示推力和扭矩的增加。然而,當(dāng)螺紋成形進(jìn)入全速時(shí),推力顯示出下降的趨勢伴隨著扭矩的增加和攻絲縮回,在螺紋孔口也可以看到負(fù)扭矩的出現(xiàn)。圖3.1負(fù)推力值是攻絲偏離中心的結(jié)果是因?yàn)橐环讲徽?dāng)?shù)墓ぜ?,刀具的安裝或定位空的表面粗糙度。 上述不確定的因素是定位孔的表面粗糙度。當(dāng)有TiN涂層第一孔的攻螺紋的攻絲扭矩值8.7 Nm而沒有涂層的值是11.2Nm,得到扭矩信號。因而,第一孔有涂層的相比沒有涂層的扭矩減少了28 。而對第8孔有TiN涂層的扭矩相比沒有涂層減少了52 。初始階段和在攻絲突破點(diǎn)前扭矩信號的比較表明,沒有涂層的攻絲扭矩減少要明顯于有TiN涂層的攻絲??梢哉f,就形成的攻絲而言,在車螺紋時(shí)工作是均勻分布在刮削端。扭矩的比較結(jié)果總結(jié)在圖3.3 。結(jié)果表明,有TiN涂層的攻絲扭矩一般低于那些沒有涂層的攻絲。3.2螺紋形式的比較有TiN涂層和沒有涂層的攻絲的螺紋形式如圖3.4 。在螺紋孔, ,位置的橫截面的放大圖像以及1,4,8號孔作了比較。圖3.4是不同位置螺紋的照片模型,而圖3.5是八號孔放大的圖像。可以從圖3.5 中看出,有TiN涂層攻絲形成的螺紋的側(cè)面 沒有異常。相反,沒有涂層表明孔的進(jìn)口和出口相應(yīng)的號和號位置無規(guī)律。圖3.3 比較扭矩信號同類型 圖3.4 闡明的軸向截面建制線程為了驗(yàn)證上述的意見,對孔和進(jìn)行詳細(xì)的分析進(jìn)行。結(jié)果總結(jié)在圖3.6 。圖3.6(a)和(b)給出了1號和8號螺紋孔各自的和位置的結(jié)果??梢杂^察圖3.6(a),有TiN涂層的攻絲齒形遠(yuǎn)遠(yuǎn)優(yōu)于沒有涂層的。3.3比較加工硬化當(dāng)采用有TiN涂層和沒有涂層的攻絲車螺紋時(shí),研究比較加工硬化的嚴(yán)重性。本研究結(jié)果歸納于圖3.7 。選用了兩種類型中1號攻絲。 有TiN涂層和沒有涂層的結(jié)果分別在圖3.7(a)和(b)。用能受100 gw的硬度測量硬度儀測量硬度。結(jié)果表明,有TiN涂層的攻螺紋的硬度低于沒有涂層的。上述結(jié)果表明,在以下幾個(gè)方面,如螺紋形式和加工硬化等,有TiN涂層的攻絲優(yōu)于沒有涂層的攻絲。圖3.5 比較線程形式 圖3.6 比較擴(kuò)大線程形式3.4刀具壽命的比較有TiN涂層和沒有涂層的攻絲被用來調(diào)查性能和攻絲的刀具壽命一樣高。每種類型的攻絲反復(fù)進(jìn)行3次試驗(yàn),。結(jié)果總結(jié)在圖3.8 。螺紋規(guī)讀數(shù)用A,B值評估。結(jié)果表明,在刀具壽命達(dá)到限制前,螺紋孔的平均數(shù),是沒有TiN涂層攻絲的X = 13和有涂層攻絲的X = 49。有TiN涂層攻絲的刀具壽命是沒有涂層的3.8倍。3.5比較塔磨損圖3.9顯示各種類型攻絲的刀具磨損,在實(shí)驗(yàn)中車螺紋后如圖3.8所示。應(yīng)當(dāng)指出的是,所有用于比較的攻絲已充分達(dá)到刀具壽命。有TiN涂層和沒有涂層的攻絲分別如圖3.9(a)和(b),。可以看出,所有攻絲的刀具磨損點(diǎn)。此外,可以看到大量的磨損在分界線上。有TiN涂層和沒有涂層攻絲的比較,如放大點(diǎn),結(jié)果表明,后者的磨損明顯高于前者。就有TiN涂層攻絲來說,在刀具磨損區(qū)可以看到覆蓋的TiN涂層。圖3.7 比較硬度分布 圖3.8 用攻絲的刀具壽命的比較 圖3.9 用攻絲的刀具磨損比較4.結(jié)論4.1有TiN涂層的刀具的壽命大約是沒有涂層的刀具壽命的4倍。 4.2和沒有TiN涂層的刀具相比,有涂層刀具的扭轉(zhuǎn)力下降了28 。 4.3和沒有TiN涂層的刀具相比,帶有涂層的齒形螺紋刀具則顯示出更少的不規(guī)則性。 4.4有TiN涂層的刀具的硬度低于沒有涂層的刀具。 4.5從以上結(jié)果顯示, 有TiN涂層的刀具在以下方面優(yōu)于沒有涂層的刀具:刀具壽命,螺紋樣式和加工硬化等。參考文獻(xiàn)1 WOLFGANGSTRACHE : Alternative Strategies for the Production of Threads in Aluminum-based SIC Reinforced Metal Matrix Composite (MMC) Alloy,1993.2 Beitz.W : Dubbel-Taschhenbuch fuer den Maschinenbau. ISBN 3-540-52381-2, (1990), G15.外文原文A Study on Tapping Viewed from Eco-Machining TechnologyAbstractThis study deals with machining characteristics of thread tapping (torque, tap, wear, workhardness etc.) The tapping of MMC (aluminum alloy metal matrix composite) with TiN coated forming taps under eco-machining technology operation, where chips are not produced and ejected from the tap flute, was investigated and compared with the characteristics during uncoated tapping. The following results are obtained from this study. 1.The tool life of TiN coated taps was 4 times longer than that of uncoated tap;2.Threads formed with the TiN coated taps exhibit lower work hardening than those formed with uncoated taps.Keywords: Tap; Tapping; Thread; Eco-Machining; Drilling1. IntroductionThreads form the mechanical joint of a boltscrew connection, which is one of the most important fastening systems for mechanical components. There are many ways of thread making, especially that of tapping which has been employed as an efficient technique for the production of internal threads.Recently, the rise of productivity has been emphasized year by year. Also it is said that the improvement of productivity is one of the most important and serious problem in todays machine shops. The improvement of hole making production (drilling/reaming and tapping) has become a serious matter. One factor limiting productivity gains has been that conventional tool materials such as HSS exhibit very short tool lives when machining an aluminum alloy metal matrix composite (MMC) due to the abrasive nature of the SiC particles. Therefore, the improvement has been obstructed by various problems as rapid tool wear and failure. As a mean of achieving the desired productivity gains, forming taps have caught the attention of machine shop engineers.In this study, cutting characteristics of tapping (torque, taps wear, work hardness, etc.) during the tapping of MMC with forming taps, both TiN coated and uncoated was investigated.2. Experimental Methods2.1 Experimental EquipmentThe tapping tests were conducted on a Cincinati 5NC-MC (5HP). The (drilling and tapping) apparatus and data acquisition system are presented in Figure 2.1. The cutting forces (thrust and torque) were measured using a three component Kistler Type 9273 Piezo-electric dynamometer and the corresponding locus was amplified by a Kistler type 5007 charge amplifier. The signal obtained was then passed to a Towa A/D converter type AZI-16-12, connected to a personal computer. A schematic diagram of the cutting force measuring setup is presented in Figure 2.2.2.2 Workpiece, Drill and TapThe workpiece used in this experiment is aluminum alloy (2618 MMC) reinforced with 15 vol% silicon carbide (SiC) particulate. The thread forming fluteless taps were M10 as shown in Figure 2.3 and two types of taps were used during the course of the investigation.The shape of the taps was similar to the shape of a screw (M10, Pitch:1.5), either uncoated or coated with Titanium nitride (TiN).Pilot holes of 9.3mm diameter were used for all trials and PCD tipped drills (HSS cemented tungsten carbide and polycrystalline diamond drilling) were employed in all the tests. The shape of drill used in this test is shown in Figure 2.4.2.3 Gauge and Inspection Method of ThreadThe estimate of threads was performed with a thread gauge (Go-NoGo gauge).The results were classified as A and B quality1. Where, 1.4tapped diameter is Diameter is the recommended depth of thread of hard Aluminum alloy2.A quality : Gauge can be turned through the whole thread.B quality : Gauge can be turned in at least 15mm.Figure 2.5 shows the appearance of gauge (M101.5 ISO 6H).2.4 Experimental CharacteristicsTapping tests were conducted at a cutting speed (rotational speed of tap) of 215 rpm and feed rate of 0.1mm/rev (322.5mm/min). Coolant oil (Chlorine and sulphur free heat cutting oil) was supplied manually.3. Experimental Results And DiscussionCutting Forces in Tapping (thrust, torque) The thrust and torque signals produced in this tapping operation with a M10 tap are shown in Figure 3.1. The results show that torque increases with number of threads formed and decreases at the instant that the tap is about to break through the outlet of the hole. Whereas, little increase in thrust can be observed.3.1 Comparison of TorqueFigure 3.2 shows torque signals of tap in the 1st hole and 8th holes for the TiN-coated and uncoated taps mentioned in the previous section.At the initial stage of the tapping operation both thrust and torque show an increase in magnitude. However, when the thread forming operation enters full gear, the thrust force shows a decreasing trend accompanied with in increase in torque and as the tap retracts after breakthrough, a negative torque of 5N magnitude can be observed across a few threads at hole outlet.The negative thrust value observed in Figure 3.1 is the outcome of the deflection of the tap from the center due to either improper workpiece, tool setup or poor finish of the pilot holes. The inconclusive results observed above led to the investigating of the factors responsible for the poor finish of the pilot holes.The torque signals derived while threading taps for the 1st hole show tapping torque values of 8.7 Nm for the TiN coated tap and11.2 Nm for the uncoated and tap respectively. Thus, for the 1st hole, the TiN coated tap exhibits a 28% reduction in torque compared to the uncoated tap. While for the 8th hole the reduction in torque for the TiN coated tap is approximately 52% as compared to uncoated tap.Comparison of the torque signals at the initial phase and prior to breakthrough of the taps shows that the uncoated tap exhibits a sharper decrease in torque than the TiN coated tap. It can be said that, in the case of forming taps, work is evenly distributed at the scrape point during threading. A comparison of the torque results is summarized in Figure 3.3. Results indicate that tapping torque of the TiN coated tap is generally lower than those of the un-coated tap.3.2 Comparison of Thread FormsThe thread forms for the TiN coated and uncoated taps are shown in Figure 3.4. Magnified images of the axial cross-section of the formed threads at position No., and in holes and 1.4 and 8 were used in the comparison.Figure 3.4 is a model of the photographed threads at the various positions, while Figure 3.5 shows magnified images for hole No.8As it can be seen from Figure 3.5, the thread profile at position No. to of threads formed with the TiN coated tap show no abnormalities. On the contrary, with the uncoatedtaps the root shows irregularities at position No. and corresponding to the hole inlet and outlet.In order to validate the observations mentioned above, a detailed analysis was performed on holes No. and . Results are summarized in Figure 3.6. Figure 3.6(a) and (b) give results for hole No. and 8 at thread position No. and respectively. As it can be observed in Figure 3.6(a), the tooth profile of the TiN coated is far superior to the uncoated tap.3.3 Comparison of Work HardeningA comparative study was performed to investigate the magnitude of work hardening when using the TiN coated and uncoated taps to form threads.Results of this study are summarized in Figure 3.7. Tap No.1 of both tap types were used. Results for the TiN coated and uncoated tap are given in Figure 3.7(a) and (b) respectively. Hardness was measured on a hardness tester loaded with a 100 gw.The results show that the hardness of the TiN coated tapping thread is lower than theuncoated tapping thread. The above results show that the TiN coated tap is superior to the uncoated tap in the following aspects, thread form and work hardening etc,.3.4Comparison of Tool LifeThe TiN coated and uncoated taps were used to investigate the performance level with respect to tool life of taps. Tests were repeatedly performed three times with each type of tap. The results are summarized in Figure 3.8.Thread gauge readings were evaluated using A, B values. The results indicate that the average number of thread holes before tool life limit is reached are uncoated X =13 and TiN coated tap X =49 hole tap. The tool life of the TiN coated tap is 3.8 times longer than that of uncoated tap.3.5 Comparison of Tap WearFigure 3.9 shows the tool wear of the various taps after threading in the experiments indicated in Figure 3.8. It should be noted that all the taps used for this comparison have already attained full tool life. TiN coated and uncoated taps are shown in Figure 3.9(a) and (b), respectively. It can be seen that the point of all the taps show tool wear. In addition, extensive wear can be observed at the boundary between the full thread form with the chamfer thread run-out of same 35 threads from the scrape point. A comparison of the TiN coated and the uncoated tap, as exemplified by the magnified point, shows that wear of the latter is more pronounced than the former. In the case of the TiN coated tap, an overlay of TiN coating can be observed at the tool wear zone.4. Conclusions4.1The tool life of the TiN coated tap was approximately 4 times longer than that of the uncoated tap.4.2The TiN coated tap (for the 1st hole) exhibits 28% reduction in torque compared to the uncoated tap.4.3The tooth profile of the thread produced by the TiN coated tap shows fewer irregularities than for the uncoated tap.4.4 The hardness of the TiN coated tapping thread is lower than the uncoated tapping thread.4.5From the above results, the TiN coated tap is superior to the uncoated tap in the following aspects, tool life, thread forms and work hardening etc,.References1 WOLFGANGSTRACHE : Alternative Strategies for the Production of Threads in Aluminum-based SIC Reinforced Metal Matrix Composite (MMC) Alloy,1993.2 Beitz.W : Dubbel-Taschhenbuch fuer den Maschinenbau. ISBN 3-540-52381-2, (1990), G15.13 中國地質(zhì)大學(xué)長城學(xué)院 本 科 畢 業(yè) 設(shè) 計(jì)題目 連桿生產(chǎn)線連桿體鉆兩孔夾具設(shè)計(jì) 系 別 工程技術(shù)系 專 業(yè) 機(jī)械設(shè)計(jì)制造及其自動化 學(xué)生姓名 郭濤 學(xué) 號 05208328 指導(dǎo)教師 沈貴水 職 稱 教授 2012 年 5 月 5 日中國地質(zhì)大學(xué)長城學(xué)院畢業(yè)設(shè)計(jì)(論文)任務(wù)書學(xué)生姓名郭濤學(xué)號05208328班 級機(jī)械設(shè)計(jì)制造及其自動化3班指導(dǎo)教師沈貴水職稱教授單 位河北農(nóng)業(yè)大學(xué)機(jī)電院畢業(yè)設(shè)計(jì)(論文)題目連桿生產(chǎn)線連桿體鉆兩孔夾具設(shè)計(jì)畢業(yè)設(shè)計(jì)(論文)主要內(nèi)容和要求:一.主要內(nèi)容:連桿是發(fā)動機(jī)主要零件,外形復(fù)雜,屬模鍛鋼件,加工工藝復(fù)雜,定位夾緊困難,加工精度要求高,需要專用機(jī)床,專用夾具在加工生產(chǎn)線上大量生產(chǎn)完成。二.設(shè)計(jì)要求 1.年生產(chǎn)綱領(lǐng)25萬件年 2.連桿體蓋分開模鍛 3.采用氣動夾具設(shè)計(jì) 4.組合機(jī)床,專用生產(chǎn)線加工 5.盡量采用多件夾緊機(jī)構(gòu) 6.連桿體的視圖完整,尺寸、公差及技術(shù)要求齊全畢業(yè)設(shè)計(jì)(論文)主要參考資料:1顧崇衍 機(jī)械制造工藝學(xué) 陜西:科技技術(shù)出版社,19812楊叔子 機(jī)械加工工藝師手冊 北京:機(jī)械工業(yè)出版社,20013倪森壽 機(jī)械制造工藝與裝備 化學(xué)工業(yè)出版社,20014張進(jìn)生 機(jī)械制造工藝與夾具設(shè)計(jì)指導(dǎo) 機(jī)械工業(yè)出版社,19945姜敏鳳 工程材料及熱成型工藝 高等教育出版社,20036王啟平 機(jī)床夾具設(shè)計(jì) 哈爾濱 哈爾濱工業(yè)大學(xué)出版社,19987劉越 機(jī)械制造技術(shù) 化學(xué)工業(yè)出版社,20018齊世恩 機(jī)械制造工藝 哈工大出版社,19899孟少農(nóng) 機(jī)械加工工藝手冊 北京 機(jī)械工業(yè)出版社,200010趙家齊 機(jī)械制造工藝學(xué)課程設(shè)計(jì)指導(dǎo)書 北京 機(jī)械工業(yè)出版社,2000畢業(yè)設(shè)計(jì)(論文)應(yīng)完成的主要工作: 1.連桿體總體夾具設(shè)計(jì)裝配圖一張(零號) 2.夾具的部件和零件圖 3.合計(jì)零號圖3張左右 4.夾具說明書一份 5.連桿工序圖一張 6.外文資料翻譯不少于3000字 7.開題報(bào)告,文獻(xiàn)綜述各一份 8.連桿工藝規(guī)程一套畢業(yè)設(shè)計(jì)(論文)進(jìn)度安排:序號畢業(yè)設(shè)計(jì)(論文)各階段內(nèi)容時(shí)間安排備注1學(xué)生在接到畢業(yè)設(shè)計(jì)(論文)任務(wù)書后,撰寫畢業(yè)設(shè)計(jì)(論文)開題報(bào)告。12月10日-20日2召開“開題報(bào)告會”,對學(xué)生的開題報(bào)告進(jìn)行審核。12月21日-22日3結(jié)合畢業(yè)設(shè)計(jì)(論文)課題進(jìn)行外文資料閱讀,并翻譯外文資料。12月23日-31日4撰寫文獻(xiàn)綜述2012年1月1日-1月20日5進(jìn)入畢業(yè)設(shè)計(jì)(論文)的撰寫階段2012年1月21日-3月6日6學(xué)生提交畢業(yè)設(shè)計(jì)(論文)工作計(jì)劃,經(jīng)指導(dǎo)教師審閱同意后方可實(shí)施。3月8日前7學(xué)生完成畢業(yè)設(shè)計(jì)(論文)雛形,并學(xué)生定期向指導(dǎo)教師匯報(bào)進(jìn)度。3月9日3月31日8進(jìn)入中期檢查階段,根據(jù)檢查情況,填寫“中期檢查表”。4月1日4月15日9學(xué)生根據(jù)中國地質(zhì)大學(xué)長城學(xué)院畢業(yè)設(shè)計(jì)(論文)撰寫規(guī)范完成畢業(yè)設(shè)計(jì)(論文)的寫作4月17日前10學(xué)生提交論文終稿給指導(dǎo)教師4月21日前11教研室負(fù)責(zé)檢查畢業(yè)設(shè)計(jì)(論文)完成情況,并組織專家進(jìn)行評閱,填寫“專家批閱書”。4月22日-28日12系里召開畢業(yè)設(shè)計(jì)(論文)中期檢查總結(jié)會,匯集意見,整改論文。4月29日-30日課題信息:課題性質(zhì): 設(shè)計(jì) 論文 課題來源: 教學(xué) 科研 生產(chǎn) 其它發(fā)出任務(wù)書日期: 指導(dǎo)教師簽名: 年 月 日教研室意見:教研室主任簽名:年 月 日 學(xué)生簽名:中國地質(zhì)大學(xué)長城學(xué)院畢業(yè)設(shè)計(jì)中國地質(zhì)大學(xué)長城學(xué)院本科畢業(yè)設(shè)計(jì)文獻(xiàn)綜述系 別: 工程技術(shù)系 專 業(yè): 機(jī)械設(shè)計(jì)制造及其自動化 姓 名: 郭濤 學(xué) 號: 05208328 2012年4月20日機(jī)械手冊可以用于企事業(yè)單位從事機(jī)械設(shè)計(jì)的工程技術(shù)人員進(jìn)行機(jī)械設(shè)計(jì); 理工科大學(xué)、中專以上機(jī)械專業(yè)學(xué)校教師指導(dǎo)學(xué)生進(jìn)行課程設(shè)計(jì)、畢業(yè)設(shè)計(jì); 理工科大學(xué)、中專以上機(jī)械專業(yè)學(xué)校學(xué)生進(jìn)行機(jī)械類課程學(xué)習(xí)、設(shè)計(jì)的參考書;廣大技術(shù)人員和機(jī)械類各專業(yè)師生的參考書。 手冊包括內(nèi)容涉及設(shè)計(jì)方法及最新國家標(biāo)準(zhǔn),全面、系統(tǒng)地介紹了所有現(xiàn)代設(shè)計(jì)和常規(guī)設(shè)計(jì)方法、數(shù)據(jù)、圖表、內(nèi)容豐富、具有信息量大,標(biāo)準(zhǔn)新、取材廣、規(guī)格全、常用結(jié)構(gòu)多、并增加了許多國內(nèi)外常用的新產(chǎn)品的結(jié)構(gòu)、規(guī)格、選用范圍、實(shí)用性強(qiáng)、查找方便等特點(diǎn)。在夾具設(shè)計(jì)方面,主要參考了機(jī)械設(shè)計(jì)教材,機(jī)床夾具設(shè)計(jì)。通過查閱資料得:一個(gè)優(yōu)良的機(jī)床夾具必須滿足下列基本要求:1) 保證工件的加工精度保證加工精度的關(guān)鍵,首先在于正確地選定定位基準(zhǔn)、定位方法和定位元件,必要時(shí)還需進(jìn)行定位誤差分析,還要注意夾具中其他零部件的結(jié)構(gòu)對加工精度的影響,確保夾具能滿足工件的加工精度要求。2) 提高生產(chǎn)效率專用夾具的復(fù)雜程度應(yīng)與生產(chǎn)綱領(lǐng)相適應(yīng),應(yīng)盡量采用各種快速高效的裝夾機(jī)構(gòu),保證操作方便,縮短輔助時(shí)間,提高生產(chǎn)效率。3) 工藝性能好專用夾具的結(jié)構(gòu)應(yīng)力求簡單、合理,便于制造、裝配、調(diào)整、檢驗(yàn)、維修等。專用夾具的制造屬于單件生產(chǎn),當(dāng)最終精度由調(diào)整或修配保證時(shí),夾具上應(yīng)設(shè)置調(diào)整和修配結(jié)構(gòu)。4) 使用性能好專用夾具的操作應(yīng)簡便、省力、安全可靠。在客觀條件允許且又經(jīng)濟(jì)適用的前提下,應(yīng)盡可能采用氣動、液壓等機(jī)械化夾緊裝置,以減輕操作者的勞動強(qiáng)度。專用夾具還應(yīng)排屑方便。必要時(shí)可設(shè)置排屑結(jié)構(gòu),防止切屑破壞工件的定位和損壞刀具,防止切屑的積聚帶來大量的熱量而引起工藝系統(tǒng)變形。5) 經(jīng)濟(jì)性好專用夾具應(yīng)盡可能采用標(biāo)準(zhǔn)元件和標(biāo)準(zhǔn)結(jié)構(gòu),力求結(jié)構(gòu)簡單、制造容易,以降低夾具的制造成本。因此,設(shè)計(jì)時(shí)應(yīng)根據(jù)生產(chǎn)綱領(lǐng)對夾具方案進(jìn)行必要的技術(shù)經(jīng)濟(jì)分析,以提高夾具在生產(chǎn)中的經(jīng)濟(jì)效益。工序的劃分:確定加工順序和工序內(nèi)容,安排工序的集中和分散程度,劃分工序階段,這項(xiàng)工作與生產(chǎn)綱領(lǐng)有密切關(guān)系,具體可以根據(jù)生產(chǎn)類型、零件的結(jié)構(gòu)特點(diǎn)、技術(shù)要求和機(jī)床設(shè)備等。生產(chǎn)條件確定工藝過程的工序次數(shù);如批量小時(shí)可采用在通用機(jī)床上工序集中原則,批量大時(shí)即可按工序分散原則,組織流水線生產(chǎn),也可利用高生產(chǎn)率的通用設(shè)備,按工序集中原則組織生產(chǎn)。定位基準(zhǔn)的選擇:根據(jù)粗基準(zhǔn),精基準(zhǔn)的選擇原則;遵循基準(zhǔn)統(tǒng)一、基準(zhǔn)重合。在鉆床夾具設(shè)計(jì)方面,由于在鉆床上鉆孔不便于用試切法把鉆頭調(diào)整到規(guī)定的位置,如用劃線法加工,其加工精度和生產(chǎn)率又較低,在本次設(shè)計(jì)任務(wù)規(guī)定下,不符合生產(chǎn)效率高的要求,所以設(shè)計(jì)為專用鉆床夾具。在專用夾具上,一般都裝有距定位元件有一定尺寸的鉆套,即鉆模。鉆模的主要特點(diǎn)是通過鉆套引導(dǎo)刀具進(jìn)行加工。這種加工方式易于保證被加工孔對其定位基準(zhǔn)和各孔間的位置精度;有助于提高刀具系統(tǒng)的剛性,防止鉆頭在切入后的偏引;并有利于提高孔的尺寸精度和表面光潔度。用這種方法不需要劃線和找正,工序時(shí)間大為縮短,可以顯著提高工作效率。查閱此書,可得鉆床夾具設(shè)計(jì)要點(diǎn)如下:1、 鉆模類型的選擇:鉆模的類型很多,在設(shè)計(jì)鉆模時(shí),首先要根據(jù)工件的形狀、尺寸、重量和加工要求,并考慮生產(chǎn)批量、工廠工藝設(shè)備的技術(shù)狀況等具體條件來選擇夾具的結(jié)構(gòu)類型。在選擇時(shí)應(yīng)注意一下幾點(diǎn):1) 被鉆孔的直徑大于10mm時(shí)(特別是鋼制件),鉆床夾具應(yīng)固定在工作臺上。2) 翻轉(zhuǎn)式和自由移動式鉆模是用于加工中小件,包括工件在內(nèi)的重量不宜超過100N(10kgf),否則,應(yīng)采用具有回轉(zhuǎn)式或直線分度裝置的鉆模。3) 當(dāng)加工幾個(gè)不在同心圓上的平行孔系時(shí),如工件和夾具的總重量超過150N(15kgf),宜采用固定式鉆模在搖臂鉆床上加工。4) 對于孔的垂直度和孔距精度要求不高的中小型工件,宜優(yōu)先采用滑柱鉆模,以縮短夾具設(shè)計(jì)的設(shè)計(jì)制造周期。5) 鉆模板和夾具體為焊接結(jié)構(gòu)的鉆模,因焊接應(yīng)力不能徹底消除,精度不能長期保持,故一般只在工件孔距公差要求不高(大于0.5mm)時(shí)才采用。6) 工件被加工孔與定位基準(zhǔn)的距離公差或孔距公差小于0.5mm時(shí),宜采用固定式鉆模板和固定鉆套進(jìn)行加工。2、 鉆套的選擇和設(shè)計(jì)鉆套和鉆模板是鉆床夾具的特殊元件。鉆套裝配在鉆模板或夾具體上,而鉆模板則以各種形式與夾具體或支架連接。按鉆套的結(jié)構(gòu)和使用情況,可分為:1) 固定鉆套 其主要優(yōu)點(diǎn)就是經(jīng)濟(jì),鉆孔的位置精度也較高。2) 可換鉆套 其適用于生產(chǎn)量較大的場合,當(dāng)生產(chǎn)量較大時(shí),需要更換磨損后的鉆套時(shí),使用這種鉆套較為方便。3) 快速鉆套 其適用于當(dāng)加工孔需要依次進(jìn)行鉆、擴(kuò)、鉸時(shí),由于刀具的直徑逐漸增大,需要使用外徑相同,而孔徑不同的鉆套來引導(dǎo)刀具。使用快速鉆套可減少更換鉆套的時(shí)間。根據(jù)本次設(shè)計(jì)需要,我暫定使用可換鉆套。3、 鉆模板設(shè)計(jì)鉆模板多裝配在夾具體或支架上,或與夾具上的其它元件相連。常見類型有:1)固定式鉆模板2)鉸鏈?zhǔn)姐@模板3)可卸式鉆模板4)懸掛式鉆模板4、 支腳設(shè)計(jì)為保證在較小的接觸面積的基礎(chǔ)上使夾具體放置平穩(wěn),支腳設(shè)計(jì)時(shí)要注意一下幾點(diǎn):1) 支腳必須四個(gè)2) 矩形支腳斷面的寬度或圓柱支腳的直徑必須大于機(jī)床工作臺T形槽的寬度,以免陷入槽中3) 夾具的重心、鉆削壓力必須落在四個(gè)支腳所形成的支承面內(nèi)4) 鉆套軸線與支腳所形成的支承面垂直或平行,使鉆頭能正常工作,為防止折斷,能保證被加工孔的位置精度在氣動系統(tǒng)設(shè)計(jì)中主要應(yīng)用了其中的機(jī)械零部件與傳動設(shè)計(jì)氣動傳動與控制,機(jī)械設(shè)計(jì)基礎(chǔ)等內(nèi)容。通過查閱資料對于氣動系統(tǒng)的設(shè)計(jì)步驟并無嚴(yán)格的順序,各步驟間往往要相互穿插進(jìn)行。一般來說,在明確設(shè)計(jì)要求之后,大致按如下步驟進(jìn)行:1) 確定氣動執(zhí)行元件的形式;2) 進(jìn)行工況分析,確定系統(tǒng)的主要參數(shù);3) 制定基本方案,擬定氣動系統(tǒng)原理圖;4) 選擇氣動元件;5) 氣動系統(tǒng)的性能驗(yàn)算;6) 繪制工作圖,編制技術(shù)文件。設(shè)計(jì)要求是進(jìn)行每項(xiàng)工程設(shè)計(jì)的依據(jù)。在制定基本方案并進(jìn)一步著氣動系統(tǒng)各部分設(shè)計(jì)之前,必須把設(shè)計(jì)要求以及該設(shè)計(jì)內(nèi)容有關(guān)的其他方面了解清楚:1) 主機(jī)的概況:用途、性能、工藝流程、作業(yè)環(huán)境、總體布局等;2) 氣動系統(tǒng)要完成哪些動作,動作順序及彼此聯(lián)鎖關(guān)系如何;3) 氣動驅(qū)動機(jī)構(gòu)的運(yùn)動形式,運(yùn)動速度;4) 各動作機(jī)構(gòu)的載荷大小及其性質(zhì);5) 對調(diào)速范圍、運(yùn)動平穩(wěn)性、轉(zhuǎn)速精度等性能方面的要求;6) 自動化程度、操作控制方式的要求;7) 對防塵、防爆、防寒、噪聲、安全可靠性的要求;8) 對效率、成本等方面的要求。經(jīng)過參考?xì)鈩佑嘘P(guān)資料資料得知:氣動程序控回路的選擇:在實(shí)踐中,各種自動生產(chǎn)線,大多是按程序工作的。所謂程序控制,就是根據(jù)生產(chǎn)過程中的位移、壓力、時(shí)間、溫度、液位等物理量的變化,使被控制的執(zhí)行元件,按預(yù)先規(guī)定的順序協(xié)調(diào)動作的一種自動控制方式。這種控制方式,能在一定的范圍內(nèi)滿足工種不同程序的需要,實(shí)現(xiàn)一機(jī)多用。根據(jù)控制方式的不同,程序控制可分為時(shí)間程序控制、行程程序控制和混合程序控制三種,時(shí)間程序控制,是指個(gè)執(zhí)行元件的動作順序按時(shí)間順序進(jìn)行的控制。在時(shí)間程序控制中,各時(shí)間信號通過控制路線,按一定的時(shí)間間隔分配給相應(yīng)的執(zhí)行元件,令其產(chǎn)生有序的動作。這是一種開環(huán)控制系統(tǒng)。行程程序控制可以在給定的位置準(zhǔn)確實(shí)現(xiàn)動作的轉(zhuǎn)換。在行程控制時(shí),執(zhí)行元件完成某一動作后,由行程發(fā)信器發(fā)出相應(yīng)信號,此信號輸入邏輯控制回路中,經(jīng)放大、轉(zhuǎn)換回路處理后成為主控閥可以接受的信號,控制主控閥換向,在驅(qū)動執(zhí)行元件,實(shí)現(xiàn)對被控制對象的控制。執(zhí)行元件的運(yùn)動狀態(tài)經(jīng)行程發(fā)信期器檢測后,反饋至邏輯控制回路,經(jīng)運(yùn)算處理并確信上以動作已經(jīng)完成后,在發(fā)出開始下一個(gè)動作的控制信號。如此循環(huán)往復(fù),直至完成全部預(yù)訂動作為止。這是一種閉環(huán)控制系統(tǒng)。然而,在行程程序控制中,行程發(fā)信裝置是一種位置傳感器,其作用是把由執(zhí)行機(jī)構(gòu)接受來的信號轉(zhuǎn)發(fā)給邏輯控制回路,常用的有行程閥、行程開關(guān)、邏輯“非門”等,此外,液位、壓力、流量、溫度等傳感器也可看做行程發(fā)信裝置;常用的執(zhí)行元件有氣缸、氣液缸、氣動馬達(dá)等;主控閥為氣動換向閥;邏輯控制回路、放大轉(zhuǎn)換回路一般由各種氣動控制元件組成,也可以由各種氣動邏輯元件等組成;動力源主要包括氣壓發(fā)生裝置和氣源處理設(shè)備兩部分。行程程序控制的優(yōu)點(diǎn)是結(jié)構(gòu)簡單、維修方便、動作穩(wěn)定,特別是當(dāng)程序控制中某節(jié)拍出現(xiàn)故障時(shí),通過運(yùn)行停止程序可以實(shí)現(xiàn)自動保護(hù)。因此在此設(shè)計(jì)中考慮到生產(chǎn)需要我初步?jīng)Q定選擇行程程序控制方式。4
收藏