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中國(guó)地質(zhì)大學(xué)長(zhǎng)城學(xué)院
本科畢業(yè)設(shè)計(jì)外文資料翻譯
系 別: 工程技術(shù)系
專 業(yè): 機(jī)械設(shè)計(jì)制造及其自動(dòng)化
姓 名:
學(xué) 號(hào):
2015年 2 月 15 日
Comparative analysis of processing scheme of automobile steering section
Have a shape as a processing method, all machining process for the production of the most commonly used and most important method. Machining process is a process generated shape, in this process, Drivers device on the work piece material to be in the form of chip removal. Although in some occasions, the workpiece under no circumstances, the use of mobile equipment to the processing, However, the majority of the machining is not only supporting the workpiece also supporting tools and equipment to complete.
Machining know the process has two aspects. Small group of low-cost production. For casting, forging and machining pressure, every production of a specific shape of the workpiece, even a spare parts, almost have to spend the high cost of processing. Welding to rely on the shape of the structure, to a large extent, depend on effective in the form of raw materials. In general, through the use of expensive equipment and without special processing conditions, can be almost any type of raw materials, mechanical processing to convert the raw materials processed into the arbitrary shape of the structure, as long as the external dimensions large enough, it is possible. Because of a production of spare parts, even when the parts and structure of the production batch sizes are suitable for the original casting, Forging or pressure processing to produce, but usually prefer machining.
Strict precision and good surface finish, machining the second purpose is the establishment of the high precision and surface finish possible on the basis of. Many parts, if any other means of production belonging to the large-scale production, Well Machining is a low-tolerance and can meet the requirements of small batch production. Besides, many parts on the production and processing of coarse process to improve its general shape of the surface. It is only necessary precision and choose only the surface machining. For instance, thread, in addition to mechanical processing, almost no other processing method for processing. Another example is the blacksmith pieces keyhole processing, as well as training to be conducted immediately after the mechanical completion of the processing.
Primary Cutting Parameters
Cutting the work piece and tool based on the basic relationship between the following four elements to fully describe : the tool geometry, cutting speed, feed rate, depth and penetration of a cutting tool.
Cutting Tools must be of a suitable material to manufacture, it must be strong, tough, hard and wear-resistant. Tool geometry -- to the tip plane and cutter angle characteristics -- for each cutting process must be correct.
Cutting speed is the cutting edge of work piece surface rate, it is inches per minute to show. In order to effectively processing, and cutting speed must adapt to the level of specific parts -- with knives. Generally, the more hard work piece material, the lower the rate.
Progressive Tool to speed is cut into the work piece speed. If the work piece or tool for rotating movement, feed rate per round over the number of inches to the measurement. When the work piece or tool for reciprocating movement and feed rate on each trip through the measurement of inches. Generally, in other conditions, feed rate and cutting speed is inversely proportional to.
Depth of penetration of a cutting tool -- to inches dollars -- is the tool to the work piece distance. Rotary cutting it to the chip or equal to the width of the linear cutting chip thickness. Rough than finishing, deeper penetration of a cutting tool depth.
Rough machining and finishing machining
There are two kinds of cuts in machine- shop work called, respectively, the "roughing cut" and the "finishing cut". When a piece is "roughed out", it is quite near the shape and size required, but enough metal has been left on the surface to finish smooth and to exact size." Generally speaking, bars of steel, forging, castings, etc. are machined to the required shape and size with only one roughing and one finishing cut. Sometimes, however, certain portions of a piece may require more than one roughing cut. Also, in some jobs, for example, when great accuracy is not needed, or when a comparatively small amount of metal must be removed, a finishing cut may be all that is required. The roughing cut, to remove the greater part of the excess material, should be reasonably heavy, that is, all the machine, or cutting tool, or work, or all three, will stand. So the machinist’s purpose is to remove the excess stock as fast as he can without leaving, at the same time, a surface too torn and rough, without bending the piece if it is slender, and without spoiling the centers. The finishing cut, to make the work smooth and accurate, is a finer cut. The emphasis here is refinement - very sharp tool, comparatively little metal removed, and a higher degree of accuracy in measurement. Whether roughing or finishing, the machinist must set the machine for the given job. He must consider the size and shape of the work and the kind of material, also the kind of tool used and the nature of the cut to be made, then he proceeds to set the machine for the correct speed and feed and to set the tool to take the depth of cut desired.
Automatic Fixture Design
Assembly equipment used in the traditional synchronous fixture put parts of the fixture mobile center, to ensure that components from transmission from the plane or equipment plate placed after removal has been scheduled for position. However, in certain applications, mobile mandatory parts of the center line, it may cause parts or equipment damage. When parts vulnerability and may lead to a small vibration abandoned, or when their location is by machine spindle or specific to die, Tolerance again or when the request is a sophisticated, it would rather let the fixture to adapt to the location of parts, and not the contrary. For these tasks, Elyria, Ohio, the company has developed Zaytran a general non-functional data synchronization West category FLEXIBILITY fixture. Fixture because of the interaction and synchronization devices is independent; the synchronous device can use sophisticated equipment to replace the slip without affecting the fixture force. Fixture specification range from 0.2 inches itinerary, 5 pounds clamping force of the six-inch trip, 400-inch clamping force. The characteristics of modern production are becoming smaller and smaller quantities and product specifications biggest changes. Therefore, in the final stages of production, assembly of production, quantity and product design changes appear to be particularly vulnerable. This situation is forcing many companies to make greater efforts to rationalize the extensive reform and the previously mentioned case of assembly automation. Despite flexible fixture behind the rapid development of flexible transport and handling devices, such as backward in the development of industrial robots, it is still expected to increase the flexibility fixture. In fact the important fixture devices -- the production of the devices to strengthen investment on the fixture so that more flexibility in economic support holders.
According to their flexibility and fixture can be divided into: special fixture, the fixture combinations, the standard fixture, high flexible fixture. Flexible fixture on different parts of their high adaptability and the few low-cost replacement for the characteristic.
Forms can transform the structure of the flexible fixture can be installed with the change of structure components (such as needle cheek plate, Multi-chip components and flake cheek plate), a non-standard work piece gripper or clamping elements (for example: commencement standard with a clamping fixture and mobile components fixture supporting documents), or with ceramic or hardening of the intermediary substances (such as : Mobile particle bed fixture and heat fixture tight fixture). To production, the parts were secured fixture, the need to generate clamping function, its fixture with a few unrelated to the sexual submissive steps.
According to the processing was part of that foundation and working characteristics to determine the work piece fixture in the required position, then need to select some stability flat combination, These constitute a stable plane was fixed in the work piece fixture set position on the clamp-profile structure, all balanced and torque, it has also ensured that the work features close to the work piece. Finally, it must be calculated and adjusted, assembly or disassembly be standard fixture components required for the position, so that the work piece firmly by clamping fixture in China. In accordance with this procedure, the outline fixture structure and equipped with the planning and recording process can be automated control.
Structural modeling task is to produce some stable flat combination, Thus, these plane of the work pieces clamping force and will fixture stability. According to usual practice, this task can be human-machine dialogue that is almost completely automated way to completion. A man-machine dialogue that is automated fixture structure modeling to determine the merits can be conducted in an organized and planning fixture design reduce the amount of the design, shortening the study period and better distribution of work conditions. In short, can be successfully achieved significantly improve fixture efficiency and effectiveness.
Fully prepared to structure programs and the number of material circumstances, the completion of the first successful assembly can save up to 60% of the time.
Therefore fixture process modeling agencies is the purpose of the program has appropriate documents.
中文翻譯
汽車轉(zhuǎn)向節(jié)加工工藝方案對(duì)比分析
機(jī)械加工是所有制造過(guò)程中最普遍使用的而且是最重要的方法。機(jī)械加工過(guò)程是一個(gè)產(chǎn)生形狀的過(guò)程,在這過(guò)程中,驅(qū)動(dòng)裝置使工件上的一些材料以切屑的形式被去除。盡管在某些場(chǎng)合,工件無(wú)承受情況下,使用移動(dòng)式裝備來(lái)實(shí)現(xiàn)加工,但大多數(shù)的機(jī)械加工是通過(guò)既支承工件又支承刀具的裝備來(lái)完成。
機(jī)械加工過(guò)程中具備兩方面。小批生產(chǎn)低費(fèi)用。對(duì)于鑄造、鍛造和壓力加工,每一個(gè)要生產(chǎn)的具體工件形狀,即使是一個(gè)零件,幾乎都要花費(fèi)高額的加工費(fèi)用??亢附觼?lái)產(chǎn)生的結(jié)構(gòu)形狀,在很大程度上取決于有效的原材料的形式。一般來(lái)說(shuō),通過(guò)利用貴重設(shè)備而又無(wú)需特種加工條件下,幾乎可以以任何種類原材料開(kāi)始,借助機(jī)械加工把原材料加工成任意所需要的結(jié)構(gòu)形狀,只要外部尺寸足夠大,那都是可能的。因此對(duì)于生產(chǎn)一個(gè)零件,甚至當(dāng)零件結(jié)構(gòu)及要生產(chǎn)的批量大小上按原來(lái)都適于用鑄造、鍛造或者壓力加工來(lái)生產(chǎn)的,但通常寧可選擇機(jī)械加工。
嚴(yán)密的精度和良好的表面粗糙度,機(jī)械加工的第二方面用途是建立在高精度和可能的表面粗糙度基礎(chǔ)上。許多零件,如果用別的其他方法來(lái)生產(chǎn)屬于大批量生產(chǎn)的話,那么在機(jī)械加工中則是屬于低公差且又能滿足要求的小批量生產(chǎn)了。另一方面,許多零件靠比較粗糙的生產(chǎn)加工工藝制造其表面形狀,而僅僅是在需要高精度的且選擇過(guò)的表面才進(jìn)行機(jī)械加工。例如內(nèi)螺紋,除了機(jī)械加工之外,幾乎沒(méi)有別的加工方法能進(jìn)行加工。又如已鍛工件上的小孔加工,也是被鍛后緊接著進(jìn)行機(jī)械加工才完成的。
基本的機(jī)械加工參數(shù)
切削中工件與刀具的基本關(guān)系是以以下四個(gè)要素來(lái)充分描述的:刀具的幾何形狀,切削速度,進(jìn)給速度,和背吃刀量。
切削刀具必須用一種合適的材料來(lái)制造,它必須是強(qiáng)固、韌性好、堅(jiān)硬而且耐磨的。刀具的幾何形狀——以刀尖平面和刀具角為特征——對(duì)于每一種切削工藝都必須是正確的。
切削速度是切削刃通過(guò)工件表面的速率,它是以每分鐘英寸來(lái)表示。為了有效地加工,切削速度高低必須適應(yīng)特定的工件——刀具配合。一般來(lái)說(shuō),工件材料越硬,速度越低。
進(jìn)給速度是刀具切進(jìn)工件的速度。若工件或刀具作旋轉(zhuǎn)運(yùn)動(dòng),進(jìn)給量是以每轉(zhuǎn)轉(zhuǎn)過(guò)的英寸數(shù)目來(lái)度量的。當(dāng)?shù)毒呋蚬ぜ魍鶑?fù)運(yùn)動(dòng)時(shí),進(jìn)給量是以每一行程走過(guò)的英寸數(shù)度量的。一般來(lái)說(shuō),在其他條件相同時(shí),進(jìn)給量與切削速度成反比。
背吃刀量——以英寸計(jì)——是刀具進(jìn)入工件的距離。它等于旋削中的切屑寬度或者等于線性切削中的切屑的厚度。粗加工比起精加工,背吃刀量更大。
粗切削與精切削
工廠的切削加工有兩種,分別稱為“粗切削”和“精切削”。工件經(jīng)“粗切削”后,十分接近所要求的形狀和尺寸,但加工表面仍留有足夠的金屬余量,以供精加工,使工件表面粗糙、尺寸準(zhǔn)確。一般地說(shuō),鋼質(zhì)棒料、鍛件、鑄件等只經(jīng)一次粗切削和一次精切削即可達(dá)到所要求的形狀和尺寸。不過(guò),有時(shí)工件的某些部位可能需要不止一次的粗切削。有些加工,如精度要求不高或需要切除的金屬量較小,也可能只需一次精切削。粗切削因?yàn)橐コ蟛糠值挠嗔?,切削力量肯定是相?dāng)大的,這就意味著,整個(gè)機(jī)器、刀具、工件或這三者都要能承受得了。機(jī)加工工人的目的是盡可能快地切除余料,而留下的加工表面又不能太粗糙,細(xì)長(zhǎng)的工件不能抗彎,也不能損壞頂尖。精切削是使工件表面光滑、尺寸準(zhǔn)確,因而是一種更精細(xì)的切削。精加工強(qiáng)調(diào)的是精度——使用非常鋒利的刀具,切除的金屬量較少,測(cè)量時(shí)的精密度要求較高。無(wú)論是粗切削還是精切削,機(jī)加工工人都必須按給定的工作來(lái)調(diào)好機(jī)床,必須考慮工件的大小和形狀,材料的種類,刀具的種類,以及行將切削的性質(zhì)。然后開(kāi)始把機(jī)床調(diào)到正確的轉(zhuǎn)速和進(jìn)刀量,調(diào)好刀具使其達(dá)到要求的切削深度。
自動(dòng)夾具設(shè)計(jì)
用做裝配設(shè)備的傳統(tǒng)同步夾具把零件移動(dòng)到夾具中心上,以確保零件從傳送機(jī)上或從設(shè)備盤上取出后置于已定位置上。然而在某些應(yīng)用場(chǎng)合、強(qiáng)制零件移動(dòng)到中心線上時(shí),可能引起零件或設(shè)備破壞。當(dāng)零件易損壞而且小小振動(dòng)可能導(dǎo)致報(bào)廢時(shí),或當(dāng)其位置是由機(jī)床主軸或模具來(lái)具體時(shí),再或者當(dāng)公差要求很精密時(shí),那寧可讓夾具去適應(yīng)零件位置,而不是相反。為著這些工作任務(wù),美國(guó)俄亥俄州Elyria的Zaytran公司已經(jīng)開(kāi)發(fā)了一般性功能數(shù)據(jù)的非同步西類柔順性?shī)A具。因?yàn)閵A具作用力和同步化裝置是各自獨(dú)立的,該同步裝置可以用精密的滑移裝置來(lái)替換而不影響夾具作用力。夾具規(guī)格范圍是從0.2英寸行程,5英鎊夾緊力到6英寸行程、400英寸夾緊力。
現(xiàn)代生產(chǎn)的特征是批量變得越來(lái)越小而產(chǎn)品的各種規(guī)格變化最大。因此,生產(chǎn)的最后階段,裝配因生產(chǎn)計(jì)劃、批量和產(chǎn)品設(shè)計(jì)的變更而顯得特別脆弱。這種情形正迫使許多公司更多地致力于廣泛的合理化改革和前面提到過(guò)情況那樣裝配自動(dòng)化。盡管柔性?shī)A具的發(fā)展很快落后與柔性運(yùn)輸處理裝置的發(fā)展,如落后于工業(yè)機(jī)器人的發(fā)展,但仍然試圖指望增加夾具的柔順性。事實(shí)上夾具的重要的裝置——生產(chǎn)裝置的專向投資就加強(qiáng)了使夾具更加柔性化在經(jīng)濟(jì)上的支持。
根據(jù)它們?nèi)犴樞?,夾具可以分為:專用夾具、組合夾具、標(biāo)準(zhǔn)夾具、高柔性?shī)A具。柔性?shī)A具是以它們對(duì)不同工件的高適應(yīng)性和以少更換低費(fèi)用為特征的。
結(jié)構(gòu)形式可變換的柔性?shī)A具裝有可變更結(jié)構(gòu)排列的零件(例如針形頰板,多片式零件和片狀頰板),標(biāo)準(zhǔn)工件的非專用夾持或夾緊元件(例如:?jiǎn)?dòng)標(biāo)準(zhǔn)夾持夾具和帶有可移動(dòng)元件的夾具配套件),或者裝有陶瓷或硬化了的中介物質(zhì)(如:流動(dòng)粒子床夾具和熱夾具緊夾具)。為了生產(chǎn),零件要在夾具中被緊固,需要產(chǎn)生夾緊作用,其有幾個(gè)與夾具柔順性無(wú)關(guān)的步驟:
根據(jù)被加工工件基礎(chǔ)的部分和工作特點(diǎn),確定工件在夾具中的所需的位置,接著必須選擇若干穩(wěn)定平面的組合,這些穩(wěn)定平面就構(gòu)成工件被固定在夾具中確定位置上的夾具上,均衡所有的力和力矩,而且保證接近工件工作特點(diǎn)。最后,必須計(jì)算、調(diào)整、組裝可拆裝的或標(biāo)準(zhǔn)夾具元件的所需位置,以便使工件牢牢地被夾緊在夾具中。依據(jù)這樣的程序,夾具的輪廓結(jié)構(gòu)和裝合的規(guī)劃和記錄過(guò)程可以進(jìn)行自動(dòng)化控制。
結(jié)構(gòu)造型任務(wù)就是要產(chǎn)生若干穩(wěn)定平面的組合,這樣在這些平面上的各夾緊力將使工件和夾具穩(wěn)定。按慣例,這個(gè)任務(wù)可用人—機(jī)對(duì)話即幾乎完全自動(dòng)化的方式來(lái)完成。一人—機(jī)對(duì)話即以自動(dòng)化方式確定夾具結(jié)構(gòu)造型的優(yōu)點(diǎn)是可以有組織有規(guī)劃進(jìn)行夾具設(shè)計(jì),減少所需的設(shè)計(jì)人員,縮短研究周期和能更好地配置工作條件。簡(jiǎn)言之,可成功地達(dá)到顯著提高夾具生產(chǎn)效率和效益。
在充分準(zhǔn)備了構(gòu)造方案和一批材料情況下,在完成首次組裝可以成功實(shí)現(xiàn)節(jié)約時(shí)間達(dá)60%。
因此夾具機(jī)構(gòu)造型過(guò)程的目的是產(chǎn)生合適的編程文件。