【正文】 is being specified to millimeter scopes of sizes can be of in general use business trips can be applicable to such as the angle and drill a hole with blunt bore, The casting, the fing, the welded joint and weld the angle） etc. situation. Can make reference to the diagram of past or general engineering to practice while giving the appointed business trip of a spare business trip of typical model39。t certainly too big with as for make to assemble the function of the piece to bee the variety allowed by spare parts is called business trip. Business trip this technical term not only is applicable to from the acceptable scope of the parts size of[with] manufacturing craft creation, but also is applicable to a machine or processes of example, a give already set number of thepower each pedestals of . engine have , we usually discover this kind of variety model will be a frequency to distribute curve, for example distributes. call the Gauss distribute again One of the work which designs a personnel is the variety which specifies size for a spare parts and allows, this value canproduce acceptable function. Spare parts business trip When there is no appointed accurate size in the diagram, most anizations all have in general use business trip of being applicable to the process size, in general use business trip39。t make into Mr. to call size39。s don39。And, can acquire an experience document from pute past needing the design for ising similar to, the past record will have a tremendous help. The check of puting with diagram top size is the most decimal point39。t only the right answer of[with] problem that can be from the numeral put forward wanting him to resolve only, not only only is give should dint value, the size works to limit can put forward more extensive views, for the purpose of improvement norm or in the analysis the front or the analysis the process, he will acquaint with to equip and its work condition, he is fully placed in a beneficial position which conceives outline to choose a he can put forward a suggestion change shape to Elimination moment of force or should dint concentration, not allow to set up to have to cut the anization that noodles and excessive dynamic state carry a lotus greatly best is he discards his meticulous of design but is not see a machine discard afterwards. For stiring up to create sex thinking, the suggestion designs a personnel and analytical the personnel use following ex standards are particularly applicable to an analysis personnel, although he may involve to all this 10. the physical function that sex land utilization need when using bine the control don39。s satisfaction and manufacturing costs to all have something to do with design, the success which designs ability and engineering investment is closely related. Some design standards At this part, someone suggests the attitude of the usage creation carries on of analysis, this kind of analysis can cause a graveness improvement and to back up the product conceive outline with perfect, perhaps the product function is more, more economic and more the stage39。 Mechanical Design Abstract: A machine is a bination of mechanisms and other ponents which transforms, transmits, or utilizes energy, force, or motion for a useful purpose. Examples are engines, turbines, vehicles, hoists, printing presses, washing machines, and movie cameras. Many of the principles and methods of design that apply to machines also apply to manufactured articles that are not true machines, from hub caps and filing cabis to instruments and nuclear pressure vessels. The term mechanical design is used in a broader sense than machine design to include their design. For some apparatus, the thermal and fluid aspects that determine the requirements of heat, flow path, and volume are separately considered. However, the motion and structural aspects and the provisions for retention and enclosure are considerations in mechanical design. Applications occur in the field of mechanical engineering, and in other engineering fields as well, all of which require mechanical devices, such as switches, cams, valves, vessels, and mixers. Keywords: Mechanical Designmechanisms Design Process Tolerance Design process The design begins from real of or the demand of existing instrument may need to take in to improve on the enduring, efficiency, weight, speed or the need new instrument to plete before function done by person, such as Assemble or target is all or partly after making sure, design of the next move is to conceive outline the anization that can plete the function needed and it arranges for this, drawing grass diagram to be worth barehanded biggest, it isn39。 產(chǎn)生了初步的解決方案，下一步就是表達(dá)它們，以便它們能與所有涉及總體設(shè)計(jì)過程的人交流實(shí)際上，這一步可以采用繪制草圖或三維模型的形式，既可是物理模型也可是計(jì)算機(jī)生成的模型。如果合適，準(zhǔn)則的重要性可以加權(quán)，最適合的構(gòu)思會(huì)具有最高總分。 產(chǎn)生了想法和構(gòu)思后，下一步就是對(duì)它們進(jìn)行評(píng)估并選擇最佳構(gòu)思．一種評(píng)估方法是使用列表矩陣。應(yīng)該抵抗這種誘惑，因?yàn)檫@樣結(jié)果總會(huì)更好些。 產(chǎn)生盡可能多的或經(jīng)濟(jì)便利的構(gòu)思和想法是重要的。 Ion 和 Smith 把初步設(shè)計(jì)描述為由一系列形成和評(píng)估階段組成的一個(gè)反復(fù)的過程，各階段合在一起形成好的解決方案。 初步設(shè)計(jì)產(chǎn)生滿足指定需求的解決方案。 上偏差：最大尺寸極限與其對(duì)應(yīng)的基本尺寸的代數(shù)差 下偏差：最小尺寸極限與其對(duì)應(yīng)的基本尺寸的代數(shù)差 公差：最大尺寸極限與最小尺寸極限的差值。 實(shí)際尺寸：通過測量得到的部件尺寸尺寸極限：零件允許的最大和最小尺寸。通常使用的是基孔制，因?yàn)檫@會(huì)使公 司內(nèi)部所需的鉆頭、絞刀、拉刀和計(jì)量工具種類的減少。但是，變化的范圍不應(yīng)太大以免裝配時(shí)受損 為了不至于有無窮無盡的被指定的公差尺寸，已經(jīng)制定了國家和國際標(biāo)準(zhǔn)確定了公差帶，比如 hll/cll。再者，滑動(dòng)軸承的直徑必須大于軸的直徑以使其旋轉(zhuǎn)。下面這段將給出關(guān)于裝入孔內(nèi)的軸或柱形配合的具體例子。典型的公差被指定為英武成 JSO 標(biāo)準(zhǔn)所定義的幅度。其他通用公差可以適用于如角度、鉆孔和沖孔，鑄件、鍛件、焊縫和焊角等情形。 毫米。 零件公差 當(dāng)圖中沒有指定確切尺寸時(shí)，大多數(shù)組織都有適用于尺寸的通用公差。實(shí)際上，我們常常發(fā)現(xiàn)這種變化模型會(huì)是頻率分布曲線，例如 （又叫高斯分布）。 公差這一術(shù)語不僅適用于由制造工藝產(chǎn)生的部件尺寸的可以接受的范圍，而且適用于機(jī)械或加工的輸出。但是，所允許的變化一定不能太大以至于使裝配 件的性能變差。典型地，設(shè)計(jì)人員給一個(gè)零件指定公稱尺寸以使其滿足其需要。繪圖和設(shè)計(jì)人員如果不熟悉現(xiàn)代方法和材料就可能失去作用。實(shí)驗(yàn)室提供了 很多建立基本概念所需的信息，然而，還可用它們獲得一些關(guān)于產(chǎn)品在現(xiàn)場會(huì)如何工作的認(rèn)識(shí) 最后，一個(gè)成功的設(shè)計(jì)人員應(yīng)盡最大努力跟上時(shí)代步伐。通過這樣的系統(tǒng)，就可能把一個(gè)初步構(gòu)思傳送到打孔紙帶用于數(shù)字加工控制而無須繪制正式的施工圖。 計(jì)算機(jī)對(duì)于工作人員來講是一個(gè)很有用的工具，可以減輕乏味的計(jì)算并且對(duì)現(xiàn)有數(shù)據(jù)提供擴(kuò)展分析。例如，如果一個(gè)人要設(shè)計(jì)一個(gè)能支撐 100 磅的托架，而它本應(yīng)該能支撐 1000 磅，結(jié)果肯定會(huì)失敗。 計(jì)算（