理论机械设计毕业论文外文翻译.doc

外文翻译Machine design theory machine design is through designs the new product or improves the old product to meet the human need the application technical science. It involves the project technology each domain, mainly studies the product the size, the shape and the detailed structure basic idea, but also must study the product the personnel which in aspect the and so on manufacture, sale and use question. Carries on each kind of machine design work to be usually called designs the personnel or machine design engineer. The machine design is a creative work. Project engineer not only must have the creativity in the work, but also must in aspect and so on mechanical drawing, kinematics, materials mechanics and machine manufacture technology has the deep elementary knowledge. If front sues, the machine design goal is the production can meet the human need the product. The invention, the discovery and technical knowledge itself certainly not necessarily can bring the advantage to the humanity, only has when they are applied can produce on the product the benefit. Thus, should realize to carries on before the design in a specific product, must first determine whether the people do need this kind of product Must regard as the machine design is the machine design personnel carries on using creative ability the product design, the system analysis and a formulation product manufacture technology good opportunity. Grasps the project elementary knowledge to have to memorize some data and the formula is more important than. The merely service data and the formula is insufficient to the completely decision which makes in a good design needs. On the other hand, should be earnest precisely carries on all operations. For example, even if places wrong a decimal point position, also can cause the correct design to turn wrongly. A good design personnel should dare to propose the new idea,moreover is willing to undertake the certain risk, when the new method is not suitable, use original method. Therefore, designs the personnel to have to have to have the patience, because spends the time and the endeavor certainly cannot guarantee brings successfully. A brand-new design, the request screen abandons obsoletely many, knows very well the method for the people. Because many does this certainly is not an easy matter. A mechanical designer should unceasingly explore the improvement existing product the method, should earnestly choose originally, the process confirmation principle of design in this process, with has not unified it after the confirmation new idea. Newly designs itself can have the question occurrence which many flaws and has not been able to expect, only has after these flaws and the question are solved, can manifest new goods come into the market the product superiority. Therefore, a performance superior product is born at the same time, also is following a higher risk. Should emphasize, if designs itself does not request to use the brand-new method, is not unnecessary merely for the goal which transform to use the new method. In the design preliminary stage, should allow to design the personnel fully to display the creativity, not each kind of restraint. Even if has had many impractical ideas, also can in the design early time, namely in front of the plan blueprint is corrected. Only then, only then does not send to stops up the innovation the mentality. Usually, must propose several sets of design proposals, perform the comparison. Has the possibility very much in the plan which finally designated, has used certain not in plan some ideas which accepts. Another important question, project engineer must be able to carry on the exchange and the consultation with other concerned personnel. In the initial stage, designs the personnel to have to carry on the exchange and the consultation on the preliminary design with the administrative personnel, and is approved. This generally is through the oral discussion, the schematic diagram and the writing material carries on. In order to carry on the effective exchange, needs to solve the following problem: (1) designs whether this product truly does need for the people? Whether there is competitive ability (2) does this product compare with other companies'' existing similar products? (3) produces this kind of product is whether economical? (4) product service is whether convenient? (5) product whether there is sale? Whether may gain? Only has the time to be able to produce the correct answer to above question. But, the product design, the manufacture and the sale only can in carry on to the above question preliminary affirmation answer foundation in. Project engineer also should through the detail drawing and the assembly drawing, carries on the consultation together with the branch of manufacture to the finally design proposal. Possibly can request to some components size or the common difference makes some changes, causes the components the production to change easily. But, in the project change must have to pass through designs the personnel to authorize, guaranteed cannot damage the product the function. Sometimes, when in front of product assembly or in the packing foreign shipment experiment only then discovers in the design some kind of flaw. These instances exactly showed the design is a dynamic process. Always has a better method to complete the design work, designs the personnel to be supposed unceasingly diligently, seeks these better method Recent year, the engineerig material choice already appeared importantly. In addition, the choice process should be to the material continuously the unceasing again appraisal process. The new material unceasingly appears, but some original materials can obtain the quantity possibly can reduce. The environmental pollution, material recycling aspect and so on use, worker''s health and security frequently can attach the new limiting condition to the choice of material. In order to reduce the weight or saves the energy, possibly can request the use different material. Comes 3 from domestic and international competition, to product service maintenance convenience request enhancement and customer''s aspect the and so on feedback pressure, can urge the people to carry on to the material reappraises. Because the material does not select when created the product responsibility lawsuit, has already had the profound influence. In addition, the material and between the material processing interdependence is already known by the people clearly. Therefore, in order to can and guarantees the quality in the reasonable cost under the premise to obtain satisfaction the result, project engineer makes engineers all to have earnestly carefully to choose, the determination and the use material. Makes any product the first step of work all is designs. Designs usually may divide into several explicit stages: (a) preliminary design; (b) functional design; (c) production design. In the preliminary design stage, the designer emphatically considered the product should have function. Usually must conceive and consider several plans, then decided this kind of thought is whether feasible; If is feasible, then should makes the further improvement to or several plans. In this stage, the question which only must consider about the choice of material is: Whether has the performance to conform to the request material to be possible to supply the choice; If no, whether has a bigger assurance all permits in the cost and the time in the limit develops one kind of new material. In the functional design and the engineering design stage, needs to make a practical feasible design. Must draw up the quite complete blueprint in this stage, chooses and determines each kind of components the material. Usually must make the prototype or the working model, and carries on the experiment to it, the appraisal product function, the reliability, the outward appearance and the service maintenance and so on. Although this kind of experiment possibly can indicate, enters in the product to the production base in front of, should replace certain materials, but, absolutely cannot this point take not earnestly chooses the material the excuse. Should unify the product the function, earnestly carefully considers the product the outward appearance, the cost and the reliability. Has the achievement very much the company when manufacture all prototypes, selects the material should the material which uses with its production in be same, and uses the similar manufacture technology as far as possible. Like this has the advantage very much to the company. The function complete prototype if cannot act according to the anticipated sales volume economically to make, or is prototypical and the official production installment has in the quality and the reliable aspect is very greatly different, then this kind of prototype does not have the great value. Project engineer is best can completely complete the material in this stage the analysis, the choice and the determination work, but is not remains it to the production design stage does. Because, is carries on in the production design stage material replacement by other people, these people are inferior to project engineer to the product all functions understanding. In the production design stage, is should completely determine with the material related main question the material, causes them to adapt with the existing equipment, can use the existing equipment economically to carry on the processing, moreover the material quantity can quite be easy to guarantee the supply.1Research Status Development of mechanical design theory and methods and future trends1.1Development of mechanical design theory and method ofDesign is a complex human thought process , creative work, is one of the basic activities of human transformation of nature .In the long history of human understanding of the world and transform the world ,Has been engaged in the design activity .In a sense,PeopleOngoing class innovative design activities to promote the progress of human civilization.From the perspective of the development of design methods , design methods development has gone through four stages as follows .(1)Intuitive design phaseThe design is an intuition of ancient design,It is time to get inspiration from natural phenomena ,Or intuitive sense of their ownSense to design tools.Design exists in the minds of craftsmen ,The expression can not be recorded ,Product is relatively simpleThe . Intuitive design stage has experienced a long period of time in human history ,17Century ago, basically belong to this stage.(2)Experience in the design phaseWith the development of production,Experienced craftsmen part of his experience or express ideas with drawings,HoweverAfter the organization of production according to drawings .Drawings emergenceCan make crafts people experienced their experiences through drawings or configurationBest recordBiography with others,Drawing on the product easy to analyze ,Improve and enhancePush forward the development of the design work ,Also meet more people to participate in productive activities while the same product ,Meet the social demand for products and increase productivityRequirements.(3)Semi-theoretical semi-empirical design phase20Since centuries, due to the scientific and technological development and progress , the basic theory and experimental research study design has been addedStrong, with the accumulation of in-depth theoretical study , test data and design experience , has formed a semi- semi-empirical theoryDesign . Experience with this approach and the theoretical calculation and the formation of long-term design practice , formulas, charts, manuals and other designAs a basis for design , design by empirical formula , approximate coefficients or analog methods . Produced using this methodProduct design, a traditional design .(4)Modern design phaseIn recent decades, the rapid development of science and technology , the theoretical foundation and tools needed for the design work has made great progress , especiallyAnother is the development and application of computer technology,Its computing speed continues to accelerate,Storage capacity continues to strengthen ,Water Engineering SoftwareLevel continues to improve,And the emergence of a comprehensive database of network technology ,Design work had a revolutionary impactDesign workProvides aimplementation for design automation and precision computing conditions.1.2Research Status mechanical design theory and method ofApplication in product designCAD, CAE,Optimized design, dynamic design and other technical methods , widely used tests and computer skillsSurgery for product design .The application of modern design of the new product development cycle is shortened,Product quality and product producedDegree of automation has been improved , reducing production costs and enhance the competitiveness of their products .According to scholars at home and abroad design methods used in mechanical product design ,Modern design approach can be summarized into four categories :1.21Systematic design methodsSystematic approach to the design of the main features are: Several design elements of a system consisting of design , every design proThere are separate design elements,Presence of an organic link between the elements ,And has a hierarchy , in this case ,All are designed to beCombining the elements , the system can be designed to achieve desired tasks.1.22Modular structure design methodsThrough a combination of structural modules , methods to achieve product design is called modular structure design methods. The specificApplications to : apply to specific types of machinery products : As part of its function is more clear and relatively stableThe divided structure of the module easier2Structure modular design approach by combining structural modulesAchieve product designThe method is called modular structure design methods.Specific applications are:Applicable to specific types of machinery products :By thePart of its function is more clear and relatively stable , relatively easy to divide the structure of the module .1.23Intelligent Design MethodBy means of three-dimensional graphics software , intelligent design software and virtual reality technology , design methodology based on the theory , as well as multi-Media ,Hypermedia tools for product development and design ,Expression of the product concept ,Schema products are intelligent designerThe main features of law1.24Knowledge -based design method of product characteristicsLanguage to describe the characteristics of the product with a computer can identify the main features of the product is based on knowledge of the design features of the method , whichFeatures can be expressed knowledge and experience as well as its desi