【正文】
gy as far as possible. Like this has the advantage very much to the pany. The function plete 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 pletely plete 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 pletely 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. In the manufacture process, inevitably can appear to uses the material to make some changes the situation. The experience indicated that, may use certain cheap materials to take the substitute. However, in the majority situation, in will carry on the production later to change the material to have in to start before the production to change the price which the material will spend to have to be higher than. Completes the choice of material work in the design stage, may avoid the most such situations. Started after the production manufacture to appear has been possible to supply the use the new material is replaces the material the most mon reason. Certainly, these new materials possibly reduce the cost, the improvement product performance. But, must carry on the earnest appraisal to the new material, guarantees its all performance all to answer the purpose. Must remember that, the new material performance and the reliable very few pictures materials on hand such understood for the people. The majority of products expiration and the product accident caused by negligence case is because in selects the new material to take in front of substitution material, not truly understood their longterm operational performance causes. The product responsibility lawsuit forces designs the personnel and the pany when the choice material, uses the best procedure. In the material process, five most mon questions are: (a) did not understand or cannot use about the material application aspect most newly the best information paper。設(shè)計(jì)工程師不僅在工作上要有創(chuàng)造性,還必須在機(jī)械制圖、運(yùn)動(dòng)學(xué)、工程材料、材料力學(xué)和機(jī)械制造工藝學(xué)等方面具有深厚的基礎(chǔ)知識(shí)。例如,即使將一個(gè)小數(shù)點(diǎn)的位置放錯(cuò),也會(huì)使正確的設(shè)計(jì)變成錯(cuò)誤的。很有可能在最后選定的方案中,采用了某些未被接受的方案中的一些想法。但是, 產(chǎn)品的設(shè)計(jì)、制造和銷(xiāo)售只能在對(duì)上述問(wèn)題的初步肯定答案的基礎(chǔ)上進(jìn)行。 近些年來(lái),工程材料的選擇已經(jīng)顯得重要。因此,為了能在合理的成本和確保質(zhì)量的前提下獲得滿意的結(jié)果,設(shè)計(jì)工程師的制造工程師都必須認(rèn)真仔細(xì)地選擇、確定和使用材料。 通常要制造出樣機(jī)或者實(shí)物模型,并對(duì)其進(jìn)行試驗(yàn),評(píng)價(jià)產(chǎn)品的功能、可靠性、外觀和維修保養(yǎng)性等。 在生產(chǎn)設(shè)計(jì)階段中,與材料有關(guān)的主要問(wèn)題是應(yīng)該把材料完全確定下來(lái),使它們與現(xiàn)有的設(shè)備相適應(yīng),能夠利用現(xiàn)有設(shè)備經(jīng)濟(jì)地進(jìn)行加工,而且材料的數(shù)量能夠比較容易保證供應(yīng)。應(yīng)當(dāng)記住,新材料的性能和可靠性很少像現(xiàn)有材料那樣為人們所了解。 從以上的討論可以看出,選擇材料的人們應(yīng)該對(duì)材料的性