【正文】 t 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。 (e) the personnel which pletely is not petent for the post by some chooses the material. Through to the above five questions analysis, may obtain these questions is does not have the sufficient reason existence the conclusion. May for avoid these questions to these questions research analyses the appearance indicating the direction. Although uses the best choice of material method not to be able to avoid having the product responsibility lawsuit, designs the personnel and the industry carries on the choice of material according to the suitable procedure, may greatly reduce the lawsuit the quantity. May see from the above discussion, the choice material people should to the material nature, the characteristic and the processing method have prehensive and the basic understanding. 。 (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。s basic responsibility is diligently causes the machine to adapt the people. This certainly is not an easy work, because certainly does not have to all people to say in fact all is the most superior operating area and the operating process. 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 petitive ability (2) does this product pare with other panies39。在材料過(guò)程中，五個(gè)最常見(jiàn)的問(wèn)題為：（ a）不了解或者不會(huì)使用關(guān)于材料應(yīng)用方面的最新最好的信息資料； (b)未能預(yù)見(jiàn)和考慮擦黑年品可能的合理用途（如有可能，設(shè)計(jì)人員還應(yīng)進(jìn)一步預(yù)測(cè)和考慮由于產(chǎn)品使用方法不當(dāng)造成的后果。然而，在大多數(shù)情況下，在進(jìn)行生產(chǎn)以后改換材料要比在開(kāi)始生產(chǎn)前改換材料所花費(fèi)的代價(jià)要高。一個(gè)很有成就的公司在制造所有的樣機(jī)時(shí)，所選用的材料應(yīng)該和其生產(chǎn)中使用的材料相同，并盡可能使用同樣的制造技術(shù)。在初步設(shè)計(jì)階段，設(shè)計(jì)者著重考慮產(chǎn)品應(yīng)該具有的功能。環(huán)境污染、材料的回收利用、工人的健康及安全等方面經(jīng)常會(huì)對(duì)材料選擇附加新的限制條件?？赡軙?huì)要求對(duì)某個(gè)零件尺寸或公差作一些更改，使零件的生產(chǎn)變得容易。這并不是一項(xiàng)容易的工作，因?yàn)閷?shí)際上并不存在著一個(gè)對(duì)所有人來(lái) 說(shuō)都是最優(yōu)的操作范圍和操作過(guò)程。應(yīng)該強(qiáng)調(diào) 的是，如果設(shè)計(jì)本身不要求采用全新的方法，就沒(méi)有必要僅僅為了變革的目的而采用新方法。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。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)。機(jī)械設(shè)計(jì)是一項(xiàng)創(chuàng)造性的工作。另一方面，應(yīng)該認(rèn)真精確的進(jìn)行所有運(yùn)算。因此，一個(gè)性能優(yōu)越的產(chǎn)品誕生的同時(shí)，也伴隨著較高的風(fēng)險(xiǎn)。設(shè)計(jì)人員的基本職責(zé)是努力使機(jī)器來(lái)適應(yīng)人們。 通常 ，在制造過(guò)程中會(huì)出現(xiàn)某個(gè)問(wèn)題。新材料不斷出現(xiàn)，而一些原有的材料的能夠獲得的數(shù)量可能會(huì)減少。設(shè)計(jì)通常可以分為幾個(gè)明確的階段：（ a）初步設(shè)計(jì)；（ b）功能設(shè)計(jì)；（ c）生產(chǎn)設(shè)計(jì)。應(yīng)該結(jié)合產(chǎn)品的功能，認(rèn)真仔細(xì)地考慮產(chǎn)品的外觀、成本和可靠性。經(jīng)驗(yàn)表明，可采用某些便宜材料作為替代品。 產(chǎn)品的責(zé)任訴訟迫使設(shè)計(jì)人員和公司在選擇材料時(shí)，采用最好的程序。39。 (b) functional de