【正文】
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 pletely 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 brandnew design, the request screen abandons obsoletely many, knows very well the method for the people. Because many person of conservativeness, 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 e 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 brandnew 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, then perform the parison. Has the possibility very much in the plan which finally designated, has used certain not in plan some ideas which accepts. How does the psychologist frequently discuss causes the machine which the people adapts them to operate. Designs personnel39。盡管采用最好的材料選擇方法也不能避免發(fā)生產(chǎn)品責(zé)任訴訟,設(shè)計(jì)人員和工業(yè)界按照適當(dāng)?shù)某绦蜻M(jìn)行材料選擇,可以大大減少訴訟的數(shù)量。 通過對上述五個(gè)問題的分析,可以得出這些問題是沒有充分理由存在的結(jié)論。在材料過程中,五個(gè)最常見的問題為:( a)不了解或者不會使用關(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)測和考慮由于產(chǎn)品使用方法不當(dāng)造成的后果。大部分的產(chǎn)品失效和產(chǎn)品責(zé)任事故案件是由于在選用新材料作 為替代材料之前,沒有真正了解它們的長期使用性能而引起的。但是,必須對新材料進(jìn)行認(rèn)真的評價(jià),以確保其所有性能都滿足要求。在生產(chǎn)制造開始后出現(xiàn)了可供使用的新材料是更換材料的最常見的原因。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始生產(chǎn)前改換材料所花費(fèi)的代價(jià)要高。 在制造過程中,不 可避免地會出現(xiàn)對使用中的材料做一些更改的情況。因?yàn)?,在生產(chǎn)設(shè)計(jì)階段材料的更換是由其他人進(jìn)行的,這些人對產(chǎn)品的所有功能的了解不如設(shè)計(jì)工程師。功能完備的樣機(jī)如果不能根據(jù)預(yù)期的銷售量經(jīng)濟(jì)地制造出來,或者是樣機(jī)與正式生產(chǎn)的裝置在質(zhì)量和可靠性方面有很大不同,則這種樣機(jī)就沒有多大的價(jià)值。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)。雖然這種試驗(yàn)可能會表明,在產(chǎn)品進(jìn)入到生產(chǎn)階段之前,應(yīng)該更換某些材料,但是,絕對不能將這一點(diǎn)作為不認(rèn)真選擇材料的借口。在這個(gè)階段要繪制出相當(dāng)完整的圖紙,選擇并確定各種零件的材料。在此階段,關(guān)于材料選擇唯一要考慮的問題是:是否有性能符合要求的材料可供選擇;如果沒有的話,是否有較大的把握在成本和時(shí)間都允許的限度內(nèi)研制出一種 新材料。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。 制造任何產(chǎn)品的第一步工作都是設(shè)計(jì)。此外,材料與材料加工之間的相互依賴關(guān)系已經(jīng)被人們認(rèn)識得更清楚。來自國內(nèi)和國際競爭、對產(chǎn)品維修保養(yǎng)方便性要求的提高和顧客的反饋等方面的壓力,都會促使人們對材料進(jìn)行重新評價(jià)。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)常會對材料選擇附加新的限制條件。此外,選擇過程應(yīng)該是一個(gè)對材料的連續(xù)不斷的重新評價(jià)過程??偸谴嬖谥?