Engineering Design. by : Dr.farshidianfar. References:. 1 - The Science of Engineering Design by : Percy H. Hill pub : Holt , Rinehart & Winston , Inc . New York , 1970 2 - Engineering Design Graphics by : James H. Earle
by : Dr.farshidianfar
1 - The Science of Engineering Design
by : Percy H. Hill
pub : Holt , Rinehart & Winston , Inc. New York ,1970
2 -Engineering Design Graphics
by : James H. Earle
pub : Addison_Welsy publishing co , 1992
New products are basic to company growth and survival today more than ever before.
Statistics show that between 55 & 60 good ideas found to obtain one successful new product valuable enough to have a significant effect on sales profit.
The ideas can be found from internal sources as well as external sources.
What’s wrong with it ?
How can it be improved?
Identification of need :
The beginning of the design process is an idea . Often the idea is motivated by an company’s urgent desire to lunch a new product . (or solved a social problem).
Definition of goal :
An expression in general terms of one’s commitment to a system , device or process to satisfy the nee.
Collection of all available information related to the goal.
Task specification :
Listing of pertinent data & parameters that will tend to control the design toward the desired .
The process of originating new idea .
Ingenious , innovative , creative activity in the form of the generation of alternative possible solutions to required goal . This usually takes the form of free-hand sketches.
Decision matrix :
An excellent technique to guide the designer in making the best decision regarding alternative is a scoring matrix.
Testing selective concepts against physical laws.
Construction of prototype , & laboratory testing to determine performance , workability , reliability & durability.
Solution description :
Specific information that defines the system , process or device. It consist of a report containing a description of the device , drawings, specifications, part list, cost estimation.
Consideration of volume of production , shop requirements ,fabrication techniques, stock acquisition , automation ,scheduling , quality control , inspection .
Competitive pricing , advertising , marketing , profit margin .
Consumer feed back , repairing , servicing.
موفقیت در زمینه علمی و صنعتی مستلزم داشتن :
1- توانایی تحقیق
2- توانایی طراحی
3- توانایی تولید
از عوامل موثر بر توانائی طراحی را میتوان استعداد و خلاقیت نام برد
توانائی عملی برای دادن ایده های جدید جهت اهداف مهندسی که دارای شرایط زیر باشند:
مفید یا هنری وبا ارزش
ایجاد تسهیل در کاری که با عث پیچدگی است
گشودن راه ارتباطات جدید.
عوامل موثر بر خلاقیت:
3-تعلیم و تربیت گذشته
Brainstorming : انتقاد و ترس از انتقاد همیشه مانع بروز ایدههای ابتکاری می شود لذا در این روش انتقاد ممنوع است
inversion : با تغییر دیدگاه یا نقطه نظر ایده های جدید رشد میکند
Analogy : مشابه سازی از منابع و طبیعت
Empathy :تلقین و انتقال فکر خود را بجای دیگران قرار دادن
Fantasy : خیالبافی (آرزو دارم چنین با شد )
Identification of need :
Assume that an engineer in private practice (consultant) is bothered by the time & trouble of removing fallen leaves from his lawn-that he would rather play golf. finally provoked by a recent newspaper headline “autumn rite of leaf-burning adds to air pollution.” he decides that there is an urgent need for a device to re move leaves.
Definition of goal :
Design a device or system for removing autumn leaves from suburban lawns that is simple to use & will not add to air pollution.
The collection of all available information . Information sources may include the following technical &trade journals, abstracts , research reports, technical libraries, the competition catalogues of component suppliers , the patent office. this information may reveal an already available design solution ,the state-of-the-art ,& availability of hardware to accomplish the goal.
Since this stage requires imaginative thinking involving the overall design plan , the designer often questions the goal , may wish to revise it & may abandon the project if it is proven risky.
Device must be safe to operate, specially when used near small children.
Controls must be such that the average house wife will have little to no difficulty in learning to operate .
Device may collect and remove leaves in following ways :
Shredded and bagged
Shredded and deposited as mulch calready available
Compressed into blocks to be burned in fire place during winter
Shredded and compressed into a type of peat for planting and covering
4. Type of power to be considered
c. i. c engine (2 cycle or 4 cycle )
d. Manual power through gearing
Device should be easily stored in garage or basement
Possibility of combining lawn tasks such as :
Collecting leaves & mowing lawn
Collecting leaves & fertilizing
Collecting leaves & spreading lime
Collecting leaves, moving lawn, &spreading lime
7. Device should use presently available hardware and require only sheet metal and tube forming work or possibly fabricated plastic or vacuum forming .
8. material should be selected on the basis of workability , strength . Cast , appearance and ability to with stand varying weather conditions.
Device must be reliable , require little to no maintenance , and sell at a price below the average power lawn mower
نخ بخیه از روده ساخته می شود!!
Microsoft US$ 62 Billions
GE US$ 55,83 Billions
Coca-cola US$41,41 bilions
China Mobile US$ 39,168 billions
Google US$ 37,445 Bilions
IBM US$ 36,084 billions