Đang chuẩn bị liên kết để tải về tài liệu:
Ebook The mechanical design process (4th edition): Part 2

(BQ) Part 2 book "The mechanical design process" has contents: Concept evaluation and selection, product generation, product evaluation for performance and the effects of variation, wrapping up the design process and supporting the product, properties of 25 materials most commonly used in mechanical design,. and other contents. | ullman-38162 ull75741_07 December 17, 2008 15:55 C H 7 A P T E R Concept Generation KEY QUESTIONS ■ ■ ■ ■ ■ ■ How can understanding the function help developing form? What does flow have to do with function? How can patents help generate ideas? How can you get the best out of brainstorming and brainwriting? How do contradictions lead to new ideas? What is a morphology and what does it do? 7.1 INTRODUCTION In Chap. 6, we went to great lengths to understand the design problem and to develop its specifications and requirements. Now our goal is to use this understanding as a basis for generating concepts that will lead to a quality product. In doing this, we apply a simple philosophy: Form follows function. Thus we must first understand the function of a device, before we design its form. Conceptual design focuses on function. A concept is an idea that is sufficiently developed to evaluate the physical principles that govern its behavior. Confirming that a concept will operate as anticipated and that, with reasonable further development, it will meet the targets set, is a primary goal in concept development. Concepts must also be refined enough to evaluate the technologies needed to realize them, to evaluate their basic architecture (i.e., form), and, to some limited degree, to evaluate their manufacturability. Concepts can be represented in a rough sketch or flow diagram, a proof-of-concept prototype, a set of calculations, or textual notes—an abstraction of what might someday be a product. However a concept is represented, the key point is that enough detail must be developed to model performance so that the functionality of the idea can be ensured. On the average, industry spends about 15% of design time developing concepts. Based on a comparison of the companies in Fig. 1.5, this should be 20–25% 171 ullman-38162 172 ull75741_07 December 17, 2008 CHAPTER 7 15:55 Concept Generation If you generate one idea, it is probably a poor one. If you .