Họ có thể phân tích một giải pháp cơ chế thử nghiệm rất nhanh chóng, năng động, sản lượng đồ họa của họ cung cấp cho gần như tức thời thông tin phản hồi trực quan về chất lượng của thiết kế. Chương trình thương mại như * Mô hình làm việc cũng cho phép phân tích nhanh chóng của một thiết kế cơ khí đề xuất. Quá trình này sau đó trở thành một trong những thiết kế chất lượng bằng cách phân tích tiếp. | VELOCITY ANALYSIS from Ir 3. You can see that the wheel center has a significant horizontal component of motion as it moves up over the bump. This horizontal component causes the wheel center on that side of the car to move forward while it moves upward thus turning the axle about a vertical axis and steering the car with the rear wheels in the same way that you steer a toy wagon. Viewing the path of the instant center over some range of motion gives a clear picture of the behavior of the coupler link. The undesirable behavior of this suspension linkage system could have been predicted from this simple instant center analysis before ever building the mechanism. Another practical example of the effective use of instant centers in linkage design is shown in Figure 6-13 which is an optical adjusting mechanism used to position a mirror and allow a small amount of rotational adjustment. 1 A more detailed account of this design case study 2 is provided in Chapter 18. The designer K. Towfigh recognized that Ir 3 at point E is an instantaneous fixed pivot and will allow very small pure rotations about that point with very small translational error. He then designed a one-piece plastic fourbar linkage whose pin joints are thin webs of plastic which flex to allow slight rotation. This is termed a compliant linkage one that uses elastic deformations of the links as hinges instead of pin joints. He then placed the mirror on the coupler at 11 3. Even the fixed link 1 is the same piece as the movable links and has a small set screw to provide the adjustment. A simple and elegant design. CENTRODES Figure 6-14 illustrates the fact that the successive positions of an instant center or centra form a path of their own. This path or locus of the instant center is called the centrode. Since there are two links needed to create an instant center there will be two centrodes associated with anyone instant center. These are formed by projecting the path of the instant center first on .
