The mating relation in assembly drawing plays an important role in drawing design towel. Generally speaking, in addition to indicating the position relationship and structure of the components, the assembly drawing is very important to determine the mating relationship between the components, especially to determine the dimensions of the precision and performance of the mechanical work. Be careful to show how they fit together. Otherwise, the mechanical performance is not guaranteed.
When doing assembly drawing design. The methods to determine the limit tolerance and fit are analogy method, calculation method and test method. Calculation method and test method is through the calculation or test means, to determine the relationship between the ten thousand method, it has reliable, accurate, scientific characteristics, but must spend a lot of time and cost, stone is too economic. The analogy method is a method to determine the matching according to the application of parts and referring to the existing matching experience data of similar machinery. The basic point is a statistical survey, which investigates the coordination and use of parts of the same structure or similar structure of the same type, and then conducts an analysis and analogy to determine the coordination.
The analogy method is simple and easy to operate, and the selected cooperation focuses on inheriting the practical experience of the past design and manufacturing, and most of them have been verified by the actual situation, with high ordering, which is also convenient for product serialization and standardized production. It also has good manufacturability. Due to the above advantages, the determination of limit fit L has been used as an effective method. At present, this method is still the main method of mechanical design and manufacturing, this chapter discusses how to use the analogy method to design orange.
The mechanical precision design of cutting machine is an important part of machine design. No matter the design is complex and precise to seek the machine, the rocket. Still be like decelerate decelerate this kind of simpler machine. Need to consider the principle of conceptual design, both of them [: art design and design precision. When accuracy design v not instrument need to consider how to realize the functional requirements of the machinery, but also to consider whether it can made according to the requirements. In reality one hundred percent orange machinery is indeed impossible. Precision is set outside the task is how to use the coarse extreme limit matching, geometric tolerance, surface, etc. Expression of machinery spare parts manufacturing allow poor, thereby creating meet various performance index of the machinery.