23. What are the factors that affect process margin?

1. The dimensional tolerance Ta of the previous process; 2. The surface roughness Ry and surface defect depth Ha produced by the previous process; 3. The spatial error left by the previous proces24. What does the working hour quota consist of?

T quota = T single piece time + t accurate final time/n number of pieces

25. What are the technological ways to improve productivity?

1. Shorten the basic time; 2. Reduce the overlap between auxiliary time and basic time; 3. Reduce the time of arranging work; 4. Reduce the preparation and completion time.

26. What are the main contents of the assembly process regulations?

1. Analyze the product drawing, divide the assembly units, and determine the assembly method; 2. Develop the assembly sequence and divide the assembly processes; 3. Calculate the assembly time quota; 4. Determine the assembly technical requirements, quality inspection methods and inspection tools for each process; 5. Determine The transportation method of assembly parts and the required equipment and tools; 6. Select and design the tools, fixtures and special equipment required in the assembly process

27. What should be considered in the assembly process of machine structure?

1. The machine structure should be able to be divided into independent assembly units; 2. Reduce repairs and machining during assembly; 3. The machine structure should be easy to assemble and disassemble.

28. What does assembly accuracy generally include?

1. Mutual position accuracy; 2. Mutual motion accuracy; 3. Mutual cooperation accuracy

29. What issues should be paid attention to when searching for assembly dimension chains?

1. The assembly dimension chain should be simplified as necessary; 2. The assembly dimension chain consists of "one piece and one link"; 3. The "directionality" of the assembly dimension chain. In the same assembly structure, there is assembly accuracy in different positions and directions. When required, the assembly dimension chain shall be supervised in different directions

30. What are the methods to ensure assembly accuracy? How are the various methods applied?

1. Interchange method; 2. Selection method; 3. Modification method; 4. Adjustment method