Table of contents
1 Introduction 1
1.1 The development status of the pneumatic industry 1
1.2 The development trend of the pneumatic industry 2 1.3
The challenges and opportunities faced by the pneumatic industry in China 3
2 Analysis of the parts of the 5WB right crankcase 4
2.1 The characteristics and functions of the 5WB right crankcase 4
3 Selection of blank 5
3.1 Type of blank material 5
3.2 Factors to be considered when determining the blank 5
3.3 Several technological measures when determining the blank 6
3.4 Determine the manufacturing form of the blank 6
4 Process specification design of 5WB right crankcase body 7
4.1 Process specification 7
4.2 Principles of formulating process regulations 7
4.3 Manufacturability analysis of parts 7
4.4 Main problems in crankcase machining and corresponding measures to be taken in process design 8
5 Selection of benchmarks 10
5.1 Concept of benchmarks 10
5.2 Classification of benchmarks 10
5.3 Analysis of datum problem 10
5.4 Selection of positioning datum 11
6 Drafting of process route 13
6.1 Process route plan 13
6.2 Determination of machining allowance, process size and blank size 14
6.3 Determination of cutting amount and basic working hours (motor time) 16
7 Fixture Design 23
7.1 The Function and Composition of Machine Tool Fixtures 23
7.2 Parts Manufacturability Analysis 23
Conclusion 31
Acknowledgments 32
References 33
2 Parts analysis of 5WB right crankcase
2.1 Characteristics and functions of 5WB right crankcase
2.1.1 Function of 5WB right crankcase
This part is 5WB right crankcase, which is the basis of motorcycle engine Parts, which combine the left crankcase to assemble the shafts, sleeves, gears and other related parts in the machine or components into a whole, so that they maintain the correct mutual position and coordinate the transmission of motion or power according to a certain transmission relationship. Therefore, the processing quality of the box will directly affect the accuracy, performance and life of the engine [2].
2.1.2 Features of 5WB right crankcase
The specific structure of parts of 5WB right crankcase is shown in the appendix "5WB right crankcase parts diagram".
From the parts diagram, we can see that the structural characteristics of the box body are: complex shape, many processing parts, difficult processing, and holes and planes with high precision requirements. Therefore, the machining labor of general box parts accounts for about 15%-20% of the entire product processing. The following is the joint surface and reverse surface of the right crankcase, as shown in the figure below:
图2.1 零件结构图
