Part Manufacturing Technology

Contents

Introduction

1. Part purpose and operating conditions

2. Part Processability Analysis

2.1 Qualitative evaluation of workability of the part

2.2 Quantitative evaluation of workability of the part

3. Define Production Type

4. Procurement Selection and Design

4.1 Analysis of procurement methods and selection of optimal

4.2 Economic justification for selection of procurement method

5. Basic Machining Process Analysis

6. Selection of process bases

7. Establishing a Processing Route

8. Calculates allowances and interoperative dimensions for two surfaces. Assigning tolerances and tolerances to all surface standards

9. Selection of equipment and process equipment

9.1 Equipment Selection

9.2 Cutting Tool Selection

9.3 Selection of accessories

9.4 Selection of instrumentation

10. Development of technological operations

11. Calculation and assignment of cutting modes

12. Process rationing

13. Process Automation

Conclusion

Bibliographic list

Introduction

Technology largely determines the state and development of production. Its level depends on labor productivity, economic consumption of material resources, energy resources, quality of products and other indicators. For the further accelerated development of the machine-building industry, as the basis of the entire national economy of the country, it is necessary to develop new technological processes, constantly improve new and traditional processing methods, strengthen machine parts and assemble them in a unit.

An important role in accelerating the scientific and technical process in mechanical engineering is assigned to the training of highly qualified personnel of engineers, the development or modern methods of manufacturing and control of products, and methods of designing progressive technological processes. Therefore, the graduation by higher educational institutions of engineers in the specialty "Engineering technology, metal cutting machines and tools" is becoming increasingly important.

In the system of education of mechanical engineers, course design according to mechanical engineering technology occupies a special place. This independent work of students is the most important stage of preparation for graduate design and largely determines the formation of the technological orientation of future engineers.

Course design consolidates, deepens and summarizes the knowledge gained during lecture and practical classes. Course design teaches the student to use reference literature, GOST, tables, norms and prices, skillfully combining reference data with theoretical knowledge. When performing the project, decisions on the selection of technological process options, tooling, equipment, and procurement methods are made on the basis of technical and economic calculations, which makes it possible to offer the optimal option.

2. Part Processability Analysis

2.1 Qualitative processability analysis

Half-coupling part - is a cast from gray cast iron SCh 20. The casting is quite simple in configuration, but requires the use of rod molding to form an internal cavity. The surfaces to be treated are not difficult to process in terms of accuracy and roughness. except for the precise surfaces 100h6 and 190h8, the access of the cutting tool to all surfaces is free, the part material is easy to process and wide-spread, the part configuration allows the part to be machined with a set of standard tools for CNC machines, the part has clearly expressed bases and signs of orientation, as well as uniform in shape and location of the surface for basing and grasping, design of the part enables reliable gripping, holding and transfer by gripping devices of an industrial robot. The processing of parts of the type of bodies of revolution at the TOC, in the conditions of the HA, imposes special requirements that expand the set of processability criteria, to which, in addition to the above listed requirements, include:

- the configuration and material of the parts should allow the use of the most advanced initial blanks, reducing the amount of machining, as well as the most productive methods of machining;

- normalization and unification of components that are prerequisites for unification of cutting and measuring tools;

providing the possibility of processing the maximum number of surfaces from one installation when using a mainly cantilevered tool;

-Samples the machined features based on NC device capabilities.

- the presence of elements convenient for fixing the workpiece in the appliance while reducing the number of installations to a minimum;

- the presence of structural elements of the part necessary for its relative orientation in the machine tool.

Thus, it can be concluded that the part is technological. This makes it possible to use high-performance methods of processing it, all surfaces of the part should be processed at the TOC, except for the treatment of the key slot, which is more rational to do on a long machine.

4. Procurement Selection and Design

4.1 Analysis of procurement methods and selection of optimal

Workpieces processed on automated lines and sections shall meet the following basic requirements:

- minimum allowance sufficient to ensure the specified accuracy and roughness of the treated surface;

- allowance distribution shall be uniform over the billet surface and stable for the whole batch of parts;

- consistency of physical and mechanical properties over the whole surface;

- the allowance variation shall not exceed the allowable value providing effective clamping of the workpiece into the pre-tuned tooling;

- the base must have relatively high accuracy of shape and arrangement of surfaces and ensure reliable attachment of the part during machining;

- the nature of chip removal from cutting edges of tools must be free, preventing jamming and breakage of tools, especially when processing holes of small diameter;

- deviation from non-perpendicular of billet ends to generatrix not

more than 0.5 mm for blanks up to 100 mm in diameter, and not more than 1.0 mm for

blanks with a diameter of more than 100 mm.

Experience has shown that blanks manufactured in the same manner have significant variations in allowance. This usually requires additional effort when performing the initial part processing operations: the processing program must be individual for each part, incoming inspection is required, etc.

Considering that the creation of automated production is carried out as a rule in the conditions of existing production with established requirements for blanks, it is necessary to provide for the creation of auxiliary sections from universal or special machines for cutting operations, ensuring the identity of the distribution of allowances in blanks. It should be borne in mind that the higher the accuracy of the workpiece, the more likely it is possible to include surface preparation operations in the production processes of the GPS.

The selection of the procurement method is influenced by the part material; its purpose and technical requirements for manufacture; volume and serial quality of production; the shape of the surfaces and the dimensions of the part.

The optimal method of obtaining the workpiece is determined on the basis of a comprehensive analysis of these factors and a technical and economic calculation of the technological cost of the part. The method of obtaining a workpiece, which ensures the processability of making a part from it at a minimum cost of the latter, is considered optimal.

The project performs a brief analysis of the existing procurement method in the plant. It should reflect the technological process, if necessary illustrated by sketches, its positive and negative aspects, the quality of the procurement, the causes of the scrap and the possibility of its elimination. It is necessary to provide data on the cost of the method of obtaining the workpiece in the conditions of the plant, its labor intensity, productivity, material capacity.

Based on the analysis, the study of advanced methods for obtaining similar blanks at other enterprises, as well as literary data and a feasibility study, it is necessary to propose an optimal method for obtaining the blanks for the accepted production conditions. The drawing must be worked on the processability of the design of the part in order to reduce the cost of labor, funds, material and time for the manufacture of the workpiece using the proposed method. It is also necessary to provide for the use of unavoidable metal wastes obtained during the mechanical treatment of blanks (rolled stock cutting, etc.).

In our case, since the material of the part SC20 is cast, it is advisable to obtain the workpiece by casting.

Since we have small-scale production - 135 pieces per year, we choose a method for producing castings in sandy-clay forms.

Casting into sand molds is the most versatile method, but the manufacture of the mold takes a long time. So, packing 1m3 of the moulding mixture manually takes 1.5... 2 hours, and using air ramming - 1 hour. The use of sandwich reduces the packing time of the mold to 6 minutes. Shaking machines accelerate it compared to manual by 15 times, and press machines - by 20 times.

Casting into shell molds is used mainly in the production of responsible shaped castings. By automating the workpiece manufacturing process, up to 450 half molds per hour can be produced.

Casting into a chill is economically feasible for a batch of at least 300... 500 pcs - for small castings, 30... 50 pcs - for large ones. Capacity - 30 castings per hour.

Casting according to smelting models is economically feasible for parts of very complex configuration from any alloys with a lot of more than 100 pcs.

Injection molding is mainly used to produce shaped castings from zinc, aluminum, magnesium and brass alloys. The method is considered expedient in the batch of 1000... 2000 pcs and more. Performance - up to 1000 per hour.

Centrifugal casting has become widespread when making blanks that have the form of bodies of revolution. Capacity - up to 15 castings per hour.

Liquid metal stamping is promising. Using this method, it is possible to obtain fairly accurate blanks with deep protrusions and thin walls at a pressure of 6... 8 times less than with hot stamping.

5. Basic Machining Process Analysis

The basic process consists of the following operations:

Operation 005 - Turning-screw-cutting. End faces, external cylindrical surfaces Ø190h8 and Ø100h6, internal cylindrical surface Ø55H9, chamfers, groove are treated.

Operation 010 - Radial Drill. 8 holes Ø18 are processed.

Operation 015 - Vertical Milling. The hole Ø10 and lug are processed.

Operation 020 - Long. The keyway 16D10 is processed.

Operation 025 - Round Grinding. External cylindrical surface Ø100h6 is processed.

By analyzing a typical part processing process, we identify the following disadvantages that increase the cost of machining and the labor intensity of manufacturing a part. Since the part is processed on several machines, the auxiliary time for installing and removing the workpiece from the machine, for transporting the workpieces between the machines, for installing and changing tools is quite long. All auxiliary operations are carried out manually - this increases the labor (time) of machining. The use of several machines involves the cost of their operation and repair, as well as the production space for the placement of machines. The processing accuracy is monitored manually, which also increases the manufacturing time of the part. Process operations of multi-operation TP become process transitions during single-operation processing on RTK or MRG. This reduces the auxiliary processing time of the part and, if properly organized, reduces the machining costs of the part.

Conclusion

In the course of this course project, the workability of the half-coupling part was analyzed, the method of producing the workpiece was selected, the progressive manufacturing process of the half-coupling part was developed, and the proposed process was compared with the basic one. For the developed process, the issue of automation has been worked out.