Development of the manufacturing process of the primary shaft of the car transfer box

Contents

CONTENTS

Introduction

1 Analysis of source data

2 Preliminary Process Development

part fabrication

3 Procurement Design

4 Determination of machining allowances

5 Selection of cutting modes

6 Rationing of process operations

7 Analysis of possible types and causes of damage or

failure of the part. Description of how to defect a part

8 Development of proposals for recovery methods

part operating properties

9 Development of part recovery process

Conclusion

List of information sources

Introduction

Mechanical engineering is the most important industry. Its products - machines for various purposes are supplied to all branches of the national economy. The growth of industry, as well as the pace of re-equipment with their new technology and technology, is largely dependent on the level of development of engineering.

The state of mechanical engineering largely determines the development of other sectors of the national economy. Machines and mechanisms with worm-type parts are used in various fields of science and technology. These parts, based on high requirements for technical, economic and operational parameters of machines and mechanisms, should have high reliability, repairability, processability, minimum dimensions, convenience in operation. In many ways, these indicators are provided in the process of designing and manufacturing shafts.

The main tasks of mechanical engineering technology are the design of the entire complex of technological means that ensure the production of products of a given quality in a given amount and in a given time, as well as reducing the cost of production, improving quality, reducing the time spent on the production of the product, increasing the coefficient of material use, automation of technological processes.

The main tasks of mechanical engineering technology are: the use of automatic systems, adaptive control systems, GPS, the introduction of the latest technological equipment into production, the use of computers, the latest cutting, measuring tools and equipment.

Technological preparation of production is a decisive stage in the cycle of production of machines and mechanisms. One of the stages of technological preparation of production consists in the development of a technological process for the manufacture of machine parts.

The course project is devoted to the development of the technological process for the manufacture of the primary shaft of the transfer box of the car. Such parts are made in large volumes.

The main tasks that need to be solved when designing new technological processes are to increase the accuracy and quality of processing, stability and durability of parts and maximize the reduction of the cost of processing by improving technological processes. In the course project, these tasks will be solved by analyzing the design process, identifying its main shortcomings and methods for solving them.

The purpose of the course project is to consolidate the knowledge gained at lectures, practical exercises and acquire skills to fulfill the main stages of the development of the technological process and independently search for the most optimal technical solutions based on the latest achievements of science and technology.

Select how to obtain the workpiece

For manufacturing of part "GP drive shaft" the blank can be a forging obtained by method of hot volume forging on GKM and closed die.

Advantages of this method of obtaining a blank are:

The shape of the workpiece is as close as possible to the shape of the part;

High surface quality;

High physical and mechanical properties;

Easy production of the workpiece;

Disadvantages:

Expensive.

Alternative methods of obtaining a workpiece: A workpiece can be obtained using the slice from rolled stock method.

Disadvantages of this method:

Low material utilization for a given part design;

Large Machining Volume;

Long manufacturing time of the part;

Expensive.

Advantages

Easy to obtain a workpiece

Casting

Disadvantages:

high consumption of metal and molding materials;

large allowances on m/o;

large production areas;

large capital expenditures to create normal working conditions;

a significant number of marriages.

Advantages:

low cost

Conclusion: of the methods discussed above, the most rational method is to obtain a part by stamping on a GCM in a closed die.

Analysis of possible types and causes of damage or failure of the part. description of how to defect a part

In this part, damages such as:

- Wear of cylindrical necks for bearings;

- Bending and deformation of the shaft;

- Wear of teeth.

Damage of splines operation is related to their engagement with each other.

The reason for their failure can be insufficient lubrication of the contact surfaces, disruption of operation modes, high loads, rotation speeds, overheating, etc. Also hidden production defects, aging and fatigue.

Damages of the journal for the bearing are associated with violation of the manufacturing technology of the part, incorrect operation modes, incorrect fitting of the shaft bearings.

The bend is associated with a violation of bearing adjustments and gear engagement of the shaft, it can also be associated with an incorrect mode of operation of the part, the appearance of scratches, roughness, chips.

How parts are defected:

Neck Wear - Determined by measuring the dimensions, shape, and interposition of surfaces. In this case, we use calipers, micrometers, brackets, etc.

The bending of the shaft is determined on specialized stands with installation in centers using indicator heads.

Develop suggestions on how to restore part performance

By identifying possible damage to individual surfaces of the part and the reasons for their occurrence, it becomes possible to choose how to repair damaged elements.

To restore the necks for bearings, it is possible to use the following methods:

- surfacing (under flux, in the environment of protective gases, vibration, plasma arc);

- application of galvanic coatings (chrome plating, nickel plating);

-metallization (electric arc, gas, high-frequency, detonation, plasma arc).

It is also worth noting that in order to restore the above-mentioned surfaces, the use of methods of repair dimensions and additional parts is not possible due to minor differences in the diameters of neighboring necks and standardization of bearings and seals.

To eliminate the bending of the shaft, use the method of editing it on a special stand for editing and testing the shaft.

The choice of the particular recovery method depends on the nature of the surface damage. I.e. in case of minor wear, it is rational to use the method of metallization or electroplating. In case of significant damage, one of the metal surfacing methods is used. This is mainly due to the maximum thickness of the metal deposited.

Based on all these considerations, we accept a method of restoring the neck for bearings - chroming.

Part Recovery Process Development

The process of restoring the neck under the bearing by chromium plating.

When chroming, in addition to restoring the size of the surface, the internal structure of the metal of the part is not violated. Therefore, despite the complexity of the process, chromium plating is quite widely used in automotive repair production.

The chroming process can be divided into several stages:

1) Preparatory:

- Mechanical treatment of the surface to be restored (grinding and polishing, degreasing);

- Insulation of places not in need of restoration (application of trunnion on them);

-Installation of parts;

- Repeated degreasing (cleaning from contaminants, fats, etc.);

-Decapation - removal of the finest film of oxides (etching in a solution of sulfuric acid with washing in water);

2) Direct deposition of chromium on the surface;

3) Washing of parts first in distilled water (removal of electrolyte), then in hot water. Then removal from suspension, removal of insulation, quality control of applied chromium layer;

Final machining to give the reconstituted surfaces original dimensions and shapes.

For direct chromium plating, the following equipment is required: a galvanic bath with an electrolyte of the required density and concentration, a chromium plate, a current source, a device for hanging parts. As a result of chroming, the part returns operability.

Conclusion

During the course design, an analysis of the processability of the part-shaft structure, possible types and causes of damage and failure of the part was carried out; technological processes of part manufacturing and restoration have been developed; working drawings of the workpiece and part are made, allowances for mechanical treatment of the workpiece surface are assigned by the tabular method; selected cutting modes for turning, grinding, milling; technical rationing was carried out, as well as operational processing schemes were compiled.