Course project in the discipline "Machinery and equipment repair technology"

Contents

1 FEATURES OF PART DESIGN

2 PATENT ANALYSIS OF ROTOR AXLE REPAIR TECHNOLOGIES

2.1 Patent No. 139386 Mechanism for Vibration Generation of Welding Electrode during Automatic Vibration Surfacing and Welding

2.2 Patent No. 149167 Method of vibration-medium surfacing

2.3 Patent No. 1119638 Electromagnetic vibrator for vibration surfacing

3 MECHANICAL PROPERTIES OF PART MATERIAL

4 SELECTION OF RATIONAL METHODS OF RESTORING PART AND INSTALLATION BASES

4.1 Wear of landing surfaces

4.2 Thread Wear

5 PREPARATION OF PROCESS OPERATIONS PLAN WITH SELECTION OF EQUIPMENT, ACCESSORIES AND TOOLS

6 CALCULATION OF CUTTING MODES BY OPERATIONS

6.1 Calculation of processing allowances

6.2 Calculation of cutting modes at turning (turning of surface for thread after surfacing)

6.3 Calculation of grinding cutting modes (grinding of bearing surface A before surfacing)

6.4 Calculation of cutting modes during surfacing

7 TIME RATIONING, PART REPAIR COST DETERMINATION

7.1 Calculation of lathe time

7.2 Calculation of time for surfacing operation

7.3 Calculation of Grinding Time

8 PREPARATION OF DOCUMENTS OF A SINGLE TECHNICAL PROCESS

9 ACCESSORY FOR WORKS PERFORMANCE

10 SAFETY AND ENVIRONMENTAL SAFETY DURING WORKS

CONCLUSION

LIST OF LITERATURE

APPENDIX A

Introduction

Car repair production in industrial potential occupies a significant place. The purpose of car repair in the national economy can be formulated as follows: to ensure the maintenance of cars in working condition, to reduce the rate of elimination of effective equipment from the field of consumption and to satisfy consumers in equipment, if necessary, due to partial reproduction of it by repair methods.

However, the existing technical level of repair production hinders the development of vehicles due to the poor quality of repairs and, as a result, relatively high costs for subsequent operation (units) compared to similar costs of the pre-repair period.

The quality of repair of car units can be estimated by comparing the pre-repair and inter-repair operating hours.

Repair efficiency is also determined by the choice of the optimal repair strategy, the choice of optimal solutions in the field of technology, organization, management, ecology, sociology and repair economics.

In order to effectively manage such a large field of activity as automotive repair, it is necessary to rely on modern scientific knowledge and have a well-organized engineering service, in which engineers with special education and perfect knowledge of both theory and the skills of organizing car repairs capable of carrying out scientific and technological progress must work.

Mechanical properties of part material

The axis of the rotor of the SMD14 engine is made of steel 45.

Steel 45 relates to high-quality carbonaceous steels. These steels (GOST 105074) are smelted under strict conditions with respect to the composition of the charge and smelting and casting than ordinary quality steels. They are subject to higher requirements for chemical composition and structure: content, as well as fewer non-metallic inclusions, regulated macro and microstructure.

High-quality carbon steels are marked with numbers 08, 10, 15, 20,..., 85, which indicate the average carbon content in hundredths of a percent.

Steel 45 refers to medium carbon steel (), it is applied after normalization, improvement and surface hardening. This steel in normalized state compared to low-carbon steel has higher strength at lower ductility (). Steel in annealed condition is well treated by cutting. After improvement, the steel 45 has the following mechanical properties: Hardenability is small: the critical diameter after hardening in water does not exceed 1012 mm (95% martensite). Therefore, it should be used for parts that do not require great hardenability. To increase hardenability, steels are usually alloyed with manganese (40G, 50G).

6 CALCULATION OF CUTTING MODES BY OPERATIONS

Calculation of processing allowances

Based on the available defects and the assigned repair operations of the CMD14 rotor axis, we accept the following allowances:

- allowance for surface A grinding before surfacing a = 0.14 mm;

- allowance for surface B grinding before surfacing a = 0.19 mm;

- allowance for surface A grinding after surfacing a = 0.25 mm;

- allowance for surface B grinding after surfacing a = 0.25 mm;

- allowance for surface turning for thread before surfacing a = 0.35 mm;

- allowance for surface turning for thread after surfacing a = 0.8 mm;

- allowance for thread cutting by cutter a = 0.23 mm.

Preparation of documents of a single technical process

The main document of technical documentation is the roadmap, which indicates all operations and transitions, as well as equipment, accessory, cutting and measuring tools, number of workers. Profile and dimensions specified.

The route chart of technological process of repair of an axis of the rotor of the SMD14 engine of representation in appendix A.

The second process document is an operating map. It indicates transitions to one operation, indicates its number and material of the workpiece, its mass and hardness of the part. A cutting tool and a measuring tool are specified for all transitions. In addition, calculated dimensions, cutting depth number of passes, spindle rpm and speed of processing modes are calculated. Machine and auxiliary time calculated. Operating cards are drawn up respectively for lathe, surfacing and grinding operations.

Operational maps are presented in Appendix A.

The sketch map is shown on the first sheet A1 of the graphic part of the course work.

Conclusion

During the course work, the recovery technology of the SMD14 engine orphan was studied. The course work provides brief information on the details of its working conditions, the equipment for restoration is given.

The methods in question for restoring the engine part allow to locally and quickly eliminate most types of wear on the part. Equipment for the technology of vibration surfacing is constantly being modernized and improved, so this equipment is widely used in production and repair sites.

Coursework develops students' ability for logical thinking and self-development, the student acquires the skills that he will need in subsequent work in an engineering specialty.