Recovery of YaMZ-236 crankshaft

Contents

Contents

Introduction

1. Calculation and processing part

1.1 Initial data

1.2 Analysis of part defects and selection of their detection methods

1.3 Selection of rational ways to eliminate defects

1.4 Operation sequence and development of part recovery process

1.5 Calculation of the quantity of parts in the batch

1.6 Calculation and development of roadmap

1.7 Calculation of processing modes and technical time standards

1.7.1 Technical normalization of works on restoration of connecting rod and main journals of engine crankshaft

1.7.2 Technical normalization of surfacing works for restoration of connecting rod and main journals of engine crankshaft

1.7.3 Rationing of works on metal cutting machines (rationing of turning operations)

3. Design Part

3.1 Purpose of device and operation principle of accessory

Conclusion

List of literature

Introduction

To restore the working capacity of worn-out parts, 5-8 times less technological operations are required compared to the manufacture of new parts. According to GOSNITI, 85% of the parts are restored with wear of no more than 0.3 mm, i.e. their operability is restored when applying a coating of insignificant thickness. However, the life of restored parts compared to new ones, in many cases, remains low. At the same time, there are examples where the resource recovered by progressive methods is several times higher than the resource of new parts.

The basis for improving quality is the use of advanced technologies for restoring parts. When restoring engine crankshafts, there is a need to find new, more progressive methods of restoration that could increase the life of parts at a relatively low cost.

The company plans to repair 11,000 crankshafts in 2013. The purpose of the course work in the educational discipline of repair of cars and engines is:

consolidation of theoretical knowledge and acquisition of practical skills on assessment of technical condition (defects) of repair stock.

Coursework tasks:

disassembling recovery routes.

Select how to restore parts.

selection of necessary equipment and justification of rational operating modes on it.

normalizing part repair operations.

Calculation and development of roadmap

The technological process being developed should be progressive, ensure increase of labor productivity and quality of parts, reduction of labor and material costs for its implementation, reduction of harmful effects on the environment.

Basic initial information for process design are: detail drawings, technical requirements governing accuracy, surface roughness parameter and other quality requirements; Volume of annual production of products, which determines the possibility of organization of in-line production.

To develop the part processing process, it is necessary to preliminary study its design and functions performed in the assembly, mechanism, machine, analyze the processability of the design and check the drawing.

Routing technology is developed by choosing technological bases and baselines for the entire technological process. Two base systems are selected: main and black bases used for basing in processing main bases.

According to the data calculated in paragraph 1.7, we accept the data for the roadmap, which is shown in A1.

Calculation of processing modes and technical time standards

When selecting equipment for each process operation, it is necessary to take into account the purpose of processing, the overall dimensions of the parts, the size of the batch of processed parts, the location of the processed surfaces, requirements for the accuracy and quality of the processed surfaces.

Abrasive treatment is most often used to treat parts reclaimed by a coating under a flux layer.

A universal fixture is used for checking and editing. The bend is controlled on the manual or hydraulic press until the defect is eliminated. A radial run-out detection machine is used for monitoring.

For grinding the necks, round grinding machines 3A432 with grinding wheels 15A40PST1X8K are used. The dimensions are controlled by a micrometer with a fission price of 10 μm.

Conclusion

In the process of course work, knowledge in the discipline was deepened and consolidated. A calculation was made for a certain task and practical knowledge was obtained on the design of the process of restoring a car part. In accordance with the heading task, the process of restoring the YaMZ236 crankshaft was developed and the necessary technical equipment was selected, as well as the modes and time standards for mechanical processing were calculated.