Thesis in mechanical engineering technology

Contents

Introduction. Design Objective and Objectives

1 General section

1.1 Description of the machine, part structure assembly and its purpose in the assembly or machine. Part material and its properties

1.2 Part processability analysis. Quantitative and qualitative evaluation of processability

1.3 Selection of production type and optimal lot size

2 Process section

2.1 Selection and justification of procurement method

2.1.1 Feasibility study of the best procurement option (at CMM and cost)

2.1.2 Calculation of intermediate allowances and workpiece dimensions

2.2 Analysis of the factory process including its metrological control and compliance with the requirements of the ISO international standard

2.3 Overview of technical information on processing technology of similar parts

2.4 Development of the design version of the process and its feasibility study

2.4.1 Selection of processing route and its justification

2.4.2 Substantiation of selection of base surfaces, process equipment and equipment

2.4.3 Feasibility study of the adopted option

technical process

2.5 Detailed development of machining operations

2.6 Rationing of machining operations

2.7 Special part. Part handling at Hessapp DVT- lathe machining center

2.8 Album of process documentation

3 Design section

3.1 Machine Tool Design

3.1.1 Description of design and principle of operation

3.1.2 Calculation of clamping force, workpiece basing accuracy

3.2 Description and calculation of cutting tool

3.3 Description and calculation of measuring tool

4. Organizational and Economic Division

4.1 Calculation of equipment quantity and its loading

4.2 Calculation of shop area (area) and description of equipment layout

4.3 Calculation of the number of employees

4.4 Organization of workplaces and production maintenance

4.5 Calculation of FWP and average monthly salary

4.6 Part Cost Calculation

4.7 Determination of efficiency of proposed solutions and summary indicators of the designed workshop

5 Safety and fire safety

5.1 Identification of possible damaging hazardous and harmful production factors in the mechanical workshop

5.2 Development of measures to reduce the negative impact of hazardous and harmful factors and emergencies

5.2.1 Organization of microclimate at workplaces

5.2.2 Design of plenum and exhaust ventilation

5.2.3 Protection of personnel against mechanical hazards

5.2.4 Organizational and planning solutions of vibration and noise problems in the designed workshop

5.2.5 Electrical safety and fire safety measures in the shop

5.2.6 Disposal of production wastes. Environmental safety

5.2.7 Calculation of natural and artificial lighting in the designed workshop

6 General conclusions

7 Literature Used

Appendix A Process Kit

Appendix B Article

Appendix B Installation fixture specification

Appendix D Drilldown Specification

Appendix D Video Presentation (CD-R)

Summary

The explanatory note contains 157 pages, including 20 figures, 34 tables, 23 sources, 5 annexes. The graphic part is made on 10 sheets of A1 format.

This draft outlines the main provisions and calculates the mechanical workshop for the production of parts for tractor trailers. The process of the Hub part with a production volume of 30000 pieces per year has been developed in detail.

The project provides for the use of progressive high-performance equipment, a special device with a pneumatic clamp, the use of a combined tool for processing accurate holes. All this made it possible to reduce the labor intensity of the part, increase labor productivity and improve the quality of processing.

Introduction. Purpose and objectives of development.

The production efficiency, its technical progress, quality of products in many respects depend on the advancing development of production of the new equipment, machines, machines and devices, on every possible introduction of methods of the technical and economic analysis providing the solution of technical questions and cost efficiency of technological and design developments.

The importance of raising all these issues in the training of qualified personnel of production specialists who have fully mastered the engineering methods of designing production processes is obvious. In this regard, the final part of the educational process of higher educational institutions is graduate design.

Diploma design consolidates, deepens and summarizes the knowledge gained by students during lecture and practical classes in almost all disciplines mastered during their studies. Thesis is an independent creative work of a student and has the goal of teaching him to correctly apply the theoretical knowledge they received during his studies, to use his practical work experience to solve professional technological and economic problems.

In accordance with this, the following tasks are solved during the thesis:

rework of the drawing from the point of view of its processability;

determining the type of production, the timing of the production of parts and the quantity of the batch simultaneously launched for processing in the case of serial production;

Calculation and justification of procurement method;

technical and economic calculation of machining of surfaces;

calculation and design of the machine tool;

organizational and economic calculations;

development and consolidation of skills in conducting independent creative engineering work.

The thesis should reflect savings in labor costs, materials, energy, improvement of working conditions, compliance with environmental requirements. The solution of these complex tasks is possible only on the basis of the fullest use of the capabilities of progressive technological equipment and equipment, the economically justified degree of automation of design and production, and the creation of flexible technologies.

The main task is that when working on a diploma project, proposals are made to improve the existing technology, equipment, organization and economics of production, significantly ahead of the modern production process for the manufacture of the part for which the task is given. Therefore, in order to achieve this goal, it is necessary to study the progressive directions of the development of technological methods and tools and, based on the analysis and comparison of qualitative and quantitative indicators, to give their proposals.

In the degree design, considerable attention is paid to the economic justification of the methods of obtaining blanks for the choice of process options, etc., so that in the end the project proposes the optimal option.

2.2 Analysis of the factory process, including its metrological control and compliance with the requirements of the international standard ISO 9000

The workpiece of the hub assembly, in the basic process, is obtained by welding two parts - a bushing and a flange.

But since the "Hub" itself is a fairly simple unit, and the welding process is associated with the occurrence of residual stresses and metal warping, which will have to be eliminated by additional thermal operations and increased processing allowances, we consider it advisable, instead of a blank - an assembly unit, to use a blank - stamping obtained in a closed die on a crank hot stamping press

The process plan in repetitive manufacturing is developed in an expanded manner, that is, it is divided into separate operations with a detailed listing of the sequence of all work methods within each operation.

The factory technological process is executed by process documents of general and special purpose according to GOST 3.110274 (currently replaced by GOST 3.110281 AESTD. Stages of development and types of documents).

The roadmap is a required document. In the factory process, it is filled in accordance with the requirements of GOST 3.110574 (currently replaced by GOST 3.111882 AETD. Forms and rules for issuing roadmaps).

The roadmap contains a description of the manufacturing process of the Hub part, including control over all operations in the process sequence with information on equipment, accessories, tool, material and labor standards.

Sketch maps according to GOST 3.110574 are attached to the roadmap (currently replaced by GOST 3.110584 AETD. Form and Rules for General Purpose Documents), which are required to process the process, operation, or part manufacturing transition, including control.

Description of plant process:

Operation 05 Turning.

Equipment - Six-position turning and carousel machine. 1B284.

Item 1. Remove machined part. Install and attach the workpiece.

Item 2. Trim end 1 and end 2 at the same time.

Item 3.Sharpen ø1740.5. Remove chamfer 6x45 °.

Item 4. Bore ø120 + 0.5 by length 39. Sharpen ø1720.16.

Item 5. Bore ø124 + 0.16 by length 39.

Position 6. Trim the end of hole ø124 + 0.16, end ø250. At that maintain size 39 and size 6 with formation of groove b = 5, depth 1.5 and cut the hub end at the same time.

The following tool monitors surfaces:

brace 1720.16 (81135488);

plug 124 + 0.16 (PR 81405141, NOT 81405142);

caliber 6 ± 0.2 (81505038).

Operation 10 Turning.

Equipment - Six-position turning and carousel machine. 1B284.

Item 1. Remove machined part. Install and attach the workpiece.

Item 2. Cut the hub end to the size of 1210.2.

Position 3. Bore the hole ø110 + 0.87 on the passage.

Item 4. Bore the hole ø116 + 0.87, maintain the size 46.

Item 5. To chisel an opening of ø119+0.2, having sustained size 46, to chamfer 3.6х45 ° in an opening of ø119+0.16.

Position 6. Trim the hub end with dimension ø120 ± 0.43, trim the hole end with dimension 460.62 with formation of groove b = 5, depth 1.5.

The following tool monitors surfaces:

Caliper of ShTsII2500,8 of GOST 16680;

Caliper of ShTsIII2500,05 of GOST 16680;

pattern 460.62 (81026211);

plug 119 + 0.16 (PR 81405139, NOT 81405140).

Operation 15 Diamond boring.

Equipment - Diamond boring machine. OS 2706.

Install the part in the accessory. Pin.

1. Bore the hole ø

2. Bore the hole ø

Remove Part. Put on the conveyor.

The following tool monitors surfaces:

Plug (PR 81405075, NOT 81405076);

Plug (PR 81405043, NOT 81405044);

Ring for nutrometer ø120 (81255094);

Ring for nutrometer ø125 (81255095);

Rider 120/125 (87015057);

Nutromer 120 (87015028);

Nutromer 125 (87015028);

Reference for tuning (84505237).

Operation 20. Carousel.

Equipment - Carousel fashion machine. 1512.

Install the part in the accessory, attach.

1. Trim the flange end, withstand size ø1601 and size 15 ± 0.21.

Remove the part, put on the conveyor.

The following tool monitors surfaces:

Bracket 1601.0;

The caliper of SC is III1600,05 GOST 16680.

Operation 25. Assembly.

(See separate process plan)

Equipment - Press P2326.

Operation 30. Drill.

Equipment - mod drilling machine. SS 2157.

Install the part in the accessory. Pin.

1. Drill simultaneously 6 holes ø 22,+,0,052

Remove the part, put on the support.

Countersink 6 holes on both sides with pneumatic rail until blunting of sharp edges.

The following tool monitors surfaces:

Plug 22,+,0,052 (81335558)

Operation 35. Drill.

Equipment - Radial mod drilling machine. 2H135.

Install the part in the accessory. Pin.

1. Drill in sequence 3 holes ø 4.95 + 0.26;

Change Tool;

2. To chamfer in 3 openings it is consecutive 1х45 °

Change Tool;

3. Cut M67H thread in three holes in series;

Remove the part, put on the support.

The following tool monitors surfaces:

Plug M67N (PR 82210030 GOST 1775672, NOT 82211030 GOST 1775772)

From the viewpoint of correctly establishing a process sequence to achieve a given accuracy of the part, it can be said that the process is well constructed. Rough operations are performed on equipment other than the holes intended for finishing point. Machining of flange end to achieve runout tolerance relative to surfaces D and D is performed after machining of base surfaces or in one installation together with them.

The mismatch of the design and process bases is noteworthy, which leads to recalculation of the process dimensions of the part processing. For example, it is not possible to treat the flange end by holding the dimension 6 (actually holding the dimension 1203546 + 6 = 45). This inevitably leads to tighter manufacturing tolerances for the part.

Since the technological process was developed in relation to the large-scale type of production, the level of its technical equipment is very high: multi-spindle machines of the 1B284 model, a special machine OS2706 for the diamond boring operation, a special machine of the SS2157 model for drilling 6 holes ø22 are used. Devices (cams, supports, holders, etc.) are designed at each junction. A special drill drill tool is designed. Disadvantages include the absence of a cutting tool with a non-rolling replaceable working part, which can lead to frequent loss of working time for sharpening and re-fitting the cutting tool.

The disadvantages of the process include the treatment of all surfaces on 1B284 machines with the same cutting modes. This is due to the capabilities of the machine. I believe that the use of CNC equipment will make it possible to reduce the processing time of the part by using higher speeds for surfaces with a smaller diameter, for trimming ends and other transitions. Also in the process there are no cutting modes for drilling operations.

For size control, specialized measuring tools for calibrating, calibrations-staples have been developed. For more accurate control of finishing dimensions, indicator nutrometers with rings and a reference for tuning are used.

After analyzing the process, it can be concluded that the technology of manufacturing the Hub part is morally outdated, and it can be revised in relation to the modern level of development of machine-building production and metal cutting equipment, which will lead to a decrease in the cost of processing the part compared to the basic technology. It is also necessary to eliminate existing flaws in Job Instructions.

If we consider the basic technological process regarding compliance with the requirements of the ISO 9000 international standards system, it is regrettable that the basic enterprise is an organization with a conservative approach to the quality management system. This can be explained by the fact that the administrative and management system at the enterprise developed in the 1970s and due to crises and falling production volumes, a decrease in the level of demand for manufactured products, the introduction of new modern production methods was given too little funds and attention.

The ISO 9000 quality management system is part of the organization's management system, which aims to achieve results in accordance with quality goals to meet the needs, expectations and requirements of stakeholders. The ISO 9000 family of standards contributes to the design of a quality management system that is legalized internationally.

Unfortunately, in the USSR the definition of "qualitative" was replaced by another - "simple and reliable." When competing imported products appeared on the domestic market, many managers realized that quality requires special work. So there was a movement to introduce SUCP (product quality management systems), a five-year quality plan, and a "Quality Mark." However, by and large, this did not lead to anything. In technical departments, enterprise standards (STP) were created, which were then introduced into production. For its time, this was a progressive factor, since it was assumed that by describing and documenting production processes, it is possible to restore order and thus ensure product quality. However, this did not happen, and as is now clear, could not happen.

One of the reasons - the SUCP did not have a regulatory framework. STP was written by highly qualified specialists who knew well the production at their enterprise. Their ideas about what the technological process should be, and were the bar to which they sought to tighten production. It was not expected that the system would be checked by an independent party, since only in this case a regulatory framework would be needed.

Another reason is that the goal of the developers was to describe the correct and effective, in their opinion, technological process, and not to ensure the implementation of this process. In other words, SUCP was made "out of love for art," and not so that this system actually works. In the quality system based on ISO 9000 standards, the focus of the developers is on creating regulations that cannot be failed.

When analysing the conformity of the ISO 9000 LCS and SC in terms of quality system requirements, if the ISO 9000 IC requirements are taken as 100%, such items as :

Quality system to express customer-oriented quality policy;

control of the organization's management over quality assurance;

The regular evaluation by management of the effectiveness of the quality system;

regulatory framework of quality system documents;

ensuring the development of the quality system - the presence of an improvement subsystem ;

elimination of repetition of errors and inconsistencies in production; predicting possible errors and inconsistencies in the future and preventing them ;

prevention of inadvertent use of non-conforming products;

regular checks of quality system functioning;

the use of statistical methods to improve the effectiveness of the quality system;

cost-effectiveness of the quality system. Planning and accounting of quality assurance costs;

The guarantee of implementation of the system was not taken into account at all in the VCC and amounted to 0%;

quality as satisfaction of established and expected requirements of the customer - 20... 30%;

the quality system should be an organizational and management system - 70... 80%;

providing the quality system with all the necessary resources... 70 80%;

conformity of the quality explanation processes to the terms of the sub-contract (contract with the customer) - 30... 40%;

documenting quality assurance - 100%;

providing the customer with the opportunity to track the creation of products at all stages - 30... 40%.

Now in Russia there are about 2500 companies (2% of the total number of all Russian firms) certified in accordance with international standards ISO 9000. Unfortunately, the basic enterprise is not one of them.