Mechanical Shop Area Design for Worm Part

Contents

Introduction

Organizational Section

Purpose, device, principle of part operation

Constructability Analysis

Define Production Type

Process Section

2.1. Justification of procurement type and method

2.2. Calculation of allowances

2.3. Selection of equipment, cutting tools

2.4. Calculation of cutting modes and technical time standards

2.5. Procurement Processing Route

2.6. Means and methods of control

Design Section

Fixture selection, fixture calculation

Conclusion

List of literature

Task

For graduate design to a student "OKTU"

Zaitsev Vladimir Yuryevich

TM Group 41-17

Specialty "Engineering Technology" specialty code - 15.02.08

Project Theme: Mechanical Shop Run Design for Worm Part Machining.

Annual Release Program ______________________________

Source Data: Worm Part Drawing.

The degree project on this topic is carried out in the following scope:

Project Content:

A. Explanatory note

Introduction

1. General part

2. Process Part

3. Design part

4. Occupational safety at the enterprise

5. Process Documentation Package

6. Economic part of the project

B. Graphic part:

Part, Workpiece Drawing

Cutting Tool Drawing

Measuring tool drawing

Introduction

Increasing the efficiency of machine-building production, moving to market principles of farming, increasing competition involves expanding the range of products, reducing their number in the series. As a result, there is an increase in the number of enterprises and workshops focused on serial and small-scale types of production. The peculiarities of modern machine-building production, the desire for its intensification in conditions of frequent turnover of products put the task of reducing the time for the development of technological processes and improving the quality of design solutions to the fore.

Process design taking into account the nature of production and the operational possibility of adjusting the process depending on the change in the production situation largely determines the efficiency of the production system. The renewal of modern industrial potential should be carried out in the conditions of increasing financial equipment, technical re-equipment and modernization of production, accelerated renewal of fixed capital, reductions in the life cycle of new equipment, which entails reducing the time for its development and development, increasing the competitiveness of products. Such a strategy involves involving the scientific potential of the country, its scientists in the development of innovative projects.

This work is carried out on the basis of a comprehensive analysis, both of the design of products (parts) and the technology of their manufacture, starting with the selection of more progressive types of billets. Serious attention is paid to improving the quality of manufactured products, improving their reliability and durability.

The basis of the project is a detailed technological part. All other parts of the project shall be solved on the basis of data and process requirements.

Changing the process allows not only to improve the form of organization of production, but also in some cases to get a tangible effect from the introduction of new methods for obtaining the workpiece and processing the part.

General part

1.1. Purpose, device, principle of part operation.

A reducer is a mechanism consisting of gear or worm gears, made in the form of a separate unit and serving to transfer power from the engine to the working machine.

Worm gears are used to transfer motion between crossing (usually at right angles) axes. One of the significant advantages of worm gearboxes is the ability to obtain a large gear ratio in one stage (up to 80 in general-purpose gearboxes and up to several hundred in special gearboxes). These gearboxes have high smoothness and quiet operation and self-braking at certain gear ratios, which makes it possible to exclude braking devices from the drive.

Worm gear consists of worm and worm wheel. The worm is made of steel as a whole with a shaft (shaft - worm) by cutting, milling or rolling (in a hot state) with subsequent strengthening of the side surfaces of the worm turns. In the supports of the worm shaft, both roller conical single-row and ball radial - thrust single-row bearings can be installed. The worm wheel is an assembly unit consisting of a center and a gear rim. The rim is put on the center with interference, which is selected based on the condition that the torque is transmitted from the wheel. The wheel, in turn, is put on the shaft with interference (for better alignment), and the torque is transmitted to the shaft by a key connection.

Structural alloy steel 40X GOST454371 is used as material for the part considering the operating conditions.

1.3. Define the production type.

In accordance with the specified program for the production of 1000 parts per year and the mass of the part of 9.1 kg, we choose the serial type of production.

The serial production type is characterized by the following process parameters:

· Form of technological process organization - variable-constant;

· Output repeatability - batch repetition periodically;

· Process type - single;

· Procurement - casting, stamping, rolled stock;

· Equipment - universal, partially specialized;

· Equipment loading - periodic change of parts on machines;

· Arrangement of equipment in the area - during the process;

· Tooling - universal and special;

Based on the above, we will consider the project strategy to obtain an economic effect by reducing the piece time, presumably at the procurement operation, the introduction of a new method for obtaining the procurement; use of upgraded equipment.

Process Part

Justification of procurement type and method.

A workpiece is an object of production from which a part or an integral assembly unit is made by changing the shape, dimensions, surface roughness and material properties.

The procurement before the first process operation is called the original procurement.

The selection of the workpiece consists in establishing the method of its manufacture, calculating or selecting the allowances for cutting processing and determining the dimensions of the original workpiece.

The method of making the workpiece is determined by the shape and size of the part, the technological properties of the material, its melting point, structural characteristic (fiber direction and grain size). When selecting a workpiece, the material grade (rolled stock), the available equipment, the production program, the type of production, the degree of its mechanization and automation are taken into account. Optimal version of workpiece manufacturing is established on the basis of technical and economic calculations. Increasing the accuracy of the blanks (reduction of allowances) allows to save metal, reduce the cost and labor intensity of cutting, but at the same time the cost of producing the initial blanks can increase. With a small production program, the use of some workpiece manufacturing processes (hot stamping, etc.) may not be economically feasible due to the high cost of technological equipment and tooling.

The following types of procurement are most common:

- procurement from rolled stock and special profiles;

- cast blanks;

- forged and stamped blanks;

- combined blanks;

- blanks obtained by powder metallurgy method.

Billets from rolled stock

From high-grade round hot rolled stock, optimal blanks are obtained for the manufacture of stepped shafts with a small difference in diameters, axes, propellers, rods and other similar parts of extended cylindrical shape with any types of production.

Round, square, hexagonal, strip and sheet rolled stock are widely used in single production for the manufacture of parts of any configuration. Even with a low metal utilization rate, this is often more advantageous than using special methods for producing precise blanks that require complex, expensive tooling. Naturally, with a small volume of production, such equipment cannot pay for itself.

Pipe rolling is advantageous for the manufacture of hollow shafts, rings, cylinders, sleeves, etc.

The profile long products in the form of corners, channels are, etc. used for welded metalwork, frames, beds, cases, etc.

Cast blanks are used when:

- the material does not allow to obtain the workpiece in another way;

- at large dimensions of the workpiece, which cannot be obtained by other methods;

- if cast procurement is more profitable for economic reasons.

Casting in sandy-clay forms is used in all types of production, as it is distinguished by technological versatility. By this method, ~ 80% of all castings are obtained, and only 20% is accounted for by all other casting methods. In mass production, more accurate blanks obtained by machine molding according to metal models are used, in a single one - with low accuracy, when manual molding according to wooden models.

By casting into shell molds, blanks of complex configuration are obtained. They are much more accurate than castings obtained in sandy-clay forms, but require more complex equipment and therefore more expensive.

Forging and stamped blanks

Such blanks are used in the following cases:

1) For fabrication of blanks with large section difference (stepped and crankshafts, levers, etc.

2) At large dimensions of the billet exceeding the dimensions of the rolled stock.

3) To give high mechanical properties to particularly responsible parts.

Conclusion

1 The relevance of the problem is assessed, the purpose and objectives of the project are defined.

2. The service purpose of the worm has been evaluated, the workability of the part design has been evaluated.

3. The type of production and the form of organization of the technological process are defined.

4. According to the economic criterion, the method of obtaining the workpiece was chosen - stamping in GKShP. The mass of the billet has decreased significantly.

5. Based on the methods of part surfaces processing and developed a progressive technological route of its manufacture.

7. Improved worm cutter based on patent studies, due to which the quality of the machined surface was improved.

8. The worm processing area plan has been designed and equipment load factors have been calculated.

9. Hazardous harmful production factors of the facility, its impact on the environment, emergency and emergency situations are considered and measures to eliminate them are proposed.

The changes made to the technological process made it possible to fulfill the goal of the project and reduce the cost of manufacturing the worm, having an integral economic effect of 122 thousand rubles.