Milling device within the framework of the diploma project

Contents

Contents

Introduction

1. General part

1.1. Formulation of the purpose and objectives of the work

1.2. Operating modes of the enterprise and time funds

1.3. Define Production Type

1.4. Release Program Calculations

2. Development of worm manufacturing process

cylindrical reduction gear box

2.1. Service purpose of worm worm - cylindrical reduction gear box and

its surfaces

2.2. Critical review of worm specification -

cylindrical reduction gear box

2.3. Worm Specification Wording -

cylindrical reduction gear box

2.4. Methods of inspection of technical requirements for worm worm -

cylindrical reduction gear box

2.5. Analysis of workability of worm design

cylindrical reduction gear box

2.6. Select the type and form of organization of worm manufacturing processes

worm-cylindrical reduction gear box

2.7. Select the original workpiece and how to obtain it

2.7.1. Select Source Procurement

2.7.2. Select a forging method

2.8. Process basis selection and sequencing

worm treatment of worm-cylindrical reduction gear box

2.8.1. Analysis of basing options

2.8.2. Determining the Sequence of Worm Surfaces

worm-cylindrical reduction gear box

2.9. Select Processing Methods and Define Number of Transitions

2.10. Worm manufacturing process route -

cylindrical reduction gear box

2.11. Calculation of allowances, cross dimensions and tolerances

2.12. Equipment refinement

2.13. Selection of process equipment

2.13.1 Selection of accessories

2.13.2.Rectification of cutting tool

2.14. Selection of process lubricants

2.15. Calculation of cutting modes

2.16. Rationing of Manufacturing Process Operations

worm worm - cylindrical reduction gear

2.17. Process Mapping

2.18. Dimensional Analysis

3. Process Tooling Design

3.1. Service purpose of the accessory

3.2. Calculation of fixture

3.2.1. Defining Cutting Forces and Moments

3.2.2. Calculation of clamping force

3.2.3. Determination of initial force and diameter of pneumatic cylinder

3.3. Development of technical requirements for the accessory

3.3.1. Selection of calculated parameters

3.3.2. Determination of calculation factors

Bibliographic list

Application

Application

Paper

p. 87, Table 10, il. 4

PROCESS, MECHANICAL PROCESSING, PART, BASING, BILLET, ACCESSORY, DIMENSIONAL ANALYSIS, WORM CYLINDER REDUCTION GEAR, ROUTE, ALLOWANCE, CUTTING MODES.

In the final qualification work, the technological process of machining the worm of the worm cylinder reduction gear was developed.

Introduction

In modern Russia, the engineering industry continues to be one of the leading, as well as strategic areas of development. The machine-building complex is leading among intersectoral complexes and reflects the level of scientific and technological progress and defense capabilities of the country, as well as determines the development of other sectors of the economy.

To increase the competitiveness of domestic engineering products, it is necessary to create conditions for the introduction of the most modern technologies into production, to widely use automation tools, to update the fleet of equipment with high-performance machines.

This work reflects the process of technological preparation of worm-cylindrical reduction gear. Decisions were made on the use of high-performance CNC equipment in certain operations: at the milling and centering operation, the XZK 8230-3000 CNC machine; on lathe operation machine 16K30F3 with NC; on the circumference of the grinding operation semi-automatic 3U142. Cutting tool with quick-change plates made of hard alloy is used. And also designed universally - adjustment device with a mechanized drive. These measures increase productivity, reduce the time for auxiliary actions, which ultimately has a positive economic effect.

General part

1.1. Formulation of the purpose and objectives of the work

The purpose of the graduation qualification work is:

- technological preparation of worm of worm-cylinder reducer;

To achieve this goal, the following objectives must be achieved:

- develop the process of worm manufacturing of worm-cylinder reducer;

- universal - adjustment device is designed.

1.2. Operating modes of the enterprise and time funds

For this work, a single-shift mode of operation is adopted, the actual fund of equipment operation is adopted equal to 2040h [1]. For 36 hour working week and 36 vacation days, the effective annual working time fund is 1520 h [1].

1.3. Define Production Type

Worm weight of worm-cylinder reduction gear is 112 kg, annual release program Ngod = 1500 pcs.

According to [1], with the weight of the product > 10 kg and the annual production program in the range from 500 to 1000 pcs, the average production type is selected.

Process Development

2.2 Critical analysis of technical requirements for worm worm - cylindrical gear box

Comparing the technical requirements in the drawing and the technical requirements arising from the service purpose of the surfaces of the worm worm - cylindrical gear box, it is concluded that all the basic requirements have been highlighted, additions and modifications to their list are not required.

2.3 Worm-Cylinder Gear Worm Specification Wording

When manufacturing worm worm-cylindrical reduction gear, it is necessary to provide the following technical requirements for location:

- coaxiality of a surface 1 with a surface 4, T=0.008 of mm [8];

- coaxiality of a surface 3 with a surface 4, T=0.010 of mm [8];

- coaxiality of a surface 6 with a surface 4, T=0.020 of mm [8];

- coaxiality of a surface 7 with a surface 4, T=0.020 of mm [8];

- coaxiality of a surface 8 with a surface 4, T=0.008 of mm [8];

- perpendicularity of a surface 5 to a surface 4, T=0.020/of Ø140mm [8];

- coincidence of an axis of symmetry of a shponochny groove 9 with an axis of a neck of a shaft 8, T=0.1 of mm [8];

- parallelism of an axis of symmetry of a shponochny groove of the 9th axis of a neck of a shaft 8, T=0.025 of mm [8];

The remaining location specifications are reflected in the part drawing.

2.5. Analysis of workability of worm-cylindrical gear box design

The worm-cylindrical gearbox was considered as an object of design, manufacture and operation for the analysis of processability of the design. During the analysis, the part revealed the following characteristics:

1. The design is noted for the simplicity of the design shapes. It lacks complex shaped surfaces, with the exception of the executive surface - turns of the worm. The remaining surfaces are a set of simple geometry that allows you to draw a part with all features in one master view.

2. The part has a minimum number of machined surface views and geometric dimensions. There are no irrational structural elements in the design, and there is also unification of the grooves for the exit of the grinding wheel.

3. Worm design corresponds to the most probable type of workpiece at the specified method of its production. The structural shapes and dimensions of the part allow you to assign allowances and allowances with a minimum metal consumption under the conditions of the selected method of obtaining the workpiece.

4. When manufacturing a part, it is possible to apply industrial methods of machining and use high-performance equipment.

5. Most surfaces are provided with cutting conditions (there are no structural elements that prevent or hinder the cutting of the tool) and the exit of the cutting tool (grooves are provided for the exit of the grinding wheel both along the cylindrical surface and at the end; groove for threaded cutter outlet complies with the standard). The exception is the recess from the collar to the beginning of the helical line.

6. Surfaces and features are provided with good access to control geometric shapes and dimensions.

7. For ease of basing, center holes are provided at most machining operations, this allows you to fulfill the conditions of the principle of base unity.

8. The worm has a design of sufficient rigidity - the ratio of length l = 906 mm to the largest diameter d = Ø192 mm is 4.6. Therefore, there is no need to establish additional supports (lunettes) during machining.

9. When assigning tolerances and surface roughness parameters, economically achievable parameters were adopted. Increased quality requirements are present only in critical surfaces, which allows you to optimize the cost of machining.

10. Lifting devices are required during maintenance and repair.

Analyzing the given properties of the worm design of the worm-cylindrical reduction gear as an object of design, production and operation, it is concluded that the design as a whole is technological and it is not required to make changes to it.

2.6. Selection of type and form of organization of worm manufacturing processes of worm-cylindrical reduction gear box

With the annual production program Ngod = 1500 pcs and the production program according to the unchanged drawings N.h.h. = 4500 pcs in the conditions of serial production, the most suitable options are the variable-flow form and the form of organization by the proximity of the service purpose of the manufactured parts. Variable - in-line production differs in that the processing time of parts in operations is equal or multiple of the production cycle, and the machines are located along the process. Due to the inability to reconcile the production cycle with the time of each operation, the use of the variable-flow form of the production organization is excluded. The form of organization by proximity of service purpose of manufactured parts is accepted.

2.7. Select the original workpiece and how to obtain it

2.7.1. Select Source Procurement

The part is a stepped shaft, which makes it possible to make a blank in the form of rolled stock or forging. Selection of stock from rolled stock reduces the labor cost of the procurement operation, since it does not require the production of expensive tooling in the conditions of serial production (Ngod = 1500 pcs). Due to the significant difference in diameters Ø192/Ø90 at a length of 906mm, a significant part of the metal will waste, which makes this type of initial workpiece irrational, the material of the Steel 40X workpiece. Selecting a workpiece as a forging allows you to assign minimal allowances and significantly reduce the metal consumption and labor costs of machining .

The analysis of the above data allows us to conclude that the most rational choice of the original stock will be forging.

Process Tooling Design

3.1. Service purpose of the accessory

Universal - adjustment device serves for installation of worm worm - cylindrical reduction gear at milling of keyway 25P9 and slot for locking ring 10H11 on vertical milling machine 6A59. The following technical requirements shall be met during manufacture of the article:

- coincidence of an axis of symmetry of a shponochny groove 25P9 with an axis of a neck of Ø90k6, mm T=0.1;

- parallelism of an axis of symmetry of a shponochny groove 25P9 of an axis of a neck of Ø90k6, mm T=0.025;

Accessory is intended for operation under the following conditions:

- air temperature 10... 50 ° С

- air humidity 40... 90%

- dust content 3-5 g/cm

Taking into account the production type, the device is provided with a power drive for clamping the part, made as a pneumatic cylinder, connected by means of a tie-rod with a tack. Installation elements in the accessory are prisms fixed on the table with T-shaped slots, which provide basing of the part along its axis. Stop is applied to the right end face.

3.2. Calculation of fixture

To form the arrangement of the device, the cutting force, the clamping force and the initial force of the pneumatic drive are calculated.

3.2.1. Defines the cutting forces and moments.

When machining this part, the maximum cutting force and moment occur when milling the keyway 25P9, and further calculation is carried out on it. As a result of calculations of cutting modes, the following values ​ ​ were obtained for milling of slot 25P9:

Smin = 40 m/min

V = 39m/min

n = 500 rpm

Pz = 1555 N

When milling the slot with a key mill, the force Pz has the following components:

RN = (1,1.1,2) Pz=1788.25 H.

PV=(0,2..0,3) Pz=388,75 Н.

5 ВАТМАН.cdw