Exchange rate project for MC

Contents

Contents

Introduction

1. Preselect Base Machine Model

2. Definition of main technical characteristics

2.1 Determination of control range

2.2 The purpose of the value a

2.3 Determination of number of switches

2.4 Selection of normalized set of rotation frequencies

2.5 Determination of electric motor power

2.6 Design of kinematic diagram of the drive

2.7 Determination of number of teeth of single and group gears

2.8 Check of correct calculation of tooth numbers

2.9 Kinematic diagram of the gearbox

3. Preliminary calculation of drive parts

3.1 Determination of gear wheel parameters

3.2 Determination of shaft diameters

3.3 Shaft check calculation

3.4 Calculation of bearings

3.5 Spindle hardness calculation

3.6 Spindle Strength Calculation

3.7 Calculation of pump capacity and lubrication system

3.8 Calculation of splined joints

4. Description of tool auto-clamping mechanism operation

Conclusion

List of literature

Introduction

Metal cutting machines with their high productivity, accuracy and versatility are the main type of technological equipment for measuring parts.

With the wide use of aggregation and unification principles, metal cutting machines can be combined into automatic machine lines and automatic machine systems with the implementation of the principles of numerical software control and direct control from electronic computers.

Modern metal cutting machines are diverse and advanced working machines, including a large number of mechanisms and using mechanical, electrical, hydraulic and other methods of movement and cycle control.

Currently, the machine-tool industry provides machine-building with all the necessary types of modern high-performance machines.

The designs of the machines created should be promising. When developing a new machine, it is necessary to lay down in the project a certain margin of excellence and novelty of the solutions of its main elements compared to the already known ones. When creating a new machine, we should strive to reduce the design and development time of its production.

The main tasks of machine tool building:

Further automation and creation of high-performance machines - the creation of automatic machines and automatic lines, machines based on new technological processes with high productivity and the use of high-speed processing methods, CNC machines, machines convenient for installation into automatic lines, universal machines with automation of auxiliary and control operations.

Increase of accuracy, vibration resistance, durability, increase of machine performance

Increasing the efficiency of machine tools - cheapening their production and design, reducing the weight, occupied areas, using unified units and parts, using new materials, including plastics, creating more technological structures.

Systematic renewal of the machine fleet - replacement of obsolete models with more advanced ones, expansion of the machine type with an increase in the size of progressive groups and machines created on the basis of technological processes, equipment modernization.

Currently, one of the most important technological operations is milling. There are a large number of machines on which the following operations can be carried out:

milling of flat surfaces and ledges;

milling of key slots on shafts;

milling splines on cylindrical and conical surfaces;

milling various grooves;

milling of T-shaped slots and dovetail slots;

milling of spur gears;

milling of shaped surfaces;

In the task given to me, it is necessary to design the drive of the main movement of the vertical milling machine with the dimensions of the working surface of the table 320 × 1250 mm.

Machining of parts on machines is carried out by end, tail, finger cutters and milling heads in conditions of individual and serial production.

Such machines may have a swivel head which allows for the treatment of inclined planes without the use of special devices.

Also, machines of this type can be included in the automatic line, since they have automatic control elements of the machine.

The purpose of this course project is to deepen the knowledge gained from the course at lectures and in the laboratory, and acquire skills in calculating and designing machine tools.

Conclusion

The task for my course project was to design a speed box of a vertical milling machine with a table size of 320 × 1250 mm.

The purpose of this course project is to improve the machine design in order to increase processing efficiency, as well as reduce the cost of the machine. The goal is also to deepen knowledge and skills in the design of complex structures.

To achieve these goals, the following tasks were solved in the design of the speed box:

1. The kinematic scheme of the main motion drive is designed.

2. The main parameters of the KS gear wheels, as well as the diameters of the shafts, are determined.

3. Check calculations of drive parts (bearings, spindle, splined joints, shafts) were made.

4. The following improvements were introduced into the machine design:

- in the rotary head there are screws that press the semi-rings, which are designed to adjust the tension in the bearing, and prevent their departure at high RPM of the spindle.

In the spindle structure, a tool auto-clamping mechanism is provided, which accelerates and facilitates the mandrel clamping process and reduces processing time.

- an increase in the number of revolutions of the intermediate shafts allowed to reduce the loads on the shafts and gear wheels.

5. In order to ensure a temperature in the COP not exceeding 60 °, a number of technical requirements were provided:

- splined joints were used to improve the centering of the wheels on the shafts, which led to an increase in the accuracy of the gears, which means an increase in efficiency and a decrease in temperature in the CC.

- due to the increase in circumferential speeds of the wheels, it is recommended to use oil with low viscosity to lubricate the combustion chamber.

- in the speed box, it is recommended to use gear wheels of 6 degrees of accuracy.

- tolerances are provided for non-parallelism of shaft axes in the combustion chamber, which make it possible to reduce inaccuracy of engagement of gear wheels.

Terms of Reference

Name, purpose, and scope of the design object.

The designed machine refers to vertical milling machines with a table working surface size of 320 × 1250 mm.

Applications of this type of machine:

milling of flat surfaces and ledges with end and end cutters;

milling of key slots on shafts;

milling of T-shaped slots and dovetail slots;

milling splines on cylindrical and conical surfaces;

milling various grooves;

milling of spur gears;

milling of shaped surfaces;

The field of application of vertical milling machines is very wide, but mainly they are predominantly used in machine-building plants and are cost-effective in conditions of serial and small-scale production.

The advantage of machines of this type is the presence of a rotary head, which allows to process inclined planes without the use of special devices.

Basis of Design

The curriculum of the VF GOU VPO IzhGTU specialty 120100 "Engineering Technology," a course project for the course "Metal Cutting Machines."

Project Objectives:

Improve the machine design to increase productivity and reduce cost.

Improving the working conditions of the main workers and maintenance personnel, including through the use of mechanisms with numerical program control.

Project Tasks

Development of a technical specification for the design of a new model of a vertical milling machine with a table size of 320 × 1250 mm .

Calculation of the main motion drive and design of the main unit of the machine - the speed box.

Assignment of technical requirements for assembly and adjustment of the designed assembly based on the condition of oil temperature in the crankcase not more than 60 ° С.

For an NC machine variant, provide a technical proposal for the mechanism design for automatic tool change.

Design Sources

Reference literature on metal cutting machines of the milling group (libraries of the VF IzhGTU, FSUE "VZ")

Reference Literature for CNC Metal Cutting Machines

Literature regulating the design documentation: AETD, ESDP and AETPP

Technical requirements

Provide axial clearance in bearings of intermediate shafts not less than 0.005 mm, in bearings of spindle shaft not less than 0.003 mm.

Ensure optimal position of contact spot: not less than 0.75 of total length of contact line, gears of blocks and gears

After assembly, roll the box in the following mode:

- run the speed box without load for 3 hours and change the oil.

- roll the box for 2 hours at load 30% from nominal one and change the oil.

4) Ensure non-parallelism of shaft axes in speed box not more than 0.01 mm.

5) Accuracy of gears not lower than 6-7 class.

6) To lubricate the speed box, it is recommended to use oil with low viscosity, for example, Industrial 20 GOST 170751.

7) The speed box shall be assembled and adjusted at ambient temperature not lower than 150 С and not higher than 250 С.

8) The design of the machine shall make it possible to change the value of speeds and supplies from the force on the handles not more than 2 kg. With reliable fixation in each position.

Stages and stages of development

Design Specification Development

Overview of existing machine models - analogues

Analysis of cutting modes for the selected manufacturing type

Kinematic calculation and construction of kinematic diagram of the designed drive

Determination of engine power

Preliminary calculation of drive parts

Selection and justification of design of mechanisms and parts of designed assembly and selection of materials of parts

Check calculations of drive parts

Description of operation of the unit and individual mechanism systems

Lubrication system calculation

Technical proposal for development of tool automatic clamping mechanism.

Completeness of developed documentation

Graphic part:

1. Node sweep - gearbox

2. Swivel head

3. General view and kinematic diagram of the machine

4. Elements of automatic clamping mechanism.

Calculation and explanatory note:

The contents of the main sections of the explanatory note shall reflect the main design stages specified in item 7. of the present TA.