EXCHANGE RATE DESIGN OF MACHINE 6P81

Contents

Contents

INTRODUCTION

1. DETERMINATION OF MACHINE TECHNICAL CAPABILITIES

2. KINEMATIC CALCULATION OF MAIN MOTION DRIVE

2.1. Calculation of cutting modes

2.2. Development of structural formula

2.3. Structural Mesh Construction and Analysis

2.4. Electric motor selection

2.4.1. Mechanical characteristics of the electric motor

2.5. Plot and analyze rotation speeds

2.6. Selection of tooth numbers

2.6.1. Check of kinematic diagram

3. VERIFICATION CALCULATIONS

3.1. Calculation of the transmission module

3.2. Calculation of gears

3.2.1. Verification calculations

3.3.Compute shafts

3.3.1. Shaft Preliminary Calculation

3.3.2. Refined Shaft Calculation

3.4. Calculation of Keyway Connection

3.5. Calculation of spline connection

3.6. Calculation of bearings for durability

4. DESCRIPTION OF STRUCTURES AND PRINCIPLE OF MACHINE MECHANISMS AND SYSTEMS OPERATION

4.1. Spindle Assembly Design Description

4.2.Recipitation of manual control system design

4.3.Description of schematic electrical diagram

4.4. Lubrication System Description

5.TECHNOLOGY OF PART "GEAR WHEEL"

5.1. Part Service Assignment

5.2. Select Source Procurement

5.3. Selection of process bases

5.4. Generating Part Processing Route

5.5. Calculation and assignment of cutting modes

CONCLUSION

LIST OF LITERATURE

APPLICATIONS

Summary

This document is a report on the sequence of works carried out during the graduation qualification bachelor's work. It describes the main stages of designing the drive of the main movement of a horizontal milling machine with a table size of BxL= 250x1000 model 6P81.

The purpose of the work is to modernize the drive of the main movement with an increase in the speed of rotation of the spindle to 18, and to develop the processing process for the part "Gear wheel 6P81.20.13.024"

The design stages of the main motion drive include kinematic and power calculation of the machine drive, calculation of drive frequencies, plot of spindle rotation speeds, determination of wheel gear numbers, calculation of machine speed box shafts, selection of the engine, as well as selection and calculation of bearings.

The explanatory note contains 49 pages. Graphic part is executed on the 4th sheets of A1 format and one sheet A0x2.

The graphic part of the course project includes:

- kinematic diagram of the machine;

- main motion drive scanning;

- convolution of machine speed box;

- spindle speed switching mechanism;

- 1 sheet with adjustments for manufacturing of the part "Gear wheel 6P81.20.13.024."

Introduction

The metal cutting machine is the basis for building modern technological systems and automated production.

Modern metal cutting machines provide extremely high accuracy of machined parts. The critical surfaces of the most important parts of machines and instruments are processed on machines with an error in fractions of micrometers, and the surface roughness at diamond turning does not exceed one hundredths of a micrometer. Requirements for accuracy in mechanical engineering are constantly growing, and this, in turn, poses new tasks for precision machine tool building .

When creating machines, all the achievements of machine and instrument engineering, electrical and electronics, automation and computer science are used.

Finding new solutions to achieve performance, reliability leads to a frequent change in machine models. Therefore, the creators of new technology should use all the achievements of machine science, apply reference materials and standards to ensure the highest technical characteristics of the machine models created.

At present and in the foreseeable future it will be necessary to create new models of machine tools, machine modules, flexible production systems, so future machine tool builders should possess the basics of machine tools design and their critical components. For the successful application of computer technology in design, it is necessary to know the content of the design process of all types of machine equipment, to be familiar with the methods of its modeling and optimization. [4]

Description of design and principle of machine mechanisms and systems operation

4.1.Description of spindle assembly structure

The spindle is one of the most important parts of the machine. It is the last link of the gearbox carrying the workpiece or tools. Processing accuracy largely depends on it.

The front journal of the spindle is mounted and rotates in two ball radial thrust bearings 75 adjustable by a nut. The rear journal of the spindle is mounted on one ball bearing 74. Between the spindle supports on the cone and the key there is a flywheel with which a gear 35 is connected. Pulley 54 is mounted on a sleeve 40 mounted on a gear hub 32 mounted on separate ball bearings 71, whereby the spindle is unloaded from belt stress.

Rotation of the spindle is transmitted from the speed box by a V-belt transmission, which is located in the rear cavity of the bed under the cover. From a pulley 54 coaxial with the spindle, the rotation of the latter is communicated either by direct connection of their toothed coupling 70, or through two gears 3233 and 3435 .

Suspension. One or two suspensions can be mounted on the body of the spindle mandrel support machine.

Hollow spindle is mounted on two ball radial thrust bearings, between external rings of which washer is installed.

Preliminary tension in bearings required to increase system stiffness is created by nut. Covers attach external rings of bearings and simultaneously serve for labyrinth sealing.

4.2.Recipitation of manual control diagram design

The switching of the blocks 48 and 49 is performed by the drum-associated handle 47, on which a groove is formed on which the rollers 46 are moved and connected to the fork 38 by the moving block 49 and the fork 39 by the unit 48. The locking is effected by a spring 50 which presses the ball 52 against special slots.

4.3.Recipitation of machine circuit diagram

The following values ​ ​ of AC and DC voltages can be used on the machine: power circuit 3: ~ 50, 60 Hz - 220, 380, 400, 415, 440 V;

Control circuit ~ 50, 60 Hz; - 110V;

Local lighting circuit ~ 50, 60 Hz - 24V (lamp EL1);

Signal lamp circuit HL1 ~ 5V;

Power supply circuit of brake electromagnetic coupling YC5 24V.

Electric cabinet is fixed on the left side of machine bed, its body is connected to the base of machines by grounding bus. Electric cabinet door is closed by turning of handle connected in locking circuits by lever

input circuit breaker. When the door is opened, the electrical circuit of the machines is automatically disconnected from the power supply network. For inspection and adjustment of electrical equipment under voltage, the electric circuit can be connected with a handle when the electric cabinet door is open.

The machine is connected to the mains by the input circuit breaker QF1. The direction of rotation of the spindle is selected by the reversing switch QF4. If cooling liquid is used in operation, the M3 electric pump is prepared by the QF3 switch, after which it is switched on simultaneously with the spindle motor M2.

Actuation of the M1 spindle drive motors and the M2 feed drive is performed by separate buttons SB1 u SB2 using magnetic starters KM1, KM8 and KM2 in the following sequence: first, the M1 motor and then the M2 motor.

When the motor M1 is not in operation, the motor M2 is not switched on.

Button SBt is intended for short-term actuation of motor M1 in order to facilitate speed switching. When the SBt button is pressed, the magnetic starters KM1 and KM8 (one or both of them) are activated via the circuit SBt (811) -KT (1110) - coils KM1 and KM8. The magnetic starters KM1 and KM8 with contacts (8-9) turn on the CT relay, which will turn off the starters KM1 and KM8 with its contact (1011).

Thus, work duration elektrodvigatelyam1 does not depend on duration of pressing of the SBt button.

All engines stop both when SBc "common stop" button is pressed and when KM5 push-button switch is actuated.

Braking of spindle drive after power supply of M1 motor is performed by brake electromagnetic clutch. Power is supplied to coupling coil from selenium rectifier

VP by circuit: contacts of KM1 magnetic starters (2425) and contact of CT relay. Time of the brake coupling under voltage is determined by setting of CT time relay.

Zero protection of machine motors is provided by magnetic starters. Protection of electrical components from damage in case of short circuit is performed automatically by QF1 switch, as well as FU1 u FU2 fuses.

Protection of electric motors against overheating in case of long-term overloads is provided by KK3KK6 thermal relay .

Selection of process bases

The development of the technological process begins with the search for similar technological processes, the choice of a rational method for the manufacture of parts (elements) and the assembly of products, the development of new technological processes. Decisions are made on the organization of specialized production sites, production lines, flexible automated production facilities, on the development of technological layouts of workshops and sites.

The route of the part passing through the workshops is drawn up, starting from the receipt of the workpiece until it arrives at the central picking warehouse or at the assembly workshop. The route is drawn up on the basis of the current standard and group technological processes, taking into account the load of equipment and the volume of product production.

The technologist who develops the technological process determines the type and method of procurement, selects technological bases, sequence and content of technological operations. The next stage is the rationing of technological operations of the production process and the determination of professions or qualifications of performers. At the same time, work is underway to calculate material resource consumption rates.

A list of material standards for the product as a whole is then drawn up, which is transferred to the logistics department to ensure that the necessary materials are produced.

Generating Part Processing Route

The manufacturing process of the "Gear Wheel" part is developed on the basis of the composition of elementary technological operations, each of which can be obtained on the basis of combining typical processing routes of the workpiece surfaces performed in one or two installations.

Merging of transitions into plants and operations is carried out taking into account typical manufacturing processes of parts of this class ,

basic route of this part processing, as well as taking into account selected schemes of workpiece installation on the machine and technological possibilities of several transitions on equipment of the selected type.

Based on the combination of elementary transitions into installations and operations, a part processing route is formed, which is presented in the applications. and in the annex to the calculated explanatory note in the form of a process roadmap.

Conclusion

During the final qualification bachelor's work, the necessary calculations were made when designing the given technological metalworking equipment (machine); existing designs of similar machines were analyzed and a prototype machine was selected from them. They also substantiated the technical characteristics of the machine; kinematic calculation of the main motion drive and calculation of the main parts of the drive; selected the spindle assembly scheme and calculated its main parameters.

According to the calculated data, the convolution and scanning of the speed box, the spindle unit, were drawn. The general view of the designed machine is taken as the general view of the prototype machine.

Developed the technological process of manufacturing the part "gear wheel"; calculated cutting modes for each operation of manufacturing the part "gear wheel" and consolidated all this into job instructions. Designed adjustments for lathe and denture operations.