Development of the main movement drive of the milling machine to the CNC under the control of the SINUMERIC 820 C system

Contents

Introduction

Main part

Development of a scheme for driving the main movement of the milling machine to ECC under the control of the SINUMERIC 820 C system

1 Technical analysis on quality control, electrical diagrams, machine coordinate systems, parts, tools

1.1 Types and types of diagrams

1.2 Product Quality Assessment

1.3Information of CNC Machines

1.4 Axes of coordinates and structures of NC machine movements

1.5 Debugging and Adjusting the Program

2 Control of the diagram of the main movement of the milling machine to the bench

SINUMERIC 820 C Management

2.1 Overview of SINUMERIC 820 C

2.2 CNG 40 CNC E Universal Tool Milling Machine

3 Technical description of components of the power circuit of the machine

3.1 Arrangement of electrical equipment

3.2 Installation and removal of SINUMERIK 802S base line

3.3 Connection of components

3.4 Schematic diagram

3.5 Frequency converters

3.5.1 Frequency converters: structure, operation principle

3.6 ALTIVAR Frequency Converter

3.6.1 Why a frequency converter is needed

3.6.2 Operating principle

3.6.3 Process Equipment

3.6.5 Safety functions

3.6.4 Protection functions

4 Calculation of feasibility study for development of drive diagram

of the main movement of the milling machine to ECC SINUMERIC 820 c

4.1 Calculation of depreciation charges

4.2 Calculation of Energy Costs

4.3 Calculation of the programmer's salary

4.4 Calculation of total costs of development creation

4.5 Determination of minimum development price

4.6 Calculation of annual development operation costs

4.7 Calculation of annual costs of works execution in the usual way

4.8 Annual Savings

4.9 Design Cost Efficiency Factor

4.10 Payback Period

Conclusion

List of sources used

Applications

Annex A. Certificate project statement

Introduction

The technical need for automation is due to the growing contradiction between the limited capabilities of the operator and the increasing speeds and power parameters of the equipment. The search for new ways to increase labor productivity, the struggle to increase production efficiency, to reduce costs lead to the economic need for automation.

A set of mechanisms with a motion source for actuating an actuator of a machine with predetermined speed and accuracy characteristics is called a drive. Therefore, the need to control the equipment arises from all that is said. In production, a huge variety of control systems are used, in this case, the SINUMERIC 820 C ECC system will be considered. Machine control is called automatic if operations are provided by a set of devices and communication means that provide the required coordinated interaction between the actuators of the machine, billet, tool.

The software control system consists of a number of devices designed to perform certain functions: a software carrier, on which the program of work of the machine actuators is recorded; program input devices; a reader capable of sensing program symbols and converting them into electrical control signals; a converting device processing operating commands for movement of the machine actuators; drive of machine actuators; feedback system, which monitors compliance of performed movement of actuators with programmed parameters.

The creation of modern, accurate and high-performance milling machines leads to increased requirements for their main units. Special attention is paid to the drives of the main movement and supply: to increase rigidity, increase the accuracy of rotation of shafts, spindle units.

Actuators are motion drives installed on milling machine and use DC and AC electric motors, hydraulic motors and pneumatic motors. Electric motors were most widely used as machine drives. Where stepless shaft speed control is not required, asynchronous AC motors are used (as the cheapest and simplest). For stepless speed control, especially in feed mechanisms, direct current motors with thyristor control are increasingly used.

Let us consider in more detail milling machines which are intended for processing of external and internal flat and shaped surfaces, cutting of grooves, cutting of external and internal threads, gears. A feature of these machines is a working tool - a cutter with many cutting blades. The main movement is the rotation of the cutter, and the supply is the movement of the product together with the table on which it is fixed. In the process of processing, each blade of the cutter removes chips during a fraction of the revolution of the cutter, and the cross section of the cutter changes continuously from the smallest to the largest. Two groups of milling machines are distinguished: general purpose (for example, horizontal, vertical and longitudinal-milling) and specialized (for example, copy-cutting, tooth-cutting).

Depending on the number of degrees of freedom of movement of the table, cantilever-cutting (three movements - longitudinal, transverse and vertical), non-cantilever-cutting (two movements - longitudinal and transverse), longitudinal-milling (one movement - longitudinal) and carousel-cutting (one movement - circular working supply) machines are distinguished. All of these machines have the same master drive for rotating the spindle and different feed drives.

In the spindle head body there is a spindle motor, a speed box and a spindle for a cutter. Spindle head moves along crossbeam guides along its axis, and crossbeam, in its turn, along fixed post with vertical guides.

Thus, the machine has three mutually perpendicular movements: horizontal movement of the table, vertical movement of the spindle head together with the crosspiece, transverse movement of the spindle head along its axis. Volumetric processing is carried out in horizontal or vertical lines. Working tool: finger cylindrical and cone or end cutters.

The electric equipment of milling machines includes the main movement drive, feed drive, auxiliary movements drives, various electric control, control and protection devices, alarm systems and local lighting of the machine.

Machine drive is a set of devices that transmit motion from a motion source to working elements of the machine. Modern machines have individual drives, that is, each machine is driven by a separate electric motor, all the movements of the machine are carried out either from one or from several electric motors. There are the main movement drive, the supply drive, the quick movement drive.

The source of motion is an electric motor, most often asynchronous, short-circuited, installed in the immediate vicinity of the machine or on the machine itself. Motors that are installed directly on the machine and attached to it by their cover (flange) are called flange ones. Most often, such engines are used on drilling machines. On grinding and sharpening machines, built-in motors are widely used. These are engines in which the rotor is seated on the spindle of the machine.

By the nature of the control of the speed of the machine working elements, stepped and stepless drives are distinguished. Stepped drives allow to obtain within the specified limits a certain number of rotation speeds, double strokes or feed values. Stepless control systems allow you to set the most advantageous parameters of the cutting mode on the machine, in addition, this can be done without stopping the machine (on the go). In modern machines, stepless drives are used electric, hydraulic and mechanical (variators).

Stepped drives

Drives with stepwise adjustment are made in the form of gear gearboxes. The stepwise control mechanisms are simple in design and reliable in operation, so they are more widely used in modern machines than stepless control mechanisms. Since general purpose machines are used to process parts of various materials and different sizes (diameters), the value of spindle speeds in modern machines varies within quite large limits.

Limit speeds of rotation of machine spindle are found by maximum and lowest permissible cutting speeds and limit diameters of machining.

Stepless drives

In modern machines, stepless drives are electric, hydraulic, pneumatic and mechanical (variators).

Electric drives of stepless control. DC motors are often used as a source of motion. Since industrial enterprises are not centrally supplied with direct current, special sources are required to obtain it.

In modern machines, thyristor-controlled engines according to the thyristor converter-engine scheme are widely used. The drive allows to increase spindle rotation speeds up to 4000 rpm and more with stepless adjustment. The wide range of spindle speed control allows to ensure the required working and fast (idle) movements of the working elements without the use of intermediate mechanical gears. The thyristor is a semiconductor device. Thyristors are manufactured for current up to hundreds of amperes and voltage up to 1000 V or more. They have high efficiency, relatively small sizes, high speed. They can operate in a wide temperature range (from - 60 to + 60 ° C).

The main disadvantages of thyristor converters include a high sensitivity to overloads. Therefore, reduction is required for full use of the drive power when operating at low speeds of rotation of the spindle. The required control range in this case is obtained by combining an adjustable DC motor with a simplified speed box.

Hydraulic actuators. In modern metal cutting machines, drives are quite widespread. They are mainly used for rectilinear movements and to a lesser extent for rotational movements. Hydraulic drives are used both in mechanisms of the main movement (in long, strict, long), and in feeding mechanisms (grinding, software-controlled machines, copying, aggregate and others). Hydraulic drives are widely used in machine control mechanisms.

The main advantages of hydraulic drives: the ability to continuously adjust speeds, receive significant forces with relatively small drive dimensions; simplicity of overload protection; long service life, since the working medium itself simultaneously performs lubrication functions; low weight and volume per unit of power compared to an electric drive.

Disadvantages of hydraulic drives: the possibility of leakage of working fluid through seals and gaps, air penetration into working fluid, changing the properties of working fluid under the influence of pressure and temperature. One of the significant drawbacks of the hydraulic drive is its non-rigid characteristic.

Currently, frequency drives have become widespread.

The control of the electric motor involves the automation of all its operation, including starting, braking, reversing and changing the speed of rotation of the electric motor.

Automatic start-up ensures smooth start-up of the starting resistances, the possibility of adjusting the current within the required limits, which allows to reduce the number of errors that occur during start-up, and improves the performance of the whole system. The same goes for reverse and braking.

The frequency control eliminates one of the significant disadvantages of short-circuited motors - the constant rotor speed of the motor, independent of the load. The frequency control makes it possible to control the speed of the motor according to the nature of the load. This, in turn, avoids complex transient processes in electrical networks, ensuring that the equipment operates in the most economical mode.

Frequency control of the electric motor is effectively used in industrial enterprises, in the field of energy, utilities and other fields. This is due to the fact that frequency control allows you to automate production processes, economically spend electricity and other resources involved in production, improve the quality of products, as well as increase the reliability of the entire system.

Frequency control also improves the reliability and durability of the process system. This is ensured by reducing starting currents, eliminating overloads of system elements.

Relevance of the work: in the final qualification work, the technical solution for the development of the drive diagram of the main movement of the milling machine was considered. This is due to the fact that a constant increase in the requirements for the quality of production and processing of parts on milling machines leads to the automation of equipment and this system serves as the SINUMERIC 820 C ECC. Therefore, the issue of developing a scheme for connecting the drive of the main movement of the milling machine to the ECC under the control of the SINUMERIC 820 C system is relevant.

The purpose of the graduation qualification work is to develop a scheme for connecting the drive of the main movement of the milling machine to the ECC under the control of the SINUMERIC 820 C system.

In order to achieve this goal, a number of objectives must be met:

perform analysis of technical literature on quality control issues, electrical diagrams, coordinate systems of the machine, part, tool;

analyze the technical literature of the study and principle of interaction of the SINUMERIC 820 C ECC system;

develop a technical description of the components of the power scheme of the milling machine;

analyze the operation of the power scheme of the milling machine;

analyze possible faults of power circuit and ways of their elimination;

analysis of quality control of the main motion drive circuit.

The object of the study is a milling machine.

The subject of the study is the power scheme of the milling machine.

Control of the scheme of driving the main movement of the milling machine to the ground under the control of sinumeric 820c

SINUMERIC 820C complex solutions are often used among modern machine actuator control systems.

Thus, due to the constant increase in requirements for the quality of production and processing of parts and automation of production, it becomes necessary to develop a machine control system. This section discusses the development of a scheme for driving the main movement of the milling machine to ECC under the control of the SINUMERIC 820C system based on the CNG 40 CNC E milling machine. CNG 40 CNC E milling machines are equipped with modern components of SINUMERIC 820C. Therefore, this section addresses a number of issues on quality control of connection of the main motion drive to the ECC for control of the cutting process and for reliable operation of the equipment.

In this section the following types of analyses are performed as: and principle of frequency converters operation, electrical circuit analysis, technical description of components of power circuit of milling machine, analysis of operation of power circuit of milling machine, analysis of possible faults of power circuit and methods of their elimination, as well as analysis of technical documentation on quality control issues and quality control of main motion drive circuit.

2.1 Overview of SINUMERIC 820C

SINUMERIK 820C is a fully digital system for almost all types of applications. This is a system platform with progressive features

SINUMERIK 820C in the NCU module (NumericControlUnit - numerical control device) combines NC, PLC and communication tasks. Installed in the frame, the NCU is built directly into the SIMODRIVE 611D digital conversion system, while it is located on the right, directly at the power supply-recovery module. NCU processor variants and system software allow optimal adaptation to the machine and to the processing task. This modular principle allows you to equip a number of machines of various types

A maximum of 31 axles/spindles can be controlled with SINUMERIK 820C. With maximum use, up to 10 channels are supported for each group of operating modes and a maximum of 12 axes/spindles for each channel. Each channel may have its own group of operating modes. SINUMERIK 820C enables easy and cost-effective protection of service personnel and machines with built-in certified protection features. All NCUs initially have a built-in connection of 4 fast CNC digital inputs/outputs. Multiple management systems can be merged into one. The following components can be connected to SINUMERIK 820C:

- operator panel with PCU or MMC module and machine panel - SIMATIC OP7/OP17;

- PP 031MC push-button panel;

- BHG manual control panel, BMPI type;

- SINUMERIK HT 6 manual terminal;

- PHG manual programming device, MPI type - manual mini-console;

- periphery of SIMATIC S7300;

- simple peripheral EFP module;

- PP 72/48 peripheral module;

- NCU terminal unit with compact DMP modules;

- 2 flywheels, 2 measuring probes and 4 quick NC I/O via cable distributor;

- decentralized periphery of PLC connected via PROFIBUS;

-DP - digitization module;

- SIMODRIVE 611D digital drive;

- programmer, for example, FieldPG;

- 1FK6, 1FT6, 1FN, 1PH, 1FE1 and 1LA engines.

2.2 CNG 40 CNC E Universal Tool Milling Machine

Universal tool milling machine CNG 40 CNC E precise milling metal cutting machine. The machine is connected to the electrical network according to the following parameters:

Voltage 400V 3 + PE + N

Frequency 50 Hz

Power consumption 15 kW

Maximum oscillation + 6, -10%

Protection in front of 25 A machine

Minimum section of drive cable

The machine can be connected and adjusted by specialists of appropriate qualifications. The machine is connected to the network only after it is installed. The junction box is located in the junction cabinet. The drive cable is driven through a sealing end bushing PG 29 which is located at the bottom of the distribution cabinet. The 6 mm2Cu drive cable is connected to the terminals in the letters U, V, W and RE. On the machine, it is necessary to observe phase alternation, namely, rotation of the field to the right. Otherwise, all motors will rotate in the opposite direction. On the foundation of the machine there is a protective terminal, which is used if the main protection is supplemented by protective connections.

Technical description of the components of the power scheme of the machine

3.1 Arrangement of electrical equipment

The main part of the electrical equipment is located in the distribution cabinet, which is attached to the side of the machine bed. The junction box is placed in the lower left part of the junction cabinet. The junction box is equipped with a panel with the inscription "Caution under voltage and when the central switch is off."

The central switch is three-phase, rotary. Indicated by SQ1. This switch can be locked by a hanging lock.

On the side of the distribution cabinet is the RS232 communication interface connector for connecting the computer to the control system.

Connection bolts that are energized and in the off position of the central switch are equipped with a protective cover and a warning panel

All electrical circuits of the machine are controlled from the control panel SINUMERIKS802.

SINUMERIK 802S and SINUMERIK 802C are full-fledged SCGC developed specifically for the lowend machine market.

An integration vision:

control panel separate from NC unit;

compact dimensions;

only a small amount of design data is required for commissioning. This enables quick and easy matching with compact machines;

simple programming and easy control ensure fast start-up of production and thus optimal use of the machine.

SINUMERIK 802S/802C consists of the following components:

OP 020 Operator Panel

MCP machine panel;

ECU NC unit;

Module PLC D I/O (1 pc included in scope of supply)

Toolbox.

The CNC unit and PLC module can be installed on the SIMATIC S7 common mounting bus. The ECUNC CNC unit is service-free, i.e. no batteries are required. The buffer capacitor keeps the data safe when the power is cut off. Changes to the program and new programs are saved through the softkey.

In addition, ECU offers the following connections:

RS 232 C: interface for PC connection;

terminal block: reference point sensor connections;

terminal block: 24BDC power connection;

terminal block: connecting max. 2 handwheels;

bus plug: connecting max. 4 PLC modules.

The supply axes: SINUMERIK 802S/802C is designed for three supply axes. The SINUMERIK 802S interface is designed for stepper motor drives with pulse and direction signals. SINUMERIK 802C has a traditional ± 10V interface.

Spindle

Connection of spindle with adjustable number of revolutions (without C-axis mode) at both SCC is performed via ± 10V interface.

Toolbox: The NCC software is on the FlashEPROM in the NC unit and is included in the scope of supply. The software is supplied for turning and milling and can be loaded individually, the volume being determined by the operator. For quick commissioning, the Toolbox has one PLC program as an example for turning and milling. All necessary downloads are included in the scope of supply.

The integrated PLC can control 64 inputs and 64 outputs. The PLC can be freely programmed through a contact plan (KOPLadder) with a maximum of 4000 operators. Use PLCTool for programming.

PLC-Tool

Running under Windows (MicroStep), PLCTool is a programming tool that allows the user to program the 802S/802C PLC integrated into SINUMERIK. You can also use it to negotiate or modify demos on the Toolbox.

If only Toolbox demos are used, PLCTool is not required. PLCTool is a tool for commissioning SCC for machine manufacturers.

OP 020 Operator Panel

The OP 020 operator panel can be installed independently of other components. The operator panel is connected to the NC unit by only one cable (maximum length: 15 m). Communication and power is provided through this cable.

Machine panel MCP

In addition to the operator panel, an MCP machine panel is supplied, on which, along with the control and movement keys, there are 6 light keys. Freely programmable light keys can be subordinated to the corresponding functions of the machine.

For MCP installation next to OP 020, the connection cable (length: about 200 mm) is included in the scope of supply. If the MCP is to be installed at a greater distance from the OP 020, order the two cables separately.

OP 021 Operator Panel

In combination with the operator panel OP 021, SINUMERIK 802S and SINUMERIK 802C can also be used for conventional machines.

With the help of operator panel OP 021 and included in the scope of standard software, it is possible to control conventional machines through the flywheel. The program keys and symbols displayed on the display support the operator during processing.

The SINUMERIK 802S Manual Machine and SINUMERIK 802C Manual Machine give conventional machines greater flexibility, precision and comfort without affecting simple control.

SINUMERIK 802S Manual machine/802C Manual machine consists of the following components:

OP 021 Operator Panel

NC unit ECUmodule PLC D I/O (1 pc included in scope of supply).

Features:

very compact mounting dimensions;

Easy to use with DIN programming

high reliability due to operator panel mounting;

Compact control device including CNC, PLC, MCP and I/O unit

Complete delivery with NC, Toolbox and magazine

all instruments are included in the scope of supply;

does not require maintenance: without a battery and a fan.

Functions:

up to 3 analog axes and one analog spindle (without C axis);

analog spindle via ± 10 V interface;

Free selection of turning or milling

predetermined machine tool data;

RS 232 C interface;

48 digital inputs and 16 digital outputs (0.5 A);

Typical program and examples of PLC;

Toolbox.

The hardware components of SINUMERIK 802S baseline are compact SCR. It consists of the following components :

Liquid crystal monitor, ECC keys, MSTT, external drives, STEEP drive.

The SINUMERIK 802S baseline software components consist of the following software components:

System software on permanent Flashpam of SCC

- BootSoftware downloads other system PAI from permanent memory to user memory (DRAM) and starts the system;

- MMC software (ManMachineCommunication), implements all operating functions;

- NCK (NC Core) implements all NC functions.

This software controls one NC channel with a maximum of 3 feed axes and one spindle.

— ПО PLC (ProgrammableLogicControl; program control from memory device) cyclically executes built-in electrical automation program;

- the built-in electrical automation program configures SINUMERIK 802S baseline for machine functions (see also function description, chapter on the integrated electrical automation program for SINUMERIK 802S baseline ).

Toolbox

- WINPCIN for PC/PG (programmer) for transmitting user data and programs;

- text manager;

- a set of cycles, loaded from WINPCIN to NCC;

- user program library;

- machine data files for the required technology;

is a utility for programming.

Update Diskettes

- update program with user actions control system;

- software package with 802S baseline system software for loading and programming SINUMERIK 802S baseline through the update program.

User Data

User data includes:

machine data;

installation data;

tool data;

R-parameters;

Zero point offsets

correction data;

part processing programs;

standard cycles.

3.6 ALTIVAR Frequency Converter

The ALTIVAR frequency converter is used to solve the most difficult tasks of the electric drive, where the accuracy of maintaining the torque on the shaft is required, can be used on any equipment from transportation to transportation and elevator. Can be used with synchronous and asynchronous motors

The ALTIVAR frequency converter meets the most stringent application requirements due to the use of a variety of engine control laws and numerous functionality. It is adapted to solve the most difficult tasks of electric drive - moment and increased accuracy when operating at very low speed and improved:

dynamic characteristics with vector flow control algorithms in an open or closed drive system;

extended range of output frequency for high-speed motors;

parallel actuation of motors and special drives using scalar control law;

accuracy of speed maintenance and energy saving for open drive with synchronous motor;

smooth, impact-free control of unbalanced mechanisms using the Energy Adaptation System (ENA).

3.6.1 Why a frequency converter is needed

An asynchronous motor significantly exceeds other types of electric machines in performance and power, but does not deviate from characteristic disadvantages. For example, to control the speed of rotation of the rotor, the device must be equipped with additional elements. The same with starting - the starting current of the asynchronous motor exceeds the nominal value by 5-7 times. Due to this, additional impact loads, loss of electricity arise, which together only reduces the life of the unit.

To solve these problems, as a result of persistent research, a class of special devices was created designed for automatic electronic control of starting currents - frequency converters.

The frequency converter for the electric motor reduces the value of starting currents by 4-5 times and not only performs a smooth start, but also controls the rotor by adjusting the voltage and frequency. The use of the device has other advantages:

saves up to 50% of power during start-up;

it provides feedback of adjacent drives.

In fact, this is not a converter, but a generator of three-phase voltage of the necessary magnitude and frequency.

Conclusion

At the end of each section of the diploma project, logical conclusions are indicated in a compressed form.

Also, a calculation of the economic justification was made, in which the effect of the implementation of the automation system was calculated.

In the final qualification work on the topic: "Development of the scheme for driving the main movement of the milling machine to the ECC under the control of SINUMERIC 820C," the diagram was developed and the connection of the SINUMERIC 820C system to the milling machine was analyzed using the example of the CNG 40 CNC E. This material was structured. The structure and principle of operation of frequency converters on the example of ALTIVAR converter are considered in detail. The manual for operation and installation of the SINUMERIC 820C SCC was studied, functional decomposition of the schematic diagrams of the milling machine was made, the diagrams for connection of the main movement supply and drive drives of the SINUMERIC 820C ECC were given.

All points regarding the subject have been worked out. During the work, the material of the technical literature on the issues of coordinate systems of machines with numerical program control, types and types of schemes was studied.

In the course of the thesis project, I applied the following general and professional competencies to cover the above tasks:

Professional competencies:

PC 1.1. Perform performance analysis of measuring instruments and automation equipment.

PC 3.2. Monitor and analyze operation of system parameters during operation.

PC 4.1. Perform analysis of automatic control systems taking into account the specifics of technological processes.

PC 4.3. To make schemes of specialized knots, blocks, devices and the systems of automatic control.

PC 5.2. Analyze reliability characteristics of automation systems.

General competencies (QA):

OK 1. To understand the essence and social significance of your future profession, to show steady interest in it.

OK 2. Organize your own activities, choose standard methods and methods for performing professional tasks, evaluate their effectiveness and quality.

OK 3. Make decisions in standard and non-standard situations and be responsible for them.

OK 4. Search and use information necessary for the effective performance of professional tasks, professional and personal development.

OK 5. Use information and communication technologies in professional activities.

OK 6. Work in a team and team, communicate effectively with colleagues, management, consumers.

OK 7. Take responsibility for the work of team members (subordinates), the result of completing tasks.

OK 8. Independently determine the tasks of professional and personal development, engage in self-education, consciously plan for advanced training.

OK 9. To be guided in conditions of frequent change of technologies in professional activity.

Thus, I consider the goals and tasks set and the final qualification work fulfilled.