Overview of CNC machine
The main difference between machine tools and other machines is that machine tools are not only machines for manufacturing machines, but also machines for manufacturing machine tools themselves.
Therefore, machine tools are also known as “industrial machine tools” or “tool machines”.
In the machine tool industry, numerical control machine tools are generally based on the number of axes.
Those below three axes are low-grade machine tool, those from three to five axes are medium and high-grade machine tool, and those above five axes are high-grade machine tool.
For industry, the mark of the difference between traditional and modern production equipment is traditional machine tools and CNC machine tools, which has become the industry consensus.
Machine tools provide production equipment for the equipment manufacturing industry.
All parts that require high machining accuracy and fine surface roughness need to be processed by machine tools.
Therefore, machine tools play an important role in the development of the manufacturing industry and national economy.
The intellectualization and automation of single machine tools, that is, CNC machine tools, is the direction of machine tool industry. Its high precision, high fineness, high speed, flexibility and intelligence are the symbols of modern industry.
The modern equipment industry is developing towards extreme manufacturing.
First, it is becoming larger and larger;
Second, it is becoming smaller and smaller;
Third, it is becoming more and more complex, and the production process is highly integrated.
With the development of electronic information technology, the current machine tool industry has entered the electromechanical integration era with CNC machine tools as the representative products.
CNC machine tool is an automatic machine tool equipped with the program control system, which solves the processing problems of complex, precise, small batch and multi-variety parts.
It is a flexible and efficient automatic machine tool, which represents the development direction of modern machine tool control technology.
What is CNC machine?
Computer numerical control machine tool, an automatic machine tool equipped with program control system, is referred to as CNC machine.
This kind of control system can logically process the relevant programs with control codes / other symbolic instructions, express them with coded numbers after decoding, and input them into the numerical control device using the information carrier.
After calculation and processing, the numerical control device sends various control signals to control the action of the machine tool, so that the machine tool can automatically process the parts according to the shape and size required by the drawing.
Numerical control machine tool integrates machinery, automation, computer, microelectronics and other technologies to solve the processing problems of complex, precise and small batch parts.
It is a flexible and efficient automatic machine tool.
The sensors used in CNC machine tools mainly include photoelectric encoder, linear grating, proximity switch, temperature sensor, hall sensor, current sensor, voltage sensor, pressure sensor, liquid level sensor, resolver, inductosyn, speed sensor, etc., which are mainly used to detect position, linear displacement and angular displacement, speed, pressure, temperature, etc.
CNC machine have the characteristics of strong adaptability to processing objects, high processing accuracy, stable processing quality, high productivity, high reliability, and can improve working conditions.
Main features of CNC machine tools
The operation and monitoring of CNC machine tools are all completed in this CNC unit, which is the brain of CNC machine tools.
Compared with ordinary machine tools, CNC machine tools have the following characteristics:
- It has strong adaptability to the processing objects, adapts to the characteristics of single-piece production of molds and other products, and provides a suitable processing method for mold manufacturing;
- High machining accuracy and stable machining quality;
- It can carry out multi-coordinate linkage, and can process parts with complex shapes;
- When machining parts are changed, generally only the NC program needs to be changed, which can save production preparation time;
- The machine tool itself has high precision, high rigidity, favorable processing consumption and high productivity (generally 3-5 times that of ordinary machine tools);
- The machine tool has a high degree of automation, which can reduce the labor intensity;
- It is conducive to the modernization of production management. CNC machine tools use digital information and standard code to process and transmit information, and use computer control methods, which lays the foundation for the integration of computer-aided design, manufacturing and management;
- Higher quality requirements for operators and higher technical requirements for maintenance personnel;
- High reliability.
CNC machine vs traditional machine tools
- Highly flexible
Processing parts on CNC machine tools mainly depends on the processing program.
It is different from ordinary machine tools.
It does not need to manufacture, or replace many molds and fixtures, and does not need to readjust the machine tools often.
Therefore, CNC machine tools are suitable for the occasions where the processed parts are frequently replaced, that is, for the production of single piece and small batch products and the development of new products, so as to shorten the production preparation cycle and save a lot of process equipment costs.
- High machining accuracy
The machining accuracy of the NC machine tool can generally reach 0.05-0.1mm.
The NC machine tool is controlled in the form of digital signals.
For each pulse signal output by the NC device, the moving parts of the machine tool move a pulse equivalent (generally 0.001mm), and the average error of the reverse clearance of the machine tool feed transmission chain and the screw pitch can be compensated by the NC device.
Therefore, the positioning accuracy of the NC machine tool is relatively high.
- Stable and reliable processing quality
When processing the same batch of parts, on the same machine tool, under the same processing conditions, using the same tools and processing procedures, the tool path is exactly the same, the consistency of parts is good, and the quality is stable.
- High productivity
CNC machine tools can effectively reduce the processing time and auxiliary time of parts.
The range of spindle sound speed and feed rate of CNC machine tools is large, allowing the machine tools to carry out powerful cutting with a large cutting amount.
CNC machine tools are entering the era of high-speed machining.
The rapid movement and positioning of moving parts of CNC machine tools and high-speed machining have greatly improved productivity.
In addition, when used with the tool magazine of the machining center, it can realize the continuous processing of multiple processes on a machine tool, reduce the turnover time between processes of semi-finished products, and improve productivity.
- Improve working conditions
After adjustment, the NC machine tool can automatically and continuously process until the end of processing by inputting the program and starting it.
All the operators have to do is program input, editing, part loading and unloading, tool preparation, observation of processing state, part inspection, etc.
The labor intensity is greatly reduced, and the labor of machine tool operators tends to be intelligent work.
In addition, machine tools are generally combined, which is both clean and safe.
- Utilize the modernization of production management
The processing of CNC machine tools can accurately estimate the processing time in advance, standardize and modernize the tools and fixtures used, and it is easy to realize the standardization of processing information.
NC machine tool machining has been organically combined with computer-aided design and manufacturing (cad/cam), which is the basis of modern integrated manufacturing technology.
How does CNC machine work?
In the traditional field of metal processing, the manufacturing of parts is the casting, forging and welding with sparks splashing and the turning, milling, planing and grinding pliers.
Any slightly shaped metal we see in life has experienced many times of iron and fire quenching in the factory before we see it.
Since metal parts are made by machines, how are machines made? Originally, It is completed by the machine tool.
（1） From machine tools to CNC machine tools, machines are no longer brainless
Machine tool is the “mother machine” of other machines.
The steel produced by the steel plant is not all kinds of strange shapes we see in life, but plates, pipes, ingots and other materials with regular shapes.
These materials need to be machined into parts of various shapes with machine tools;
There are also some parts that require high precision and fine surface roughness, which need to be cut or ground on the machine tool with fine and complex processes.
Gas turbine impeller
Like all machines, the original machine tool includes a power device, a transmission device and an execution device.
The power is input by the rotation of the motor, and the workpiece or tool to be processed is moved relative through the transmission device.
As for where to cut, how much to cut, how fast to cut and so on, it is directly controlled by people in the processing process.
Because the rotation speed of the motor used in traditional machine tools is basically constant during operation, in order to achieve different cutting speeds, traditional machine tools have designed extremely complex transmission systems.
Such complex machinery is rare in today’s design.
The transmission structure of traditional machine tools (X5032 vertical milling machine) is very complex
With the development of servo motor (servo motor is a motor that can accurately control the position and speed of the motor within a certain range) technology and its application in CNC machine tools, direct control of the speed of the motor has become convenient, fast and efficient, and basically step-less speed change.
The structure of the transmission system has been greatly simplified, and even many links have appeared.
The motor is directly connected to the actuator, and the transmission system has been omitted.
This “direct drive” mode is now a major trend in the field of mechanical design.
The transmission structure of the CNC vertical milling machine is greatly simplified by the direct drive of the servo motor
The simplification of structure is not enough.
In order to realize the processing of parts with various shapes, it is also necessary to let the machine tool control multiple motors efficiently and accurately to complete the whole processing process.
This will make the machine tool a CNC machine tool with “brain”. And this brain is the numerical control system.
The level of the numerical control system determines how complex and precise the numerical control machine tool can be, and also determines the value of this machine tool and its operator.
（2） What can CNC system do? Process information and control power.
The numerical controller system is the brain of numerical control machine tools.
Composition of general CNC machine tools
For general CNC machine tools, it often includes man-machine control interface, CNC system, servo drive device, machine tool, detection device and so on.
With the help of some computer-aided manufacturing software, the operators express various operations required in the processing process (such as the steps of spindle speed change and the shape and size of the workpiece) with part program codes and input them to the NC machine tool through the human and control interface.
Then the NC system processes and calculates this information, and controls the servo motor according to the requirements of the part program to realize the relative movement between the tool and the workpiece, to complete the processing of parts.
Machining process of CNC machine tool
The numerical control system completes the storage and processing of many information and transmits the processing results of information to the subsequent servo motor in the form of control signals.
The working effect of these control signals depends on two core technologies: one is the interpolation operation of curves and surfaces, and the other is the multi axis motion control of machine tools.
（3） Part shape is too “free”? It’s done by interpolation.
If the motion trajectory can be expressed analytically, the whole movement can be decomposed into the synthetic motion of independent motion with several coordinates, and the motor generation can be directly controlled.
However, the shape of many parts in the manufacturing process can be said to be very “free”, which is neither round nor square, and even does not know what shape it is.
For example, products such as cars, ships, aircraft, molds, and works of art often encounter curves and surfaces that cannot be described analytically.
Such curves and surfaces are called free-form curves or free surfaces.
Parts containing free-form surfaces
To cut out these “free” shapes, the relative motion between the tool and the workpiece is also correspondingly very complex.
Specifically, in the operation, it is necessary to control the workpiece table and the tool to move according to the designed position time curve, and control them to reach the specified position with the specified attitude at the specified time.
The machine tool can well complete the relative motion of linear segments, arcs or other analytical spline curves between the workpiece and the tool, and how to complete this complex “free” motion?
The answer is to rely on interpolation.
NC machine tool for complex surface machining
The so-called interpolation is the process of determining the motion path of the tool on the NC machine tool according to a certain method.
According to the given speed and track, add some new intermediate points between the known points of the track, and control the workpiece table and the tool to pass through these intermediate points, so as to complete the whole movement.
These intermediate points are connected by line segments, arcs or splines.
It is equivalent to using a few tiny segments and arcs to approach the required curves and surfaces, which is the essence of interpolation.
Popular interpolation algorithms include point by point comparison method, digital increment method and so on.
NURBS spline interpolation is favored by high-end CNC machine tools because of its high efficiency and good accuracy.
（4） The posture of the knife is wrong and cannot be processed? The five coordinate linkages will be completed in minutes.
Machining complex surfaces not only needs to be able to be machined in theory, but also needs to consider the relative position relationship between the tool and the machined surface.
On the one hand, if the tool posture is not appropriate, it will lead to low surface quality;
On the other hand, the tool will interfere with the processed part structure, and there is no way to process without adjusting the relative posture of the tool.
This requires giving CNC machine tools more degrees of freedom of movement to make them more dexterous.
Six degrees of freedom in space
Since the relative motion in our three-dimensional space only contains six degrees of freedom (three translational degrees of freedom and three rotational degrees of freedom), the five coordinate linkage is to increase the rotational degrees of freedom in two directions in addition to the translational degrees of freedom in X, Y and Z directions in space, plus the rotational degrees of freedom for cutting of the tool itself.
In this way, the relative motion between the tool and the workpiece has all six degrees of freedom, so that the tool and the workpiece can present any relative position and attitude.
A five coordinate linkage machine tool
As shown in the above fig., although the fig. wins four translational degrees of freedom, in essence, it only realizes the movement in the X, Y and Z directions.
One degree of freedom is redundant, which is essentially a five coordinate linkage machine tool.
Machining complex curved surface with five coordinate linkage machine tool
Different types of CNC machine
Based on the material shaping method, machine tools can be divided into 8 types:
- metal cutting machine tools
- metal forming machine tools
- casting machines
- woodworking machine tools
- machine tool accessories
- measuring instruments
- grinding machines
- other metal machine tools.
Metal cutting and forming machines account for a relatively high proportion.
Based on the selection/movement control mode, machine tools include traditional machine tools and CNC high-precision machine tools.
CNC high-precision machine tool refers to the machine tool that performs high-precision machining under the control of the CNC program control system.
According to the classification standard of China Machine Tool Association, machine tools can be divided into 7 categories.
There are a total of 595 sub categories in the machine tool industry, and there are still 552 sub categories after excluding non key categories such as abrasives. Among them, there are 319 sub categories belonging to the whole machine sub industry.
After refining the sub categories, we can get seven major categories.
The whole machine part includes metal cutting machine tools, metal forming machine tools, casting machinery and woodworking machine tools;
Other parts include accessories, measurement & display, cutting tools & abrasives and CNC system.
According to the press select/move control method, machine tools can be divided into traditional machine tools and CNC machine tools.
CNC machine tool is an automatic machine tool equipped with the program control system, which is a typical product of electromechanical integration.
Compared with traditional machine tools, CNC machine tools have the advantages of high precision, good flexibility, high efficiency, complex functions, intelligent control and so on, and have become the mainstream development direction of modern machine tools.
Metal cutting machine tools are the most important type of machine tools, accounting for about 2/3.
Metal cutting machine tools use cutting, grinding or special processing methods to process various metal workpieces to obtain the required geometric shape, dimensional accuracy and surface quality, mainly including seven processes of “turning, milling, planing, grinding, boring, broaching”.
Metal forming machine tools, mainly including bending machines, plate shears, punches, forging machines and other products, are designed to physically deform metals by applying strong forces to them.
In 2020, the consumption of metal processing machine tools in China was US $21.31 billion, of which the consumption of metal cutting machine tools was US $13.87 billion, accounting for 65.1%, and the consumption of metal forming machine tools was US $7.44 billion, accounting for 34.9%.
Metal cutting machine tools include lathes, grinders, milling machines, boring machines, machining centers, drilling machines and many other sub categories.
Taking the output structure of Japan in 2019 as an example, machining centers accounted for the highest proportion, accounting for 34.2% (vertical machining centers 18.4%, horizontal machining centers 12.8%), followed by lathes 29.8%, grinders 12.6%, and special machine tools 7.9%.
The turning tool is used to turn the rotating workpiece.
The movement feature is that the rotating workpiece rotates around its own axis, and the tool makes the forming feed movement.
It is mainly used for machining inner and outer cylindrical surfaces, forming annular surfaces and annular grooves, turning sections and various threads, and can be used for drilling, reaming, reaming, working threads and other processes.
Grinding tools are used to grind the workpiece surface.
Most grinding machines use high-speed rotating grinding wheels for grinding, and a few use oilstone, abrasive belt and other grinding tools and free abrasives for machining.
The milling cutter is used to process various surfaces of the workpiece.
Usually, the cutter rotates around its own axis, and the workpiece and/or cutter make feed motion.
It can process planes, grooves, various curved surfaces, gears, etc., and drill and bore workpieces.
The machining center is a highly automated multi-function CNC machine tool with tool magazine and automatic tool change device, which greatly improves production efficiency and automation.
According to the number of control axes, it can be divided into three-axis, four axis and five axis machining centers, and according to the structure, it can be divided into vertical, horizontal and gantry machining centers.
Vertical machining center:
The spindle axis is set perpendicular to the workbench, which is mainly suitable for processing complex parts such as plates, discs, molds and small shells.
It is convenient to install the card, easy to operate, easy to observe the processing situation, easy to debug the program, and widely used.
However, due to the height of the column and the limitation of the tool changing device, too high parts cannot be processed.
Horizontal machining center:
The spindle axis is set parallel to the workbench, which is mainly suitable for processing box parts.
Chip removal is easy during processing, but the structure is complex and the price is high.
Gantry machining center:
The spindle axis is set perpendicular to the workbench.
The overall structure is a large machining center machine with a portal structure frame composed of double columns and top beams.
There is a beam in the middle of the double columns, which is mainly suitable for processing large workpieces and workpieces with complex shapes.
Advantages & disadvantages of CNC machine
Advantages of CNC machine tools
- The modification of processing objects has strong adaptability, which can quickly change from processing one part to processing another part, which provides great convenience for single piece, small batch and trial production of new products. Save time and money.
- High machining accuracy Firstly, the ball screw is introduced into the structure, secondly, the software accuracy compensation technology is adopted, and finally, the whole process of machining is controlled by program, so as to reduce the influence of human factors on the machining accuracy. It can process workpieces with complex structures, such as propellers.
- High production efficiency
- High degree of automation
- Good economic benefits
- Conducive to the modernization of production management
Disadvantages of CNC machine tools
- Due to the high cost, it is unfavorable to process large quantities of parts.
- Operators require high quality and high salary costs.
- The system is complex and the maintenance cost is high.
Parts & functions of CNC machine
|Structural member||It is mainly cast iron, steel and other products. After being processed and refined into machine tool bed and beam column, it plays a role of structural support for the machine tool, accounting for the largest proportion in the cost of raw materials.|
|Control system||It is composed of PLC (programmable controller), CNC system, CO server control module, position detection module, etc. it is the “brain” of machine tools to generate and transmit work orders through programming.|
|Transmission system||Including guide rail, ball screw, spindle and other parts, as well as hydraulic system and starting system, which are mainly used to assist machine tool movement.|
|Driving system||It is composed of high-speed spindle, ordinary motor, Hefu motor, etc. In the market, ordinary motors are usually used for machine tool products less than 1million, and Hefu motors are mostly used for machine tool products more than 1million. Compared with ordinary motors, the selling price of Hefu motors is 3-4 times that of ordinary motors, but Hefu motors are far superior to ordinary motors in terms of precise positioning, high-speed performance, adaptability, stability, timeliness and so on, and become the first choice of high-end CNC machine tools.|
|Magazine, turret and components||The part of the machine tool that performs the cutting function.|
|Grating ruler||The measurement feedback device used in CNC machine tools is often used to detect the coordinates of tools and workpieces to observe and track the tool walking error.|
The foundation and frame of the whole machine tool and the main parts supporting the machine tool are composed of bed, column, sliding seat, workbench, beam, spindle box, etc.
It is composed of program, input/output equipment, CNC system, programmable controller, servo control module, etc.
The generation and transmission of work orders are realized through programming.
The servo system accurately controls the speed and position of each machining coordinate axis by receiving the instructions of the CNC system.
Its dynamic response and servo accuracy are important factors that affect the machining accuracy, surface quality and production efficiency of CNC machine tools.
The servo system can be divided into open-loop, closed-loop and semi closed-loop systems according to different control modes, and can also be divided into DC servo system and AC servo system according to different motors.
It is mainly used to assist the movement of machine tools, including guide rails, ball screws, spindles, etc.
It is composed of high-speed spindle, motor, etc. Machine tools below 1million usually use ordinary motors, and machine tools above 1million mostly use servo motors.
The selling price of servo motor is 3-4 times that of ordinary motor, but servo motor is far superior to ordinary motor in terms of precise positioning, high-speed performance, adaptability and stability, timeliness, etc., and has become the first choice of high-end CNC machine tools.
The frame is the largest cost item.
Among the production costs of machine tools, raw materials account for the highest proportion, accounting for 73.9%, followed by labor, depreciation and other manufacturing expenses, accounting for 11.9%, 7.9% and 6.4% respectively.
In the cost of raw materials, structural parts account for the highest proportion, up to 40%, and the price is greatly affected by steel;
The second is the control system, transmission system and drive system, accounting for 21%, 18% and 13% respectively.
Specifications of CNC machine
Numerical control parameters are the external devices of the software used in the numerical control system, which determines the function and control accuracy of the machine tool.
Whether the parameters of the machine tool are used correctly or not directly affects the normal work of the machine tool and the full play of its performance.
According to the representation of parameters, the parameters of CNC machine tools can be divided into: state parameters, ratio parameters, and real value parameters.
According to the nature of the parameter itself, it can be divided into ordinary parameters and secret level parameters.
Applications of CNC machine
(1) Aviation Industry:
For aircraft wing, fuselage, tail, etc. and engine parts, the required models are high-speed five axis machining center, gantry mobile high-speed machining center, precision CNC lathe, precision horizontal machining center, multi coordinate filing and milling center, precision gear and thread processing and control machine tool, etc.
(2) Railway locomotive manufacturing industry:
For high-speed railway locomotive body, axle, wheel and other parts, large and medium-sized CNC machine tools are needed: CNC lathe, vertical and horizontal machining center, five axis machining center, gantry file milling machine, auxiliary milling machining center, etc.
(3) Weapon manufacturing industry:
It is aimed at tanks, armored vehicles, bullets, guns, core pulling and other products, and needs CNC lathes, vertical and horizontal machining centers, five axis machining centers, gantry file milling machines, file milling machining centers, gear processing machines, etc.
(4) Mold manufacturing:
It is aimed at auto panel molds, die-casting molds, forming extrusion molds, etc., which need high-speed CNC milling machines, precision electrical machining machines, high-precision machining centers, precision grinders.
(5) Electronic information equipment manufacturing industry:
For the shell of high-end electronic products, motor rotor stator, motor shell cover, etc., we need small precision CNC machine tools: high-speed milling center, high-speed machining center, small precision lathe, small precision punch, special CNC machine tools for precision and ultra precision machining, and precision electrical machining machine tools.
(6) Power equipment manufacturing:
For power generation equipment, heavy CNC gantry file milling machine, large floor file milling machine, large CNC lathe, special milling machine for blade root groove and blade CNC machining machine are required.
(7) Metallurgical equipment manufacturing:
For the complete set of continuous casting and rolling equipment, large gantry milling machine and large CNC lathe are required.
(8) Construction machinery manufacturing:
For gearbox, mining arm, car body, engine and other parts, small and medium-sized CNC machine tools are needed: CNC lathe, medium-sized machining center, CNC milling machine and gear processing machine tools.
(9) Shipbuilding Industry:
For diesel engine bodies, heavy and ultra heavy gantry milling and filing machines and Heavy CNC Floor milling and filing machines, as well as large CNC lathes and turning and milling centers, large CNC gear grinding machines, crankshaft controlled milling machines, large crankshaft turning and milling centers and crankshaft grinders are required.
(10) Automobile manufacturing:
For vehicle components: Engines need high-efficiency, high-performance, special CNC machine tools and flexible production lines;
For parts processing, CNC lathes, vertical and horizontal machining centers, CNC efficient grinders, etc. are required
What is the price of CNC machine?
In addition, even if a certain CNC machine tool is selected, it will vary according to different brands, sizes and configurations.
In general, the price range of CNC machine tools ranges from US $10000 to US $1million.
Generally speaking, the choice of CNC machine tools needs to be customized according to customer needs, so the specific price should be confirmed with the CNC machine tool manufacturer.
How to use CNC machine?
At present, many operators who are just engaged in the classification of CNC machine tool operators, some of whom are very familiar with machining, but are relatively unfamiliar with the programming of CNC machine tools, and some of whom are newly graduated students, who are familiar with the knowledge of machining, the theory of CNC machining and programming, but lack actual machining experience;
There are also many operators who have never been exposed to machining and programming, so it is very difficult for them to learn the operation of CNC machine tools.
For those who are beginning to learn CNC machine tools, it is very important to master certain operating skills of CNC machine tools.
On the one hand, they can avoid machine tool collision accidents, resulting in machine tool damage;
Second, in a relatively short time, it can quickly improve the operator’s CNC machine tool operation skills and be competent for the job.
For these operators who have just come into contact with CNC machine tools, I hope that the following theoretical knowledge of the operation skills of CNC machine has some reference significance for them.
First, the operator needs to have a comprehensive understanding of the CNC machine tool to be operated;
Understand the mechanical structure of the machine tool: understand the mechanical structure of the machine tool;
Master the shafting distribution of the machine tool;
It is necessary to master the functions and use of various parts of the machine tool, such as the principle and function of a simple pneumatic system and the working principle and function of a simple hydraulic system;
In addition, it is necessary to master the working principle and function of each auxiliary unit of the machine tool, such as the working principle, function and use method of the tool magazine, cooling unit, voltage regulator, electrical cabinet cooler and other units, as well as the working principle, function and use method of each safety door lock of the machine tool.
Firmly grasp the functions of each operation button of the machine tool:
Know how to execute the program; how to check the workpiece processing state after suspending the program, how to resume the program after resuming the suspended state, and how to stop the program; how to change the program before executing it, and so on.
Know what kind of operating system your machine tool is;
Simply understand the control principle and working method of CNC system; What kind of working language is used in the system, the software used in machine tool processing and the language used.
If the operator does not know the language or the professional vocabulary of the language, professional training is required.
If you don’t want to be an operator at the bottom of the machining center all the time, you need to take notes carefully during the training.
You must memorize and master the Chinese meaning of each word in the machine tool software, so that you can use the machine tool correctly in the future.
The second key point is to master the manual or automatic operation of the CNC machine tool and the movement of each CNC axis of the machine tool.
The operator must reach the state that practice makes perfect, so that he can retract and release freely in any case;
In case of collision or failure, the operator can correctly and timely deal with the problem, and the operator will form a conditioned reflex and decisively take braking measures.
In addition, the operator should be very familiar with the processing program of CNC machine tools;
You should be very familiar with what kind of process and operation, and what kind of action the machine tool should have.
When the machine tool executes the program, you can know at the first time whether the action of the machine tool is correct and whether braking measures need to be taken.
In addition, every novice operator has more or less some fear in the early stage of operating the machine tool, fearing that the machine tool will collide with the knife and machine.
Only after the operator has mastered the operation of CNC machine tools, can he overcome similar fear and learn to master higher CNC machine tool operation skills on this basis.
Third, we should master program editing, parameter compensation of each process and compensation of the diameter and length of the cutter or grinding wheel.
First, after training, master the programming language, programming method and parameter compensation method of the NC machine tool you want to operate.
If you don’t want to be engaged in the operation of the bottom of the machining center all the time, now most advanced CNC machines are equipped with PC workstations for programming or simulation.
Then beginners can first carry out software editing and simulation learning of machine tool cutting on the workstation.
In the process of learning programming, we should not only pay attention to the simulation results, but also learn the process of simulation processing.
We should understand what kind of cutting tools or grinding wheels are needed for the processing of workpieces, and what kind of motion path the NC axis of the machine tool completes the cutting process;
Master the position and direction of the relevant parts in the machine tool when the machine tool performs a specific process;
Pay attention to the movement direction and cutting direction of each axis during machining, including how to feed and withdraw the tool, and pay attention to the fast forward speed and displacement of each step during machining, and the speed and displacement of each step during machining.
When processing through simulation software, pay attention to the correct input of all parameters in the simulation process, and do not input carelessly because of simulation, which may lead to incorrect simulation processing results;
Or cause collision accidents during actual processing in the future, or parts are scrapped.
If the simulation software has the function of anti-collision test, it is necessary to use this function to check the correctness of programming.
In addition, the operator needs to pay special attention: simulation processing is only a theoretical result, which does not mean that the machine tool will not collide in the actual cutting process, nor does it mean that qualified products can be processed.
The purpose of the simulation is to save programming time, improve the actual utilization of machine tools, and reduce the debugging time when processing workpieces, which does not represent the actual part processing.
The completion of perfect workpiece processing is inseparable from the wisdom and sweat of CNC machine tool operators.
Key point 4: the processing skills in the actual processing process should be carefully prepared.
First, read the drawing, confirm the position of the workpiece to be processed, confirm the accuracy tolerance of the part of the workpiece to be processed, and then edit the processing program.
Prepare the workpiece, cutter or grinding wheel required in the processing, the testing instruments required in the processing, and the auxiliary tooling and fixtures required in the processing.
Tips for using CNC machine
At present, in the field of machining, numerical control machine tools have many advantages compared with traditional machine tools, so they are increasingly used.
However, the equipment is a combination of machine, electricity, hydraulic, gas, microelectronics and other technologies, and it is difficult to eliminate and maintain after faults occur.
This requires operators to pay attention to prevention when using CNC machine tools, so as to reduce the probability of failure and improve the utilization of machine tools.
1. Before use:
Before using the machine tool, the machine tool should be placed in a relatively dust-free place with constant temperature and humidity according to the technical requirements of the NC machine tool for the installation and use environment.
Although it is difficult to do so at present, we should try to create conditions as close as possible to such a use environment.
In addition, when the machine tool is installed and used normally, the following contents should also be paid attention to:
Before using the machine tool, checking the machine tool can reduce the failure of the machine tool in the process of use and the impact on production.
(1) Before power on, check the appearance of the CNC machine tool, electrical pipelines and some external auxiliary equipment for abnormalities.
Especially for external auxiliary equipment: if there is a hydraulic system pump station, observe whether the amount of hydraulic oil is sufficient;
For those with air pressure system, regular drainage of air compressor and gas storage pressure vessel shall be carried out to prevent excessive moisture from accumulating and entering the machine tool under the drive of air flow, causing corrosion and even damage of parts and components.
(2) Power on, according to the normal power on sequence:
The main power supply of the machine tool – the power supply of the CNC system – the power supply of the servo system – release the emergency stop button to reduce the impact on the electrical components of the CNC system and prolong the service life.
(3) After power on, lubrication is an indispensable condition for any moving parts to maintain normal motion trajectory, reduce motion friction and improve service life.
This requires us to pay attention to check whether the amount of lubricating oil in the lubricating device is sufficient, and replenish it in time when it is insufficient.
In addition, we should regularly check whether the liquid filter screen is blocked, whether the oil circuit is smooth, and whether there is normal outflow of lubricating oil at each oil outlet.
Once such problems are found, they must be dealt with in time.
If the moving parts such as machine tool guide rails and lead screws work without lubricating oil, on the one hand, it will increase the friction resistance, increase the power consumption of the machine tool, and waste electric energy.
On the other hand, it will accelerate the wear of moving parts, affect the accuracy of the machine tool, and affect the quality of workpiece processing.
2. In use:
During the use of the NC machine tool, it should be strictly controlled within the range of its use parameters, otherwise, it may cause damage to the machine tool.
For example, the workpiece and its fixture accessories placed on the workbench of the machining center and NC milling machine should not exceed the maximum load of the workbench, otherwise, it will cause damage to the moving guide rail;
Try not to overload the cutting force, otherwise, it will cause damage and failure of the transmission mechanism, and even burn the spindle motor or feed shaft motor due to excessive current.
At the same time, try to avoid the natural frequency of the machine tool to prevent resonance, affect the machining accuracy, and even cause damage of cutting tools and machine tool components.
In the use of machine tools, we can fully mobilize our various senses, listen, touch, see, smell, etc., and timely find and solve problems.
(1) Listen to the sound.
When the machine tool is running, there will be a certain sound, but we also need to pay attention to whether there is any abnormal sound, such as the sound of air pipe bursting and leakage, the sound of sudden change of the lubrication system “click”, the “squeak” of tool cutting, etc.
In case of such abnormal sound, we must stop in time to prevent the situation from expanding.
(2) Touch the temperature of the machine tool.
It is normal for the machine tool to have a certain temperature rise when it is running, because there is friction during the operation process, resulting in heat.
Generally, when the machine tool operates for a certain time, it will reach the heat balance, that is, the temperature will basically remain constant, about 50-60 degrees.
If you put it on and dare not stay, it means that the temperature is on the high side at this time, and you should check whether the lubrication is sufficient.
(3) Look at the parts with poor working conditions of the machine tool. When the NC machine tool is processing, it is necessary to spray coolant most of the time to wash and cool the workpiece and tools at one time.
In this way, the working conditions of some parts are very poor due to the presence of scrap iron and cutting fluid.
In particular, the travel switch of the tool holder moving forward and backward on the NC machine tool is very likely to rush into the scrap iron, so the expansion and contraction of its contact are not flexible enough.
At this time, we need to be diligent and clean it in time.
In addition, during partial cutting, banded iron filings may also be produced, which are easy to wrap around the tools and workpieces, affecting the cooling effect and causing extrusion, causing damage to the tools, which also need to be cleaned in time.
3. After use:
(1) To shut down the machine correctly, follow the correct shutdown sequence: emergency stop button – servo system power supply – CNC system power supply – machine tool main power supply.
(2) Clean the machine in time and carry out daily maintenance.
After the use of the machine tool, clean it in time, and then apply engine oil on the moving guide rail surface of the machine tool and the surface of some parts for rust prevention maintenance.
The above are some problems that should be paid attention to in the use of CNC machine tools.
We should pay attention to them in the whole process, so as to give full play to the efficiency of machine tools, improve processing quality and produce expected benefits.
Maintenance of CNC machine
- Operating environment of CNC machine tool: For CNC machine tools, it is best to place them in a constant temperature environment and away from equipment with large vibration (such as punch) and equipment with electromagnetic interference;
- Power requirements;
- CNC machine tools should have operating procedures: Carry out regular maintenance, record and protect the site in case of failure;
- CNC machine tools should not be sealed for a long time, which will lead to storage system failure and data loss;
- Pay attention to the training and allocation of operators, maintenance personnel and programmers.
Maintenance of CNC system
- Strictly abide by the operating procedures and daily maintenance system.
- Prevent dust from entering the numerical control device: Floating dust and metal powder are easy to cause the insulation resistance between components to drop, resulting in failure or even damage to components.
- Regularly clean the heat dissipation and ventilation system of the data control cabinet.
- Frequently monitor the grid voltage of the CNC system: The grid voltage range is 85% – 110% of the rated value.
- Replace the storage battery regularly.
- Maintenance of CNC system when it is not used for a long time: Often power on the CNC system or make the CNC machine run the warm-up program.
- Maintenance of spare circuit board and mechanical parts.
Maintenance of mechanical parts
(1) Maintenance of tool magazine and tool changing manipulator
- When manually loading the tool into the tool magazine, ensure that it is installed in place, and check whether the locking on the tool base is reliable;
- It is strictly prohibited to load overweight and overlong tools into the tool magazine to prevent the manipulator from dropping the tool or collision between the tool and the workpiece, fixture, etc;
- When using the sequential tool selection method, pay attention to whether the order of placing the tools on the tool magazine is correct. Other tool selection methods should also pay attention to whether the tool number changed is consistent with the required tool, so as to prevent accidents caused by changing the wrong tool;
- Pay attention to keeping the tool handle and sleeve clean;
- Always check whether the zero return position of the tool magazine is correct, check whether the position of the tool change point of the machine tool spindle is in place, and adjust it in time, otherwise the tool change action cannot be completed;
- When starting up, the tool magazine and manipulator should be operated empty first, and check whether all parts work normally, especially whether all travel switches and solenoid valves operate normally.
(2) Maintenance of ball screw pair
- Regularly check and adjust the axial clearance of the screw nut pair to ensure the reverse transmission accuracy and axial stiffness;
- Regularly check whether the connection between the lead screw support and the bed is loose and whether the support bearing is damaged. In case of the above problems, tighten the loose parts in time and replace the support bearing;
- For ball screw with lubricating grease, clean the old grease on the screw every six months and replace it with new grease. The ball screw lubricated with lubricating oil shall be lubricated once a day before the machine tool works;
- Pay attention to prevent hard dust or chips from entering the protective cover of the lead screw and hitting the protective cover during work. Replace the protective device in time if it is damaged.
(3) Maintenance of main drive chain
- Regularly adjust the tightness of the spindle drive belt;
- Prevent all kinds of impurities from entering the oil tank. Replace the lubricating oil once a year;
- Keep the connecting part between the spindle and the handle clean. The displacement of the hydraulic cylinder and piston shall be adjusted in time;
- Adjust the counterweight in time.
(4) Hydraulic system maintenance
- Filter or change the oil regularly;
- Control the temperature of the oil in the hydraulic system;
- Prevent hydraulic system leakage;
- Regularly check and clean the oil tank and pipeline;
- Implement the daily point inspection system.
(5) Maintenance of the pneumatic system
- Remove impurities and moisture from compressed air;
- Check the oil supply quantity of the oil atomizer in the system;
- Maintain the tightness of the system;
- Pay attention to adjusting the working pressure;
- Clean or replace pneumatic components and filter elements.
Troubleshooting of CNC machine
In CNC machine tools, most of the faults have data to check, but there are also some faults.
The alarm information provided is vague or even no alarm at all, or the occurrence period is long, irregular and irregular, which brings many difficulties to the search and analysis.
For this kind of machine tool failure, it is necessary to analyze the specific situation and find it patiently, and the comprehensive knowledge of machinery, electrical, hydraulic and other aspects is particularly needed during the inspection, otherwise, it is difficult to find the real cause of the failure quickly and correctly.
Abnormal processing accuracy fault: Changes or changes in system parameters, mechanical failures, non-optimization of machine tool electrical parameters, abnormal motor operation, abnormal machine tool position ring, or improper control logic are common causes of abnormal machining accuracy of CNC machine tools in production.
Find out the relevant fault points and deal with them, and the machine tools can return to normal.
In production, we often encounter the fault of abnormal machining accuracy of CNC machine tools. Such faults are hidden and difficult to diagnose.
There are five main reasons for such failures:
- The feed unit of the machine tool is changed;
- The zero offset (null offset) of each axis of the machine tool is abnormal;
- The axial reverse clearance is abnormal;
- Abnormal motor operation status, i.e. electrical and control part failure;
- Mechanical failure, such as screw, bearing, coupling and other components.
In addition, the compilation of machining program, the selection of cutting tools and human factors may also lead to abnormal machining accuracy.
For abnormal machining accuracy caused by mechanical failure, the following aspects should be checked one by one.
- Check the processing program segments that are running when the machine tool accuracy is abnormal, especially the tool length compensation, the calibration and calculation of the processing coordinate system (G54 ~ G59).
- In the inching mode, repeatedly move the Z-axis, and through the diagnosis of its motion state through sight, touch and hearing, it is found that the sound of Z-direction motion is abnormal, especially the rapid inching, and the noise is more obvious. Judging from this, there may be hidden dangers in the mechanical aspect.
Initialization reset method:
Generally, the system alarm caused by transient fault can be cleared by hardware reset or by switching the system power supply in turn.
If the system working storage area is confused due to power failure, plugging in and unplugging the circuit board or undervoltage of the battery, the system must be initialized and cleared.
Before clearing, pay attention to make a copy of the data and record it.
If the fault still cannot be eliminated after initialization, carry out hardware diagnosis.
Parameter change, program correction method:
System parameters are the basis for determining system functions.
Wrong parameter settings may cause system faults or invalid functions.
Sometimes, due to user program errors, it can also cause fault downtime.
For this, the block search function of the system can be used to check and correct all errors to ensure its normal operation.
Adjustment, optimization adjustment method:
Regulation is the simplest way.
Correct the system fault by adjusting the potentiometer.
For example, in the maintenance of a factory, the system display screen is chaotic and normal after adjustment.
For example, in a factory, the belt slipping of its main shaft occurs during startup and braking, because the load torque of its main shaft is large, and the ramp up time of the driving device is set too small, which is normal after adjustment.
Optimization adjustment is a comprehensive adjustment method to systematically achieve the best match between the servo drive system and the driven mechanical system.
The method is very simple.
Use a multi line recorder or a dual trace oscilloscope with storage function to observe the response relationship between command and speed feedback or current feedback respectively.
By adjusting the proportional coefficient and integral time of the speed regulator, the servo system can reach the best working state with high dynamic response characteristics and no oscillation.
When there is no oscilloscope or recorder on site, according to experience, adjust to make the motor vibrate, and then slowly adjust in the opposite direction until the vibration is eliminated.
Spare parts replacement method:
Replace the diagnosed bad circuit board with good spare parts, and do the corresponding initialization startup, so that the machine tool can be put into normal operation quickly, and then repair or repair the bad board, which is the most commonly used troubleshooting method.
Method of improving power quality:
Generally, regulated power supply is used to improve power fluctuation. For high-frequency interference, the capacitance filtering method can be used to reduce the failure of the power board through these preventive measures.
Maintenance information tracking method:
Some large manufacturing companies constantly modify and improve the system software or hardware according to the accidental faults caused by design defects in actual work.
These modifications are constantly provided to maintenance personnel in the form of maintenance information.
Taking this as the basis for troubleshooting, the fault can be eliminated correctly and completely.
The electrical fault diagnosis of CNC machine tools has three stages: fault detection, fault judgment, isolation and fault location.
The first stage of fault detection is to test the CNC machine tool to determine whether there is a fault;
The second stage is to determine the nature of the fault and separate the faulty components or modules;
The third stage is to locate the fault to the replaceable module or printed circuit board to shorten the repair time.
In order to find the fault of the system in time, quickly determine the location of the fault and eliminate it in time, it is required that the fault diagnosis should be as few and simple as possible, and the time required for fault diagnosis should be as short as possible. For this purpose, the following diagnostic methods can be used:
1. Intuitive method
Using the sensory organs, pay attention to various phenomena in the event of failure, such as whether sparks and light are produced, whether there is abnormal noise, where there is abnormal fever, and whether there is coke and smell, etc.
It is the most basic and commonly used method to carefully observe the surface condition of each printed circuit board that may fail, and whether there are signs of burning and damage, so as to further narrow the scope of the inspection.
2. Self-diagnosis function of CNC system
Relying on the ability of rapid data processing of CNC system, multi-channel and rapid signal acquisition and processing are carried out for the wrong part, and then the logic analysis and judgment are carried out by the diagnostic program to determine whether there is a fault in the system and locate the fault in time.
The self-diagnosis function of modern CNC system can be divided into the following two categories:
- Power on self-diagnosis Power on self-diagnosis refers to the function test of CPU, memory, bus, i/o unit and other modules, printed circuit board, CRT unit, photoelectric reader, floppy disk drive and other equipment before the operation, which is automatically performed by the diagnostic program inside the system from the beginning of each power on to enter the normal operation preparation state, to confirm whether the main hardware of the system can work normally.
- Fault information prompt When a fault occurs during the operation of the machine tool, the number and content will be displayed on the CRT display.
According to the prompt, consult the relevant maintenance manual to confirm the cause of the fault and troubleshoot.
Generally speaking, the more abundant the fault information prompted by the diagnostic function of CNC machine tools, the more convenient the fault diagnosis can be.
It should be noted that some faults can be directly confirmed according to the fault content prompt and the manual;
However, the real cause of some faults is inconsistent with the fault content prompt, or a fault shows multiple fault causes, which requires the maintenance personnel to find out the internal relationship between them and indirectly confirm the fault cause.
3. Data and status check
The self-diagnosis of CNC system can not only display fault alarm information on CRT display, but also provide machine tool parameters and status information in the form of multi page “diagnostic address” and “diagnostic data”.
Common data and status checks include parameter check and interface check.
- Parameter check the machine data of the NC machine tool is an important parameter obtained through a series of tests and adjustments, which is the guarantee of the normal operation of the machine tool.
These data include gain, acceleration, contour monitoring tolerance, reverse clearance compensation value and lead screw pitch compensation value.
When subjected to external interference, the data will be lost or confused, and the machine tool will not work normally.
- Interface check the input/output interface signals between CNC system and machine tool, including the input/output signals between CNC system and PLC, and between PLC and machine tool.
The input/output interface diagnosis of the CNC system can display the status of all switching signals on the CRT display, and use “1” or “0” to indicate whether the signal is present or not.
Using the status display, you can check whether the CNC system has output the signal to the machine side, and whether the switching value and other signals on the machine side have been input to the CNC system, so that the fault can be located on the machine side or in the CNC system.
4. Alarm indicator display failure
In the CNC system of modern CNC machine tools, in addition to the above “software” alarms such as self diagnosis function and status display, there are many “hardware” alarm indicators, which are distributed on power supply, servo drive, input/output and other devices.
According to the indications of these alarm indicators, the cause of the fault can be determined.
5. Spare circuit board replacement method
Using the spare circuit board to replace the template with fault doubts is a fast and simple method to judge the cause of the fault, which is often used in the functional modules of CNC systems, such as CRT module, memory module, etc.
It should be noted that before replacing the spare board, relevant circuits should be checked to avoid damage to the good board due to short circuit.
At the same time, it should also be checked whether the selection switch and jumper wire on the test board is consistent with the original template.
For some templates, attention should also be paid to the adjustment of the potentiometer on the template.
After replacing the memory board, initialize the memory according to the requirements of the system, otherwise, the system still cannot work normally.
6. Exchange method
In CNC machine tools, there are often modules or units with the same function.
By exchanging the same modules or units with each other and observing the fault transfer, the fault location can be quickly determined.
This method is often used to check the fault of servo feed drive, and it can also be used to exchange the same modules in the CNC system.
7. Percussion method
The CNC system is composed of various circuit boards.
There are many solder joints on each circuit board. Any faulty soldering or poor contact may cause failure.
When gently tapping the circuit board, connector or electrical components with suspected faults with insulation, if the fault occurs, the fault is likely to be at the striking part.
8. Measurement comparison method
For the convenience of detection, the module or unit is equipped with detection terminals.
Using the multimeter, oscilloscope and other instruments and meters, the normal value is compared with the value at the time of fault through the level or waveform detected by these terminals, and the cause and location of the fault can be analyzed.
Because CNC machine tools have the characteristics of comprehensiveness and complexity, there are many factors that cause faults.
Sometimes, the above fault diagnosis methods need to be applied at the same time to comprehensively analyze the fault and quickly diagnose the fault position, so as to eliminate the fault.
At the same time, some fault phenomena are electrical, but the cause is mechanical;
On the contrary, it is also possible that the fault phenomenon is mechanical, but the cause is electrical; Or both.
Therefore, its fault diagnosis can not be simply attributed to electrical or mechanical aspects, but must be comprehensively considered.
Best CNC machine manufacturers
Top 10 machine tool manufacturers in the world in 2019 (unit: million dollars)
|Rankings||Company||Country||Revenue (million $)|
|3||DMG MORI||Germany & Japan||38.2|
Source: CCID Consulting
Top 10 machine tool enterprises in China in 2019 (unit: million yuan)
|2||Qinchuan machine tool||14.3|
|6||Shenyang Machine Tool||10.02|
|8||Kunming Machine Tool||4.97|
According to the statistics of the National Bureau of statistics, as of July 2020, there were 817 metal cutting machine tool enterprises in China, and the industrial sales profit margin was only 3.95%;
There are 526 metal forming machine tool enterprises in China, and the profit margin of the industry is 4.80%.
From November 2015 to July 2020, the sales profit margin of the metal cutting machine tool industry and forming machine tool industry was only 5.49% and 7.88% at the highest time.
At present, there are many domestic enterprises on the whole, but they are generally small in scale, weak in market competitiveness and poor in profitability.
How to choose the right CNC machine?
The following principles apply to the purchase of CNC machine tools:
- Stability and reliability.
If the selected CNC machine tool cannot work stably and reliably, it will completely lose its significance.
Therefore, when purchasing, we must try to choose famous brand products (including host, control system and accessories), because these products are technically mature, have a certain production batch, and have been used normally by users.
The purpose is to solve one or more problems in production.
Practicality is to make the selected CNC machine tools finally achieve the predetermined goal to the best extent.
Be careful not to trade for more complex CNC machine tools with too many functions and not practical at a high cost.
With a clear goal and targeted selection of machine tools, we can obtain the best effect with reasonable investment.
Economy refers to the fact that the purchased CNC machine tool pays the least or the most economical price when it meets the processing requirements.
Choose a fully functional and more advanced CNC machine tool.
If there is no proper person to operate or program, and no skilled repairman to maintain and repair, no matter how good the machine tool is, it cannot be used well and play its due role.
Therefore, when choosing CNC machine tools, we should consider whether it is convenient to operate, program and maintain.
Otherwise, it will not only bring difficulties to the use, maintenance, repair and other aspects of CNC machine tools, but also cause a waste of equipment.
- Shop around.
Strengthen market research, conduct technical consultation with departments that know about CNC machine tools or experienced users of CNC machine tools to have a more comprehensive understanding of the market situation of CNC machine tools at home and abroad as far as possible.
And make full use of various exhibitions to select equipment with high quality, low price and reliable performance, so as to strive to compare goods.
We must choose mature and stable products according to the actual needs of our unit.
Precautions for purchasing CNC machine tools:
- Reasonably determine the functions of CNC machine tools.
When selecting the functions of CNC machine tools, we should not pursue large and complete functions, because if we excessively pursue the number of coordinate axes of CNC machine tools, large power of worktops and motors, high machining accuracy and complete functions, the more complex the system will be and the lower the reliability will be.
Purchase and maintenance costs will also increase.
On the one hand, the processing cost will increase correspondingly.
On the other hand, it will cause a great waste of resources.
Therefore, CNC machine tools should be selected according to the specifications, dimensions and accuracy of the products.
- Determine the processed parts.
CNC machine tools should be reasonably selected according to the typical parts that need to be processed.
Although CNC machine tools have the characteristics of high flexibility and strong adaptability, the best effect can be achieved only by processing certain parts under certain conditions.
Therefore, before choosing equipment, we must first determine the typical parts to be processed.
- Reasonable selection of CNC system.
The CNC system that can meet the requirements of various performance parameters and reliability indicators should be considered in detail, and the convenience of operation, programming, maintenance and management should be considered.
Try to be centralized and unified.
If it is not a special case, try to use the same series of CNC systems familiar to the unit and produced by the same manufacturer for future management and maintenance.
- Configure necessary accessories and tools.
In order to give full play to the role of CNC machine tools and enhance their processing capacity, necessary accessories and tools must be equipped.
Do not buy a machine tool that costs hundreds of thousands of yuan or millions of yuan.
It cannot be used normally due to the lack of an accessory or cutting tool that costs tens of thousands of yuan.
When purchasing the host, purchase some vulnerable parts and other accessories.
Foreign metal cutting experts believe that the efficiency of a $250000 CNC machine tool depends largely on the performance of a $30 end mill.
It can be seen that equipping CNC machine tools with good performance tools is one of the key measures to reduce costs and obtain the maximum comprehensive economic benefits.
Generally, NC machine tools should be equipped with enough tools to give full play to the functions of NC machine tools, so that the selected NC machine tools can process multiple product varieties and prevent unnecessary idleness and waste.
- Pay attention to the installation, commissioning and acceptance of CNC machine tools.
After entering the factory, CNC machine tools should be carefully installed and debugged, which is very important for future operation, maintenance and management.
During the installation, commissioning and trial operation of CNC machine tools, technicians must actively participate, carefully study, and humbly accept the technical training and on-site guidance of suppliers.
Carry out a comprehensive acceptance of the geometric accuracy, positioning accuracy, cutting accuracy, machine performance and other aspects of the NC machine tool.
Carefully check the supporting technical materials, operation manuals, maintenance manuals, attachment instructions, computer software and instructions, and keep them properly, otherwise some additional functions will not be developed in the future and it will be difficult to maintain and maintain the machine tool.
Finally, the after-sales service, technical support, personnel training, data support, software support, installation and commissioning, spare parts supply, tool system and machine tool accessories of the NC machine tool manufacturer should be fully considered.
Future development trend of CNC machine tools
The future development trend of CNC machine tools is intelligent manufacturing.
Intelligent manufacturing is a new production mode based on the deep integration of new generation information and communication technology and advanced manufacturing technology, which has the functions of self-perception, self-learning, self decision-making, self execution, self adaptation and so on.
Intelligent manufacturing is a new production mode based on the deep integration of new generation information and communication technology and advanced manufacturing technology, which runs through all links of manufacturing activities such as design, production, management and service, and has the functions of self perception, self-learning, self decision-making, self execution, self adaptation and so on.
The establishment of intelligent chemical plant is the internal requirement of the development of intelligent manufacturing.
Intelligent workshop is an important part of the intelligent factory, and intelligent equipment is an important support for intelligent workshop.
Intelligent manufacturing has the characteristics of taking intelligent factory as the carrier, intelligentization of key manufacturing links as the core, end-to-end data flow as the basis, and network interconnection as the support.
The establishment of intelligent chemical plant is the internal requirement of the development of intelligent manufacturing.
Intelligent machine tools are machine tools that can monitor themselves, analyze many information related to machine tools, processing status, environment and other factors, and then take countermeasures to ensure optimal processing.
With the development of computer network, communication and artificial intelligence technology, intelligent machine tool technology theory based on eight technologies has gradually formed a system.
Compared with ordinary CNC machine tools, data collection, control and communication modules play an important role in intelligent machine tools.
Data collection is mainly completed by intelligent sensors arranged on site.
The main purpose of intelligent machine tools determines the type of intelligent sensors.
Common intelligent sensors are powerful, temperature, vibration, sound, energy, liquid, identity recognition and other intelligent sensors.
The control module is mainly based on the on-line adjustment algorithm of NC program, intelligent decision-making and optimization method of process parameters, coordination technology of executive parts, automatic loading and unloading control technology and other methods.
The communication module is based on wireless communication network technology.
Comparison between traditional workshop and intelligent workshop.
|Traditional workshop||Intelligent workshop|
|Equipment||CNC machine||Intelligent machine tool|
|Communication mode||Mobile storage device copy (USB flash disk, etc.)||Wireless communication technology (Wifi/Zigbee)|
|Production process||Open loop / half open loop|
Parts processing; One person with one device.
Monitor the machine, one person with multiple devices