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History of metal manufacturing

Hardware manufacturing industry has a long history. Exploring the source of its development can almost keep pace with the history of China. Computer gong processing after thousands of years of history of ups and downs, to now, all aspects have gradually matured and improved. Dongguan high-speed computer gong processing, but China’s hardware enterprises are mainly small and medium-sized enterprises. In recent years, under the fierce competition at home and abroad, some small and medium-sized enterprises are facing various difficulties, struggling in the edge of life and death.

Change is the only way out.

Many hardware manufacturing enterprises have recognized this problem and began to make changes, but they often treat the symptoms rather than the root causes, ignoring the most important things. In order to find a way out, some enterprises began to learn the advanced western marketing methods and conduct in-depth research on the market, such as computer gong processing, Dongguan computer gong processing, Shenzhen computer gong processing, mechanical parts processing, Guangzhou computer gong processing, selling through the Internet, or changing to service-oriented, making the slogan “customer is God, service is life”, or thinking “channel” Tao is the king. “I think the ultimate goal of producing products is to sell them.

Some small and medium-sized hardware enterprises with low technology content and labor-intensive attribute their deficiencies to the lack of advanced machines. Dongguan mold processing thinks that the reason why they can’t be bigger and stronger is because of the lack of capital and strength, and they can not increase the investment in science and technology independently. They can only cooperate with a number of small enterprises or be absorbed by large enterprises to strengthen their strength. Finally, they lose themselves on the stage of hardware and gradually lose themselves Die out.

No doubt, these changes in technology and sales have stimulated the traditional hardware products, making them glow with new vitality. Computer gong processing, Dongguan computer gong processing, Shenzhen computer gong processing, mechanical parts processing, Guangzhou computer gong processing, but most of these improvements are temporary, and have changed vigorously for more than ten years, but the difficulties faced by China’s hardware manufacturing industry have never been solved Fundamentally changed, most of the small and medium-sized hardware enterprises are still in the world market, unable to get steady development.

If we stop to look at the manufacturing power – “Germany”, we will find that in fact, we are not too many small and medium-sized enterprises, but neglect the most basic thing – a heart that wants to make high-quality products. Dongguan Machinery parts processing when an enterprise to put a stable mind, no longer for profit and production, do not rely on low-cost labor, do not blindly invest money for equipment, machinery and technology is only icing on the cake, CNC processing brand and success is only a natural thing. Germany’s manufacturing industry is well-known in the world, and some small companies can also become big brands, thus being sought after by the world

CNC machining machine maintenance content

Maintenance contents:

1. Replace X-axis screw rod, screw nut, wire rail and bearing, adjust and repair the parallelism, twist degree, horizontal equal height of two line rails, manual scraping, screw rod and screw mother seat, and the comprehensive accuracy of bearing seat processed by Dongguan high-speed computer gong (parallel, equal height, center, twist, etc.) error is within 0.005 range. (remarks: one set of Haiwei ball screw, one set of Taiwan Haiwei linear guide rail, and six Japanese original nskp4 bearings).

2. Replacement of y-axis screw rod, screw nut, wire rail, bearing, adjustment and repair of the parallelism, twist, level and equal height of the two line rails, manual scraping, screw rod, screw mother seat, computer gong processing, Dongguan computer gong processing, Shenzhen computer gong processing, mechanical parts processing, Guangzhou computer gong processing

The comprehensive accuracy of the bearing pedestal (parallel, equal height, center, twist, etc.) error is in the range of 0.005. CNC processing (Note: Taiwan Haiwei ball screw set of 2500 yuan, Taiwan Haiwei linear guide rail set, Japanese original nskp4 level bearing 6).

3. Check and repair x, Y axis, mutual comprehensive accuracy, complementary accuracy, perpendicularity, displacement error (range 500mm ≤ 0.01mm)

4. Z axis precision adjustment, eliminate working clearance, vertical error 500mm ≤ 0.01mm, adjust the level of two line rails, Dongguan mold processing | twist degree, screw rod, screw nut adjustment, eliminate clearance, positioning accuracy, control within 0.005 range.

5. Unit maintenance, geometric accuracy, adjustment and repair, oil channel dredging, to make it meet the normal use standard. Positioning accuracy, linear interpolation, clockwise circular arc interpolation, screw interpolation, counter clockwise circular arc, spiral interpolation, cylindrical column difference compensation, etc. Dongguan machine parts processing system adjustment, mechanical adjustment, control panel, repair reset, replace the required accessories button, to achieve a clean appearance, flexible operation

The future of machining

(1) There are tens of thousands of old and backward machine tools in our country, which are the realistic basis of machine tool overhaul and CNC transformation industry

China is a developing country. Due to the long-term inadaptability of its own mechanism, the economic strength is too low, the technology is backward and the equipment is obsolete. The computer gong processing, Dongguan computer gong processing, Shenzhen computer gong processing, mechanical parts processing, Guangzhou computer gong processing have greatly restricted the development of the national economy. In order to change the backwardness of China’s machinery manufacturing industry as soon as possible, in the past 20 years, while developing the national machine tool manufacturing industry, we have actively introduced the world’s advanced technology and equipment. On the one hand, it cooperates with the world’s advanced machine tool manufacturers to continuously produce all kinds of machine tools with the world’s advanced level; on the other hand, it has directly purchased a large number of various types of machine tools. All these have played a huge role in the rapid development of China’s national economy. Dongguan computer gong Processing Factory Dongguan machine parts Processing Factory Dongguan mold processing factory Shenzhen computer gong processing.

However, the long-term operation of machine tools even overload use, and lack of serious repair and maintenance, resulting in serious wear and loss of precision; some machine tools are idle for a long time due to the change of enterprise personnel and product structure, or due to the lack of technical force, they are found to be rusty and the electronic control system can not be started up when they are used; due to the need of new product manufacturing, the machine tool has been seriously worn and lost its precision Due to the rapid development of computer and network technology in the world, the product update of CNC system and drive system factory is accelerated, and the original product is stopped prematurely, which brings some difficulties for the replacement and maintenance of spare parts. Moreover, the service life of CNC system is generally 5-10 years, while most of the machine tools in China are in the process of upgrading Extended service. Computer gongs processing, Dongguan computer gongs processing, Shenzhen computer gongs processing, mechanical parts processing, Guangzhou computer gongs processing, all of these factors need to be overhauled and CNC upgraded.

(2) A large number of new used machine tools have become the catalyst for machine tool overhaul and numerical control transformation industry. Since the reform and opening up, many enterprises have introduced a large number of obsolete machine tools from abroad. Although some of them can still meet the use requirements, most of them are still lack of experience, technology, data and spare parts, resulting in the embarrassment that although they are purchased cheaply, they can not continue to play a role The situation. Among them, there are many old machine tools and production lines introduced for use after transformation. Most of the second-hand machine tools here can play a role as long as they have appropriate capital investment, after overhaul and transformation, Dongguan computer gong processing factory, Dongguan machine parts processing factory, Dongguan mold processing factory, Shenzhen computer gong processing factory.

(3) Significant economic benefits are the driving force for the development of machine tool overhaul and numerical control transformation industry. For machine tool owners, they can get the same effect by spending less than 30% of the cost of purchasing the same new machine tool. According to the international records of the industry, even if the structural performance of the original machine tool is completely transformed and upgraded, it only costs about 60% of the price of the new machine tool.

Three elements of cutting conditions

The three elements of cutting conditions: cutting speed, feed and cutting depth directly cause damage. With the increase of cutting speed, the point temperature will rise, resulting in mechanical, chemical and thermal wear. If the cutting speed is increased by 20%, the tool life will be reduced by 1 / 2.

Back feed conditions and tool wear are kept to a minimum. But feeding behind, cutting temperature rise, wear. It is less than the effect of cutting speed. Cutting depth has no effect on cutting speed and feed, small cutting depth, but cutting material in hardened layer will also affect tool life.

According to the user’s processing material, hardness, cutting conditions, material selection, feed and cutting depth, the cutting speed is used.

Based on the selection of the most suitable process conditions, these factors are selected. Regular life and stable wear are the most ideal conditions.

However, in practice, the selection of tool life and tool wear, through machining size, surface quality, noise reduction, heat and so on. Under certain processing conditions, it is necessary to study according to the actual situation. Difficult to machine materials such as stainless steel, heat-resistant alloy, can use coolant or choose a good rigid blade.

Reasonable selection of cutting tools

1。 Rough rotation, should choose high strength, good durability knife, in order to meet the large car turning, feedback.

2。 The essence of automobile is to select high precision, durable and good cutting tools to ensure the machining accuracy.

3。 Reduce the conversion time and knife convenience, should try to use machine knife and machine clip blade.

Select fixture

1。 General fixture should be selected to clamp workpiece as much as possible, and special fixture should be avoided;

2。 The coincidence of parts positioning datum reduces the positioning error.

Determine the processing route

Machining path is the part of tool path and direction relative to each other in the process of exponential control.

1。 It should be able to meet the requirements of machining accuracy and surface roughness;

2。 Computer gong processing | Dongguan computer gong processing | Shenzhen computer gong processing | mechanical parts processing | Guangzhou computer gong processing

Shorten the processing route as far as possible and reduce the idle travel time of the tool.

Direction of foundry machine tool industry

Compared with the casting machine tool industry, computer gong processing, Dongguan high speed computer gong processing, Dongguan mold processing, Dongguan Mechanical parts processing, CNC processing, China’s casting machine tool industry is obviously backward in the production process level, which makes it has obvious deficiencies in the technical level and running speed of the core operating parts, the accuracy of the finished products and the reliability of the machine tools. It can be seen that the development of China’s foundry machine tool industry must start to actively seek new direction and concept.

Revolution becomes a new driving force in the field of casting machine tools

In order to meet the needs of industrial structure adjustment and low-carbon economy development and realize the scientific development of precision casting industry, the following work should be focused on:

1. To cultivate strategic emerging industries and modern production and service industries, so as to adapt to the transformation requirements of downstream areas, and provide support for the stable and rapid development of China’s equipment production industry. Dongguan CNC processing provides the basis for the establishment of modern casting industry system.

2. The network system of education and training in the field of precision casting has been constructed comprehensively. Various forms of school running can effectively cover the whole field of foundry education and training.

3. To help enterprises effectively use WTO and other international rules to deal with trade disputes such as anti-dumping and strive for the right of discourse in the international trade system.

4. Adhering to the principle of “go out, please come in”. On the basis of well running the high-level forum on China’s precision casting industry and the high-level forum on casting industry in mainland China, high-speed computer gongs processing in Dongguan, mold processing in Dongguan, mechanical parts processing in Dongguan, CNC processing, etc., will further improve the high-level forum of Asian casting industry and the high-level forum of BRICs casting industry, and actively participate in the world foundry industry Layer forum.

5. Substantive participation in international standardization work. During the 12th Five Year Plan period, several draft International Foundry specifications formulated by China will be submitted to the international standardization organization.

6. To carry out the National Foundry credit rating evaluation.

Operation method of CNC machining

Easy to operate: users only need to follow the menu to operate correctly. Convenient programming: it has a variety of programming functions, automatic program verification and simulation functions. Convenient maintenance and repair: some routine maintenance work is carried out automatically (lubrication, regular inspection of key components, etc.), and the self diagnosis function of CNC machine tool can quickly realize accurate fault location.

1. Computer gong processing is easy to realize mechatronics

The small volume of CNC system control cabinet, computer gong processing, Dongguan computer gong processing, Shenzhen computer gong processing, mechanical parts processing, Guangzhou computer gong processing (using computer, the number of hardware is reduced; the integration of electronic components is higher and higher, and the hardware is decreasing), which makes it possible to combine it with the machine tool in physics, reduce the floor area and facilitate operation.

2. Computer gong processing has flexibility and versatility

Most of the functions of mechanical parts processing device are realized by software, and the software and hardware adopt modular structure, which makes the modification and expansion of system functions more flexible. The basic configuration of mechanical parts processing device is universal. Different CNC machine tools only configure corresponding specific function modules to achieve specific control functions.

3. Computer gong processing has rich functions of numerical control

Interpolation function: quadratic curve, spline, spatial surface interpolation

Compensation function: motion precision compensation, random error compensation, nonlinear error compensation, etc

Computer gong processing, Dongguan computer gong processing, Shenzhen computer gong processing, mechanical parts processing, Guangzhou computer gong processing, man-machine dialogue function: processing dynamic and static tracking display, advanced man-machine dialogue window

Comprehensive machining of parts processed by CNC

Compared with traditional machine tools, numerical control system and corresponding monitoring devices are added, and a large number of electrical, hydraulic and electromechanical devices are applied. Computer gong processing | Dongguan computer gong processing | Shenzhen computer gong processing | mechanical parts processing | Guangzhou computer gong processing

It is easy to increase the probability of failure; the fluctuation and interference of industrial power grid voltage are extremely unfavorable to the reliability of CNC machine tools, while the parts machined by CNC machine tools are more complex, and the processing cycle is long, and the average time between failures is required to be more than 20000 hours. In order to ensure the high reliability of the CNC system, we must find out the weak link of the machine tool through the analysis of the high reliability and the manufacturing mode. The average time between failures of foreign CNC systems is more than 70000 hours, while that of domestic CNC systems is only about 10000 hours. The average time between failures of foreign CNC systems is more than 800 hours, while that of domestic CNC systems is only 300 hours.

Green processing

With the increasingly strict environmental and resource constraints, the green manufacturing and processing is becoming more and more important, and China’s resources and environmental problems are particularly prominent. Computer gong processing | Dongguan computer gong processing | Shenzhen computer gong processing | mechanical parts processing | Guangzhou computer gong processing

Therefore, in recent years, no or less use of coolant, dry cutting, semi dry cutting energy-saving and environmental protection machine tools continue to appear, and in the continuous development. In the 21st century, the trend of green manufacturing will accelerate the development of various energy-saving and environmental protection machine tools and occupy more world markets.

Application of multimedia technology

Multimedia technology integrates computer, audio-visual and communication technology, so that the computer has the ability to deal with sound, text, image and video information comprehensively, so it also puts forward the requirement of graphical user interface. Reasonable and humanized user interface greatly facilitates the use of non professional users. People can operate through windows and menus to facilitate the realization of blueprint programming and rapid programming, three-dimensional color three-dimensional dynamic graphic display, graphic simulation, dynamic tracking and Simulation of graphics, different directions of view and local display scaling function. In addition, the application of multimedia technology in the field of numerical control technology can achieve comprehensive and intelligent information processing. It can be used in real-time monitoring system and fault diagnosis of production field equipment, monitoring of production process parameters, etc., so it has great application value.

With the rapid development of CNC machine tools, high-speed, high-precision, compound, intelligent, open, parallel driven, networked, extreme, green has become the trend and direction of the development of CNC machine tools. China’s numerical control industry can not be content with the status quo, should seize the opportunity to continue to develop, strive to develop their own advanced technology, increase technological innovation and personnel training, improve the comprehensive service ability of enterprises, and strive to shorten the gap with developed countries. Strive to realize the transformation of CNC machine tool products from low-end to high-end, from primary product processing to high-end product manufacturing as soon as possible, and realize the transformation from made in China to created in China, from a large manufacturing country to a manufacturing power. Shenzhen haishuoda Technology Co., Ltd. has been adhering to the business philosophy of “quality first, customer first, steady development, continuous operation” and the operation style of “high standard, strict requirements, fast pace and high efficiency”. With the advanced consciousness of continuous innovation and enterprising spirit, we have won the trust and support of a large number of customers, and the scale of the company is growing steadily and rapidly.

However, in the CNC lathe processing, must abide by the following principles. Firstly, the process requirements of typical parts and the batch of workpieces are determined in the preliminary preparation. The function of NC lathe is to prepare well. The precondition of reasonable selection of NC lathe meets the process requirements of typical parts. The process requirements of typical parts mainly include the structural dimension, processing range and precision requirements of parts. Secondly, the control accuracy of CNC lathe is selected according to the cage requirements of precision Shanghai warehouse, that is, the dimensional accuracy, positioning accuracy and surface roughness of the workpiece. Computer gong processing | Dongguan computer gong processing | Shenzhen computer gong processing | mechanical parts processing | Guangzhou computer gong processing

Reliability is the guarantee to improve product quality and production efficiency. Finally, choosing the reasonable precision hardware processing technology can avoid waste and idle

As a single CNC grinder, it is difficult to complete all the processing contents of a part, and it needs to transfer and cooperate with the processing procedures of other equipment. Therefore, it is required to balance the production rhythm and workshop production capacity.

Intelligent fault replay and fault simulation technology for CNC machining

Adaptive control technology of machining process: through monitoring the cutting force, power, current, voltage and other information of the spindle and feed motor in the process of machining, the traditional or modern algorithm is used to identify the force, wear and damage status of the cutting tool and the stability state of the machine tool, and adjust the processing parameters (spindle speed, feed speed) in real time according to these states In order to improve the machining accuracy, reduce the surface roughness and improve the safety of the equipment operation, the equipment is in the best operation state;

(2) Intelligent optimization and selection of processing parameters: the experience of process experts or technicians, the general and special laws of parts processing, and the modern intelligent methods, such as computer gong processing, Dongguan computer gong processing, Shenzhen computer gong processing, mechanical parts processing, Guangzhou computer gong processing, are used to construct the intelligent optimization and selector of processing parameters based on expert system or model The optimized processing parameters are obtained to improve the programming efficiency and process level and shorten the production preparation time;

(3) Intelligent fault self diagnosis and self repair technology: according to the existing fault information, the application of modern intelligent methods to achieve rapid and accurate fault location;

(4) Intelligent fault playback and fault simulation technology: it can record all kinds of information of the system, replay and simulate all kinds of errors and accidents of CNC machine tools, so as to determine the causes of errors, find out solutions to problems, and accumulate production experience;

(5) Intelligent AC servo drive device: it can automatically identify the load and automatically adjust the parameters of the intelligent servo system, including intelligent Spindle AC drive device and intelligent feed servo device. The driving device can automatically identify the moment of inertia of the motor and load, and automatically optimize and adjust the parameters of the control system, so that the drive system can get the best operation;

(6) Intelligent 4m numerical control system: in the manufacturing process, the integration of processing and testing is an effective way to realize rapid detection and response of rapid manufacturing, computer gong processing, Dongguan computer gong processing, Shenzhen computer gong processing, mechanical parts processing, Guangzhou computer gong processing, measuring, modeling, manufacturing, and manufacturing The four parts (namely 4m) are integrated into one system to realize information sharing and promote the integration of measurement, modeling, processing, clamping and operation.

5. Open system

(1) Open to the future technology: because the software and hardware interfaces follow the recognized standard protocol, only a small amount of redesign and adjustment is needed, the new generation of general software and hardware resources may be adopted, absorbed and compatible by the existing system, which means that the development cost of the system will be greatly reduced, and the system performance and reliability will be continuously improved and will be in a long life cycle;

(2) Open to users’ special requirements: update products, expand functions, provide various combinations of hardware and software products to meet special application requirements;

(3) Establishment of numerical control standard: a new CNC system standard iso14649 (STEP-NC) is being researched and formulated internationally to provide a neutral mechanism independent of specific system, which can describe the unified data model of the whole product life cycle, so as to realize the standardization of product information in the whole manufacturing process and even in various industrial fields. The standardized programming language is not only convenient for users to use, but also reduces the labor consumption directly related to operation efficiency.

6-drive parallelization

Parallel motion machine tool overcomes the inherent defects of traditional machine tool series mechanism, such as high mass of moving parts, low system stiffness, tool can only feed along fixed guide rail, low degree of freedom of operation, and insufficient flexibility and mobility of equipment processing The length of the rod enables the platform supported by the bar system to obtain the corresponding degree of freedom movement, which can realize multi coordinate linkage NC machining, assembly and measurement functions, and can meet the processing of complex special parts. It has the advantages of high modularity, light weight and fast speed of modern robot.

As a new type of processing equipment, parallel machine tool has become an important research direction of current machine tool technology. It has been highly valued by the international machine tool industry. It is considered as “the most significant progress in the machine tool industry since the invention of numerical control technology” and “a new algebraic control processing equipment in the 21st century”.

7. Extreme (large scale and miniaturization)

The development of national defense, aviation and aerospace and the large-scale of energy and other basic industrial equipment need the support of large-scale and good performance CNC machine tools. Ultra precision machining technology and micro nano technology are strategic technologies in the 21st century, and new manufacturing processes and equipment that can adapt to micro size and micro nano machining accuracy need to be developed. Therefore, the demand for micro machine tools, including micro cutting (turning, milling, grinding) machines, micro electro machining machines, micro laser machining machines and micro presses, is gradually increasing.

8. Information exchange networking

For the enterprises facing fierce competition, it is very important to make CNC machine tools have bidirectional and high-speed network communication function, so as to ensure the smooth flow of information among various departments in the workshop. Computer gong processing | Dongguan computer gong processing | Shenzhen computer gong processing | mechanical parts processing | Guangzhou computer gong processing | not only can realize the network resource sharing, but also can realize the remote monitoring, control, training, teaching and management of CNC machine tools, and also can realize numerical control equipment

Use and maintenance of CNC machining

The use of integrated electronic components, chips and VLSI is the guarantee of the reliability of large-scale mechanical parts processing equipment. Many functions are realized by software, which reduces the number of hardware. Rich fault diagnosis and protection functions (mostly realized by software) can reduce the frequency of system failure and the repair time after failure.

2. Computer gong processing, easy to use and maintain

3. Computer gong processing is easy to realize mechatronics

The small volume of CNC system control cabinet (using computer, the number of hardware is reduced; the integration of electronic components is higher and higher, and the hardware is constantly decreasing), which makes it possible to combine it with machine tool in physics, reduce the floor area and facilitate operation.

4. Computer gong processing has flexibility and versatility

5. Computer gong processing has rich functions of numerical control

Interpolation function: quadratic curve, spline, spatial surface interpolation

Compensation function: motion precision compensation, random error compensation, nonlinear error compensation, etc

Man machine dialogue function: dynamic and static tracking display of processing, advanced man-machine dialogue window

Control of CNC machine tool point by point

Multi coordinate CNC machine tool. Some complex shape parts can not be processed with three coordinate CNC machine tools, such as propeller, aircraft curved surface parts processing, etc. it needs more than three coordinate synthesis movement to process the required shape. Therefore, the multi coordinate CNC machine tool appears, which is characterized by the number of axes controlled by the numerical control device, and the structure of the machine tool is also relatively complex. The number of coordinate axes usually depends on the process requirements of processing parts. Now commonly used is 4, 5, 6 coordinates of CNC machine tools. Computer gong processing, Dongguan computer gong processing, Shenzhen computer gong processing, mechanical parts processing, Guangzhou computer gong processing, figure 1 is a five axis CNC machining schematic diagram. At this time, x, y, Z coordinates can be linked with the rotation of the turntable and the swing of the cutting tool at the same time to process the wing and other parts.

2. Classification according to the motion track of CNC machine tools

According to the relative motion trajectory between the tool and the workpiece that can be controlled, CNC machine tools can be divided into point control CNC machine tools, point position linear control CNC machines, contour control CNC machines, etc. They are as follows:

(1) Point control CNC machine tool. The numerical control device of this kind of machine tool can only control the moving parts of the machine tool to move accurately from one position (point) to another, that is, only the coordinate value of the end of travel is controlled, and no cutting is carried out in the moving process. As for the moving speed and route between the two key points, it depends on the productivity. In order to achieve as high productivity as possible on the basis of accurate positioning, the movement between the two related points first moves quickly to the new position, and then slows down by 1-3 levels to make it approach the positioning point slowly to ensure its positioning accuracy.

This kind of machine tools are mainly CNC coordinate boring machine, CNC drilling machine, CNC punch and CNC measuring machine, and the corresponding CNC device is called point position control device.

(2) Point position linear control CNC machine tool. When this kind of machine tool works, it is necessary to control not only the position (i.e. distance) between two related points, but also the moving speed and route (i.e. trajectory) between the two related points. Its route is generally composed of straight lines parallel to each axis. It is different from the point position control CNC machine tool in that when the moving parts of the machine tool move, it can cut along a coordinate axis (generally, it can also cut along a 45 ° oblique line, such as computer gong machining, Dongguan computer gong machining, Shenzhen computer gong machining, mechanical parts processing, Guangzhou Electric gongs processing, but not along any slope straight line cutting), and its auxiliary functions There are more CNC machine tools than point position control, for example, to increase spindle speed control, cycle feed processing, tool selection and other functions.

This kind of machine tools mainly include simple CNC lathe, CNC boring and milling machine and CNC machining center. The corresponding numerical control device is called point position linear control device.

(3) Contour control CNC machine tool. The control device of this kind of machine tool can control two or more coordinate axes continuously at the same time. During processing, not only the starting point and the end point should be controlled, but also the speed and position of each point in the whole processing process should be controlled, so that the machine tool can process the parts with complex shapes that meet the requirements of drawings. Its auxiliary functions are relatively complete.

This kind of machine tools are mainly CNC lathes, CNC milling machines, CNC grinding machines and electrical machining machines. Its corresponding numerical control device is called contour control device (or continuous control device).

3. According to the control mode of servo system

CNC machine tools can be divided into open-loop and closed-loop according to whether there is a feedback device for the controlled quantity. In the closed-loop system, according to the position of the measuring device, it can be divided into full closed-loop and semi-closed-loop. Based on the open-loop system, an open-loop compensation CNC system is developed.

(1) Open loop control CNC machine tool. In the open-loop control, there is no feedback device for the machine tool (see Fig. 2). The signal sending process of the numerical control device is unidirectional, so there is no system stability problem. Because of the unidirectional flow of the signal, it does not check the actual position of the moving parts of the machine tool, so the machining accuracy of the machine tool is not high, and its accuracy mainly depends on the performance of the servo system. The working process is as follows: the input data is calculated by the numerical control device, and the command pulse is distributed, and the controlled working table is moved by the servo mechanism (the servo element is usually the stepping motor).

This kind of machine tool has the advantages of stable operation, quick response, convenient debugging and simple maintenance, but its control accuracy is limited. It is suitable for medium and small NC machine tools with general requirements.

(2) Closed loop control CNC machine tool. Because the precision of open-loop control can not meet the requirements of precision machine tool and large-scale machine tool, its actual working position must be detected. Therefore, a feedback device is added to the open-loop control CNC machine tool to detect the position of the moving parts of the machine tool at all times during the processing, so as to make it consistent with the position required by the CNC device, so as to achieve high machining accuracy.

The block diagram of closed-loop control system is shown in Fig. 3. In the figure, a is the speed measuring element and C is the position measuring element. When the command value is sent to the position comparison circuit, if the table does not move, there is no feedback in computer gong processing, Dongguan computer gong processing, Shenzhen computer gong processing, mechanical parts processing, Guangzhou computer gong processing, and the command value makes the servo motor rotate. The speed feedback signal is sent to the speed control circuit through a, and the actual displacement of the workbench is fed back to the position by C Set the comparison circuit with the command value, control with the difference value of comparison until the difference is eliminated, and finally realize the accurate positioning of the workbench. This kind of machine tool