2020 – Page 63 – CNC Machining & Turning, Milling, Metal parts

NC Machining Technology

CNC machining mainly refers to the use of digital information recorded on the media to control the machine tool. Dongguan computer gong processing makes it automatically perform the specified processing tasks. NC machining can ensure the products to achieve high machining accuracy and stable processing quality; the operation process is easy to realize automation; the productivity is high and the production cycle is short; it can greatly reduce the process equipment to meet the needs of rapid product update; it is usually closely linked with CAD to realize the transformation of design ideas to final products.

In the whole CNC processing process, we should focus on the relationship between the processes and the significance of each step. In a broad sense, the whole process consists of product analysis, graphic design, process planning, path generation, path simulation, path output, processing and inspection.

1. Some specific product information should be obtained through product analysis.

2. Graphic design the design of graphics should be based on the detailed analysis of the products. Dongguan computer gong processing determines the type of graphics by analyzing the processing requirements, and draws them by graphics software.

3. In fact, the process of path generation is to realize the process planning through software, and optimize the tool path by setting parameters.

4. Process planning is based on the analysis of the appearance and processing requirements of the workpiece products in the early stage, so as to reasonably establish each processing step from the overall processing situation.

5. After the path simulation path is generated, we generally have no intuitive feeling about the performance effect of its final processing on the machine tool. Here we can check the possible problems through path simulation, thus reducing the actual processing scrap rate. The key point of undercut is to check whether the process is reasonable or not.

6. Path output path output is a necessary step for software design and programming to realize on the machine tool. Through the path output, the relationship between the two can be established by the intermediate reference. If you have a professional background in CNC, it can also be understood as the post-processing of tool path.

Characteristics of CNC machining machine parts

Advantages: 1. High reliability

The reliability of large-scale mechanical parts processing equipment is guaranteed by using highly integrated electronic components, chips and VLSI.

Many functions are realized by software, which reduces the number of hardware.

Rich fault diagnosis and protection functions of mechanical parts processing (mostly realized by software), which can reduce the frequency of system failure and repair time after failure.

2. Easy to use and maintain

Easy to operate and use: Dongguan computer gong processing users only need to follow the menu prompts, you can operate correctly.

Programming and simulation functions are convenient and automatic.

Convenient maintenance and repair: some daily maintenance work is carried out automatically (lubrication, regular inspection of key components, etc.), the self diagnosis function of CNC machine tool for machining mechanical parts can quickly realize accurate fault location.

3. 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. Flexibility and versatility

The functions of Dongguan machine parts processing device are mostly 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 Dongguan machine parts processing device is universal. Different CNC machine tools only configure corresponding specific function modules to achieve specific control functions.

5. Rich CNC functions

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

Programming function: G code, basket chart programming, partial automatic programming function.

CNC machining and programming

Advantages: 1. High reliability

The reliability of large-scale mechanical parts processing equipment is guaranteed by using highly integrated electronic components, chips and VLSI.

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. Easy to use and maintain

Easy to operate and use: Dongguan computer gong processing users only need to follow the menu prompts, you can operate correctly.

Programming and simulation functions are convenient and automatic.

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.

3. Easy to realize mechatronics

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

4. Flexibility and versatility

Most of the functions of Dongguan Mechanical parts processing device are realized by software. The modular structure of software and hardware makes the modification and expansion of system functions more flexible.

5. Rich CNC functions

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

Programming function: G code, basket chart programming, partial automatic programming function.

CNC processing and maintenance

1. Before machining in each program, it is necessary to strictly confirm whether the tool is consistent with the program.

2. When installing the tool, it is necessary to confirm whether the length of the tool and the selected tool holder are suitable.

3. It is forbidden to open the door when the machine tool is running to avoid flying knife or workpiece.

4. In case of knife collision during the processing of computer gongs, the operator must stop immediately, such as pressing the “emergency stop” button or “reset key” button or setting the “feed rate” to zero.

5. In the same workpiece, each tool setting should be kept in the same area, so as to ensure the accuracy of the tool when connecting the tool, and the operation rules of CNC machining center.

6. If too much machining allowance is found in the machining process, the “single section” or “pause” must be used to clear the X, y, Z values, and then manually mill them off, and then swing back to the “zero” to let them run by themselves.

7. During self operation, the operator shall not leave the machine tool or regularly check the operation status of the machine tool. If it is necessary to leave midway, relevant personnel must be designated to check.

8. Clean the aluminum slag in the machine tool before the smooth knife oil injection to prevent the aluminum slag from absorbing oil.

9. Try to blow with air in the rough opening procedure and spray oil in the light knife program.

10. After the workpiece is off the machine, the burr must be removed in time.

11. When off duty, operators must make timely and accurate handover to ensure the normal follow-up processing.

12. Before shutdown, make sure that the tool magazine is in the original position and the XYZ axis is in the middle position. Turn off the power supply and the general power supply on the operation panel of the machine tool in turn.

13. In case of thunderstorm, the power supply must be cut off immediately.

In addition to the above points, there are many things that we need to pay attention to from time to time. The system should pay attention to, and the machine should also pay attention to maintenance. In fact, most of the time, the machine will break down, to a large extent, and the user’s operation is improper. We do not pay attention to check the machine before starting up, and do not warm up. Some companies have long been in the dark and humid environment because of the bad environment In fact, if we deal with these problems in time, the service life of our machine will definitely be much longer. The machining accuracy and performance of the machine will be as new as before, and the loss will be greatly reduced, and the replacement frequency of parts and components will be greatly reduced It saves a lot of time and cost

If there is any abnormal phenomenon in the operation process, please contact the manufacturer in time to avoid unnecessary loss.

Advantages of CNC machining

CNC computer gongs processing refers to the processing with CNC tools.

1. The accuracy of the work is relatively high, and the quality of the processed products is guaranteed.

2. Even if there are multiple coordinates, there is no need to worry, because it can realize the linkage between the coordinates, and can process parts with complex geometry structure.

3. It is necessary to replace the processed parts, but only need to change the relevant data to realize the work and simplify the work

4. Because the computer gong is automatic, it can reduce the labor force and increase the productivity.

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

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.

3. Computer gong processing is easy to realize mechatronics

4. Flexibility and versatility of gongs

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.

Daily maintenance of mould

The mold is generally stored in the warehouse until the next production cycle. However, some processing enterprises do not pay enough attention to the mold preservation. Dongguan mold processing makes the mold rust and surface finish decline during the storage period, resulting in the decline of product quality and high rejection rate. Some molds are even difficult to reuse, so a large amount of funds need to be invested to replace new molds, resulting in great waste. The data show that use and maintenance account for 15% – 20% of the factors affecting the service life of molds. The service life of injection moulds can reach 800000 times in general, and some well maintained moulds abroad can even be extended by 2-3 times. However, due to the neglect of maintenance in domestic enterprises, the service life of injection mold is relatively short, which is only equivalent to 1 / 5 ~ 1 / 3 of that in foreign countries. Due to the short service life of die, steel processing time and energy waste, as well as the impact on product quality, the loss of billions of yuan per year.

Regular maintenance can keep the injection mold in good condition. After the new die is tested, no matter whether it is qualified or not, the stress relief tempering should be carried out before the mold is cooled to room temperature. When the new die is used to 1 / 6 ~ 1 / 8 of its design life, i.e., 10000 times of aluminum die casting, 5000 times of magnesium and zinc die casting, and 800 times of copper die casting, the mold cavity and die base should be tempered at 450-480 ℃, and the cavity should be polished and nitrided to eliminate the internal stress and slight cracks on the surface of the cavity. After that, the same maintenance should be carried out every 12000-15000 mould times. When the mould is used for 50000 times, it can be maintained every 25000 ~ 30000 mould times.

Therefore, the maintenance of injection mold is very important. The following editor will tell you the specific methods of mold maintenance:

1. First of all, the processing enterprise should provide a resume card for each pair of molds, recording and counting the use, care (lubrication, cleaning, rust prevention) and damage in detail, so as to find out which parts and components have been damaged, and the degree of wear, so as to provide information for finding and solving problems, as well as the molding process parameters and product materials of the mold, so as to shorten the trial run time of the mold Improve production efficiency. 2. The processing enterprise should test the performance of the injection molding machine and mold under normal operation, and measure the size of the final molded plastic parts. Through this information, the existing state of the mold can be determined, and the damage of the cavity, core, cooling system and parting surface can be found. According to the information provided by the plastic parts, the damage status of the mold and the maintenance measures can be judged. Dongguan Mechanical parts processing 3. To focus on tracking inspection of several important parts of the mold: the function of ejecting and guiding components is to ensure the opening and closing movement of the mold and the ejection of the plastic part. If any part of the mold is stuck due to damage, it will lead to production stop. Therefore, it is necessary to keep the lubrication of the mold ejector pin and guide pillar (the most suitable lubricant should be selected), and regularly check whether the ejector pin and guide pillar are in good condition Once deformation and surface damage are found, they should be replaced in time; after completing a production cycle, the working surface, moving and guiding parts of the mold should be coated with professional antirust oil, especially the protection of the elastic strength of the bearing parts of the mold with gear and rack and the spring mold, so as to ensure that they are always in the best working state; with the continuous production time, the cooling channel It is easy to deposit scale, rust, sludge and algae, which makes the cross-section of cooling channel smaller and the cooling channel narrow, which greatly reduces the heat exchange rate between the coolant and the mold and increases the production cost of the enterprise. Therefore, attention should be paid to the cleaning of the flow channel. For the hot runner mold, the maintenance of heating and control system is helpful to prevent the occurrence of production failure, so it is particularly important. Computer gong processing, Dongguan high speed computer gong processing, Dongguan mold processing, Dongguan Mechanical parts processing, CNC processing, therefore, after the end of each production cycle, ohmmeter should be used to measure the belt heater, rod heater, heating probe and thermocouple on the mold. If there is any damage, it should be replaced in time, and compared with the mold resume, and make records, so as to timely find out Problems, take countermeasures. 4. Pay attention to mold surface maintenance, it directly affects the surface quality of products, the focus is to prevent corrosion, therefore, it is particularly important to select a suitable, high-quality, professional anti rust oil. After the mold has completed the production task, different methods should be taken according to different injection molding to carefully remove the residual injection molding and other deposits in the mold with copper rod, copper wire and professional mold cleaning agent, and then air dry. It is forbidden to clean iron wire, steel bar and other hard objects to avoid scratching the surface. If there are rust spots caused by corrosive injection molding in CNC processing, grind and polish with a grinder, spray professional antirust oil, and then store the mold in a dry, cool and dust-free place.

Through the above four points to do a good job in the maintenance of the mold, can shorten the mold assembly, reduce production failure, make the production run smoothly, ensure product quality, reduce waste loss, and reduce the enterprise’s operating costs and fixed assets investment. At the beginning of the next production cycle, the enterprise can smoothly produce qualified products.

CNC machining process of precision parts

Machining process card: the process documents are required to be as detailed and complete as possible. In addition to the process catalog, there are also process cards for each process. Mechanical processing refers to the process of changing the overall dimension or performance of the workpiece through a kind of mechanical equipment. Dongguan mold processing has a variety of meanings: broadly speaking, it refers to the process of manufacturing products by mechanical means; in a narrow sense, it refers to the process of manufacturing parts with special machinery such as the lathe, milling machine, drilling machine, grinding machine, stamping machine, die-casting machine, etc.

There will be some errors in machining. Let’s talk about the original error related to the initial state of the process system itself

① Principle error is the error of machining method.

② Geometric error of process system

The relative position errors between workpiece and tool exist in static state, such as manufacturing error of tool and fixture, adjustment error and installation error;

The relative position error of workpiece and cutter exists in the motion state, such as the spindle rotation error of machine tool, the guide error of guide rail, the transmission error of transmission chain, etc.

(2) Original error related to cutting process

① The deformation caused by the force effect of the process system, such as the deformation caused by the stress deformation of the process system and the deformation caused by the generation and disappearance of the internal stress of the workpiece.

② Deformation caused by thermal effect of process system, such as the error caused by thermal deformation of machine tool, cutting tool and workpiece. In the machining process of Dongguan machine parts, when the position relationship between the tool and the workpiece processing surface is reasonable, the machining surface accuracy can meet the processing requirements, otherwise it can not meet the processing requirements. CNC machining accuracy analysis is to analyze and study various factors when the machining accuracy can not meet the requirements, that is, the possibility of various original errors, and take effective measures In order to improve the machining accuracy.

Characteristics of milling machine processing

It is characterized by:

1. The vertical milling head is equipped with tx400 heavy gantry milling head and double rectangular guide rail with strong rigidity;

2. The milling head is equipped with ball screw, pneumatic broach device and driven by servo motor;

3. The side milling head is equipped with V5 type gantry milling head, Dongguan high-speed computer gong processing is equipped with independent lubrication device, and the lifting is driven by ordinary reducer and frequency conversion speed regulation;

4. The three-axis CNC system with one key conversion from general milling to CNC milling can be programmed and operated manually by using the extended panel, which is highly realizable in the actual machining process;

5. The machine bed forward and backward, beam up and down, vertical milling head up and down are equipped with Taiwan ball screw, driven by servo motor;

6. Equipped with synchronous belt and synchronous wheel;

7. Hand held electronic hand wheel unit, convenient for three axis tool setting;

8. Dongguan machine parts processing unique beam lifting safety interlock device, CNC processing to ensure the repeated positioning accuracy of the machine tool;

9. The cycloid pump set is lubricated continuously with low failure rate.

Principle of CNC machining

According to the principle of “first rough then fine”, for parts with high precision requirements, the machining accuracy is gradually improved by the sequence from coarse to fine. Dongguan high-speed computer gong processing this point for poor rigidity parts, especially can not be ignored. In order to solve such problems, the characteristics of titanium alloy materials, machining characteristics, tool data selection, milling processing characteristics, coolant and other aspects are analyzed to improve the one-time acceptance rate of titanium alloy parts, so as to control the product quality of the parts. In order to better control the product quality, computer gongs processing, Dongguan computer gongs processing, high-speed computer gongs processing, mechanical parts processing, computer gongs processing must first control the cutting parameters of non-standard equipment parts processing, and grasp the processing characteristics of materials.

Mechanical processing technology is to change the shape, size, relative position and nature of the production object on the basis of the process. CNC processing makes it a finished product or semi-finished product. It is a detailed description of each process. For example, as mentioned above, rough machining may include blank manufacturing, grinding, etc., and finishing may be divided into turning, fitter, milling machine, etc., and each step is just like this There must be detailed data, such as how much roughness and tolerance should be achieved.

The classification of machining is as follows:

Design datum: the datum used to determine the position of other points, lines and planes on the part drawing, which is called design datum.

Process datum: the datum used in the process of machining and assembling parts, which is called process datum. According to different uses, the process datum of Dongguan mould can be divided into assembly datum, measuring datum and locating datum.

(1) Assembly datum: the datum used to determine the position of parts in parts or products during assembly, which is called assembly datum.

(2) Measurement datum: the datum used to check the size and position of machined surface, which is called measuring datum.

(3) Positioning datum: the datum used for workpiece positioning during machining, which is called positioning datum. For the surface (or line, point) as the positioning reference, only the rough surface can be selected in the first process, such as computer gong processing, Dongguan computer gong processing, high-speed computer gong processing, mechanical parts processing, computer gong processing. This positioning surface is called rough datum. In the future, the machined surface can be used as the positioning reference, and this positioning surface is called precision reference.

Fundamentals of CNC machining

The width of the worktable is less than 400mm for small and medium-sized CNC milling machines, which are suitable for the machining of small and medium-sized parts and the contour milling of complex surfaces. Large specifications such as the Dragon Gate milling machine, the worktable in 500-600mm above, used to solve the processing needs of large-scale complex parts.

Design datum: the datum used to determine the position of other points, lines and planes on the part drawing, which is called design datum.

Process datum: the datum used in the process of machining and assembling parts, which is called process datum. According to different uses, process datum can be divided into assembly datum, measuring datum and locating datum.

(1) Assembly datum: the datum used to determine the position of parts in parts or products during assembly, which is called assembly datum.

(2) Measurement datum: the datum used to check the size and position of machined surface, which is called measuring datum.

(3) Positioning datum: the datum used for workpiece positioning during machining, which is called positioning datum. Computer gong processing, Dongguan high speed computer gong processing, Dongguan mold processing, Dongguan Mechanical parts processing, CNC machining as the positioning reference surface (or line, point), in the first process, only the rough surface can be selected. This positioning surface is called the rough datum. In the following processes, the machined surface can be used as the positioning reference, and the positioning surface is called the precise reference.

In the process of turning a blank into a finished product, the total thickness of the metal layer cut off on a machining surface is called the total machining allowance of the surface. The thickness of the metal layer cut by each process is called the machining allowance between processes. For the rotating surface such as outer circle and hole, the machining allowance is considered from the diameter, so it is called symmetrical allowance (i.e. bilateral allowance), that is, the actual thickness of the metal layer cut off is half of the machining allowance on the diameter. The machining allowance of the plane is the unilateral allowance, which is equal to the actual thickness of the metal layer removed. The purpose of leaving machining allowance on the workpiece is to remove the machining errors and surface defects left by the previous process, such as the surface cold and hard layer, air hole and sand inclusion layer on the casting surface, oxide scale, decarburization layer and surface crack on the forging surface, internal stress layer and surface roughness after cutting. The precision and surface roughness of the workpiece are improved. The size of machining allowance has great influence on machining quality and production efficiency. If the machining allowance is too large, it not only increases the labor of machining, reduces the productivity, but also increases the consumption of materials, tools and power, and increases the processing cost. If the machining allowance is too small, it can not eliminate all kinds of defects and errors in the previous process, and can not compensate for the clamping error in this process, resulting in waste products. The selection principle is to make the allowance as small as possible on the premise of ensuring the quality. Generally speaking, the more finish machining, the smaller the process allowance.

Applicability:

In the process of turning a blank into a finished product, the total thickness of the metal layer cut off on a machining surface is called the total machining allowance of the surface. The thickness of the metal layer cut by each process is called the machining allowance between processes. For the rotating surface such as outer circle and hole, the machining allowance is considered from the diameter, so it is called symmetrical allowance (i.e. bilateral allowance), that is, the actual thickness of the metal layer cut off is half of the machining allowance on the diameter. The machining allowance of the plane is the unilateral allowance, which is equal to the actual thickness of the metal layer removed. The purpose of leaving machining allowance on the workpiece is to remove the machining errors and surface defects left by the previous process, such as the surface cold and hard layer, air hole and sand inclusion layer on the casting surface, oxide scale, decarburization layer and surface crack on the forging surface, internal stress layer and surface roughness after cutting. Computer gong processing, Dongguan high speed computer gong processing, Dongguan mold processing, Dongguan Mechanical parts processing, CNC processing, so as to improve the accuracy and surface roughness of the workpiece. The size of machining allowance has great influence on machining quality and production efficiency. If the machining allowance is too large, it not only increases the labor of machining, reduces the productivity, but also increases the consumption of materials, tools and power, and increases the processing cost. If the machining allowance is too small, it can not eliminate all kinds of defects and errors in the previous process, and can not compensate for the clamping error in this process, resulting in waste products. The selection principle is to make the allowance as small as possible on the premise of ensuring the quality. Generally speaking, the more finish machining, the smaller the process allowance. In order to formulate the machining process, it is necessary to determine the number of working procedures and the sequence of working procedures for the workpiece, and only list the name of the main process and its processing sequence, which is called the process route.