China Shenzhen Perfect Precision Product Co., Ltd. company news

Hardware surface processing can be subdivided into: hardware oxidation processing, hardware painting processing, electroplating, surface polishing processing, hardware corrosion processing, etc Surface processing of hardware parts: 1. Oxidation processing: the hardware factory adopts oxidation processing on the finished hardware products (mainly aluminum parts) to make the surface of the hardware products hard, Make it less susceptible to wear. 2. Spray painting processing: the hardware factory adopts spray painting processing when producing large hardware finished products, which can prevent the hardware from rusting, For example: daily necessities, electrical enclosures, handicrafts, etc 3. Electroplating: electroplating is also the most common processing technology for hardware processing. The surface of hardware is electroplated through modern technology to ensure long product length There is no mildew or embrittlement under the use of time. The common electroplating processes are: screws, stamping parts, battery chips, car parts, small accessories, etc 4. Surface polishing: surface polishing is generally used in daily necessities for a long time, and the surface burrs of hardware products are treated, such as: We produce a comb. The comb is a metal part made by pressing. The corners of the punched comb are very sharp. We need to Sharp edges and corners are polished into smooth face, so that no harm will be caused to human body during use. The machining method of cnc workpiece surface depends on the technical requirements of the machined surface. However, it should be noted that these technical requirements are not necessarily parts The requirements specified in the drawing may be higher than those on the part drawing in some aspects due to technological reasons. If it is increased due to non coincidence of datum Machining requirements for the surface of some cnc machined parts. Or it may put forward higher processing requirements because it is regarded as precision reference. After the technical requirements for the surfaces of CNC machined parts are clarified, the final machining method that can guarantee the requirements can be selected accordingly, and the number of Steps and processing methods of each step. The selected processing method of CNC machining parts should meet the requirements of parts quality, good processing economy and High production efficiency requirements. For this reason, the following factors should be considered when selecting the processing method: 1. The machining accuracy and surface roughness obtained by any CNC machining method have a considerable range, but only in a narrow range The range of is economic, and the machining accuracy of this range is economic machining accuracy. Therefore, when selecting the processing method, the corresponding The processing method that can obtain economic processing precision. 2. The properties of CNC machining materials shall be considered. 3. The structural shape and size of CNC machined parts shall be considered. 4. Productivity and economy requirements shall be considered. High efficiency and advanced technology shall be adopted for mass production. It can even fundamentally change the blank The manufacturing method can reduce the amount of labor in machining. 5. The existing equipment and technical conditions of the factory or workshop shall be considered. When selecting the processing method, the existing equipment shall be fully used to tap the potential of the enterprise The enthusiasm and creativity of workers. However, continuous improvement of existing processing methods and equipment, adoption of new technologies and improvement of process level should also be considered.

1. What is the purpose of inserting an insert into a plastic part? The purpose of inserting inserts into plastic parts is to improve the local strength, hardness, wear resistance, conductivity, magnetic conductivity, etc. of the plastic parts, or to increase the stability of the size and shape of the plastic parts, or to reduce the consumption of plastic. 2. What is the working principle of the single parting injection mold? The single parting surface injection mold is also called the two plate injection mold, as shown in Figure 5.4. When closing the mold, the moving mold and the fixed mold are closed under the guidance and positioning of the guide pillar 8 and the guide sleeve 9. The cavity is composed of the cavity on the fixed template 2 and the core 7 fixed on the movable template 1, and is locked by the clamping force provided by the mold closing system of the injection machine. Then the injection machine starts to inject, the plastic melt enters the cavity through the gating system on the fixed mold, the cavity is filled with the melt, and the mold is opened after pressure holding, plastic filling and cooling. When opening the mold, the mold closing system of the injection machine drives the moving mold to retreat, the driven mold of the mold is separated from the parting surface of the fixed mold, the plastic part is wrapped on the core 7 and retreats with the moving mold, at the same time, the pulling rod 15 pulls out the main runner condensate of the gating system from the gate sleeve. When the moving die moves for a certain distance, the ejector pin 21 of the injection machine contacts the push plate 13, and the push plate mechanism starts to operate, so that the push rod 18 and the pull rod 15 push the plastic part and the pouring system condensate from the core 7 and the cold feed cavity respectively, and the plastic part and the pouring system condensate fall down from the mold together, thus completing an injection process. When closing the mold, push out the mechanism against the reset lever and prepare for the next injection. 3. How is the single parting injection mold composed? According to the composition of the mechanism, the single parting injection mold as shown in Figure 5.3 can be divided into mold cavity, molding parts, gating system, guide mechanism, ejection device, temperature regulation system and structural parts 4. How is the cavity of the single parting injection mold composed? The cavity part of the mold used to form plastic parts. Since the mold cavity is the part that directly forms plastic parts, the shape of the mold cavity should be consistent with the shape of the plastic parts. The mold cavity is generally composed of a cavity and a core. This figure is composed of cavity 2, core 7, fixed template 1 and push rod 18. 5. How are the components of single parting injection mold formed? The parts that constitute the cavity of a plastic mold are collectively called molding parts, which usually include the core (internal shape of the molding plastic part) and cavity (external shape of the molding plastic part). This drawing is composed of fixed template 2, core 7 and movable template 1. 6. How is the gating system of single parting injection mold composed? The runner that leads the plastic from the injector nozzle to the mold cavity is called the gating system. The gating system is divided into four parts: main runner, splitter, gate and cold feed cavity. It is composed of runner sleeve 6, pull rod and runner on the fixed template 2. 7. How is the guiding mechanism of the injection mold with a single parting surface composed? The guide parts are set to ensure the accurate alignment of the moving mold and the fixed mold during the mold closing. Usually, there are guide columns, guide holes or internal and external conical surfaces that are mutually matched are set on the movable and fixed molds. This legend is composed of guide post 8 and guide sleeve 9. 8. How is the ejector of the single parting injection mold composed? A device that pushes a plastic part out of a mold during mold opening. In order to avoid the deflection of the ejection plate during ejection, some ejection devices of injection molds are also equipped with guide parts to keep the ejection plate moving horizontally. It is composed of a push rod 18, a push plate 13, a push rod fixing plate 14, a reset rod 19, a main channel pull rod 15, a support pin 12, a push plate guide post 16 and a push plate guide sleeve 17. 9. How is the temperature regulation and exhaust system of the single parting injection mold composed? In order to meet the requirements of the injection process on the mold temperature, the mold is equipped with a cooling or heating system. The cooling system is generally equipped with cooling channels in the mold, and heating elements, such as electric heating elements, are installed inside or around the mold for heating. This drawing is composed of cooling water channel 3 and water nozzle. In the injection molding process, in order to exclude the gas in the cavity from the mold, it is often necessary to set up an exhaust system. 10. How are the structural components of the single parting surface injection mold composed? It is used to install and fix or support the formed parts and components and the aforementioned parts and mechanisms. The support components can be assembled together to form the basic skeleton of the injection mold. This drawing is composed of fixed mold base plate 4, movable mold base plate 10, cushion block 20 and support plate 11.

Traditional manufacturing machines cannot easily integrate multiple raw materials in the process of cutting or mold forming. With the development of multi material 3D printing technology, we have the ability to integrate different raw materials. Raw materials that cannot be mixed before will form new materials after mixing. These materials have a wide range of colors and unique properties or functions. When using 3D printing for the first time, there are various processes and materials to choose, so which process materials should we choose? The following aspects are usually considered: cost, appearance, details, mechanical properties, mechanical properties, chemical stability, and special application environment. Although there are various factors, based on the production purpose of the model, it can be roughly divided into two categories: appearance verification model and structure verification model. Appearance verification model: a prototype model designed and produced by engineers to verify the product appearance or a model directly used and with high requirements for appearance. The appearance verification model is visual and touchable, which can directly reflect the designer's creativity in the form of real objects, avoiding the disadvantage of "beautiful drawing but not beautiful making". Appearance verification model making is essential in the process of new product development and product appearance elaboration. Based on the requirements of the appearance verification model, it is recommended to select photosensitive resin 3D printing (including high-precision and high toughness ABS and transparent PC materials); Structure verification model: In the process of product design, from design scheme to mass production, it is generally necessary to make molds. The cost of mold manufacturing is very high, and the relatively large mold is worth hundreds of thousands or even millions. If the unreasonable structure or other problems are found in the mold opening process, the loss can be imagined. Therefore, making the structural verification model can avoid this loss and reduce the mold opening risk. Based on the requirements of structural verification model, if the requirements for precision and surface quality are not high, it is recommended to select materials with good mechanical properties and low prices, such as PLA, ABS and other materials. In addition, there are some special requirements. For example, if there is a requirement for conductivity, metal materials are required, or if you want to reverse make a beautiful jewelry, it is recommended to use paraffin wax. For diners, you can experience our food 3D printing and taste the taste of 3D printing chocolate!

The geometric characteristics of machined surface include surface roughness, surface waviness and surface texture. Surface roughness is the basic unit of geometric features of machined surfaces. When machining workpiece surface with metal cutting tools, surface roughness is mainly affected by geometric factors, physical factors and machining process factors. 1. Geometric factors: From the geometric point of view, the shape and geometric angle of the tool, especially the arc radius of the tool tip, the main deflection angle, the secondary deflection angle and the feed rate in the cutting parameters, have a great influence on the surface roughness. 2. Physical factors: In view of the physical essence of the cutting process, the fillet of the cutting edge and the extrusion and friction behind the tool cause plastic deformation of the metal material, which seriously worsens the surface roughness. When forming strip chips by processing plastic materials, it is easy to form high hardness chip buildup on the rake face. It can replace the rake face and cutting edge for cutting, so that the geometric angle and back cut of the tool change. The contour of the built-up chip is very irregular, so that the depth, width and width of the tool mark are constantly changing on the surface of the workpiece. Some built-up chips are embedded in the workpiece surface, which increases the surface roughness. The vibration during cutting increases the surface roughness parameter value of the workpiece. 3. Process factors: From the point of view of technology, its influence on the surface roughness of the workpiece is mainly related to the cutting tool, the workpiece material and the processing conditions.

For 3D printing and CNC processing, I believe most people do not know the difference. In order to let you better choose the corresponding method to make your prototype, let me show you the difference between the two. 3D printing board: 3D printing is a kind of rapid prototyping technology. It is a technology based on digital model files, which uses powder metal or plastic and other adhesive materials to construct objects by layer printing. It uses the principle of layered stacking to print the prototype layer by layer. The materials for 3D printing are limited. The main material is plastic. The technology for printing metal is still immature. As far as printing plastics are concerned, their processing scope is relatively limited, generally no more than 600mm. In addition, 3D printing costs are calculated in grams. Printing such a large prototype is quite expensive. In terms of material properties, the hardness and temperature resistance of 3D printed plastic products are worse than those of CNC hand boards! In terms of processing precision, the precision of 3D printing is not as fine as that of CNC machine tools! CNC hand board: The so-called CNC hand board is to carve on the raw materials according to a certain path through the processing tools of the numerical control machine tool under the command of the program. Therefore, CNC hand board processing will produce waste materials, while 3D printing is the accumulation of materials, which will not produce waste materials. CNC hand boards are made of a wide range of materials. As long as you can see the materials you want, you can process them. Moreover, CNC machine tools have a large stroke, at least more than 1m. For example, gantry machine tools can even process a whole piece within a range of two to three meters. As far as precision is concerned, the precision of the hand board processed by CNC is high, which can generally reach plus or minus ten wires. The precision of the metal hand board processed by high-speed drilling and tapping center can reach 0.05mm. Summary: 3D printing is suitable for those with low surface requirements, relatively low accuracy, complex structure, small quantity, and most of them are internal structural parts. CNC hand boards are suitable for hand boards of various sizes with high surface requirements, high precision requirements, and material properties requirements.

The process of the life of an innovative product from gestation to birth should be as follows: a small bud of creativity, and then let a designer explore the appearance of the product you have given, and then let the product upgrade in dimensions - from two-dimensional drawings to three-dimensional prototype, and then adjust the concept; Then, adjust the design; Then, adjust the material; Then, adjust the process; At last, the goddess in my mind appeared, so, mold opening, production, marketing It can be seen that in the whole process, the ring around the prototype is the most difficult stage. So, why should we do the prototype first and then open the mold? In the process of developing new products, we can evaluate whether there are technical problems, whether the appearance can achieve the expectations, whether the structure is reasonable, and whether the final assembly can be normal; Therefore, the success of prototype production will directly determine the product development. With the maturity and application of prototype rapid prototyping technology, the authenticity and simulation degree of many prototype production can reflect many problems and effects of the product itself. It can also help developers shorten the product development cycle and improve the competitiveness of their products! When the prototype manufacturing industry did not rise, after many products were developed, molds were directly made for mass production, but there would be many unexpected deficiencies after such products were developed. In the end, they can only modify the mold, which is not only a waste of time but also a waste of money. So when a good prototype is completed, the design is in place, and the market test is OK, it is time to start mass production, that is, mold opening. Definition of mold opening: Mold opening was originally a term of mechanical production or process production, referring to the manufacturing of mold groups. Now the term in industrial design refers to the tool group that forms product design, including mechanical equipment and molds. At the same time, mold opening is a production process with a high proportion of total investment. Production technology, materials and other factors may increase the cost of mold opening, so mold opening is a very important production process. What to prepare for mold opening: 1. CAD file product data; 2. Materials used; Because it is necessary to determine the shape of the gate and the final size of the mold cavity according to the shrinkage of the plastic; 3. Predict the production volume and production cycle to ensure that several products are injected into the first mock examination.

1、 What is the specific design of non-standard machinery? In short, it refers to the design of non-standard equipment, non-standard parts and non-standard tooling. For example, C616, C620, C630, C6125, M7475, B650, M131 and other equipment are already well-known standard equipment in the machining industry, so there are many special equipment not included in the standard equipment, which is the goal of non-standard designers. Non standard machinery is a mechanical product that has no definite shape. Generally, it cannot be bought directly in the market, and it should be customized from the manufacturer. Machines with the same function may be different in size and shape. In addition, non-standard equipment is also greatly affected by the user's site, and the design of equipment is often restricted by some conditions of the user. Although there is no standard for shape, there are still standards for the design of mechanisms and parts. The specific non-standard equipment can refer to the Design Manual of Non standard Mechanical Equipment. 2、 Jobs Non standard design work is a very hard work. First of all, you should have a good practice foundation. Turning, milling, planing, grinding, and clamping should be one or two of your meetings. Of course, the more you have, the better. Do you have no skill? With these foundations, you can not speak layman in machining. If you speak up, you can become a machining technician. Then, you can learn the theory course, master the professional theoretical knowledge of non-standard design, such as material mechanics, theoretical mechanics, mechanical drawing, descriptive geometry, electrical fundamentals, computer introduction, etc. Of course, you can go to school first, then practice, and practice first, then study. The non-standard design work involves a wide range of aspects. Because the nature of the profession is to solve problems in all aspects, non-standard designers are required to have a wide range of knowledge and knowledge. The more knowledge, the more effective the work, the more knowledge, the more experience, the more methods to solve problems, the faster and more accurate. (There are many examples of equipment that is not good enough to be used or scrapped.) The prospect of non-standard design work has always been very good. The world's technological progress can not be separated from non-standard design work. In enterprises, it is the blood of the enterprise (many describe it this way). In society, it is the pioneer of technological progress, so it is also glorious to do this work. When you get an invention certificate, you feel relieved that you have made some achievements for the society to promote technological progress. 3、 Purpose of non-standard design 1. Improve product quality; 2. Improve efficiency; 3. Ensure production safety. 4、 Necessary for non-standard design 1. The necessary design manual can be downloaded electronically on the Internet. The manual is your best teacher. You can find the knowledge you want from the book. For example, if gears are required during design, the parameters for designing gears can be found in the manual. Look for the manual when you encounter problems. 2. Download some atlases of mechanical equipment for you to broaden your mind. 3. The movement track of the equipment is nothing but straight line or rotation. Grasping these mechanical principles, combined with electrical, pneumatic and hydraulic, non-standard equipment can be designed. 4. It is better to download some standard parts of cad version and put them in the design center of cad for easy pasting and use, so as to improve work efficiency. 5、 Non standard design preparation 1. Understand the purpose of the equipment. Is it processing equipment? Or test equipment? Or tooling. Processing equipment: First, ensure the processing accuracy, and then load and unload conveniently, accurately and quickly. Test equipment: provide corresponding power, test necessary test points, how to combine with electrical, display data and read data. Fixture: how to limit the degree of freedom, loading and unloading fast and reliable. 2. On site investigation to understand relevant data a) Relevant data of equipment, such as overall dimensions, shall comply with drawings and dimensions accordingly b) Whether the relevant data of the equipment installation site interfere with other equipment c) Relevant electrical data for equipment installation, voltage and power 3. Prepare some industry standards and online manufacturer's product related data, and each manufacturer will provide data such as principle and installation size to prepare for drawing. 4. Propose a plan: the feasibility report of the plan includes the following contents: a) Efficiency and accuracy of the original equipment, and explain why they are updated or increased b) Features of new equipment c) Production cost, including material cost, labor cost and outsourcing processing cost d) Cost recovery period: recover the investment within half a year and do it immediately; The investment can be recovered within one year. Including how much labor cost is reduced and the value created by improving efficiency e) Production cycle estimation 6、 Design process 1. Sketch the design in your head, give play to your imagination, divide the equipment into several blocks, and how each block is structured and connected. 2. Draw and put ideas into drawings. First draw the general drawing, then draw the part drawing. Easy to change design and ideas. 3. For strength verification, materials can be selected directly for those with experience, and simple verification shall be conducted for those with less experience to prevent major mistakes. 4. Check the drawing, mainly to check whether the parts have interference, whether it is convenient to install, use and maintain. 5. Sort out the drawings, calculate the weight of accessories, and use it for quick quotation. The price of processed accessories can be checked according to the weight of materials × The material price is 2~3 times. 7、 Market research and inquiry The sub components and parts of the designed products shall be inquired in the market, and the accessories shall be universal parts as far as possible to facilitate maintenance and exchange. 8、 Design advice 1. The things designed by novices are certainly not perfect. You should consult with older engineers, who will generally give you guidance to improve yourself. Those with strong sense of responsibility may be worried and unable to sleep. Everyone has come from this step. As long as you put your heart into it, there will be no problem. Even if there are mistakes, they will inevitably depend on how you make up for them. The reason is very simple. There are few principles available. The development is also driven by the electrical industry. The effective combination of machinery and electrical, pneumatic and hydraulic systems develops. The development of new materials brings lightweight and durable benefits to machinery. 2. Mechanical principles are the same as musical notes. There are only a few, whether equipment or products, just how to match them. Look at the design of others, understand the design concept, and apply it to your own design. This is not called plagiarism, but application. 3. The designed items must be convenient for maintenance, as small as whether there is a place for the wrench, but it is really impossible to use the hexagonal socket bolt. It is convenient for processing, and processing problems should be considered during design, for example, do not drill holes on the arc surface as much as possible, if it is necessary to drill or pass through the center, or first process the platform and then drill holes. 4. After the first design draft comes out, it must be optimized. Is there a simpler way or more advanced parts to replace it. For example, electric flat cars should be built with DC and AC drives. AC drives are not very safe, and there are electric lines for transmission. The DC cost is high. Rectifiers should be provided, but batteries can also be used. The speed of the flat car is required to be very low, 60m/min, and the number of revolutions of the motor is very high, so the gearbox is usually used to change the speed. However, the speed of the DC brushless motor can reach 40r/min through online learning, so that the gearbox is not needed, investment is reduced, failure points are reduced, and maintenance costs are reduced. This is innovation.

1、 ABS material introduction In terms of chemical composition, ABS is a polymer formed by copolymerization of acrylonitrile A, butadiene B and styrene S. 1,3-butadiene can provide low temperature ductility and impact resistance for ABS; Acrylonitrile provides ABS with hardness, heat resistance, acid and alkali resistance and other chemical corrosion properties; Styrene can provide ABS with hardness, processing fluidity and product surface finish. In terms of morphology, ABS is an amorphous material, which has many characteristics, such as low temperature resistance, impact resistance, low creep, excellent dimensional stability and ease of processing, as well as high surface hardness and good chemical resistance. By changing the proportion of the above three components, various properties of ABS can be changed. ABS is widely used as engineering plastics. 2、 Basic properties of ABS The raw material of ABS is light yellow or milky white granular material with certain toughness and density of 1.04~1.06 g/cm3. ABS has strong corrosion resistance to acid, alkali and salt, and is resistant to organic solvent dissolution to a certain extent. It can be mixed with a variety of resins to form blends, such as PC/ABS, ABS/PVC, PA/ABS, PBT/ABS, etc., producing new properties and new applications. It has good formability under the environment of - 25 ℃~60 ℃. The processed products have smooth and clean surfaces and are easy to dye and electroplating. Therefore, they are often used for household appliances, toys and other daily necessities, such as the well-known "Lego building blocks". 3、 ABS performance ABS is non-toxic, tasteless, low water absorption, can be made into various colors, and also has 90% high gloss. ABS has a good combination with other materials, so surface printing, coating and plating treatment are easy. The oxygen index of ABS is 18.2, which belongs to a flammable polymer. The flame is yellow, there is black smoke, it is charred but does not drip, and it will emit a special cinnamon flavor. The addition of flame retardant can make ABS become a flame retardant material, ensuring the safety and fire prevention of finished products; At the same time, it has low smoke during combustion, reducing the pollution to the environment. ABS has high impact strength and surface hardness in a wide temperature range. Its thermal deformation temperature is higher than that of PA and PVC. Its critical surface tension is 34-38mN/cm, and its shrinkage is 0.4% ～ 0.8%. If it is reinforced with glass fiber, it can be reduced to 0.2% ～ 0.4%. The fluidity of ABS melt is better than that of PVC and PC, but worse than that of PE, PA and PS. Like POM and HIPS, ABS melt belongs to non Newtonian fluid and is more sensitive to shear rate. Mechanical properties: ABS has excellent mechanical properties, excellent impact strength, and can be used at extremely low temperatures. Even if ABS products are damaged, it is only tensile damage, not impact damage. However, the mechanical properties of ABS are greatly affected by temperature. ABS has excellent wear resistance and oil resistance, so it can be used for bearings under medium load and speed. The creep property of ABS is larger than that of PSF and PC, but smaller than that of PA and POM. The bending strength and compression strength of ABS are poor among plastics. Thermal properties: ABS is an amorphous polymer with no obvious melting point, high melt viscosity, poor fluidity and weather resistance; Ultraviolet ray can discolor ABS, and the thermal deformation temperature is 70-107 ℃ (about 85 ℃). After annealing, the product can also be increased by about 10 ℃. However, ABS can still show a certain toughness at - 40 ℃. It can be used for a long time in the temperature range of - 40 ℃ to 85 ℃, and the thermal decomposition temperature is above 270 ℃. Electrical performance: ABS has good electrical insulation and is hardly affected by temperature, humidity and frequency. It can be used in most environments. Environmental performance: ABS is not affected by water, inorganic salts, alkali alcohols, hydrocarbon solvents and various acids, but it is soluble in ketones, aldehydes and chlorinated hydrocarbons, and will produce stress cracking due to corrosion by glacial acetic acid, vegetable oil, etc. ABS is easy to degrade under the action of ultraviolet light. After being placed outdoors for half a year, the impact strength decreases by half. 4、 Application of ABS ABS has excellent performance, impact resistance, high rigidity, oil resistance, low temperature resistance, chemical corrosion resistance, electrical performance, ease of processing, low price, etc. It is widely used in the fields of electronics, instrumentation, automobile, construction industry, etc.

"CNC" is a computerized numerical control (CNC) technology in English, referred to as numerical control. Traditional machining is performed by manually operating ordinary machine tools. When machining, the machine tool is shaken by hand to cut metal, and the accuracy of products is measured by eyes with calipers and other tools. Modern industry has already used computer numerically controlled machine tools for operations. CNC machine tools can automatically process any products and parts according to the program prepared by technicians in advance. It is a method to control the machine tool movement and processing process by using digital information. The machine tool that uses numerical control technology to implement processing control, or the machine tool equipped with numerical control system, is called numerical control (CNC) machine tool. Among them, the numerical control system includes: numerical control device, programmable controller, spindle driver and feeding device. CNC machine tools are highly integrated products of machinery, electricity, fluid, gas and light. To control the machine tool, it is necessary to describe the relative motion between the tool and the workpiece with geometric information and some process parameters that the machine tool processing must have with process information, such as: feed speed, spindle speed, spindle forward and reverse rotation, tool change, coolant switch, etc. These information are formed into processing files (normally referred to as CNC processing programs) in a certain format and stored on information carriers (such as magnetic disks, perforated paper tapes, magnetic tapes, etc.), and then read in by the CNC system on the machine tool or input directly through the keyboard of the NC system, or input through communication and decoding, so that the machine tool can act and process parts Modern CNC machine tools are typical products of mechatronics, and are the technical basis of new generation production technology, computer integrated manufacturing system, etc. The development trend of modern CNC machine tools is high-speed, high-precision, high reliability, multi-function, compound, intelligent and open structure. The main development trend is to research and develop intelligent full function universal numerical control devices with open software and hardware. Numerical control technology is the basis of machining automation and the core technology of numerical control machine tools. Its level is related to the national strategic position and reflects the level of national comprehensive strength. It develops with the development of information technology, microelectronics technology, automation technology and detection technology. CNC machining center is a kind of CNC machine tool with tool magazine, which can automatically change tools, and can perform a variety of machining operations on the workpiece within a certain range. The characteristics of machining parts on the machining center are: after the parts to be machined are clamped once, the CNC system can control the machine tool to automatically select and replace tools according to different procedures, automatically change the spindle speed, feed rate of the machine tool, the movement track of the tool relative to the workpiece and other auxiliary functions, and automatically carry out multi process machining for each machining surface of the workpiece, such as drilling, spot facing, reaming, boring, tapping, milling, etc. Because the machining center can complete multiple processes in a centralized and automatic manner, it can avoid manual operation errors, reduce the time for workpiece clamping, measuring, machine tool adjustment, workpiece turnover, handling and storage, and greatly improve the machining efficiency and accuracy, so it has good economic benefits. Machining centers can be divided into vertical machining centers and horizontal machining centers according to the position of the spindle in space.

Configuration criteria of deep drawing parts a. The shape of drawing parts shall be as simple and symmetrical as possible. b. The size proportion of each part of the drawing part shall be appropriate, and the design of wide flange and deep drawing parts shall be avoided as far as possible. (D convex ＞ 3d, h ≥ 2d) Because such parts need more drawing times. c. The fillet radius of the drawing part shall be appropriate, and the fillet radius shall be as large as possible to facilitate the forming and reduce the number of drawing times. (1) Fillet radius of drawing parts. Rapid screening sheet metal sample library (2) The appropriate position for punching deep drawing parts or bending parts. (3) To prevent distortion and deformation during drawing, the width of A and B should be equal (symmetrical), that is, A=B. (4) Precautions for dimensioning on the design drawings of tensile parts The material thickness after stretching changes due to the different stress magnitude of the stretching parts. Generally speaking, the original thickness is maintained at the bottom center, the material at the bottom fillet becomes thinner, the material at the top near the flange becomes thicker, and the material at the fillet around the rectangular stretching piece becomes thicker. (5) Standard method for product dimensions of tensile parts When designing tensile products, the dimensions on the product drawing shall clearly indicate that the external dimensions or internal dimensions must be guaranteed, and the internal and external dimensions cannot be marked at the same time. (6) Marking method for dimensional tolerance of stretching parts The internal radius of the concave convex arc of the stretch piece and the height tolerance of the cylindrical stretch piece formed at one time are symmetrical deviations on both sides. The deviation value is half of the absolute value of the national standard (GB) Grade 16 accuracy tolerance, and is marked with ±.