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

There are many kinds of product appearance designs. Texture is one of the factors that affect the product appearance. Different textures can bring different styles and feelings. Let's briefly explain several surface texture realization processes. 1. Embossing Metal embossing is the process of embossing on the metal plate by mechanical equipment to make the plate surface appear concave convex patterns. The embossed metal plate is rolled with a work roll with a pattern. The work roll is usually processed with corrosive liquid. The concave and convex depth on the plate varies with the pattern, and the minimum can reach 0.02-0.03mm. After the work roll is rotated and rolled continuously, the pattern repeats periodically, and the length direction of the embossed plate is basically unlimited. At present, metal embossed plate is suitable for decorating elevator car, subway car, various cabins, building decoration, metal curtain wall and other industries. It is durable, wear-resistant, visually beautiful, easy to clean, maintenance free, impact resistant, pressure resistant, scratch resistant and does not leave fingerprints. 2. Metal wire drawing Metal wire drawing is the manufacturing process of repeatedly scraping aluminum plates out of lines with sandpaper. The metal wire drawing process can clearly show every trace of fine wire, so that the metal matt can have a fine hair luster. The product has a sense of fashion and technology. Drawing can be made into straight lines, random lines, threads, ripples and spiral lines according to the decorative needs. Straight lines: wire drawing refers to processing straight lines on the surface of aluminum plate by mechanical friction. Random lines: wire drawing is a kind of irregular, matt silk lines without obvious lines obtained by moving and rubbing the aluminum plate from front to back, left to right under the high-speed copper wire brush. Screw thread: a small motor with a round felt on the shaft is used to fix it on the table, forming an angle of about 60 degrees with the edge of the table. In addition, a carriage with fixed aluminum plates for pressing tea is made, and a polyester film with straight edges is pasted on the carriage to limit the thread race. Ripple: It is generally made on the brushing machine or the erasing machine. Use the axial movement of the upper group of grinding rollers to grind and brush on the surface of aluminum or aluminum alloy plates to obtain wavy patterns. Rotary pattern: it is a kind of silk pattern obtained by using cylindrical felt or grinded nylon wheel installed on the drilling machine, mixing kerosene with polishing paste, and rotating polishing on the surface of aluminum or aluminum alloy plate. It is mainly used for decorative processing of round signs and small decorative dials. 3. IML process: First of all, it is necessary to explain the concept: IMD includes IML, IMF and IMR IML: IN MOLDING LABEL IMF: IN MOLDING FILM IMR: IN MOLDING ROLLER The surface of IML products is a hardened transparent film, with a printing pattern layer in the middle and a plastic layer on the back. Because the ink is sandwiched in the middle, the product can prevent the surface from scratching and abrasion resistance, and can keep the color bright and not fade for a long time. The process flow is as follows: Cutting: Cut the roll shaped film into square blocks with designed size for printing and forming processes. Graphic printing: according to the required icons and characters, they are made into phenanthrene, and the icons and characters are printed on the cut film square block. Ink drying and fixing: place the printed film square in the high-temperature oven for drying, so as to fix the IML ink. Paste protective film: avoid scratching the printed film surface during the process of punching the positioning hole. Sometimes it is necessary to paste a single or double layer protective film. Punching locating hole: hot formed locating hole must be punched accurately. The positioning hole of the shearing process is sometimes punched in advance. Hot forming (high pressure or copper mold): After heating the printed film, use the high pressure machine or copper mold to form in the preheating state. Shearing peripheral shape: cut off the waste of the formed three-dimensional film. Material injection molding: put the film with the same three-dimensional shape as the front mold on the front mold, and inject the IML finished product. Textures can be realized: CD grain, brushed wire, fog surface, leather grain, wood grain, and various 3D patterns. However, because the outermost layer is made of film material, the texture has no touch. Product features: The film production cycle is short, which can show multiple colors; The pattern and color can be changed at any time during production; Excellent scratch resistance; IML production batch quantity is very flexible, and it is suitable for small quantity production of multiple varieties. Product application: 3C industry, mobile phone windows, mobile phone buttons, mobile phone LOGO, decorative pieces, etc. 4. IMR process: IMR (in mold transfer printing) This process is to print the pattern on the film, press the film with the mold cavity through the film feeder, separate the patterned ink layer from the film after extrusion, and leave the ink layer on the plastic part to obtain the plastic part with decorative patterns on the surface. There is no transparent protective film on the final product surface, and the film is only a carrier in the production process. IMR products are not easy to deform, the product edges are completely covered, and the edge adhesion is strong. It is very easy to change the roll of IMR transfer foil. The process is simple, so the defective rate can be controlled within a few points. The process is simple, so the personnel demand can be minimized. The pattern alignment is perfect, and the hardness can reach 2H. The production is highly automated and the cost of mass production is low. Textures can be realized: wood, bamboo, marble, leather and other textures Product disadvantage: The printing pattern layer is only a few microns thick on the surface of the product. After the product is used for a period of time, the printing pattern layer is easy to wear off and fade, resulting in a very ugly surface. In addition, the new product development cycle is long and the development cost is high. Product application: IMR products are widely used because they belong to the surface treatment process of plastic parts. Such as laptop shell, home appliance shell, mobile phone shell, ABS, etc. 5. Water transfer printing process: Water transfer printing technology is a kind of printing that uses water pressure to hydrolyze the transfer paper/plastic film with color patterns into polymers. With the improvement of people's requirements for product packaging and decoration, water transfer printing is used more and more widely. The principle of indirect printing and perfect printing effect have solved the problem of surface decoration of many products. There are two types of water transfer technology, one is water mark transfer technology, the other is water drape transfer technology. The former mainly completes the transfer of words and realistic patterns, while the latter tends to complete the transfer of the entire product surface. The Cubic Transfer technology uses a water-based film that is easy to dissolve in water to carry images and texts. Due to the excellent tension of the water coating film, it is easy to wind on the surface of the product to form a graphic layer, and the product surface has a completely different appearance just like painting. Covering any shape of workpiece, it can solve the problem of three-dimensional product printing for manufacturers. Curved surface coating can also add different lines on the surface of the product, and it can also avoid the virtual position often seen in general color printing. In the printing process, since the product surface does not need to contact with the printing film, it can avoid damaging the product surface and its integrity. Product application: automobile instrument panel, control panel and other automobile interiors, 3C electronic products, household appliances, building materials, etc; 6. Hot stamping Hot stamping is commonly known as "hot stamping". The essence of hot stamping is transfer printing, which is the process of transferring the patterns on the gilded paper to the substrate through the effect of heat and pressure. The pressure of the die causes depression, and the printed words or patterns are not easy to blur, so the patterns, logos, texts or pictures can be firmly adhered to the product surface. The hot stamping die and foil are two key components of the hot stamping process. The hot stamping die is generally composed of magnesium, brass and steel. Some will use silicone rubber on the surface of the metal hot stamping die for uneven surfaces. Hot stamping die foil mainly includes carrier, release layer, protective layer and decorative layer. Hot stamping process includes 4 steps: (1) The hot stamping foil contacts the substrate; (2) With heat and pressure, the transfer layer is transferred to the substrate surface; (3) Remove the pressure and peel off the polyester film; (4) Feed hot stamping foil and replace the substrate to be hot stamped. Technical application: Hot stamping is applicable to polymer, wood, leather, paper, vinyl, polyester film and other textiles, as well as metals that are not easy to color. The decoration is scratch resistant, wear-resistant and peeling resistant. For retail and cosmetic packaging, books and magazines, car decoration, advertising, consumer goods decoration, information signs, etc. 7. Laser carving (laser carving) Based on numerical control technology, laser is the processing medium. The physical denaturation of melting and gasification of metal materials under laser irradiation, so as to achieve the purpose of processing. The laser engraving machine can use the laser engraving technology to easily "print" vectorized graphics and texts onto the processed substrate. The advantages of this technology are: ① Precision: the narrowest line width of the material surface can reach 0.015mm, and it is non-contact processing, which will not cause product deformation; ② High efficiency: new products can be obtained in the shortest time, and only the vector drawing files need to be changed for multiple varieties and small batches; ③ Special machining: to meet the special machining requirements, the inner surface or inclined surface can be machined; ④ Environmental protection and energy conservation: no pollution, no harmful substances, higher than the export environmental protection requirements. 8. Metal etching It is also called photochemical etching. After exposure, plate making and development, remove the protective film on the area to be etched, contact the chemical solution during metal etching, so as to achieve the effect of dissolving corrosion, forming concave convex or hollow molding. General consumer products, patterns on aluminum plates or text LOGO are often made by etching. In addition, etching is often used to make various kinds of metal horn nets. 9. CNC machining CNC Machining refers to the processing with CNC machining tools. CNC machine tools are programmed by NC machining language to control the feed speed of machining tools, spindle speed, tool changer, coolant, etc., so as to perform physical machining on the surface of the base material. CNC machining has great advantages over manual machining, for example, the parts produced by CNC machining are very accurate and repeatable; NC machining can produce parts with complex shapes that cannot be finished by manual machining.

Five Axis Machining, as the name implies, is a mode of NC machine tool processing. Linear interpolation movement of any five coordinates in X, Y, Z, A, B, C is adopted. The machine tool used for five axis machining is usually called five axis machine tool or five axis machining center. But do you really know five axis machining? Development of Five Axis Technology For decades, it is generally believed that five axis NC machining technology is the only way to process continuous, smooth and complex surfaces. Once people encounter unsolvable problems in designing and manufacturing complex surfaces, they will turn to five axis machining technology. But... Five axis linkage CNC is the most difficult and widely used CNC technology. It integrates computer control, high-performance servo drive and precision machining technology, and is applied to efficient, precise and automatic machining of complex surfaces. In the world, the five axis linkage numerical control technology is regarded as the symbol of a country's production equipment automation technology level. Due to its special status, especially its important influence on aviation, aerospace and military industries, as well as the complexity of technology, the western industrial developed countries have always implemented the export license system as a strategic material. Compared with three-axis CNC machining, from the perspective of process and programming, 5-axis CNC machining for complex surfaces has the following advantages: (1) Improve processing quality and efficiency (2) Expand process scope (3) Meet the new direction of compound development But, haha, but again... Because of interference and tool position control in the machining space, the NC programming, NC system and machine tool structure of five axis NC machining are much more complex than those of three axis machine tools. So, five axes is easy to say, but it is really hard to realize! In addition, it is more difficult to operate well! Speaking of five axes, I have to say the true and false five axes? The difference between the true and false 5 axes mainly lies in whether the RTCP function is available. For this reason, Xiao Bian specifically searched for this word! RTCP, please explain that Fidia's RTCP is the abbreviation of "Rotating Tool Center Point", which literally means "rotating tool center". The industry often translates it into "turning around the tool center", and some people also translate it directly as "programming of rotating tool center". In fact, this is just the result of RTCP. RTCP of PA is the abbreviation of the first few words of "Real time Tool Center Point rotation". Heidegger calls similar so-called upgrade technology TCPM, which is the abbreviation of "Tool Centre Point Management", namely tool centre point management. Others refer to similar technology as TCPC, which is the abbreviation of "Tool Center Point Control". From the literal meaning of Fidia's RTCP, if the RTCP function is executed manually at a fixed point, the tool center point and the actual contact point between the tool and the workpiece surface will remain unchanged. At this time, the tool center point falls on the normal at the actual contact point between the tool and the workpiece surface, and the tool handle will rotate around the tool center point. For ball head cutters, the tool center point is the target track point of the NC code. In order to enable the tool handle to simply rotate around the target track point (i.e. the tool center point) when executing the RTCP function, the offset of the linear coordinates of the tool center point caused by the tool handle rotation must be compensated in real time, so that the included angle between the tool handle and the normal at the actual contact point of the tool and the workpiece surface can be changed while keeping the tool center point and the actual contact point of the tool and the workpiece surface unchanged, It can play the best cutting efficiency of the ball end cutter and effectively avoid interference. Therefore, RTCP seems to stand on the tool center point (i.e. the target track point of NC code) more to handle the change of rotation coordinates. Five axis machine tools and CNC systems without RTCP must rely on CAM programming and post-processing, and the tool path must be planned in advance. For the same part, if the machine tool is changed or the tool is changed, CAM programming and post-processing must be carried out again, so they can only be called false five axes. Many domestic five axis CNC machine tools and systems belong to this kind of false five axes. Of course, there is nothing wrong with people who insist on calling themselves five axis linkage, but this (false) five axis is not that (true) five axis! Xiao Bian also consulted experts in the industry. In short, the real five axis is five axis five linkage, the false five axis may be five axis three linkage, and the other two axes only play a positioning function! This is a popular statement, not a standard statement. Generally speaking, five axis machine tools can be divided into two types: one is five axis linkage, that is, all five axes can be linked at the same time; the other is five axis positioning processing, which is actually five axis three linkage: that is, two rotating axes can rotate and position, and only three axes can be linked at the same time. This is commonly known as the 3+2 mode of five axis machine tool, which can also be understood as a false five axis machine tool. Current forms of five axis CNC machine tools In the mechanical design of 5-axis machining centers, machine tool manufacturers have always been committed to developing new motion modes to meet various requirements. Considering all kinds of five axis machine tools on the market, although their mechanical structures are various, they mainly have the following forms: Two rotation coordinates directly control the direction of the tool axis (double swing head form) The two axes are at the top of the tool, However, the rotation axis is not perpendicular to the linear axis (vertical pendulum type) Two rotation coordinates directly control the rotation of space (double turntable form) The two axes are on the workbench, However, the rotation axis is not perpendicular to the linear axis (vertical worktable) One of the two rotation coordinates acts on the tool, One acts on the workpiece (one swing and one turn) Having seen these five axis machine tools, I believe we should understand what and how the five axis machine tools are moving. Difficulties and Resistance in Developing Five Axis NC Technology We have already realized the superiority and importance of five axis numerical control technology. But so far, the application of five axis CNC technology is still limited to a few departments with abundant funds, and there are still unsolved problems. The following section collects some difficulties and resistance to see if they correspond to your situation? Abstract 5-axis NC programming, difficult to operate This is a headache for every traditional NC programmer. Three axis machine tools only have linear coordinate axes, while five axis CNC machine tools have various structural forms; The same NC code can achieve the same machining effect on different three axis NC machines, but the NC code of a certain five axis machine tool cannot be applied to all types of five axis machine tools. In addition to linear motion, NC programming also coordinates the calculation of rotation motion, such as rotation angle travel inspection, nonlinear error check, tool rotation motion calculation, etc. The amount of information processed is large, and NC programming is extremely abstract. The operation of five axis NC machining is closely related to programming skills. If users add special functions to the machine tool, the programming and operation will be more complex. Only through repeated practice can the programming and operating personnel master the necessary knowledge and skills. The lack of experienced programmers and operators is a major resistance to the popularization of five axis CNC technology. Many domestic manufacturers have purchased five axis CNC machine tools from abroad. Due to inadequate technical training and service, the inherent functions of five axis CNC machine tools are difficult to achieve, and the utilization rate of machine tools is low. In many cases, it is better to use three axis CNC machine tools. Very strict requirements for NC interpolation controller and servo drive system The movement of a five axis machine tool is a combination of five coordinate axis movements. The addition of rotation coordinates not only increases the burden of interpolation, but also greatly reduces the machining accuracy due to the small error of rotation coordinates. Therefore, the controller is required to have higher calculation accuracy. The motion characteristics of the five axis machine tool require the servo drive system to have good dynamic characteristics and a large speed range. The verification of NC program of 5-axis NC is particularly important In order to improve the machining efficiency, it is urgent to eliminate the traditional "trial cut" calibration method. In 5-axis NC machining, the verification of NC program is also very important, because workpieces usually processed by 5-axis NC machine tools are very expensive, and collision is a common problem in 5-axis NC machining: cutting tools into workpieces; The tool collides with the workpiece at a very high speed; The tool collides with the machine tool, fixture and other equipment within the processing range; Moving parts on the machine tool collide with fixed parts or workpieces. In five axis NC, collision is very difficult to predict. The calibration program must comprehensively analyze the kinematics and control system of the machine tool. If the CAM system detects an error, it can immediately process the tool path; However, if NC program errors are found during machining, the tool path cannot be directly modified as in three-axis NC. On the three-axis machine tool, the machine tool operator can directly modify the parameters such as tool radius. In five axis machining, the situation is not so simple, because changes in tool size and position have a direct impact on the subsequent rotation trajectory. Tool radius compensation In the five axis linkage NC program, the tool length compensation function is still valid, but the tool radius compensation is invalid. When cylindrical milling cutter is used for contact forming milling, different programs need to be compiled for cutters with different diameters. At present, the popular CNC systems cannot complete the tool radius compensation because the ISO file does not provide enough data to recalculate the tool position. The user needs to change the tool frequently or adjust the exact size of the tool during NC processing. According to the normal processing program, the tool path should be sent back to the CAM system for recalculation. As a result, the efficiency of the whole processing process is very low. To solve this problem, Norwegian researchers are developing a temporary solution called LCOPS (Low Cost Optimized Production Strategy). The data required for tool path correction is transferred to the CAM system by the CNC application program, and the calculated tool path is directly sent to the controller. LCOPS requires a third party to provide CAM software, which can be directly connected to CNC machine tools. In the meantime, CAM system files are transmitted instead of ISO codes. The final solution to this problem depends on the introduction of a new generation of CNC control system, which can recognize workpiece model files (such as STEP) or CAD system files in a common format. Post Processors The difference between a five axis machine tool and a three-axis machine tool is that it also has two rotation coordinates, and the tool position is converted from the workpiece coordinate system to the machine coordinate system, which requires several coordinate transformations. Using the popular post processor generator in the market, the post processor of three-axis CNC machine tools can be generated by inputting the basic parameters of the machine tool. For five axis CNC machine tools, there are only some improved post processors. The post processor of five axis CNC machine tool needs further development. In three-axis linkage, the position of the workpiece origin on the machine tool workbench is not necessary to be considered in the tool path, and the post processor can automatically handle the relationship between the workpiece coordinate system and the machine coordinate system. For five axis linkage, for example, when machining on a horizontal milling machine with five axis linkage of X, Y, Z, B, C, the position size of the workpiece on the C turntable and the position size between the B and C turntables must be considered when generating the tool path. Workers usually spend a lot of time to deal with these positional relationships when clamping workpieces. If the post processor can process these data, the workpiece installation and tool path processing will be greatly simplified; Just clamp the workpiece on the workbench, measure the position and direction of the workpiece coordinate system, input these data to the post processor, and post process the tool path to obtain the appropriate CNC program.

Shaft parts are a common type of parts. Its structure is a rotating body, and its length is generally larger than the diameter. It is widely used in various mechanical equipment to support transmission parts, transmit torque and bear load. The processing of shaft parts should follow certain rules. This paper will come to the specific processing steps and some problems that need attention. Basic machining route of shaft parts The main machining surfaces of shaft parts are cylindrical surfaces and common special surfaces. Therefore, the most appropriate machining methods should be selected according to various accuracy levels and surface roughness requirements. The basic processing routes can be summarized into four. 1. The processing route from rough turning to semi finish turning and then to finish turning is also the main process route selected for the needle excircle processing of shaft parts with common materials. 2. From rough turning to semi finish turning, then to rough grinding, and finally to finish grinding, this processing route is the best choice for parts with high requirements on ferrous materials and precision, small requirements on surface roughness, and need to be hardened, because grinding is the most ideal subsequent processing procedure. 3. From rough turning to semi finish turning, then to finish turning and diamond turning, this processing route is specially used for processing non-ferrous materials. Because the non-ferrous metals have low hardness and are easy to block the gap between sand grains, it is usually not easy to obtain the required surface roughness by grinding, so the processes of finish turning and diamond turning must be used; The last processing route is from rough turning to semi fine turning, and then to rough grinding and fine grinding. 4. It is a frequently used processing route for parts that have been hardened with ferrous materials and require high precision and low surface roughness. Pre machining of shaft parts Before turning the excircle of shaft parts, some preparation procedures must be carried out, which is the pre processing process of shaft parts. The most important preparation process is straightening. Because the workpiece is often bent and deformed in the process of manufacturing, transportation and storage. In order to ensure reliable clamping and even distribution of machining allowance, various presses or straightening machines are used for straightening in cold state.   Positioning datum for machining shaft parts 1. The center hole of the workpiece is used as the positioning datum for processing. In the processing of shaft parts, the coaxiality of each external circular surface, taper hole and thread surface, and the perpendicularity of the end face to the rotation axis are important manifestations of position accuracy. These surfaces are generally designed on the basis of the centerline of the shaft and positioned with the central hole, which conforms to the principle of datum coincidence. The center hole is not only the positioning reference for turning, but also the positioning reference and inspection reference for other processing procedures, which conforms to the principle of unified reference. When two central holes are used for positioning, a plurality of outer circles and end faces can be machined to the maximum extent in one clamping. 2. The outer circle and the center hole are used as the positioning datum for processing. This method effectively overcomes the disadvantage of poor rigidity of center hole positioning, especially when machining heavy workpieces, the center hole positioning will cause unstable clamping, and the cutting amount cannot be too large. It is unnecessary to worry about this problem if the outer circle and the central hole are used as the positioning datum. In rough machining, the method of using the cylindrical surface of the shaft and a central hole as the positioning datum can bear a large cutting torque during machining, which is the most common positioning method for shaft parts. 3. The two cylindrical surfaces are used as the positioning datum for processing. When machining the inner hole of the hollow shaft, the central hole cannot be used as the positioning datum, so the two outer circular surfaces of the shaft should be used as the positioning datum. When machining the spindle of the machine tool, the two supporting journals are often used as the positioning reference, which can effectively ensure the coaxiality requirement of the taper hole relative to the supporting journal, and eliminate the error caused by the non coincidence of the reference. 4. The taper plug with the central hole is used as the positioning datum for processing. This method is most commonly used in the machining of the outer surface of hollow shafts. Clamping of shaft parts The processing of taper plug and taper sleeve mandrel must have high processing accuracy. The center hole is not only the positioning reference for manufacturing itself, but also the reference for finishing the outer circle of the hollow shaft. It must ensure that the taper surface on the taper plug or taper sleeve mandrel has a high coaxiality with the center hole. Therefore, when selecting the clamping method, attention should be paid to reducing the installation times of the cone plug as far as possible, so as to reduce the repeated installation error of the parts. In actual production, after the installation of the cone plug, generally speaking, before the completion of processing, it will not be removed or replaced during processing.

The precision of hardware parts almost determines the quality of the product, and the higher the precision of hardware parts, the higher the requirement for precision. So, why does precision parts machining accuracy become worse? First, the parts themselves are poorly machined. Generally speaking, if the dynamic error between the shafts is not well adjusted during installation or changes due to wear and tear of the shaft drive chain, the accuracy of the parts will be affected. Generally, the accuracy check caused by such errors can be solved by readjustment compensation. If the error is too large or even if there is an alarm, you need to check the servo motor and observe whether its speed is too high.   Second, machine tool overshoot during operation can also affect machining accuracy, which may be due to acceleration and deceleration time is too short, the replacement time is properly extended. Of course, it is also likely that the connection between the screw and the servo motor is loose. Third, because of the two-axis linkage generated by the roundness overshoot, the machine is not properly adjusted to form the axial deformation of the circle, the axis of the screw clearance compensation is not correct or the axis positioning offset, which may affect the precision of precision parts.

The quality of precision parts machining parts affects the effectiveness of the machining method? Precision parts processing is the most common measure and means used in the industrial stage. For this technology, the first thing to consider is the quality and structure of the part itself; if poor quality parts are chosen, it will not help, regardless of the processing method used. Therefore, the quality of parts in parts machining is a very important step; speaking of parts, it is one of the indispensable products in many mechanical devices; parts are the basic elements of machine composition. Machines generally include one or more transmission parts for receiving external energy (such as electric motors, internal combustion engines, steam engines).   The implementation of the machine production functions of the executive part (such as machine tools in the tool), the original motion and power to the executive part of the transmission part (such as machine tools in the gear and screw drive mechanism), to ensure that the machine in the coordination of the work of the various parts of the detection and control system (such as machine tools in the CNC system) constitutes (that is, the machine by the original part, the transmission part, the executive part, the measurement and control part). The machine will be further decomposed, you can get all kinds of parts. Parts processing is the basic elements of the composition of the machine, can be broadly divided into two categories: one is available for a variety of machine parts (such as gears, shafts, etc.), known as general-purpose parts; the other is only used in a certain type of machine parts (such as bolts, propellers, etc.), known as special parts; in addition to some of the synergistic work of the parts composed of a combination of parts called parts or components (such as couplings, reducers, etc.).

Technical requirements in machining. 1, first of all, in machining, parts processing surface, there should be no scratches, scrapes and other defects that damage the surface of the parts. Parts to remove the oxide skin; uninjected shape tolerance should comply with the requirements of GB1184-80, uninjected length size allowable deviation ± 0.5mm; casting tolerance zone symmetry in the basic size configuration of the blank casting.   2. Processing of rolling bearing components are allowed to use oil heating for hot installation. Oil temperature should not exceed 100 ° C. Assembly of the hydraulic system allows the use of seal packing or sealant, but should be prevented from entering the system. Parts entering the assembly are assembly must have a certificate issued by the inspection department.   3, the parts must be cleaned before assembly, there should be no burrs, flying edges, oxide, rust, debris, oil, colorant and dust; before assembly should be the main fit size of the parts, especially the interference fit size and the related accuracy of the audit; parts in the assembly process does not allow knocking, touching, scratching and rusting.   4, mechanical processing in tightening screws, bolts, nuts, knocking or use of inappropriate screwdriver, wrench is strictly prohibited. Screw slot, nut, screw, bolt head shall not be damaged after tightening; fasteners with the specified tightening torque must be tightened with a torque wrench and tightened according to the specified tightening torque, and the excess adhesive flowing out shall be removed after bonding. 5, bearing outer ring and open bearing housing, bearing cover semi-circular hole should not be stuck; bearing outer ring should be in good contact with the open bearing housing semi-circular hole and bearing cover. It should be in contact with the bearing cover in the center line symmetry 120 ° and center line symmetry 90 ° range of uniform contact. In the above range with the plug ruler check, outer ring width of 1/3 shall not insert 0.03mm plug ruler.   6, bearing outer ring after assembly, should be positioned with the end of the bearing cover end contact evenly. After the rolling bearing is installed, it should be rotated flexibly and smoothly by hand. When fixing the shaft tile with a pin, the hole should be drilled in the hinge and the pin should be arranged when the mouth and end face of the shaft tile are flush with the opening and closing face and end face of the bearing concerned. Hole. The pin shall not be loosened after punched in.   7, alloy bearing lining surface yellowing, is not allowed to use, in the specified contact angle does not allow the phenomenon of denuclearization. The denuclearized area outside the contact angle shall not be greater than 10% of the total area of the non-contact area. Gear (worm wheel) reference end face and shaft shoulder (or locating sleeve end face) should be matched and checked with 0.05mm plug gauge. And should ensure that the gear benchmark end face and axis perpendicularity requirements.   8、Castings on the sand, core sand and core bone should be clean, castings have inclined parts, its size tolerance zone should be along the inclined side of the proportional configuration, castings do not allow the existence of detrimental to the use of cold partition, cracks, holes and other casting defects. Before painting, rust, oxide, grease, dust, mud, salt and dirt must be removed from the surface of all steel parts that need to be painted.

What are the material quality requirements for precision parts processing? In the manufacturing process of precision parts processing, the manufacturing process solutions are different due to the different production requirements and conditions of various parts. When the same parts are produced by different process solutions, their production efficiency and economic benefits are also different. Under the premise of ensuring the quality of the part, the process of developing a reasonable and feasible process solution with good overall technical and economic efficiency is called the process design of the part. In addition, there are certain requirements for the selection and quality of materials.   Not all materials can be precision machined, some materials are too hard, more than the hardness of the processed parts, it is possible to make the parts collapse, so these materials are not suitable for precision machining, unless the parts are made of special materials, or laser cutting.   With the material is divided into two categories of metal materials and non-metallic materials, for metal materials, the highest hardness is stainless steel, followed by cast iron; then copper, and finally aluminum; and the processing of ceramics, plastics and other non-metallic materials belong to the processing.   Regarding the hardness requirements of the material, in some occasions, the higher the hardness of the material, the better, but only the hardness requirements of the processed parts; the material to be processed should not be too hard. The material is moderately soft and hard, at least one notch lower than the hardness of the part. Also, it depends on the function of the processing equipment and the reasonable choice of the part material.   Precision machining still has some requirements for materials, not all materials are suitable for processing, such as too soft or too hard materials, the former does not need to be processed, the latter can not be processed. Therefore, the parts must pay attention to the density of the material before processing;, if the density is too large, which is equivalent to the hardness is also large, if the hardness exceeds the hardness of the machine (lathe turning tool), it can not be processed, not only will damage the parts, but also cause danger, such as knife flying out to injure people. Therefore, in general, for machining, the quality of the material should be lower than the hardness of the machine tool so that it can be processed.

For the production and processing of metal materials, a specific process is maintained. In the whole process of processing different types of metal materials mechanical parts processing will also ensure the development trend and practical operation of different processes. Then in the trend of developing suitable process operations, large precision parts will gain a lot of expertise and maintain versatility. There is a tendency to maintain a great deal of versatility in processing methods for achieving high precision in metallic materials. They will all get a lot of professional innovations and trends based on the application of specific metal material resources. Then the whole process of operation in the production process of different metal material resources will be based on the specific working ability to ensure the whole process of rational use of resources.   Ensure that the whole process of operation of a large number of production and processing technologies to obtain a better process execution. The development of precision parts processing is to transform the trend of intelligent production and processing and the application of the process. Different features are obtained to operate the whole process of machining. And the maintenance of new work capabilities is carried out throughout the process of operating specific work capabilities. In the whole process of different production metal materials in the processing of large precision parts, a large number of metal materials will be used, and a large number of metal products and machinery and equipment will be operated in the process at one time. Therefore, in the development of different characteristics of the whole process, to ensure the use of metal materials in the whole process. Then, the whole process of maintaining a suitable process will ensure that the whole process of processing will not be affected in any way.

What are the requirements of the raw material inspection standards for automotive precision parts processing? When outsourcing parts processing, the quality of automotive precision parts processing must be given high priority. Therefore, before the production and processing, sign a good outsourcing production and processing quality assurance agreement, which is conducive to binding each other's rights and obligations and presenting a favorable treatment plan for future dispute cases. Automotive precision parts raw materials guarantee.   1, the tenderer is obliged to show the processing enterprise product approval letter and other technical documents, the processing enterprise must refer to the implementation of the test.   2, the processor's incoming inspection must be carried out with reference to the relevant industry standards.   3、The processing party is responsible for the test results. Processing party found that the quality of raw materials failed or exceeded all normal range, must immediately notify the tender party quality inspection personnel.   4, automotive precision parts processing party's storage and logistics area must be strictly distinguished between high-quality goods area, inferior goods area, stalled goods area, etc., and clearly marked to ensure that the storage of natural environment to consider the quality of raw materials regulations and properly stored and applied.   5, the bidder shall ensure that the raw material processing plant lot number attainment rate ≥ 90%, electronic device material attainment rate ≥ 95%. When lower than the overall target, the processing party must closely cooperate with the tenderer to carry out inspection and guidance, and continue to fail for three months, the tenderer should make punishment or even replace the dealer.   6, the tenderer of the finished product inspection of raw materials, such as special selection due to certain types of defects, automotive precision parts processing party should be based on the results of the tenderer's judgment, can not be returned due to the same defects.   7, for the processing party test failed raw materials, the tenderer should be resolved within 2 working days to complete the raw materials subject to return and replacement, the tenderer should order the dealer to take away failed goods in 3 working days, after the tenderer determined that the automotive precision parts processing of poor raw materials should order the dealer to return in 5 working days.

The deviation of high precision mechanical parts processing mainly comes from CNC lathes, special tools, raw materials and their human errors; in order to facilitate the application of statistical standard tolerances, the part deviation normal distribution monitor is used to predict the deviation trend and pattern when batch processing mechanical parts production parts. It is well known that with the increase in precision of machining of high-precision mechanical parts, the production costs and difficulty factors increase; after statistical analysis of batch mechanical parts machining, the purpose of dimensional tolerances is to ensure the application of the entire equipment and product pipeline. Under the specified preconditions, if the deviation of the part obeys normal distribution, the tolerance level can be moderately liberalized after full consideration of the process performance of production and processing, so that the production of batch mechanical parts has good rationality.   All adjustable measurement point values in the whole process of precision parts machining vary from person to person, and the specification, appearance and surface of the part can rarely exceed the ideal value, so it is necessary to limit the error to a certain range to dimensional tolerances. If eigenvalues independently and identically distributed under any criterion were used for probability statistics, it would be very easy to machine high precision parts in batch machining of mechanical parts. The deviation of the part is mainly influenced by the random factors of the production and processing system software, so that the result will cause the specific specifications of the machined high precision mechanical parts will be relatively idealized with an error that is close to the normal distribution; the numerical idealized value of the specific specification, so that the statistical analysis of the standard tolerance will be applied to determine the dimensional tolerance of the part. So how to define the dimensional tolerance boundaries for batch machining of mechanical parts? On the one hand, it is necessary to ensure its functionality, and on the other hand to decenter the marks that appear in the production process, which in turn will lead to a more refined economic development.