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

For precision parts, the processing is very strict, the processing process has a tool in, tool out, etc.. There are specific requirements for size and precision, such as 1mm plus or minus how many microns, etc. If the size is wrong too much will become scrap, which is equivalent to having to re-process, time-consuming and laborious, and sometimes even makes the entire processing material scrap, which causes an increase in costs, and at the same time, the parts are definitely not available. So precision parts processing in the end to follow what standards and requirements? For precision parts processing is mainly dimensional requirements, such as how much the cylindrical diameter, there are strict requirements, positive and negative error within the specified requirements to be qualified parts, otherwise they are unqualified parts; length, width and height also have specific strict requirements, positive and negative error is also specified, such as an embedded cylinder (take the most simple basic parts for example), if the diameter is too large, more than the error allowed range, it will Caused by, insert not into the situation, if the actual diameter is too small, more than the lower limit of the negative value of the error allowed, it will cause inserted too loose, not solid problems occur. These are unqualified products, or the cylindrical length is too long or too short, beyond the error tolerance range, are unqualified products, are to be scrapped, or re-processed, which will inevitably cause an increase in costs.   Precision parts processing requirements is in fact the main size problem, must be strictly in accordance with another plus drawings for processing, processing out of the actual size will certainly not be the same as the theoretical size of the drawings, only, as long as the processing size within the error tolerance is qualified parts, so the requirements of precision parts processing is in strict accordance with the theoretical size for processing. Second is the advanced precision parts processing equipment and testing equipment, advanced processing equipment makes processing precision parts easier, higher precision, better results. Testing equipment can detect the parts that do not meet the requirements, so that all the products sent to customers really meet the requirements.

Hardware processing accounts for a large part of precision parts processing. Casting properties: refers to whether the metal or alloy is suitable for casting some process properties, mainly including flow properties, the ability to fill the casting mold; shrinkage, the ability of volume shrinkage when the casting solidifies; deviation refers to chemical composition unevenness.   Welding performance: refers to the metal material by heating or heating and pressurized welding method, two or more metal materials welded together, the interface can meet the characteristics of the purpose of use.   Top gas section performance: refers to the performance of the metal material can be granted top forging without rupture. Cold bending performance: refers to the metal material at room temperature can withstand bending without rupture performance. Bending degree is generally used to bend the angle α (outer angle) or bending center diameter d to the material thickness a ratio, a the greater or d / a smaller, the better the cold bending of the material.   Stamping performance: the ability of metal materials to withstand stamping deformation processing without rupture. Stamping at room temperature is called cold stamping. The test method is to test by cupping test.   Forging performance: the ability of the metal material to withstand plastic deformation without rupture during forging processing.  

We know that shaft parts are one of the most commonly used parts in machines, and also one of the very important parts, because it is about the support role of transmission components and transmission torque, so how are shaft parts machined? The following to introduce you to. First of all, we need to understand the technical requirements of shaft parts and processing requirements, what are the general technical requirements of shaft parts? Let's look at the following specific.   1, diameter accuracy, geometric shape accuracy   In the shaft, the support journal and with the journal is very important, its diameter accuracy of IT5-IT9 level, and shape accuracy, should be controlled within the diameter tolerance, and its requirements are higher than the diameter accuracy.   2、Mutual position accuracy   If the shaft is common accuracy, then its radial circular runout, if it is to be matched with journal to support journal, is generally regarded as 0.01-0.03mm. while the high accuracy shaft is 0.001-0.005mm. if there are special requirements, then it should be specified clearly. 3、Surface roughness   Because the machine precision, running speed and other factors, resulting in shaft parts of the surface roughness requirements are also different. The surface roughness of the bearing journal is 0.16-0.63um, and that of the mating journal is 0.63-2.5um.   4、Materials, blanks and heat treatment of spindle   Shaft parts, the commonly used material is 45 steel, and through normalizing, annealing, tempering and quenching these treatments, so as to obtain a certain strength, hardness, wear resistance and toughness.   For high speed shaft parts, alloy structural steel can be used, because it will improve wear resistance and fatigue resistance after heat treatment. Blanks for spindles are usually forgings and round steel, which can reduce the amount of cutting and machining, and can improve the mechanical properties of the material.

Box-type parts said to be typical parts of mechanical parts, that today we want to box-type parts as a representative to give you an analysis of the parts of the machining process. We know like gear transmission box body, transmission box body, lathe bed box body are the basic parts of the machine, the machine parts of the shaft, bearings, sets and gears and other parts each maintain the correct mutual position, and in accordance with the pre-designed transmission relationship so that they coordinate mutual movement, combined into a whole. Box requires processing of many surfaces, each surface processing requirements are different, some of the requirements for high precision, such as the spindle hole, so the box of its machining accuracy has become a key issue in the process, in view of this, in the parts processing also pay attention to the following points:.   1, roughing and finishing stages to be separated   We also mentioned above that the box body to be processed on the surface of many, precision requirements are different, so in the operation to separate the rough and fine machining, and can not rough machining immediately after the fine machining, because this will easily lead to box body deformation, and ultimately affect the accuracy.   2, should be in accordance with the first face after the hole processing order   First processing plane, not only to remove the surface of the rough unevenness and surface sand trap, more importantly, in the processing of the distribution of the hole in the plane, scribing, find a convenient, and when the boring tool to start boring, will not be due to the unevenness of the end surface and the impact vibration, damage to the tool, therefore, the best general - should be processed first plane. 3, the arrangement of appropriate heat treatment process   Casting box structure is complex, uneven wall thickness, inconsistent cooling rate during casting, easy to produce internal stress, and the surface is hard, therefore, after casting should be reasonably arranged sandblasting, tempering people.   4, process concentration or decentralized decision   Box roughing and finishing stages are separated in line with the principle of process dispersion, but in the middle and small batch production, in order to reduce the number of machine tools and fixtures used, as well as reduce the number of handling and installation of the box, the roughing and finishing stages can be relatively concentrated, as far as possible on the same machine tool for.

CNC lathe machining is widely used, including manufacturing, aviation, medical industry and so on. Because compared to ordinary lathes, CNC lathes have incomparable advantages. 1、Compared with ordinary lathe, the rigidity of CNC lathe is high. In order to match the high precision of CNC lathe with CNC system, the rigidity requirement of CNC lathe must be very high in order to achieve the high precision processing requirements.   2、The spindle of ordinary lathe is variable speed through motor, belt and gear vice mechanism, while the CNC machine tool is completed by two servo motors driving movement in horizontal and vertical directions respectively, so relatively speaking, it does not use traditional parts such as hanging wheel and clutch, which greatly shortens the transmission chain.   3. Compared with ordinary lathe, it is easier to drag because its table movement adopts ball screw vice, which has little friction, so it moves lightly. The supporting special bearings at both ends of the screw are with larger pressure angle than ordinary bearings. The lubrication part of CNC lathe machining adopts oil mist automatic lubrication, and all these measures make CNC lathe machining move lightly. CNC machining has many advantages.   1、It can ensure the high precision of processing and guarantee the high quality of processing.   2、Automated operation reduces manual labor intensity and improves work efficiency.   3、Automated operation, as long as the operation requirements, do not need skilled machine operators.

Precision parts in the actual work of the strength and toughness requirements are relatively high, its work performance and service life with its surface performance has a great connection, and surface performance, is unable to rely solely on the material to do, is also very uneconomical practice, but the actual processing must be made to meet the performance standards, it is necessary to use the surface treatment technology, which can often achieve twice the result with half the effort! In recent years, this technology has also been rapid development. In the field of mold surface treatment mold polishing technology is a very important link, but also an important process in the processing of the workpiece. The surface treatment process of precision parts is very important in the process, so what are the surface treatment process of precision parts? It is worth reminding, precision parts of the mold surface polishing treatment work, not only received only the process process and polishing equipment, but also by the parts material mirror degree, which is not enough attention in the processing now, which is also to show that the polishing itself is affected by the material. Although now improve the surface performance of precision parts processing technology continues to innovate and upgrade, but the most used in the precision parts processing or mainly for hardening film deposition, and nitriding, carburizing technology Because nitriding technology can obtain a very high level of surface performance, and nitriding technology process and precision parts in the steel quenching process has a very high degree of consistency, and the temperature of nitriding is very low, so that after the treatment of nitriding technology does not require intense cooling process, so the deformation of precision parts will be very small, so nitriding technology is also used in the processing of precision parts to strengthen Nitriding technology is also one of the earliest technologies used in precision parts processing to strengthen surface properties, and is currently the most widely used.  

Parts in the process of processing, due to the influence of various factors, easily lead to its own existence of certain defects, such as the appearance of substandard, limited scope of use, etc.. The existence of these defects will inevitably bring certain problems to the use of parts, in order to overcome these problems and give full play to the unique value of the parts, precision parts machining is the better choice. The choice of precision parts processing, not only can effectively improve the quality of materials, parts precision, play its function, but also can make the durability of the parts greatly improved, and promote the quality of the entire machinery to improve. Precision machining is also good for improving the dimensional accuracy of the parts, so the most direct effect is that it can make the parts reach interchangeability, which in turn increases the wear resistance and service life of the parts.   It is because of all these advantages that precision machining of parts is so popular, and there are more suitable areas to be used in the assembly of equipment, so that its value can be better played. Thus, it is important to pay attention to the precision parts processing. After the processing of different parts we can get more suitable for their own parts, so in order to make these products better for their own service, to play its ultimate value, so many people are less precision machining this important link  

As we all know, the reason why the processing of precision parts is called precision machining, precisely because of its processing procedures and process requirements are very high, the precision requirements of the product is very high, and the precision of the processing of precision parts contains the accuracy of the location, size accuracy, shape accuracy, etc., Rui Sheng Technology General Manager combined with the company's more than 10 years of production and processing experience for us to summarize the following impact on the precision of precision parts processing Factors. (1) the machine tool spindle rotation runout can produce a certain error on the machining accuracy of the parts.   (2) the accuracy of the machine tool guide inaccuracy can also lead to precision parts processing workpiece shape error.   (3) transmission components can also lead to errors in the processing of the workpiece, which is also the most important factor in the production of the workpiece surface error.   (4) tool, fixture type of different will also have different degrees of impact on the accuracy of the workpiece processing.   (5) In the process of machining and cutting due to changes in the location of the force point will lead to deformation of the system, resulting in differences, which can also make the accuracy of the workpiece to produce different degrees of error. (6) The size of the cutting force is different, which can also lead to the accuracy of the workpiece being affected.   (7) the process system by heat deformation caused by the error, machining process, the process system will be in the role of various heat sources to produce a certain amount of thermal deformation.   (7) process system deformation caused by heat often leads to the accuracy of the workpiece is affected.   (8) The deformation of the machine tool by heat will lead to the deformation of the workpiece.   (9) Heat deformation of the tool can have a great impact on the workpiece.   (10) The workpiece itself is deformed by heat, mainly in the cutting process.

Parts processing process is a direct change in the appearance of raw materials (shape, size, location, performance), so that it becomes a semi-finished workpiece or finished process, the process we call the process, that is, the parts of the processing process benchmark, precision parts processing process is more complex. Precision parts processing process benchmark can be divided into different processes: casting, forging, stamping, welding, heat treatment, machining, assembly and so on categories. Precision parts processing process generally refers to the entire part of the CNC machining and machine assembly process in general, and other such as cleaning, inspection, equipment maintenance, oil seals, etc. are only auxiliary processes. Turning methods to change the surface properties of raw materials or semi-finished products, this process we call the CNC machining process, precision parts processing industry in the CNC machining process is the most important process. The following is a detailed introduction to the CNC precision parts machining process benchmark   (1) positioning datum, the positioning datum used by the lathe or fixture in the CNC lathe for processing.   (2) measurement benchmark, this benchmark usually refers to the size or position of the standard to be observed during inspection.   (3) assembly benchmark, this benchmark we usually refers to the position of the parts in the assembly process standards.

Cutting processing is roughly divided into turning, milling and cutting (drilling, end mill end cutting, etc.), the cutting heat of these cutting processes on the tip of the cutting edge is also different. Turning is a continuous cutting, the cutting force at the tip of the cutting edge does not change significantly, the cutting heat acts continuously on the cutting edge; milling is a kind of intermittent cutting, the cutting force is intermittent on the tip of the cutting edge, cutting vibration will occur, the tip of the cutting edge is affected by the heat, is alternately heated when cutting and non-cutting cooling, the total heat is less than when turning. The cutting heat during milling is a kind of intermittent heating phenomenon, and the tool teeth are cooled during non-cutting, which will contribute to the extension of tool life. Japan Institute of Physical and Chemical Research of turning and milling tool life for comparative testing, milling tools used for ball end mill, turning for general turning tools, both in the same processed materials and cutting conditions (due to different cutting methods, depth of cut, feed, cutting speed, etc. can only be roughly the same) and the same environmental conditions for cutting comparison test, the results show that milling processing to extend tool life is more The results show that milling is more beneficial to prolong the tool life. When cutting with tools such as drills and ball end mills with a central edge (i.e., the part with cutting speed = 0 m/min), the tool life near the central edge is often low, but it is still better than when turning. In cutting difficult to machine materials, the cutting edge is affected by heat, often reducing tool life, cutting method such as milling, the tool life will be relatively long. However, difficult-to-machine materials can not be used from start to finish all milling, there will always be a need for turning or drilling in the middle of the time, therefore, should be for different cutting methods, take the appropriate technical measures to improve processing efficiency.