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

The processing process of precision parts is a process that directly changes the appearance (shape, size, location, performance) of raw materials to make them semi-finished or finished products, The processing of precision parts is relatively complex. The following CNC parts processing manufacturers will provide you with the process benchmark for precision parts processing. The benchmark of precision parts processing technology can be divided into different categories: casting, forging, stamping, welding, heat treatment, machining, assembly, etc. The machining process of precision parts generally refers to the CNC machining and machine assembly process of the whole part, while other processes such as cleaning, inspection, equipment maintenance, oil seal, etc. are only auxiliary processes. CNC parts processing   The method of turning changes the surface characteristics of raw materials or semi-finished products. This process is called CNC machining process. CNC machining process is the most important process in the precision parts processing industry. Process benchmark for CNC part processing:   (1) Positioning datum, the positioning datum used by the lathe or fixture during NC lathe processing.   (2) Measurement datum usually refers to the dimension or position standard to be observed during inspection.   (3) Assembly datum, we usually refer to the position standard of components during assembly.

In the manufacturing process of mechanical parts, because the production requirements and conditions of various parts are different, the manufacturing process program is also different. The same parts using different process solutions for production, its production efficiency, economic efficiency is not the same. Under the premise of ensuring the quality of the parts, the process of drawing up a good comprehensive technical and economic benefits, reasonable and feasible process plan is called the process design of the parts. So what is the specific process production process? 1. Production process from the design drawings into products, through a series of manufacturing processes. Usually the raw materials or semi-finished products into products through the entire process is called the production process. Production process usually includes:   (1) technical preparation process including market research, forecasting, new product identification, process design, standardization review, etc. before the product is put into production.   (2) or process refers to the process of directly changing the size, shape, mutual position of the surface, surface roughness or performance of the raw material semi-finished products, so that they become finished products. For example, liquid forming, plastic into shape, welding, powder forming, cutting and machining, heat treatment, surface treatment, assembly, etc., all belong to the process. The reasonable process is written into the technical documents used to guide the production, this technical document is called process procedures.   (3) Auxiliary production process refers to the auxiliary production activities necessary to ensure the normal conduct of the basic production process.   (4) Production service process refers to the organization of raw materials, transportation, storage, storage, supply and product packaging, sales and other processes. 2. The composition of the process parts of the cutting process is a combination of many processes, each process is composed of stations, work steps, tool walking and installation.   (1) process refers to a machine tool or in the same workplace on a workpiece or a group of continuous completion of that part of the process.   The basis for dividing the process is whether the workplace changes and whether the work is continuous.   (2) step refers to a process, when the workpiece surface, cutting tool and cutting amount of speed and feed are kept constant in the completion of that part of the process. A process with a large number of machined surfaces can be divided into several work steps. The work step is the basic unit that constitutes the process.   (3) tool walking tool from the surface to be machined every layer of the margin, called a tool walking. To be removed from the balance is too large and not possible or suitable for a cut, can be divided into several cutting to complete.   (4) installation of the workpiece by a clamping (positioning and clamping) after the completion of that part of the process is called installation.   (5) Station relative to the fixed part of the tool or equipment, each processing position occupied by the workpiece is called a station. In most cases, the workpiece is mounted only once in a process, and sometimes it may be mounted several times. As shown in Figure 2-1 for a stepped axis, it is usually mounted twice in process 0. Clamp one end to turn the other end, then turn around. After the turnaround, a new workstation is formed.

Stainless steel precision parts processing is difficult, I do not know, difficult to process the reason also lies in the choice of tools, the following is a specific look at the material on the choice of tools, processing difficulties and solutions:. First, in the automatic lathe turning stainless steel, the general use of carbide tool materials are: YG6, YG8, YT15, YT30, YW1, YW2 and other materials; commonly used high-speed steel tool has: W18Cr4V, W6M05Cr4V2AL and other materials.   Second, the geometric angle of the tool and the selection of the structure is also particularly important: the   Front angle: general turning stainless steel tool front angle of 10 ° ~ 20 ° is more appropriate.   After the angle: generally take 5 ° ~ 8 ° more appropriate, the maximum is not 10 °.   Edge inclination angle: generally selected λ for -10 ° ~ 30 °.   Edge surface roughness should be no greater than Ra0.4 ~ Ra0.2.   Third, the difficulty of processing stainless steel parts are the following common types.   1, machining hardness resulting in faster tool wear, and difficult to chip removal.   2, low thermal conductivity causes plastic deformation of the cutting pin edge and tool wear faster.   3、Chip accumulation tumor is easy to cause the emblem small piece of powder chip left on the cutting pin edge, and cause bad machining surface.   4、The chemical relationship between the tool and the material to be machined causes machining hardening and low thermal conductivity of the material to be machined, which not only easily causes unusual wear, but also tool chipping and abnormal rupture. Fourth, the solution to the processing difficulties are as follows.   1, the use of high thermal conductivity of the tool.   2, sharp cutting edge edge line: chipbreaker slot edge band is wider, which can reduce the cutting pressure, so that the chip removal can be well controlled.   3, the best cutting conditions: inappropriate processing conditions will reduce tool life.   4, choose the appropriate tool: stainless steel with a tool should have excellent toughness, cutting edge strength and the combination of coating film should also be relatively high.   The above difficulties and countermeasures on the processing of stainless steel parts are shared here, I hope it will be helpful to all readers.

First, the machine tool composite technology to further expand with the progress of CNC machine tool technology, composite machining technology is becoming increasingly mature, including milling - turning composite, milling composite, turning - boring - drilling - gear processing and other composite, grinding composite, forming composite processing, special composite processing, etc., precision machining efficiency greatly improved. Second, the intelligent technology of CNC machine tools have new breakthroughs in the performance of the CNC system has been more reflected. Such as: automatic adjustment of interference anti-collision function, power failure after the workpiece automatically exit the safety zone power failure protection function, processing parts detection and automatic compensation learning function, intelligent enhance the function and quality of the machine tool. More five-axis linkage high-speed machining center was introduced.   Third, the robot makes the flexible combination of higher efficiency robot and host of flexible combination is widely used, making the flexible line more flexible, further expand the function, flexible line to further shorten, higher efficiency. Robots and machining centers, turning and milling machine tools, grinding machines, gear processing machine tools, tool grinders, electrical processing machine tools, saws, stamping machine tools, laser processing machine tools, water cutting machine tools and other forms of flexible units and flexible production lines have begun to apply. Fourth, precision mechanical parts processing technology has made new progress in CNC gold cutting machine tool processing accuracy has been upgraded from the original silk level to the current micron level, some varieties have reached about 0.0μm. Ultra-precision CNC machine tools for micro cutting and grinding, precision can be stable to 0.0μm or so, the shape accuracy of up to 0.0'μm or so. The use of light, electricity, chemical and other energy sources of special processing accuracy can reach the nanometer level. Through the optimization of machine tool structure design, machine tool components of ultra-precision machining and precision assembly, the use of high-precision full dead cycle control and temperature, vibration and other dynamic error compensation technology, thus entering the era of sub-micron, nano-level ultra-precision machining. Functional components continue to improve the performance of functional components continue to high speed, high precision, high power and intelligent direction, and to achieve mature applications. Full digital AC servo motors and drives, high technology content of electric spindle, torque motor, linear motor, high-performance linear rolling components, high-precision spindle units and other functional components to promote the application, greatly improve the technical level of CNC machine tools.

Those who know about precision parts machining know that precision machining is a very strict process, whether for tool walking or other processes, or accuracy, size are quite strict requirements of the process. So precision parts processing, in the end to follow what requirements and standards to ensure low or even zero defect rate? The following is my introduction to the specific requirements and standards for precision parts processing.   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 the cost increase.   Second is the advanced precision parts processing equipment and testing equipment, advanced processing equipment makes the processing of 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. 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 allowed are qualified parts, so the requirements of precision parts processing is in strict accordance with the theoretical size for processing.

Precision machining can be divided into cold machining and hot machining according to the temperature state of the workpiece. The so-called cold machining refers to the processing at room temperature that does not cause chemical or physical changes, and can be subdivided into cutting and pressure machining; the so-called hot machining refers to the processing at a state higher or lower than room temperature, and this processing will cause chemical or physical changes. So what specific matters should be noted in the processing process? I will introduce the following. 1, the geometry and mutual position accuracy of the part to micron or angular second level.   2, the boundaries of the parts or feature size tolerance in microns or less   3, the parts surface microscopic unevenness (surface unevenness average height difference) is less than 0.1 micron   4, interchangeable parts can meet the requirements of the fit force.   5, some parts can also meet the precise mechanical or other physical characteristics of the requirements, such as the torsional stiffness of the float gyroscope torsion bar, the stiffness coefficient of the flexural components. Precision machining is achieved by using precision machine tools and precision gauges and measuring instruments under strictly controlled environmental conditions. Machining accuracy up to and beyond 0.1 micron called ultra-precision machining. We are a professional manufacturer of metal non-standard parts, ￠0.5 - ￠20mm stainless steel, titanium, aluminum and other metal precision parts manufacturing has many years of technical precipitation.

First is the requirement of material hardness, for some occasions, the higher the hardness of the material is the better, just limited to the hardness requirements of the processed machine parts, the processed material can not be too hard, if the hardness than the machine parts is also impossible to process. Second, the material is soft and hard moderate, at least one grade lower than the hardness of the machine, but also depends on the role of the processed device is to do what with the machine reasonable selection of materials.   In short, precision machining of the material requirements or some, not what material is suitable for processing, such as too soft or too hard material, the former is not necessary for processing, and the latter is not processed. Therefore, the most basic one is in the mechanical parts processing plant before processing must pay attention to the density of the material, if the density is too large, equivalent to the hardness is also very large, and the hardness if more than the machine parts (lathe turning tool) hardness, is unable to process, not only will damage the parts, but also cause danger, such as turning tool flying out of the crash injury. Therefore, generally speaking, for mechanical processing, the material material should be lower than the hardness of the machine tool, so that it can be processed.

First of all, the part drawing should be analyzed for the process of CNC machining, the specific contents are.   (1) whether the dimensioning method in the part drawing is adapted to the characteristics of CNC machining.   (2) the adequacy of the geometric elements constituting the contour in the part drawing.   (3) whether the reliability of the positioning reference is good.   (4) whether the machining accuracy required by the part and the dimensional tolerances can be guaranteed.   For the part blank, the processability analysis is also performed, specifically.   (1) analysis of the suitability of the blank in terms of mounting and positioning, as well as the size and uniformity of the margin.   (5) whether the machining margin of the blank is sufficient, and whether the margin is stable in mass production. 1. Selection of machine tools   Different parts should be processed on different CNC machine tools, so according to the design requirements of the parts to choose CNC machine tools.   2. Tool point and tool change point selection   Tool point: is the starting point of the tool relative to the workpiece movement in the index control machining.   Tool change point: is for machining centers, CNC lathes and other multi-tool processing machine programming and set.   In programming are seen as the workpiece is stationary, and the tool is in motion. Usually the tool setting point is called the program origin, the main points of selection are: easy to find the right, easy programming, small tooling error and easy to check and reliable when processing, the tool setting point should be made to overlap with the tooling point when tool setting is carried out. 3. Selection of machining method and determination of machining plan   The principle of the selection of machining method is to ensure the machining accuracy and surface roughness requirements of the machined surface, but in the actual selection, should be combined with the shape of the part, size and heat treatment requirements, etc. for comprehensive consideration.   Machining program to determine, according to the main surface accuracy and roughness requirements, the initial determination of the processing methods required to achieve these requirements.   4. The choice of machining allowance   Machining allowance: the amount of general refers to the difference between the solid size of the blank and the size of the part. The choice of machining allowance has two principles, one is the principle of minimum machining allowance, the second is that there should be sufficient machining allowance, especially for the last process.   5. Cutting amount determination   Cutting amount includes depth of cut, spindle speed and feed. Cutting depth is based on the machine tool, fixture, tool and workpiece rigidity to determine, spindle speed is based on the allowable cutting speed to determine, and feed is based on the machining accuracy of the part and surface roughness requirements and the nature of the workpiece material to determine.

First, CNC precision machining machine maintenance   1, half an hour before work every day to clean and maintain the machine If you use an air gun or oil gun to clean the chips, the spindle must have a knife.   2, prohibit the use of air guns or oil guns to blow the spindle taper hole, to avoid chips and other tiny particles of debris are blown into the main shaft hole, affecting the cleanliness of the spindle.   3、Check whether the lubricator is working normally, whether the lubricant is sufficient, and turn on the machine according to the normal order.   4, in the machine tool before the official work to start the spindle (speed of 501R / M) in order to carry out spindle warm-up. Second, CNC precision machining machine operation   1, before the machine against the program list to confirm the processing blank type, size and machining allowance and the blank to sand and polish processing.   2, on the machine to confirm the placement of workpieces, as well as the processing process sequence, complete the more table action   3、Distribution, such as the need for "distraction bar" distraction speed of 501R/M, such as the use of knife distraction speed depends on the tool, in this process should also pay attention to the same height must be taken to ensure the accuracy of the distraction, the distraction is available after the end of the "G0 G54 X0 Y0" for inspection   4, formal processing before checking to confirm the placement of the workpiece and take the number of correct Third. CNC precision machining precautions   1、Before processing each program, you need to strictly confirm whether the tool is consistent with the program   2、When loading the tool, you should confirm the length of the tool and the suitability of the chosen clamping head.   3、Keep the tool in the same workpiece in the same area every time to ensure the accuracy of the tool connection.   4、Use air blowing in the roughing program as much as possible, and spray oil in the light tool program   5、Before spraying oil in the light knife need to clean the machine tool aluminum slag to prevent aluminum slag oil absorption   6, in the CNC precision machining operation by itself, the operator shall not leave the machine tool or regularly check the machine tool running condition, if you need to leave midway, you must designate the relevant personnel to look at the check   7, in the process of processing, such as found that the machining allowance is too much, you must use the "single segment" or "pause" to X, Y, Z value zero after the manual milling off and then swing back to the "zero point "Let it run on its own   8, the processing process, such as found in the case of collision tool operator must immediately stop, such as pressing the "emergency stop" button or "reset button" button or the "feed rate" to zero, etc.   9, in the machine operation is prohibited to open the door to avoid flying knife or flying workpiece   10. The workpiece must be cleaned and deburred in time after the machine   11, at the end of the shift, the operator must do a timely and accurate handover to ensure that the subsequent processing can be carried out normally   12, before shutting down the machine to ensure that the tool magazine in the original position, XYZ axis stop in the center position, in turn, turn off the machine operation panel on the power and the total power   13, when encountering heavy thunderstorms must immediately cut off the power to stop work

Non-standard equipment parts processing process will present tool wear accelerated, poor processing appearance integrity, chip removal difficulties and other common problems, seriously affecting the quality of such materials precision parts processing, production cycle and processing costs. According to the theory of metal technology, metal cutting, non-standard equipment parts processing principle of the above material processing difficulties to analyze, explore a set of effective stainless steel material drilling, reaming, boring processing skills. China's machinery manufacturing industry is bound by skills and talents, in the innovation of skills and product development, it is difficult to compete with the large companies in Europe and the United States. But with the influx of foreign capital, the intensification of the work competition, domestic precision parts processing plant work on independent development to increase investment, has achieved endless results, especially in the production of mechanical gauges gauge companies in the digital display skills and digital hardware gauges commodities to complete the breakthrough. Such as the current domestic success of the development of 2 m cnc gear measuring instrument, into the international also very strong competition in the precision measuring instruments. In addition, by virtue of external forces, but also to the domestic machining companies in the skills have excellent assistance, first now most of the domestic non-standard equipment parts processing companies more than the introduction of a number of foreign big brands of precision machining equipment. This center has no shortage of Japan, Germany imported equipment. With the assistance of external forces, but also to a large extent into the non-standard equipment parts processing out of the precision and color of the goods. Non-standard equipment parts processing needs to get super-lubricated processing appearance and high processing accuracy, which requires the knife has a high standard life, the tool is not worn, will be based on the processing appearance quality is not reduced super poor. Diamond tool standard life is very high, high-speed cutting tool wear is also very slow. Therefore, ultra-precision cutting, cutting speed is not subject to the constraints of tool life, which is different from the general cutting rules.   Non-standard equipment parts processing practice selected cutting speed, is often based on the use of ultra-precision machine tools and dynamic characteristics of the cutting system to select the dynamic characteristics, that is, to select the minimum vibration speed. Because at this speed the appearance of the smallest roughness, the highest quality machining. Obtaining a high quality non-standard machined appearance is the primary concern of non-standard equipment precision parts machining plants. The use of good quality, especially the dynamic characteristics of good, small vibration of ultra-precision machine tools can be used at high cutting speeds, can improve the power of processing. The selection of non-standard equipment parts processing parameters include the selection of the cutting tool point of view, the selection of cutting speed and depth of cut and feed rate selection. From the past experience we know that in the processing of plastic materials, if you select a larger front angle of the tool can be useful to press down the composition of the chip tumor, which is the front angle of the tool increases, the cutting force is reduced, cutting deformation is small, the tool and chip contact length becomes shorter, reducing the basis for the composition of the chip tumor.