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

We all know that grooving is a more complex machining process in the cnc machining process, and the main thing to understand about grooving is the type of grooving. What are the common types of grooves? It is mainly divided into external groove, internal hole groove and end groove. Although the difficulty of groove processing is high, but shenzhen cnc machining factory reasonable operation of the machining center, then you can effectively complete the groove processing, before this must understand the type of groove processing. What is grooving? Grooving is practically all cutting of tools, whether they are made of metal or non-metal tools, whether the workpiece is rotated or the tool is rotated in a machining mode, as long as the groove is removed from the workpiece using a grooved tool, it can be called grooving.   External groove machining is the easiest, and the machining form of external groove cutting is easy to evacuate chips under the action of love gravity and cooling. In addition, external circular groove machining can complete the lesson for the operator, who can directly check the quality of the relatively simple machining. However, it is also important to avoid potential obstacles in workpiece design or clamping.   However, when performing internal hole grooving, the tool blade is positioned slightly above the centerline to achieve the best machining results. When machining endface grooving special, the tool must move in the direction of the axis, and the back tool radius must be consistent with the machining radius. End face grooving tool tip position slightly higher than the center line when the best processing results. In any groove processing, cnc machining center model design and technical conditions are also the basic elements that need to be considered. cnc machining center's main performance is as follows: 1, with a strong enough machining efficiency, a high-speed spindle can ensure that the tool runs in the correct speed range and does not drop speed or jitter.   2, CNC machining center must be required to have a high enough rigidity to complete the required cutting process, will not chatter caused by the surface finish of the workpiece damage.   3, CNC machining center needs a high enough coolant pressure and flow rate to help chip removal machining center spindle center out of the water function design can meet this processing requirements.   CNC machining center in a large number of slot processing, must pay attention to the choice of tools. Hong Wisheng precision technology recommends the use of forming tools. The disadvantage of non-blade forming tools is that if one of them breaks or wears out more quickly, the entire tool must be replaced, substantially reducing machining efficiency and affecting machining accuracy. Forming tools can cut off all or most of the groove shape with a single grooving process, vacating the tool and condensing the cycle time of the process. In fact, the design and machining process of a single-round program for slot machining is not particularly difficult. The complication is the irregular shape of the workpiece and the consequent continuous testing to achieve the difference in processing method applied to the proper selection of tools is able to complete the cutting process efficiently.

The standards of the precision parts machining industry are very strict and there are different processes such as cut-in and cut-out. Dimensions can also vary depending on the product, and machining accuracy requirements can also vary. In general, precision machining is required to a high degree of accuracy, sometimes down to micron differences of less than 1mm. If there is a large dimensional variation, the product becomes scrap and needs to be reworked to meet the requirements, a time-consuming and labor-intensive process. Sometimes it will make all the raw materials scrap, resulting in increased costs, and at the same time the parts are bound to be unusable, so there are many requirements for precision parts machining.   (1) Usually, because the cutting volume, heat generation and cutting force of the part are different for the part roughness and precision, in order to ensure the machining accuracy of the part, so the rough parts and precision machined parts must be processed separately. If rough machining and precision machining are carried out continuously, the precision of the precision machined parts will be lost because of the difference in stress.   (2) The reasonableness of equipment selection. The processing of rough parts does not require high machining accuracy, but mainly reduces the machining allowance, so precision machining requires very high precision machine tools. In the processing route of precision parts, heat treatment process is often arranged. The location of the heat treatment process is arranged as follows: In order to improve the cutting performance of the metal, such as annealing, normalizing, tempering, etc., it is generally arranged to be carried out before the machining of mechanical parts.   (3) In general, almost all precision parts processing has a heat treatment process, which can improve the cutting performance of the metal. Precision parts processing and manufacturing requires not only the accuracy and stability of the machine tool and the accuracy of the tool and fixture to ensure, but also requires precision measuring instruments for calibration and measurement. Some are in the process of processing, and some are after the inspection. A fire two forging parts of a large number of hot forging forming and warm forging finishing process is the appearance of raw materials directly changed to semi-specific products or different products, the process is called process, but also the parts of the processing process benchmark, processing precision parts of the process is more complex, precision parts of the processing process standards can be divided into different categories according to the process of casting, forging, stamping, welding, heat treatment, machining, assembly, etc. .   Precision parts machining process often refers to the whole parts CNC machining and machine assembly process in general, while other processes such as cleaning, inspection, equipment maintenance, oil seals, etc., turning methods change the surface properties of raw materials or semi-products, this one process is called CNC machining, corresponding to the middle of the tool trajectory with differences in the form of switching, precision parts system are equipped with linear and circular interpolation function.

CNC lathe processing is a high-precision, high-efficiency automated machine tool with digital information to control the displacement of parts and tools mechanical processing methods. It is an effective way to solve the problems of changing varieties, small batches, complex shapes and high precision of aerospace product parts and other parts, and to achieve efficient automatic processing. In CNC lathe machining workpiece, there is generally a heat treatment process, the following points. First, prepare for heat treatment. The purpose of the preheat treatment is to improve the cutting performance of the trend, eliminate the residual stresses in the manufacturing era of CNC lathe machining blanks and improve the organization. Its process location is mostly before machining, commonly used in annealing, normalizing, etc. Second, the elimination of residual stress heat treatment. As the internal stress generated by the billet in the manufacturing and machining process will lead to deformation of the workpiece and affect the quality of processing, it is necessary to arrange the residual heat treatment. Heat treatment of residual stress should be arranged in the rough machining before finishing. For the parts with low precision requirements, the artificial aging and annealing of residual stresses are usually arranged before the billet enters the machining workshop. For complex castings with high accuracy requirements, usually arrange two aging treatments in the machining process: casting - rough machining - aging - semi-finishing - aging - finishing. For high-precision parts, such as precision steel wire, precision spindle, etc. Should be arranged for several times to eliminate residual stress heat treatment, or even cold treatment to stabilize the size.   Third, the final heat treatment. The purpose of the final heat treatment is to improve the strength, surface hardness and wear resistance of the parts, usually arranged in the finishing process (grinding process) before. Commonly used are quenching, carburizing, nitriding, carbonitriding

The formulation and use of aluminum cnc machining cutting fluid is basically the same as that of ordinary cutting fluid, but the selection of dilution water should be more strict. Because many aluminum ions in the water can have a corrosive effect, if the content of these ions is too high it will reduce the rust prevention performance of the cutting fluid, especially rusting between machining, such as chloride ions, sulfate ions and heavy metal ions.   In addition, certain ions will react with the rust inhibitor of the aluminum cutting fluid and reduce the rust resistance and stability of the cutting fluid, such as the occurrence of calcium and magnesium ions. So try to choose diluted water with less hardness, or diluted ion exchange water softening to ensure the cutting fluid's use effect and life. Aluminum cnc machining cutting fluid maintenance in addition to the daily maintenance of cutting fluid, but also need to pay attention to the following points.   1, filtration   Due to the stability of aluminum alloy aluminum soap reaction, the cutting fluid is easily damaged under alkaline conditions. Aluminum chips, aluminum shavings and cutting fluid should be filtered out immediately so that the reaction does not occur again and affect the use effect and life of the cutting fluid. The aluminum chips ground out during the grinding process are small and light, and it is difficult to continue to precipitate. If not filtered or not sufficiently filtered, the aluminum chips processing area will be taken away with the cutting fluid circulation system, while scratching the surface and affecting the gloss of the processed surface. 2、ph value   As the aluminum cutting fluid is very sensitive to ph value, therefore, the ph value of aluminum cutting fluid should be tested regularly and adjusted in time if abnormalities are found. Use ph control at 8-9 ph value to avoid excessive corrosion of the workpiece or ph value is too low to make bacteria multiply and affect the stability and performance of the cutting fluid.   3、Add new programs regularly   Not only ensure the good lubrication of cutting fluid, but also ensure the good antirust and anticorrosion performance of cutting fluid to prolong the service life of cutting fluid.

When turning slender shafts in the field of precision parts processing, the rigidity of the work body itself is poor, and if the auxiliary tools such as the center frame and the follow tool holder are not adjusted properly, the geometry and surface quality will not reach the requirements, thus leading to bending. The workpiece has a large diameter and poor rigidity; the radial cutting force and centrifugal force during turning, the workpiece produces thermal deformation elongation and cutting stress; the blank material itself is a deformed rod and other reasons, which can cause the workpiece to bend.   The solution is to use the center frame, follow the tool holder, increase the rigidity of the workpiece; reasonable selection of the geometric angle of the tool (mainly large front angle, large main deviation angle), reduce the radial cutting force, reduce the generation of cutting heat; the use of spring top, reduce the adverse effects of the workpiece line expansion, fully pour cutting fluid, reduce friction and quickly take away the heat generated, the necessary heat treatment of the blank or workpiece. In the process of precision parts processing if the blank material itself or processing bending, should be timely straightening before continuing turning. Specifically according to the need to choose hot forging straightening, cold pressing correction, counter-strike method correction, counter-strike method straightening, pry hit straightening, simple tool straightening, quenching straightening, anti-torsional groove straightening and other appropriate methods.

Aluminum alloy in the air is extremely unstable, easy to generate the naked eye difficult to identify the oxide film. Shenzhen cnc processing plant due to the different methods of aluminum cnc processing, such as casting molding, forging, extrusion or CNC precision machining, or through different processes molding and then through heat treatment or welding, the surface of the workpiece will show different states, different degrees of dirt true or traces, pretreatment according to the workpiece surface selection method. 1. CNC machining parts before anodizing need to pay attention to the problem: Although CNC machining aluminum parts surface exists oxide film time is not long, relatively easy to remove, but greasy heavy, especially in and around the eyelet (machine processing process requires lubrication and added), such workpiece must first be cleaned with organic solvents, if the direct use of alkali wash not only greasy heavy in addition to clean , and fine machining of the surface can not withstand a long time alkali corrosion The result will also affect the roughness of the surface of the workpiece and the resistance of the tie, and may eventually become scrap. 2. Casting before the problems that arise in the process of processing. Casting molding parts are not all the surface is machined, unmachined surface left castings formed in the processing there is a very thick oxide layer, some clips and sand layer, the first should first use mechanical processing or sandblasting method to remove the original oxide film of this part first, or by alkali washing after processing again, so that not only can remove the original oxide layer of the unmachined parts, but also to avoid machine processing parts tolerance size change. 3. heat treatment or welding process after the workpiece in the pretreatment process needs attention: according to the process requirements, the workpiece into the heat treatment or welding process before the need to clean with organic solvents, except for the net surface oil, but at present is generally not that, so the surface of the workpiece formed a layer of oil burn tar, this layer of tar in organic solvents is to be purged, if immersed in alkali solution will cause local corrosion, produce pockmarks or cause unevenness, seriously affecting product quality. I use concentrated nitric acid immersion method for soft tarring, and soft tarred material is slightly cleaned in alkaline solution after cleaning. Some specific methods are as follows.   ① Organic solvent degreasing. Less oil serious can be immersed in solvent for a short time; serious application of cotton cloth dipped in solvent to wipe the oil, or scrub with a pig bristle brush. Operation should be safe, and the residual solvent should be properly stored after use.   ② Drying. Regardless of organic solvent cleaning, the drying process can not be omitted, otherwise the meaning of cleaning will be lost.   ③Tying. Tie material is suitable for aluminum wire, banned copper wire and galvanized iron wire, available back to the wire layer. Slightly larger single-sided binding consider the location of the tie, as far as possible, tied to the hole closest to the edge of the part to reduce the impact on the surface of the workpiece. Different types of workpieces should not be tied to a single string, because different compositions (grades) of alumina have different processing times. Pay attention to the direction of the strip artifact wobble and avoid nesting the concave part facing downward. Clean the oil from the surface of the workpiece.   ④Alkali cleaning.   ⑤ Water rinsing. It is best to rinse with hot water after washing, it is a good way to clean the alkaline material on the surface of the workpiece. There are blind holes, grooves to strengthen the position of the workpiece flush, and pour the residual liquid, and immediately turn over nitric acid glow, so as not to suffer from oxidation.   (6) nitric acid. If it is mixed aluminum, cast aluminum or 50mL / L should be added to hydrofluoric acid according to this formula to speed up the removal of aluminum surface insoluble material when attached to the alkali. 2, the technical requirements of the oxide film formation process (1) Oxidation. Solution composition and working conditions. Immediately after pretreatment, transfer to the oxidation process to prevent the workpiece from staying in the atmosphere for too long and producing a primary oxide layer and affecting the quality of the oxide layer. Soaking in water is better than being exposed to the atmosphere again, but it should not be soaked for too long, if immersed in 3% dilute nitric acid soaked L5 ~ 30min will continue to oxidation, but if the time is too long to produce will have an impact on the film, especially the old nitric acid containing impurities such as copper. The oxidation temperature of the solution is a key process, the solution temperature is too high, film speed, easy to make the oxide film chalking; solution temperature is too low, the film coating speed is slow, resulting in the coating film depth is not uniform, poor adhesion. To achieve a consistent color on the surface of the same aluminum, it should be treated at the same temperature at the same time. Within a certain range, temperature and time are inversely proportional, that is, the higher the temperature the shorter the time required, and vice versa the longer the time required. High purity aluminum oxide requires longer processing time. Insufficient oxidation processing time, the oxide film is too pale; the purity of aluminum and oxidation reduction or aging of the oxide film, or even affect the electrical conductivity of the film. In order to obtain uniform film color, the solution of oxidation of small pieces of rock, you can use a large mixed solution, or static (not mixed solution, do not shake the workpiece), to prevent the edge of the workpiece and the solution switch over the center of the workpiece, the film color is not uniform. (2) washing cycle water. For blind holes, the workpiece will be cut, strengthen the parts of the washing, residual solution in the net dumping, to prevent oxidation solution out of oxidation damage. (3)Self-inspection. After washing circulating water, the workpiece should be seen from the quality, and if defects are found in the alkaline solution, return after slight oxidation. Removal, repair, stripping after drying is more difficult and more likely to damage the substrate. (4) Drying. Drying is the key to maintain the quality, shake the workpiece surface free water before oxidation in the drying process, and then in the sun. Can also be baked in 45 ~ 50 ℃ drying conditions, the temperature should not be too high to avoid scorching, aging, cracking, the appearance of old color.

Shenzhen fine parts processing technology touches a wide range, here only from the possibility and convenience of processing two aspects to analyze. Mainly, the size data on the part processing drawing should be in line with the programming convenience criteria, the conditions of the geometric elements that constitute the part outline should be sufficient (1) the dimensional labeling method on the part drawing should comply with the characteristics of CNC machining in the fine parts processing diagram, should be the same benchmark cited dimensions or directly give the coordinate dimensions.   1. This labeling method is not only convenient for programming, but also convenient for the mutual harmony between dimensions, in adhering to the design benchmark, process benchmark, testing benchmark and programming origin set divergence brings great convenience.   2. Because the parts designers generally in the size of the labeling more thinking about the assembly and other characteristics of the use, and had to use part of the scattered labeling method, which will bring a lot of inconvenience to the process layout and CNC machining.   3. Because of the fine parts processing accuracy and repeated positioning accuracy are very high, will not produce a large accumulation of errors and ruin the use of characteristics, and therefore can be part of the scattered labeling method to the same benchmark cited size or directly give the coordinate size of the labeling method. (2) in manual programming to calculate the base point or node coordinates. In the automatic programming, fine parts processing to constitute the part profile of all geometric elements to stop the definition. Therefore, in the analysis of the part diagram, to analyze the geometric elements of the given conditions can be sufficient.   For example, arc and line, arc and arc tangent on the drawing, but based on the dimensions given on the drawing, in the calculation of the tangent conditions, into the intersection or away from the state. Due to the constitution of fine parts processing parts geometric elements of the conditions are not sufficient, so that the programming can not start. When encountering this condition, it should be handled in consultation with the part designer.

When programming CNC lathes, it is very important to choose the correct CNC tool. cnc CNC lathe machining tool's general requirements are easy installation and adjustment, good rigidity, high precision and durability. On this basis, the cutting performance of the workpiece material, the processing capacity of the machine tool, the type of CNC machining program, cutting parameters and many factors related to the working range of the machine tool and CNC device are taken into account. In selecting the type and specification of the tool, the influence of the following factors is taken into account.   (1) Nature of production   The nature of production in this context refers to the batch size of the part, and the impact on tool selection is considered mainly in terms of machining costs. For example, the use of special tools in mass production may be cost-effective, while in single or small batch production, the choice of standard tools is more suitable.   (2) Machine type   The influence of the CNC machine tool used to complete the process on the type of tool selected (drill, turning tool or milling tool). Under the condition of being able to ensure good rigidity of the workpiece system and tool system, it is allowed to use high productivity tools, such as high-speed cutting turning tools and large feed turning tools.   (3) CNC machining program   Different CNC machining programs can use different types of tools. For example, the hole processing can be used to drill and reaming drill, but also available to drill and boring tool to process. (4) the size and shape of the workpiece   The size and shape of the workpiece also affects the choice of tool type and specifications, such as special surfaces to use special tools to process.   (5) Surface roughness   Surface roughness affects the structure of the tool shape and cutting amount, for example, rough milling of blanks, coarse-tooth milling cutters can be used, fine milling with fine tooth milling cutters.   (6) Machining accuracy   Machining accuracy affects the type and structure shape of the finishing tool, for example, the post-processing of the hole according to the accuracy of the hole available drill, reaming drill, reamer or boring tool to process.   (7) Workpiece material   Workpiece material will determine the choice of tool material and cutting part geometric parameters, tool material and workpiece machining accuracy, material hardness and other related.

cnc four-axis machining technology, materials, tools have an impact. General cnc four-axis machining machine tools can reach Ra1.6. precision high-speed machine tools for processing aluminum can reach Ra0.2. There is a speckle finish is not high. Factors are more, if you are a long axis class, perhaps the tailstock top force can not, or the tailstock is moving, if the tailstock is not a problem, tool wear, including processing parameters, cutting fluid and other aspects of the problem. There is also the parts of the material, corresponding to the selection of tools. Further contains the machine tool's own problems, this as long as in practice to figure out how to deal with the light, there is no way to deal with it, I hope you can find the reason for it.   The main reason is because of the CNC four-axis machining strength of the problem, it is possible that your CNC four-axis machining parts to probe the length of too long, or your tool length is too long. The center of the tool is high. Pick the right tool. Some are CNC four-axis machining speed is too high to cause the resonance of the machine tool and the part tool will also show the speckle.   To you to ensure the stability of the lathe is good is the lathe fixed condition is good. Then is the spindle will not show chatter when working at high speed, followed by coolant is very important. Then your tool should be well sharpened, as well as the chip groove to open well, to avoid the poor chip out of the workpiece scratch, as well as the turning tool chamfering into a rounded angle, the other is to install the tool when not anti-knife.   Is to match the spindle speed and the speed of the tool, if your lathe work is not very good, advocate buying some sandpaper to get, in the sandpaper to get the time advocate according to the direction of the work of the turning tool processing, so that the processing out of the texture better look some.

The common types of wear and tear of precision parts machining mainly include running wear, hard grain wear, surface fatigue wear, thermal wear, phase change wear and hydrodynamic wear.   Run-in wear is the wear of machinery under normal load, speed and lubrication conditions, this wear is generally slow to develop, and the short-term impact on the quality of machining is not significant. Hard particle wear is due to the part itself falling abrasive particles or by the outside world into the machine tool hard particles, mixed into the processing area, subject to mechanical cutting or grinding, causing damage to the parts, which is more serious impact on the quality of processing.   Precision parts processing surface fatigue wear is machinery in the role of alternating load, produced a small crack or class point-like crater, thus causing damage to the parts. This type of wear is usually closely related to the size of the pressure, load characteristics, machine parts materials, size and other factors.   Heat-like wear is parts in the friction process generated by the heat on the parts, so that the parts have tempering softening, scorching creasing and other phenomena. This type of wear usually occurs in the high-speed and high-pressure sliding friction, wear is more destructive, and accompanied by the nature of accidental wear. Corrosion wear is a chemical effect, that is, chemical corrosion caused by wear. When the parts surface and acid, alkali, salt liquid or harmful gas contact, it will be chemical erosion, or parts surface and oxygen combined to generate easy to fall off the hard and brittle metal oxides and make parts wear.   Phase change wear is parts of long-term work at high temperatures, parts of the surface metal tissue grain heat becomes large, the grain boundary around the oxidation, resulting in small gaps, so that parts fragile, wear resistance decreased, resulting in parts wear.