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

For the trade department of the parts processing custom service center, developing new customers and maintaining old customers are the business development work of high precision parts customization. Outreach for parts processing custom service centers, the role is also very critical. As long as the maintenance of parts processing customers, you can get a steady stream of orders, parts processing custom service centers can be a steady stream of revenue. Engaged in the trade of parts processing, is not so simple, both need to accumulate experience, but also need to be calm and reliable. So how to develop new customers for the business of custom service center for parts processing? Perseverance, perseverance, perseverance, the methods of doing business at the beginning are similar. Looking for potential customers' information on the Internet, browsing major mechanical parts processing industry forums, continuously contacting customers, and letting potential customers know that we have the service of customizing high precision parts. After a period of maintenance, slowly, customers from unfamiliar to familiar, and then introduce friends to become customers. So the development of new customers, the need for patience to communicate, only to understand the customer, slowly accumulate trust, after a gradual process, get the customer's order is a very natural thing. Promoting high precision parts customization services are hesitant in taking the first step. There is no turning back when you open the bow, and the road will get wider when you take it. As the old saying goes, Heaven rewards hard work! No talent is okay, as long as hard work and willingness to work, as long as you do not give up on yourself, the success of custom high precision parts business development will eventually belong to you. Even if the time is long, as long as you are willing to work hard, God will always see your efforts and will certainly be rewarded. The above is the parts processing custom service center business, the development of new customers need to pay attention to the place, I hope it can help you.  

CNC machining center machining process, the selection of the positioning datum is reasonable or not to determine the quality of the parts, whether to ensure the dimensional accuracy of the parts and mutual position accuracy requirements, as well as the processing sequence between the surfaces of the parts have a great impact on the arrangement, when the fixture to install the workpiece, the selection of the positioning datum will also affect the complexity of the fixture structure. This requires the fixture to be able to withstand large cutting forces, but also to meet the positioning accuracy requirements. Therefore, the choice of positioning datum is a very important process issue. So when machining parts with CNC machining center, how do we choose the positioning reference? The following is a brief introduction. 1, the selected benchmark should be able to ensure accurate positioning of the workpiece, easy loading and unloading workpiece, can quickly complete the positioning and clamping of the workpiece, clamping reliable, and fixture structure is simple.   2, CNC machining center selected benchmark and each processing part of each size operation simple, minimize the size chain calculation, avoid or reduce the calculation links and calculation errors.   3, to ensure that each processing accuracy. In the specific determination of the positioning datum of the part, the following principles should be followed. The origin of the workpiece coordinate system, the "programming zero" and the part positioning reference do not have to coincide, but there must be a definite geometric relationship between the two. The choice of the origin of the workpiece coordinate system is mainly considered to facilitate programming and measurement. For each dimensional accuracy requirements of high parts, determine the positioning reference, should consider the CNC machining center coordinates of the origin can be accurately measured through the positioning reference.   When in the CNC machining center both processing benchmark and complete the processing of each station, the selection of its positioning benchmark need to consider the completion of as much processing content. To this end, consider the positioning method that facilitates each surface to be processed, such as for the box, it is best to use the positioning method of two pins on one side, so that the tool can be processed on other surfaces.   Try to choose the design reference on the part as a positioning reference. This requires rough machining, consider how the rough benchmark to the surface of the fine benchmark, that is, the CNC machining center on the use of each positioning benchmark should be in front of the ordinary machine tools or other machine tools to complete the processing, so that it is easy to ensure the accuracy of each station processing surface relationship between each other. When the positioning datum of the CNC machining center parts and design datum is difficult to overlap, the assembly drawings should be carefully analyzed to determine the design function of the design datum of the part, through the calculation of the dimensional chain, strictly specify the positioning datum and the design datum between the form tolerance range to ensure processing accuracy.   When the CNC machining center can not be completed at the same time, including the design reference station processing, should try to make the positioning reference and design reference overlap. At the same time, we should also consider that after positioning with this datum, one clamping can complete the processing of all key precision parts.

I. Material removal manufacturing process ((10) m ＜0)   The material removal manufacturing process is to remove excess material from the workpiece in a certain way to get the desired shape and size of the part. This type of process requires sufficient excess material on the surface of the workpiece. During the material removal process, the workpiece gradually approximates the shape and size of the desired part. The greater the difference between the shape and size of the raw material or blank and the zero h, the more material is removed, the greater the material loss, and the more energy is consumed in the machining process. Sometimes the volume of material lost even exceeds the volume of the part itself. Although the material removal process has a low material utilization rate, it is still the main means of improving the quality of parts and also has a strong processing adaptability, making it the most widely used processing method in machine manufacturing. The material removal process combined with the material forming process can significantly reduce the consumption of raw materials. With the development of less cutting-free processing technology (precision casting, fine forging, etc.), the utilization rate of materials can be further improved. When production quantities are small, it is also economically reasonable to use material removal processes alone in order to reduce investment in material forming processes   Material removal processes come in many forms of machining, including traditional cutting and special machining.   Cutting machining is a process of removing excess metal from a workpiece (blank) on a machine tool with a metal cutting tool so that the shape, size and surface quality of the workpiece meet the design requirements. During the cutting process, the tool and the workpiece are mounted on the machine tool and driven by the machine tool to achieve a certain regular relative motion. During the relative motion of the tool and the workpiece, the excess metal is removed and the machined surface of the workpiece is formed. Common metal cutting processing methods are turning, milling, planing, broaching, grinding, etc. There are force, heat, deformation, vibration, wear and other phenomena in the metal cutting process. The machining process, the processing quality are certain impact on the freezing H ÒÒ to select the processing method, processing machine tools, tools, fixtures and cutting parameters, improve the quality of processing, improve the processing efficiency will be the focus of this book to tell the content.   Special machining is a processing method that uses electrical energy, light energy, etc. to remove material from a workpiece. There are EDM, electrolytic machining, laser machining, etc. EDM uses the pulse discharge phenomenon between the tool electrode and the electrode to remove the workpiece material for processing purposes. When processing, there is a certain discharge gap between the workpiece electrode and the tool electrode, and there is no direct contact, so there is no force in the processing, and any mechanical properties of conductive materials can be processed. Its main advantage in the process is that it can process the inner contour surface of complex shapes and transform its processing difficulty into the processing of the outer contour (woof of the workpiece), so it has a special role in mold manufacturing. Due to the low metal removal rate of EDM, it is generally not used for the shape processing of products. Laser processing, ion beam processing is mostly used for fine processing.   With the progress of science and technology, in the field of aerospace and computer, some parts with particularly high processing accuracy and surface roughness requirements require precision machining and ultra-precision machining. Precision and ultra-precision machining to achieve dimensional accuracy can reach sub-micron or even nanometer level. These machining methods are ultra-precision turning, ultra-precision grinding, etc. Second, the material forming manufacturing process ((10) m ＝ 0)   Material forming manufacturing process mostly uses models to make raw materials form parts or blanks. Material forming process, the shape, size, organization state of the raw material, and even the bonding state will be changed. Since the forming accuracy is generally not high, the material forming manufacturing process is often used to make blanks. It can also be used to manufacture parts with complex shapes but less demanding precision. The productivity of material forming process is high. Commonly used forming processes are casting, forging, powder metallurgy, etc.   (A) casting   Casting is the liquid metal is poured into the cavity of the mold with the shape and size of the part, after cooling and solidification to obtain the blank or parts of the process. The basic process is modeling, melting, pouring, cleaning, etc.. Due to the alloy casting filling capacity, shrinkage and other factors, the casting may have uneven organization, shrinkage, thermal stress, deformation fishy arthritis so that the accuracy of the casting, surface quality, mechanical properties are not high. Nevertheless, due to the adaptability and low production cost, casting processing is still very widely used. Complex shape, especially with complex internal cavity parts of the blank is often used casting.   At present, the common casting methods used in production are ordinary sand casting, fusion casting, metal casting, pressure casting, careful casting, centrifugal casting and so on. Among them, ordinary sand casting is the most widely used.   (B) forging and pressing   Forging and sheet metal stamping are collectively referred to as forging. Forging is the use of forging equipment to apply external force to the heated metal for plastic deformation, the formation of a certain shape, size and organizational properties of the part blank. After forging of the blank its internal organization is dense and uniform. The metal flow line distribution is reasonable, which improves the strength of the part. Therefore, forging is often used in the manufacture of comprehensive mechanical properties required for the parts of the blank. Forging can be divided into free forging, model forging and die forging.   Free forging is to place the metal between the upper and lower offset iron for metal plastic deformation, the use of free-flowing couples Sha Shang Wei 3 Shang vortex rate is low, low precision. It is generally used to produce forgings with small batches and simple shapes. Model forging is to place the metal in the die chamber of the forging die for deformation, the plastic flow of metal is restricted by the die chamber, high forming efficiency, high precision, and more reasonable metal flow distribution. However, due to the high cost of die manufacturing, it is usually used for mass production. The forging force required in free forging is large and cannot be used for forging large forgings.   Tire die forging is the forging of metal using a tire die on the equipment of free forging. The tire die is simple to manufacture, low cost and convenient to form, but the forming accuracy is not high, and it is often used to produce small forgings with low accuracy requirements. Sheet metal stamping is the process of stamping sheet metal into various shapes and sizes on a press. The stamping process has high productivity and high processing accuracy, and its processing forms include punching, bending, deep drawing and forming. Punching is the process of stamping sheet material into various flat parts. Bending, deep-drawing and other forming processes are used to stamp the sheet into various three-dimensional parts. Sheet metal stamping has a road stop in electrical products, light industrial products, automobile manufacturing   (C) Powder Metallurgy   Powder metallurgy is a process of using metal powder or a mixture of metal and non-metal powder as raw materials to manufacture certain metal products or metal materials through the process of mold pressing and sintering. It can produce both special metal materials and metal parts with less cutting process. Powder metallurgy can reach 95%, which can greatly reduce the input of cutting process and reduce production costs, so it is increasingly widely used in machinery manufacturing. Due to the high price of raw materials used in powder metallurgy and the poor flowability of the powder when forming, the shape and size of the parts are somewhat restricted. Powder metallurgy parts have a certain amount of internal microporosity, its strength is about 20% to 30% lower than castings or forgings, and plasticity, toughness is also poor.   The process of powder metallurgy production includes powder preparation, mixing, pressing and forming, sintering, shaping and so on. Among them, the powder preparation and mixing process is usually done by the manufacturer who provides the powder. Third. Material accumulation manufacturing process ((10m > 0)   The material accumulation manufacturing process is a gradual accumulation of parts grown in a micro-element superposition. In the manufacturing process, the three-dimensional solid model data of the part is processed by computer to control the accumulation process of the material to form the desired part. The advantage of this process is that it is possible to form parts of any complex shape without the need for production preparation activities such as tools and fixtures.   Prototypes are produced for design evaluation, bidding or prototype demonstration. Therefore, this process is also known as rapid prototyping. Rapid prototyping technology is used in the manufacturing of product prototypes, mold manufacturing and manufacturing of a small number of parts, becoming an effective technology for accelerating new product development and achieving parallel engineering, enabling companies to respond quickly to the market and improve their competitiveness.   The development of rapid forming technology is very rapid, and now there are several methods have entered the application stage, mainly light curing method (SL: Stereolithog -raphy), laminated manufacturing method (LO M: LaminatedObject Manufacturing), laser selection sintering method (SLS: Selec -The photocuring method is the first rapid prototyping technology to be commercially applied.   The photocuring method uses photosensitive resin as raw material, and a computer-controlled ultraviolet laser scans the liquid resin point by point according to the predetermined part layering cross-section, causing the thin layer of resin in the scanned area to produce a photopolymerization reaction, thus forming a thin layer cross-section of the part. When one layer is cured, the pallet is lowered one thin layer height. A new layer of liquid resin is applied to the surface of the previously cured resin for the next scan. The newly cured layer is firmly bonded to the previous layer and so on until the entire part is prototyped.

Precision parts in the practical application is necessarily the higher the accuracy, the more exquisite will be able to reflect the level of processing and quality, while the more these products are also loved by consumers, generally speaking in the processing of CNC machining has incomparable advantages and characteristics, our precision parts machining center Shenzhen Noble Smart staff, according to customer requirements, to choose the processing method, or according to the product, to decide, precision parts processing is also the same, then the precision parts processing several ways into which kinds? Precision parts processing processes include turning, milling, planing, grinding, clamping, stamping, casting and other methods   Stamping: stamping using pre-made molds with punching machines for cold punching processing, mainly for sheet metal processing, that is, most of the processed materials are plates, the efficiency of processing is relatively high for mass production   And precision hardware processing process is divided into engineering die and continuous die, engineering die is also called single punching die, some more complex parts have to use several sets of molds, while continuous die in the mold cavity will split the shape of the product several parts in a mold, so that the punching machine processing a stroke is a finished product. High-speed continuous punching machine can process three to four hundred products per minute.   Lathe: lathe for precision parts processing belongs to precision processing machinery, which is divided into ordinary lathe, automatic lathe, instrument lathe and computer lathe, and it carries out rotary movement by clamping the material, and the radial or axial processing is carried out by turning tool. Nowadays, automatic lathes and computer lathes are more and more widely used because both of them are fully automatic processing, which reduces the accuracy error generated by human operation to the lowest point, and the processing speed is fast, which is used for mass production, and most of the computer lathes nowadays are equipped with side rotary tools and back rotary tools. That is to say, the lathe can also perform milling processing

Machined parts are mechanical parts that are processed and shaped by various mechanical processing equipment, mainly in a way that no chemical reaction (or a very small reaction) occurs. There are two main categories of mechanical machining: manual machining and CNC machining.   Manual processing refers to the method of processing various materials through mechanical equipment such as milling machines, lathes, drilling machines and saws operated manually by mechanical workers. Manual machining is suitable for small batch and simple parts production.   CNC machining refers to machining by machinists using CNC equipment, including machining centers, turning and milling centers, EDM wire cutting equipment, thread cutting machines, etc. CNC machining processes workpieces in a continuous manner and is suitable for high volume, complex shaped parts. Technical requirements of machining   1、Tolerance requirements   (1) unnoticed shape tolerance should be consistent with the requirements of GB1184-80.   (2) uninjected length size deviation allowed ± 0.5 mm.   (3) casting tolerance zone symmetry in the basic size configuration of the blank casting. 2, cutting processing parts requirements   (1) parts should be checked and accepted according to the process, in the previous process after passing the inspection, before moving to the next process.   (2) after processing the parts are not allowed to have burrs.   (3) after finishing parts shall not be placed directly on the ground, should take the necessary support, protection measures. Processing surface is not allowed to have rust and affect the performance, life or appearance of the bump, scratch and other defects.   (4) rolling finishing surface, after rolling shall not have the phenomenon of peeling.   (5) the final process after heat treatment of the parts, the surface should not have oxide skin. After finishing with the surface, the tooth surface should not be annealed   (6) The processed thread surface shall not have defects such as black skin, bumping, messy buckle and burr.

Contour processing of mechanical parts machining   1, unannotated shape tolerance should be in line with the requirements of GB1184-80.   2, the unnoticed length size allowable deviation ± 0.5mm.   3, not note the radius of rounded corners R5.   4, not noted chamfer are C2.   5、Sharp corner chamfering blunt.   6、Sharp edge chamfering blunt, remove burr flying edge.   Mechanical parts processing surface treatment   1、The machined surface of the parts should not have scratches, abrasions and other defects that damage the surface of the parts.   2、The machined thread surface should not have defects such as black skin, bump, messy buckle and burr. Before painting, all steel parts must be free of rust, oxide, grease, dust, mud, salt and dirt.   3、Before removing rust, remove grease and dirt from the surface of steel parts with organic solvent, alkali, emulsifier, steam, etc.   4、The time interval between the surface to be coated by shot blasting or manual rust removal and the primer coating shall not be more than 6h.   5, riveted parts in contact with each other's surface, before the connection must be coated with a thickness of 30 ~ 40μm anti-rust paint. The edge of the lap joint should be closed with paint, putty or adhesive. The primer damaged due to processing or welding should be repainted Heat treatment of mechanical parts processing   1, by tempering treatment, HRC50～55.   2, medium carbon steel: 45 or 40Cr parts for high-frequency quenching, 350 ~ 370 ℃ tempering, HRC40 ~ 45.   3、Carburizing depth 0.3mm.   4、High-temperature aging treatment.   Technical requirements after precision machining   1, precision machining of the parts after placement shall not be placed directly on the ground, should take the necessary support, protection measures.   2, processing surface is not allowed to have rust and affect the performance, life or appearance of the bump, scratch and other defects.   3, rolling precision machining of the surface, after rolling shall not have the phenomenon of peeling.   4, the final process after heat treatment of the parts, the surface should not have oxide skin. After precision machining of the mating surface, tooth surface should not be annealed   Sealing treatment of mechanical parts processing   1、The seals must be soaked with oil before assembly.   2、Strictly check and remove the sharp corners, burrs and foreign objects left when the parts are machined before assembly. Ensure that the seals are not scratched when they are installed.   3、After bonding, the excess adhesive should be removed. Gear technical requirements   1、After the gear is assembled, the contact spot and side gap of the tooth surface should conform to the provisions of GB10095 and GB11365.   2, gear (worm wheel) benchmark end face and shaft shoulder (or positioning sleeve end face) should fit, and check with 0.05mm stopper does not enter. And should ensure that the gear benchmark end face and axis perpendicularity requirements.   3、The combination surface of gear box and cover should be in good contact.   Bearing technical requirements   1、The assembly of rolling bearings is allowed to be heated by oil for hot installation, and the temperature of oil shall not exceed 100℃.   2、The outer ring of the bearing and the semi-circular hole of the open bearing housing and bearing cover are not allowed to have jamming phenomenon.   3, bearing outer ring and open bearing seat and bearing cover of the semicircular hole should be in good contact, with color inspection, and bearing seat in symmetry in the center line 120 °, and bearing cover in symmetry in the center line of 90 ° range should be uniform contact. In the above range with the plug ruler check, 0.03mm plug shall not be plugged into the outer ring width of 1/3.   4, bearing outer ring assembly and positioning end bearing cover end face should be contacted evenly.   5、The rolling bearing should be flexible and smooth after assembled and rotated by hand.   6、The combination surface of the upper and lower shaft tile should be tightly fitted and checked with 0.05mm plug gauge not into.   7、When fixing the shaft tile with the locating pin, it should be drilled and reamed and matched with the pin under the condition of ensuring the opening and closing surface of the tile mouth and end surface and the end bread of the relevant bearing hole. The pin shall not be loosened after it is inserted.   8, spherical bearing bearing body and bearing seat should be uniform contact, using the coloring method to check, the contact should not be less than 70%.   9, alloy bearing lining surface into yellow is not allowed to use, in the specified contact angle is not allowed to have the phenomenon of leaving the nucleus, in the contact angle outside the area of the nucleus shall not be greater than 10% of the total area of non-contact area. Screws, bolts and nuts technical requirements   1、When fastening screws, bolts and nuts, it is strictly prohibited to strike or use unsuitable spinning tools and wrenches. Screw slot, nut and screw, bolt head must not be damaged after tightening.   2, the fasteners specified tightening torque requirements, must be used torque wrenches, and fastened according to the specified tightening torque.   3, the same part with multiple screws (bolts) fastening, the screws (bolts) need to be crossed, symmetrical, gradual and uniform tightening.   4, flat key and shaft keyway on both sides of the surface should be uniform contact, the mating surface shall not have a gap.   Patch welding technical requirements   1、The defects must be completely removed before welding, the bevel surface should be repaired smooth and round, there should be no sharp corners.   2、According to the defective situation of cast steel parts, the defective patch welding area can be removed by shovel digging, grinding, carbon arc gas planing, gas cutting or mechanical processing.   3、Sticky sand, oil, water, rust and other dirt around the filler area and bevel within 20mm must be thoroughly cleaned.   4、In the whole process of welding, the temperature of the preheating area of the cast steel parts must not be lower than 350°C.   5、Welding in the horizontal position as far as possible, if the conditions allow.   6、When welding, the welding rod should not do too much lateral swing.   7, cast steel parts surface stack welding, the overlap between the welding channel shall not be less than 1/3 of the width of the welding channel. Casting technical requirements   1, casting tolerance zone symmetry in the basic size configuration of the blank casting.   2, the casting surface is not allowed to have cold partition, cracks, shrinkage and penetrating defects and serious defective class defects (such as under-casting, mechanical damage, etc.).   3、Castings should be cleaned up, no burrs, flying edge, non-machining indicates that the sprue should be cleaned up flush with the surface of the casting.   4, castings on the non-machined surface of the castings and signs should be clear and legible, the location and font should be in line with the requirements of the drawings.   5, the roughness of the non-machined surface of the casting, sand casting R, not more than 50μm.   6, castings should be cleared of sprues, flying spurs, etc. The residue of the sprue on the non-machined surface should be leveled and polished to meet the surface quality requirements.   7、Castings on the sand, core sand and core bone should be cleared.   8, the casting has an inclined part, its size tolerance zone should be along the inclined side of the proportional configuration.   9, castings on the type of sand, core sand, core bone, succulent, sticky sand, etc. should be shovel grinding smooth, clean up.   10, the wrong type, tab casting deviation, etc. should be corrected to achieve a smooth transition, a guarantee of appearance quality.   11、The wrinkles on the non-machined surface of the casting, the depth is less than 2mm, and the spacing should be more than 100mm.   12, machine products castings of the non-machined surface are required to be shot peening or roller treatment, to achieve the requirements of cleanliness Sa2 1/2 level.   13、Castings must be treated with water toughness.   14、The surface of the casting should be flat, and the sprue, burr and sticky sand should be cleared.   15、Castings are not allowed to have cold partition, cracks, holes and other casting defects that are detrimental to use. Technical requirements of forgings   1、Each ingot should have sufficient removal amount of spout and riser to ensure no shrinkage and serious deflection of forgings.   2、The forgings should be forged and formed on the forging press with sufficient capacity to ensure that the forgings are fully forged inside.   3, forgings are not allowed to have cracks, folding and other appearance defects that affect the use of the naked eye. Local defects can be removed, but the cleaning depth shall not exceed 75% of the machining allowance, and the defects on the non-machined surface of the forging shall be cleaned up and rounded transition.   4, forgings do not allow the existence of white spots, internal cracks and residual shrinkage.   Assembly technical requirements   1、The use of sealing filler or sealant is allowed when assembling the hydraulic system, but it should be prevented from entering the system.   2, into the assembly of parts and components (including outsourced parts, outsourcing parts), must have the inspection department's certificate of compliance before assembly.   3, the parts must be cleaned and cleaned before assembly, there should be no burrs, flying edges, oxide, rust, chips, oil, coloring agents and dust, etc.   4, before assembly should be zero, parts of the main fit size, especially interference with the size and accuracy of the relevant review.   5, the assembly process parts are not allowed to bump, touch, scratch and rust.   6, taper pin assembly should be with the hole should be color coated check, the contact rate should not be less than 60% of the fit length, and should be evenly distributed.   7, spline assembly while contacting the number of tooth surface not less than 2/3, the contact rate in the direction of the length and height of the key teeth shall not be less than 50%.   8, the sliding fit of the flat key (or spline) after assembly, the phase fittings move freely, there shall be no uneven loosening and tightening.   9, all the tubes before assembly should remove the tube end flying edge, burr and chamfering. Use compressed air or other methods to clear the debris and floating rust attached to the inner wall of the tube.   10、Before assembly, all steel pipes (including prefabricated pipes) should be degreased, pickled, neutralized, washed and rust-proofed.   11, assembly of pipe clamps, standoffs, flanges and joints with threaded connections fixed parts to tighten to prevent loosening.

1、 Tool setting   The tool position is the reference point on the tool. The relative motion path of the tool position is the machining path, also called the programming path.   2, tool pairing and tool pairing point   Tool setting is the index control operator to make the tool point coincide with the tool setting point by certain measurement means before starting the CNC program. The tool setting tool can be used for tool setting. The operation is relatively simple and the measurement data is relatively accurate. After positioning the fixture and mounting the part on the CNC machine, the machine is set up using a measuring block, plug gauge, micrometer, etc. and using the coordinates on the CNC machine. The determination of the tool point is very important to the operator, and it directly affects the machining accuracy of the part and the accuracy of the program control. In the process of mass production, attention should be paid to the repeatability of the tool point. Operators need to deepen their understanding of CNC equipment and acquire more tool setting skills. (1) Principles of tool setting point selection   Easy to align on the machine, easy to check during machining, easy to calculate during programming, and small tool setting error. Tool setting point can choose a part of a point (such as the center part of the positioning hole), or a part other than a point (such as a point on the fixture or the machine tool), but there must be a certain coordination relationship between the parts of the positioning datum. In order to improve the accuracy of tool setting and alignment, the machining accuracy of the selected alignment position should be higher than the machining accuracy of other positions even if the accuracy of the part is not high or the program requirements are not strict.   Select the part with large contact surface, easy monitoring and stable machining process as the tool setting point. Tool setting point should be unified with the design or process benchmark as far as possible to avoid reducing tool setting accuracy or even machining accuracy due to size conversion and increasing the difficulty of CNC program or CNC machining of the part. In order to improve the machining accuracy of the part, should be as far as possible in the design basis or process basis of the part to choose the tooling point. For example, for parts with hole positioning, it is more appropriate to use the center of the hole as the tool setting point. The accuracy of the tool setting point of the tool setting instrument depends not only on the accuracy of the CNC equipment, but also on the requirements of the part processing. Especially in mass production, the repetition accuracy of the tool setting point needs to be considered, which can be checked by the coordinate value of the tool setting point relative to the machine origin. (2) the tooling point selection method   For CNC lathe or milling machine machining center type CNC equipment, as the center position (X0, Y0, A0) is determined by the existing CNC equipment, determining the axial position can determine the entire machining coordinate system. Therefore, only the end face (Z0 or relative position) of the axial direction needs to be determined as the cutting point.   For three-coordinate machining center, three-coordinate CNC milling machine or relatively complex CNC turning machining center, according to the requirements of the CNC program, it is necessary to determine not only the coordinates of the origin position (X0, Y0, Z0), but also with the processing and the determination of coordinates G54, G55, G56, G57, etc. Sometimes it also depends on the habits of the operator.   Tooling point can be located on the part being machined, can also be positioned in the fixture, but must have a certain coordinate relationship with the positioning datum of the part, Z direction can simply determine the plane, easy to detect, while X, Y direction according to the positioning datum, the specific part of the circle to determine the need to choose.   For four-axis or five-axis CNC equipment, the fourth and fifth axis of rotation is added, similar to the three-coordinate CNC equipment tool position selection. Because the equipment is more complex and the CNC system is more intelligent, it provides more tool setting methods, which need to be determined according to the specific CNC equipment and specific machining parts.   The coordinate relationship between the tool point and the machine coordinate system can be simply set to inter-correlation. For example, the tool point coordinates are (X0, Y0, Z0), and the relationship with the machining coordinate system can be defined as (X0+Xr, Y0+Yr, Z0+Zr), and the machining coordinate system G54, G55, G56, G57, etc., as long as they are entered through the control panel or other means. The method is flexible, proficient, and brings great convenience for subsequent CNC machining. Once the machine collides due to the wrong programming parameters input, the impact on the machine accuracy is fatal. So for high precision CNC lathe, it is necessary to eliminate the collision accident. (3) The main causes of collision   A. Incorrect input of tool diameter and length.   B. Incorrect input of workpiece dimensions and other related geometric dimensions, and incorrect initial positioning of the workpiece.   C, the machine workpiece coordinate system is not set correctly, or the machine tool zero point reset during processing, resulting in changes. Most machine collisions occur during the rapid movement of the machine tool.   So the operator should pay special attention to the machine tool in the initial stage of the implementation of the program and the machine tool in the replacement of tools, once the program editing errors, tool diameter and length input errors, it is easy to collision.   At the end of the program, the CNC axis retires the tool in the wrong order of action, may also occur collision. To avoid the above collisions, CNC operators in the operation of the machine tool, to give full play to the five senses, observe the machine tool without abnormal movement, no sparks, no noise and abnormal noise, no vibration, no burnt smell. If abnormal conditions are found, the program should be stopped immediately. After the machine problem is solved, the machine can continue to work.

Machining performance is not only related to the interests of the enterprise, but also to safety, which can effectively reduce the probability of safety accidents while bringing economic benefits to the enterprise. Therefore, it is especially important to avoid the deformation of parts during the machining process. Operators need to consider various factors and take appropriate measures to prevent deformation during the machining process so that the finished part can be used properly. In order to achieve this goal, it is necessary to analyze the causes of the phenomenon of deformation in the machining of parts and to find reliable measures for the problem of deformation of parts, with a view to laying a solid foundation for the realization of the strategic goals of modern enterprises. Internal force action leads to change in machining accuracy of parts   When lathe machining, usually the effect of centripetal force is used, and the three-jaw or four-jaw chuck of the lathe is used to clamp the part tightly, and then the mechanical part is machined. At the same time, in order to ensure that the parts do not loosen when the force is applied and to reduce the effect of internal radial force, it is necessary to make the clamping force greater than the cutting force of the machine. The clamping force increases with the increase of the cutting force and decreases with it. Such an operation can make the mechanical parts in the process of machining force stability. However, when the three-jaw or four-jaw chuck is released, the machined part will be far from the original, either polygonal or oval, with large deviations.   Heat treatment processing is easy to produce deformation problems   For the sheet-type mechanical parts, due to its very large length and diameter, it is easy to bend the straw hat after heat treatment. On the one hand, the phenomenon of bulging out in the middle and the plane deviation increases, on the other hand, due to the influence of various external factors, the bending phenomenon of the parts. These deformation problems are not only due to changes in the internal stress of the parts after heat treatment, but also the lack of solid expertise of the operators, who do not quite understand the structural stability of the parts, thus increasing the probability of deformation of the parts.   Elastic deformation caused by external forces   There are several main reasons for the elastic deformation of parts in machining. First, if the internal structure of some parts contains thin sheets, there will be higher requirements for the operation method, otherwise, when the operator is positioning and clamping the parts, it cannot correspond with the design between the drawings, which will easily lead to the generation of elastic deformation. Second, the unevenness of the lathe and fixture, so that the parts in the fixed on both sides of the force is not uniform, resulting in the cutting of the force on the side of the small role in the force will appear under the action of the translation of the parts deformation. Third, the positioning of the parts in the process is not reasonable, so that the rigid strength of the parts is reduced. Fourth, the presence of cutting forces is also a cause of elastic deformation of the part. These different causes of elastic deformation, all illustrate the effect of external forces on the quality of machining of mechanical parts.   Mechanical parts processing deformation improvement measures in the actual parts processing, resulting in parts deformation of many factors. In order to fundamentally solve these deformation problems, operators need to carefully explore these factors in practice and develop improvement measures in conjunction with the essence of their work. Use special fixtures to reduce clamping deformation   In the process of machining mechanical parts, the requirements for refinement are very strict. For different parts, the use of different special fixtures can make the parts less likely to be displaced during processing. In addition, before processing, the staff also need to carry out the corresponding preparatory work, fully check the fixed parts, check the correct position of the mechanical parts against the drawings, in order to reduce the clamping deformation.   Trimming process   Parts are prone to deformation after heat treatment, which requires measures to ensure the safety performance of the parts. After the machining of mechanical parts and natural deformation, the use of professional tools to trim. In the processing of the processed parts after the dressing process, you need to follow the standard requirements of the industry to ensure the quality of the parts and extend their service life. This method is most effective when performed after the part has been deformed. If the part is deformed after heat treatment, it can be tempered after quenching. This is because residual austenite is present in the part after quenching, and these substances are then converted to martensite at room temperature, and the object then expands. When processing parts, every detail should be taken seriously so that the probability of deformation of the parts can be reduced, the design concept on the drawings can be grasped, and according to the production requirements, the products produced can be made to meet the standards to improve economic efficiency and work efficiency, thus ensuring the quality of mechanical parts processing.   Improve the quality of the blank   During the specific operation of various equipment, upgrading the quality of the blanks is a guarantee to prevent the deformation of the parts so that the processed parts meet the specific standard requirements of the parts and provide a guarantee for the use of the parts at a later stage. Therefore, the operator needs to check the quality of different blanks and replace the problematic ones in time to avoid unnecessary problems. At the same time, operators need to choose reliable blanks in conjunction with the specific requirements of the equipment in order to ensure that the quality and safety of the processed parts meet the standard requirements and thus extend the service life of the parts. Increase part stiffness and prevent excessive deformation   In the machining of mechanical parts, the safety performance of the parts is influenced by many objective factors. In particular, after heat treatment of the part, the stress contraction phenomenon can lead to deformation of the part. Therefore, in order to prevent deformation, the technician needs to choose a suitable heat-limited treatment to change the stiffness of the part. This requires the application of the appropriate heat-limiting treatment in combination with the properties of the part, thus ensuring safety and reliability. Even after heat treatment, no significant deformation occurs.   Measures to reduce clamping forces   When machining parts with poor rigidity, it is necessary to take measures to increase the degree of rigidity of the part, for example, by adding auxiliary supports. Also pay attention to the contact area between the tightening point and the part, according to the different parts, choose different clamping methods, such as processing thin-walled sleeve class parts, you can choose to have a flexible shaft device for clamping, pay attention to the location of the tightening should choose a more rigid part. And for long shaft type of mechanical parts, you can use the two end positioning method. For the very large diameter parts, the need to use the two ends of the clamping method, can not use "one end of the clamping, one end of the suspension" method. In addition, when machining cast iron parts, the design of the fixture should be based on the principle of increasing the rigidity of the cantilevered part. A new type of hydraulic clamping tool can also be used to effectively prevent quality problems caused by clamping deformation during the machining process.   Reducing cutting forces   The cutting angle should be closely integrated with the machining requirements in order to reduce the cutting forces. You can try to increase the front angle of the tool and the main deflection angle, so that the cutting edge is sharp, and a reasonable tool in the turning of the size of the turning force is also critical. For example, in the turning of thin-walled parts, if the front angle is too large, it will make the wedge angle of the tool larger, speed up the wear rate, deformation and friction will also be reduced, and the size of the front angle can be selected according to the different tools. If you choose high-speed tools, the front angle is 6 ° to 30 ° best; if you use carbide tools, the front angle is 5 ° to 20 ° best.

The primary reason for orientation errors in cnc parts machining is the machining errors caused by the gaps and elastic deformation that occur in the transmission of the machine tool cnc parts machining process, as well as the orientation errors caused by factors such as the friction force that the tool head needs to overcome during the machining process. In the open-loop system, the orientation accuracy is greatly affected, while in the closed-loop follow-me system, the orientation accuracy depends primarily on the displacement detection The machining accuracy error caused by the few errors of cnc parts machining. In the processing of CNC machine tools, because of external forces, heat generated in the processing and other external factors, the machine tool's few accuracy is affected, the few deformation of the parts machined in the machine cnc parts can lead to few errors. According to the study, the cnc parts machining few errors have two primary causes: internal factors and external factors. The internal factors that cause cnc parts machining few errors are the few errors caused by cnc parts machining own factors, such as cnc parts machining table level, cnc parts machining guide level and straightness, cnc parts machining things and fixtures few accuracy. From the cnc parts machining long time data analysis and actual operation can be seen cnc parts machining machine tool positioning caused by machining accuracy errors. From the structural point of view, cnc parts machining processing errors are caused primarily by positioning accuracy, cnc parts machining feed system is the primary link affecting positioning accuracy. cnc parts machining machine tool feed system is usually composed of mechanical drive system and electrical control system.

I believe that everyone is no stranger to precision parts processing, in general, to judge the quality and precision of a product is only to see whether it meets the requirements. Then, wire cutting plays a role in the perfection of precision, +/-0.005mm for it is a small case! If you don't know, you may take it literally and understand that wire cutting is not the use of wire to cut products? Yes, it is true that it uses wire to cut products, but this "wire" is not ordinary wire! It is called electrode wire, which needs to have good electrical conductivity and resistance to electrical corrosion, high tensile strength, and the material should be proportional. Often used electrode wire has molybdenum wire, tungsten wire, brass wire and cored wire and so on.   Wire cutting: slow walking wire processing machine tungsten wire high tensile strength, relatively expensive, generally used in many narrow seam finishing. Brass wire is suitable for slow processing, processing surface roughness and straightness is better, less etching chip attachment, but poor tensile strength, high loss, in the slow one-way wire processing is widely used. Molybdenum wire high tensile strength, mainly used in fast wire processing, general China's machinery processing enterprises are mostly selected for the electrode wire molybdenum wire. Wire-cutting: There are three types of wire-cutting in slow-walking processing, and the precision of different types varies, respectively: fast-walking, medium-walking and slow-walking; generally the precision of fast-walking can reach +/-0.02mm, and the surface roughness can reach Ra3.2 ;the precision of medium-walking can reach +-/-0.01mm, and the surface roughness can reach ≤ Ra3.2; the precision of slow-walking can reach +/- 0.005mm, surface roughness can reach Ra0.8, therefore, the slow walking wire in the precision and quality are higher than the other two. Wire-cutting is developed on the basis of EDM piercing and forming processing. It not only makes the application of EDM has been developed, and some aspects have replaced the EDM piercing, forming processing. Today, wire EDM machine tools have accounted for the majority of EDM machines, playing a large role in the processing of precision parts, increasingly popular in today's market.