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

As the ordinary lathe does not have the same programming function as the CNC lathe, it cannot realize the automatic control of the tool head travel, so it cannot directly process the spherical surface. The inner spherical surface processed by CNC machining center has accurate size and high precision. However, for a small number of workpieces with large inner sphere diameter, it is too expensive to use a large CNC vertical lathe, and there will be some errors. So how to eliminate the errors in NC machining of spherical surfaces? Now let's introduce it in detail. 1、 Causes of Errors in NC Machining of Spherical Surfaces When machining spherical surfaces, especially quadrants of balls and curved surfaces, due to improper adjustment, it is easy to produce shoulder, backhoe, etc. The main reasons are: 1. System clearance In the transmission pair of the equipment, there is a certain gap between the lead screw and the nut. As the equipment is put into operation for a long time, the gap gradually increases due to wear. Therefore, the corresponding gap compensation during reverse movement is the main factor to overcome the shoulder on the machined surface. The clearance is usually measured with a dial gauge, and the error is controlled within 0.01~0.02mm. It should be pointed out here that the meter base and the meter rod should not be extended too far, because the meter base is easy to move under force due to the long cantilever during measurement, which will lead to inaccurate counting and untrue compensation value. 2. Uneven machining allowance of workpiece Before realizing the design surface of the part, whether the machining allowance of the surface to be machined is uniform is also an important reason for whether the formed surface can meet the design requirements, because the uneven machining allowance is easy to cause "reflection" error. Therefore, for parts with high surface shape requirements, the machining allowance shall be as uniform as possible before forming, or the design requirements shall be met by machining one more profile. 3. Improper tool selection The cutting tool removes the material through the main cutting edge during cutting. However, after the arc passes the quadrant, and the arc is tangent to the cutting edge of the tool pair (the intersection line between the back of the pair and the base plane), then the sub cutting edge may participate in the cutting (that is, the backhoe). Therefore, the wedge angle of the tool must be considered when selecting or grinding the tool. 2、 The Method of Eliminating Errors Caused by NC Machining Spherical Surface When machining a sphere, the sphere may be large in the middle and small at both ends, or small in the middle and large at both ends. In this case, the radius of the sphere should be adjusted to control. If it is large in the middle and small at both ends, increase the radius slightly. If it is small in the middle and large at both ends, the radius value will be reduced. After adjustment, the roundness error of the ball can be less than 0.05mm.

Machining center servo system fault form including the speed unit in the CNC alarm indicator and fuse blown and a variety of protection with a jump switch and other alarms. The meaning of the alarm indicator varies with the speed control unit design differences, there are generally the following. 1, high current causes the machine alarm, the occurrence of high current alarm in general there are two possibilities, is the machining center CNC speed control unit on the power drive element damage and short circuit caused by high current alarm.   2, high voltage will also lead to machine alarms, the occurrence of high voltage alarms generally have three possibilities, may be machining center CNC input voltage exceeds ten percent of the rated value, or servo motor inside the insulation performance decline, or machining center operation speed control unit line caused by high voltage.   3, the voltage is too low to cause the machine alarm, machining center the chances of this happening is rare, the occurrence of this situation may be the input voltage is lower than the rated value of eighty-five percent, or poor power supply connection caused. 4, the detection of speed feedback line break caused by the alarm, the occurrence of this is a false alarm, because the airport can be no problem, and detection feedback system problems, the occurrence of such alarms are mostly machining center CNC servo motor speed feedback line break or its detection feedback line contact caused by poor.   5, the protection switch to start the alarm, the protection switch is a device to protect the machine tool, such as large voltage will burn some components and some machine tools can not control the emergency measures, when encountering these situations the protection switch will start to avoid unnecessary component damage, similar to the safety stop and so on.   6, overload alarm, the cause of overload alarm machining center CNC mechanical load is not normal, or speed control unit on the upper limit of motor current set too low. The permanent magnet on the permanent magnet motor will also cause overload alarm, if the machining center CNC motor without brake does not turn by hand at no load or it is hard to rotate the shaft, that means the permanent magnet all off.   7、The fuse on the CNC speed control unit of the machining center is blown or the circuit breaker is tripped.

The focus of the pure fundamental level consideration is how to reduce the error and improve the accuracy, so the basic principles of selecting the essential surface are   First: the principle of datum overlap. Should choose as much as possible the design reference as the positioning reference. Especially in the final completion, to ensure accuracy, more attention should be paid to this principle. This can avoid causing position error benchmark deviation;   Second: the principle of unity of the benchmark. Should choose a unified positioning datum surface of various surface treatment, as far as possible to ensure the position accuracy between the surfaces; sometimes also follow the principle of common datum, repeated processing;   Third: the principle of self-referencing. Some small machining allowance and unified finishing process, to ensure the quality of processing and productivity, with precision machining surface itself as a base level. The role of precision machining process   First, is the main technical documents to guide the production   Mechanical machining workshop production planning, scheduling, workers' operations, parts processing quality inspection, processing cost accounting, are based on the process procedures. To deal with production problems, but also often to process procedures as a common basis. Such as dealing with quality accidents, should be in accordance with the process procedures to determine the responsibility of the relevant units, personnel.   Second, is the main basis for the production of preparatory work   Workshop to produce new parts, first of all, to develop the parts of the machining process procedures, and then according to the process procedures for production preparation. Such as: the new parts processing process in the analysis of key processes; preparation of the required tools, clamps, gauges; raw materials and blank procurement or manufacturing; the purchase of new equipment or old equipment modifications, etc., must be based on the process to carry out.   Third, is the basic technical documents of the new machinery manufacturing plant   When the new batch or high-volume machining workshop, should be based on the process regulations to determine the type and number of machine tools required and the layout in the workshop, and then from there to determine the size of the workshop area, power and lifting equipment configuration and the type of workers required, technical grade, quantity, etc.

The advantages of using Q235A (A3 steel) for large machinery processing   The main advantage of large mechanical processing in the operation of a certain degree will have high plasticity, toughness and welding properties, the whole product has a certain stamping performance and cold bending performance, in the use of mainly for the requirements of mechanical parts and welded structural parts, such as its tie rods, connecting rods, pins, shafts, screws, nuts, brackets, bases, etc.. The advantages of using 40Cr for large machining   Large-scale machining in a certain degree after the tempering process will have very good overall mechanical properties and low temperature impact toughness and low notch sensitivity, good hardenability. Oil cooling can be obtained when the higher strength, water-cooled parts are prone to cracking. Good machinability after tempering or quenching, but bad weldability, easy to produce cracks.   In the use of models mainly after tempering treatment for its manufacturing process of its fast moving mechanical parts, such as its machine tool gears, shafts, worm gears, etc.. After quenching and high frequency surface quenching is used in the manufacture of parts with high surface hardness and wear resistance, such as gears, shafts, spindles, crankshafts, mandrels, sleeves, pins, connecting rods, etc.   After quenching and medium-temperature tempering for the manufacture of heavy-duty, medium-speed mechanical parts, such as oil pump rotors, sliders, gears, spindles, etc. After quenching and low-temperature tempering for the manufacture of heavy-duty, low-impact, wear-resistant mechanical parts, such as worm shafts, spindles, shafts, etc. Carbonitriding process that is after the manufacture of larger size, low-temperature impact toughness of the transmission parts, such as shafts, gears, etc. The advantages of using 45# for large machinery processing   45# is a high-quality carbon structural steel, is currently the most commonly used medium carbon tempered steel.   In the process of operation will have very good overall mechanical properties, in the use of its low hardenability, water quenching is easy to produce cracks, welded parts need to be preheated before welding, after welding need to be annealed.   Mainly used for: the manufacture of high-strength mechanical moving parts, such as impellers, pistons, shafts, gears, racks, worm gears, etc.

The purpose of cleaning parts is to remove its surface residual casting sand, iron chips, rust, abrasives, oil, dirt and other dirt. The cleanliness of the parts after cleaning will directly affect the quality of assembly and the service life of construction machinery, so the cleaning of parts is a very important link in the assembly of construction machinery. Do a good job cleaning parts, should be based on its material, structural characteristics, pollution and its cleanliness requirements, such as the correct choice of cleaning agents and cleaning methods.   Construction machinery parts oil is mainly formed by unsaponifiable oil and dust, impurities, etc.. Not saponifiable oil can not work with strong alkali, such as a variety of mineral oils, lubricants, are not soluble in water, but can be soluble in organic solvents. Removal of such oil and electrochemical two methods; commonly used cleaning solutions for organic solvents, alkaline solutions and chemical cleaning solutions, etc.; cleaning methods are manual cleaning and mechanical cleaning two. 1. Three cleaning solutions   (1) organic solvents. Common are kerosene, light diesel, gasoline, acetone, alcohol and trichloroethylene, etc.. With this dissolving method of oil removal, can dissolve a variety of grease. Advantages are no heating, easy to use, no damage to the metal, good cleaning effect. Disadvantages are mostly flammable, high cost, suitable for precision parts and parts that should not be cleaned with hot alkali solution, such as plastic, nylon, cowhide, felt parts, etc.. But need to pay attention to the rubber parts can not be cleaned with organic solvents.   (2) alkaline solution. Alkaline solution is an aqueous solution of alkali or alkaline salt, which uses emulsifiers on the non-saponifiable oil emulsification effect of oil removal, is one of the most widely used decontamination cleaning solution.   Emulsification is the formation of very small fine particles of one liquid after the uniform distribution in another liquid. Adding emulsifier in alkali solution to form emulsion can reduce the surface tension and adhesion of the oil film, so that the oil film is broken into very small oil droplets and no longer return to the metal surface to remove oil stains. Commonly used emulsifiers are soap, water glass (sodium silicate), bone gum, tree gum, triethanolamine, synthetic detergents, etc.. It should be noted that the cleaning of different materials parts should use different cleaning solutions. Alkaline solutions have different degrees of corrosion on the metal, especially for aluminum is more corrosive.   When cleaning with alkaline solution, the solution generally needs to be heated to 80~90 ℃. After oil removal, rinse with hot water to remove the surface residual alkaline solution to prevent parts from being corroded.   (3) chemical cleaning solution. Is a chemical synthesis of water-based metal cleaning agent configuration of the aqueous solution, metal cleaning agent in the surfactant-based, with strong decontamination ability. In addition, there are some auxiliary agents in the cleaning agent, can improve or increase the comprehensive performance of metal cleaners such as anti-corrosion, rust prevention, carbon removal.   The principle is the cleaning agent with cleaning solution first wet parts surface, and then penetrate the dirt and parts contact interface, so that dirt from the parts surface off, dispersion, or dissolved in the cleaning solution, or in the parts surface to form an emulsion, suspension, to achieve the purpose of cleaning parts.   Commonly configured chemical cleaning solution cleaning agents are LCX-52 water-based metal cleaner, CW metal cleaner, JSH high-efficiency metal cleaner, D-3 metal cleaner, DJ-04 metal cleaner, NJ-841 detergent, 817-C oil washing agent, CJC-8 liquid metal cleaner.   The above cleaning agent preparation method, concentration, cleaning temperature and heating measures, are required to strictly comply with the requirements of its instructions. Manual cleaning should be more strictly control the temperature, available brush, wipe cleaning. If there is serious oil or carbon, use steel wire brush. Before cleaning, it should be soaked for a certain period of time to meet the need of wetting and soaking. Cleaning can be divided into rough and fine cleaning, cleaning solution after cleaning, if the oil is not serious, you can skim off the upper layer of floating oil, and use again. 2. Five cleaning methods   (1) scrubbing. Parts into the container with diesel, kerosene or other cleaning fluid, scrubbing with cotton or brush. This method is easy to operate, simple equipment, but low efficiency, suitable for a single small batch of small parts. Generally should not use gasoline, because it has soluble fat, will damage human health and easy to cause fire.   (2) Boiling and washing. Will be configured solution and the parts to be cleaned together into the appropriate size of steel welding cleaning pool, with the pool under the stove will be heated to 80 ~ 90 ℃, boiling and washing 3 ~ 5 min can be.   (3) spray washing. Will have a certain pressure and temperature of the cleaning fluid sprayed onto the surface of the parts to remove the oil. This method of cleaning effect, high productivity, but the equipment is complex, suitable for cleaning the shape is not too complex, the surface has a serious oil scale parts.   (4) vibration cleaning. The parts to be cleaned on the vibration cleaning machine cleaning basket or cleaning rack, and submerged in the cleaning fluid, through the cleaning machine to produce vibration simulation of manual rinsing action and the chemical action of the cleaning fluid to remove the oil.   (5) ultrasonic cleaning. Rely on the chemical action of the cleaning fluid and the introduction of ultrasonic oscillation in the cleaning fluid together to remove the oil.   Note: should be based on the causes and characteristics of oil pollution reasonable choice of cleaning methods to ensure the normal use of parts, to avoid cleaning on the parts caused by corrosion or damage, to prevent pollution of the environment and the subsequent defacement of parts.

Precision parts processing is not possible to complete all the surface processing content in one process, the entire process of precision parts processing can be divided into the following stages. 1, roughing stage. Cut off most of the machining allowance of each processing surface, and processing the precision benchmark, the main consideration is to increase productivity as much as possible.   2、Semi-finishing stage. Cut off the defects that may arise after rough machining, and prepare for the finishing of the surface, requiring a certain machining accuracy and ensuring the appropriate finishing margin, while completing the machining of the secondary surface.   3、Finishing stage. In this stage, the use of large cutting speed, small feed and depth of cut, remove the finishing margin left by the previous process, so that the surface of the part to meet the technical requirements of the drawing. 4、Light finishing stage. Mainly used to reduce the surface roughness value or strengthen the processing surface, mainly for surface roughness requirements are very high (ra ≤ 0.32μm) surface processing.   5、Ultra-precision machining stage. Machining accuracy in 0.1-0.01μm, surface roughness value ra ≤ 0.001μm processing stage. The main processing methods are: precision cutting, fine mirror grinding, precision grinding and polishing, etc.

For precision machining materials are divided into two categories, metallic materials and non-metallic materials.   For metal materials, the hardness is the largest for stainless steel, followed by cast iron, followed by copper, and finally aluminum.   The processing of ceramics, plastics, etc. is the processing of non-metallic materials. 1, first of all, the requirements of the material hardness, for some occasions, the higher the hardness of the material is the better, just limited to the hardness requirements of the processing machine parts, processing materials can not be too hard, if harder than the machine parts can not be processed.   2, secondly, the material 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 parts 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, 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 if the hardness exceeds the hardness of the machine parts (lathe turning tool), it is impossible to process, not only will damage the parts, but also cause danger, such as turning tool flying out of the crash injury. Therefore, in general, for mechanical processing, the material material should be lower than the hardness of the machine tool, so that it can be processed.

Precision parts processing technology is the process of determining the process and operation method of precision parts processing, which is a more reasonable process and operation method under specific production conditions. In accordance with the prescribed written form into a process document, after approval, used to guide production. Precision mechanical parts processing process rules generally include: the workpiece processing process route, the specific content of each process, the equipment and equipment used, the workpiece inspection items and methods, cutting volume, time quotas, etc. Precision parts machining has many advantages. First of all, precision parts machining can effectively improve labor productivity, increase production, have high economic benefits and reduce enterprise costs. Precision parts processing can also improve labor conditions, reduce labor intensity, shorten labor time, and improve the degree of civilized production. In addition, precision mechanical parts processing can reduce production workers, plant area, shorten the production cycle, reduce production costs and save energy, so precision parts processing can be said to have great benefits.   The use of automatic detection and monitoring devices in precision parts machining is conducive to improved and stable product quality, flexible automated production, and rapid adaptation to product changes. Thus, precision parts machining has a significant impact on industrial production. However, the investment in pre-processing of precision parts is too high, and companies can choose an excellent precision parts processing plant to process the workpiece, which not only reduces the cost but also improves the quality. What is the impact of precision parts machining on industrial production? It can be said that high-precision, high-efficiency automatic processing equipment can effectively improve labor productivity, increase production, have high economic benefits and reduce business costs. It can also improve working conditions, reduce labor intensity, shorten working time and improve civilized production. In addition, automatic equipment can reduce production workers, shorten the production cycle, reduce production costs and save energy, so automatic processing equipment can be said to have many benefits.

Precision parts machining technology was proposed in the 1960s, it is to improve the performance, quality, service life and reliability of electromechanical products, as well as the cross-section of the bar can be an important method, precision machining refers to the machining error less than 0.1m, surface roughness less than RA0.025IXM machining technology, also known as sub-micron machining, precision parts machining level is the level of national manufacturing important symbol. In addition to fluctuations in hydraulic and pneumatic sources in the machining of precision parts, the working environment has a great impact on the quality of machining, so the working environment is necessary to ensure the quality of machining, the working environment mainly has the requirements of temperature, purification and anti-vibration. Ambient temperature changes on machine tool accuracy is particularly significant, including temperature changes due to thermal factors caused by machining errors, total machining errors (40 70) % of dust can lead to surface scratches on the workpiece and affect the surface quality process, such as vibration occurs, the surface of the workpiece has been processed streaks or fabric traces, the surface finish is significantly reduced. With the high precision required for parts processing, the requirements of the processing environment is becoming more and more stringent, only from the precision parts processing on the impact of gas pressure fluctuations, ambient temperature changes, external and self-vibration analysis of the three aspects of the precision parts processing factors Many, in order to improve the accuracy of ultra-precision machining, not only to understand the impact of factors, but also must master the solution.

Mechanical parts processing industry is the pillar of the national economy, with a very promising future. In the processing of precision mechanical parts, processing plant will have many requirements and regulations on the processing process to ensure the qualification rate of the factory parts. So we know what are the tricks of precision machining? Let's take a look below! Precision machining tricks   Trick one: the vise jaws removed, another two M4 threaded holes, the two flush with the jaws of the 1.5mm thick steel plate 2, with aluminum countersunk rivets riveted on the 0.8mm thick hard brass plate 3 will be fastened to the jaws with M4 countersunk screws 1, forming a durable soft jaws. This also protects the hardware parts from being clamped badly, but also has interchangeability.   Tip 2: For tightening the workpiece there is first positioning and then clamping, but for a workpiece it, the first clamping and then positioning, because the clamping will certainly try the workpiece deformation, so, should first clamping and then positioning, for 6-point positioning, looking to limit its degrees of freedom.   Trick 3: When the hexagonal wrench 1 shank is short and can not be force, the tube with an inner diameter slightly larger than the wrench can be inserted into the slot from a section of the milling groove, which can be used as a long shank.   Tip 4: When the pulley drive, the pulley often slips between the pulley and the axle, and a series of nests are scratched on the axle with ￠15~18mm scratching nest drill, which can form an adsorption force to prevent slippage and turn waste into treasure, and the boss will reward. Trick five: the use of magnets to absorb small parts (fee pieces) suck and take are not convenient, you can suck an iron plate 2 under the magnet 1, not only can suck a lot of small pieces, and the iron plate will be pulled away, small pieces will immediately and automatically dumped into the collection box, not enough to impress the heart, but very practical.