A: the five axis turn milling compound machining center has a history of nearly 20 years since its emergence. The technology has been mature and accepted and recognized by users at home and abroad. From the perspective of trend, it mainly develops in the following directions:
1. Higher process range.
By adding special function modules, more process integration can be realized. For example, gear processing, internal and external grinding, deep hole processing, cavity processing, laser quenching, on-line measurement and other functions are integrated into the turn milling center to truly complete the processing of all complex parts.
2. More efficient.
By configuring the functions of double power head, double spindle and double tool holder, the simultaneous processing of multiple tools is realized and the processing efficiency is improved.
3. Large scale.
Because large parts are generally parts with complex structure, many parts and processes requiring processing, and time-consuming and troublesome installation and positioning, one of the main advantages of turn milling composite processing is to reduce the multiple reinstallation, adjustment and clamping time of parts in the process of multi process and multi process processing, so it is more advantageous to use turn milling center for composite processing. Therefore, at present, the five axis turn milling compound machining center is developing towards large-scale. For example, the htm125 series five axis turning and milling center of Shenyang machine tool has a rotation diameter of 1250mm and a processing length of 10000mm, which is very suitable for turning and milling the crankshaft of large marine diesel engine.
4. Modularization of structure and rapid reorganization of functions
The rapid reorganization of the function of the five axis turn milling center is an important condition for it to quickly respond to the market demand and seize the market, and the structural modularization is the basis for the rapid reorganization of the function of the five axis turn milling center. Many products of some technologically advanced manufacturers have realized structural modular design, and are working hard on how to realize rapid function reorganization.
A: for precision parts, the processing is very strict. The processing procedures include feeding, discharging, etc.
There are specific requirements for size and precision, such as 1mm plus or minus microns. If the size is wrong too much, it will become waste. At this time, it is equivalent to re processing, which is time-consuming and laborious. Sometimes the whole processing material will be scrapped, which will increase the cost. At the same time, the parts must not be used.
A: common surface treatments: blackening, anodizing, chromium plating, nickel plating, titanium plating, zinc plating, electropolishing, passivation, PVD film plating, ganak, etc.
Common heat treatment methods: vacuum quenching, quenching and tempering, salt bath nitriding, nitriding, carburizing, high cycle firing, carbon dipping firing, etc.
The equipment used are:
Production equipment: turning, milling, flat circular grinding, internal and external circular grinding, fast / slow wire walking, machining center, EDM and other precision machines.
Testing equipment: altimeter, projector, hardness tester, micrometer, etc.
For the machining process (heat treatment process) of precision parts, determine the machine tool, clamping method, measurement method, machining allowance, cutting parameters and man hour quota used in each process. Fill all the contents in the process specification table, which is the procedure of machining process.
The process analysis of parts and components mainly includes:
1 check whether the drawings of parts are complete and correct, and analyze whether the accuracy, surface integrity and technical requirements of main surfaces of parts can be met under existing production conditions.
2 check whether the selection of parts and materials is appropriate and whether the process will become difficult and complex.
3. Review the structural manufacturability of parts and components, and check whether the part structure can be processed economically and effectively.
A: what are the general materials for machining? This question is too wide.
The general processing materials of machining are: most metals and non metals (plastic, wood, rubber (rubber is difficult to machine)). But in fact, most machining is metal processing.
Metals are mainly divided into three categories: carbon steel, stainless steel and aluminum alloy.
For example, Shenzhen Hengtai electromechanical Co., Ltd. is a manufacturer specializing in the processing of precision mechanical parts, tooling fixtures, test fixtures, non-standard parts and other special parts.
It can meet the needs of single piece, small batch and mass production of customers. In addition, we can also provide customers with various surface treatment and heat treatment. Such as: hard oxidation, electrolytic polishing, electroless nickel deposition, chromium plating, vacuum heat treatment, gas nitriding, high cycle heat treatment, carbon immersion heat treatment, etc.
The company has Mazak five axis turning milling composite processing equipment imported from Japan, and advanced equipment such as CNC milling machine, lathe, grinder and Nikon three-dimensional measuring instrument made in Britain. The processing field covers automotive, medical, energy, shipbuilding, aerospace and other fields.
A: if you buy imported machines, German machines are durable and maintain good accuracy in 4-5 years; And Switzerland is also very good; The second is Japan, Germany's demaji five axis machining center and Japan's Mazak. However, foreign five axis machine tools are more expensive and domestic ones are cheaper. Especially for the five axis machining center, the system can be selected. You can learn more about it online.
Programming does not need special language. The five axes must be compiled with software and should be compatible. Demaji is equipped with Siemens, and Mazak has its own system.
The operating systems of five axis products processed by HSM company in Germany include Siemens 840dsl, Siemens 828d, heidenham in Germany, FAG in Spain and Fanuc in Japan.
Q: what is the biggest difference between turning milling compound machine and machining center? Which of these two functions is more extensive? For example, which is better for a precision workpiece? Is there any conflict?
Answer: 1. Different properties: compound processing is one of the most popular processing technologies in the field of machining in the world. CNC milling machine is an automatic processing equipment developed on the basis of milling machine.
2. Different processing procedures: the machining center can process parts that need to be processed in multiple processes after one clamping and positioning. Turn milling compound can be processed and formed at one time.
3. Different functions: turn milling compound is with b-axis linkage and c-axis linkage. Machining centers cannot.
(1) Mold is like making a painting. It is very beautiful, detailed and complex. You Zhi will always be exposed to different paintings and different styles. What makes a product is as like as two peas of Da Vinci's painting, and draws a circle or draw a square box every day. It repeats and monotonously, but what we need to do is to ensure that every egg is painted exactly the same, how to draw more eggs in the shortest time, and what measures are taken to ensure that it is not drawn wrong.
(2) Generally, the development of products is based on independent entrepreneurship, or technology, technicians and engineers, or management, from the line of monitor, dispatcher and director. Other specific quality inspection will not be involved. Every friend who makes products must have his own plan before entering the industry. In this way, you have a goal. You won't do it day by day. That's very boring and you haven't developed yourself. It's much simpler than molds in terms of technical content.
2. Different time:
(1) The complexity of product programming is significantly lower than that of mold tools. The salary of making products comes quickly, and you can learn technology by making molds. We should start from the foundation, understand how to do it, and be divorced from reality. No matter how good the theory is, it will not work. It is necessary to learn to program automatically with CNC programming software. Some complex processes still need to be programmed by computer.
(2) From the learning content, product programming includes two-dimensional and three-dimensional software modeling, product case programming, mold programming, and computer programming courses such as electrode removal, electrode programming, mold kernel programming, etc. In terms of learning time, it takes 2-3 months for products and 4-5 months for molds.
3. Different practices:
Thirdly, the threshold of CNC programming is not high. In fact, no matter you graduate from junior high school or university, you can learn well as long as you want to learn. How long will it take? It depends on your learning style. Some people study by themselves and some have studied in training institutions, but they still can't take the post.
Self study is still very difficult. If you encounter small problems, you may get stuck. It's useless to know the basic operation of the software. The core thing is methods and ideas, and then practice more.
1、 It is the main technical document guiding production
The production planning and scheduling of machining workshop, the operation of workers, the processing quality inspection of parts and the accounting of processing cost are all based on process procedures. In dealing with problems in production, process procedures are often used as a common basis. If quality accidents are handled, the responsibilities of relevant units and personnel shall be determined according to the process procedures.
2、 It is the main basis for production preparation
When the workshop wants to produce new parts, first formulate the machining process specification of the parts, and then prepare for production according to the process specification. For example, the analysis and research of key processes in the processing technology of new parts. Prepare necessary knives, clamps and measuring tools. Purchase or manufacture of raw materials and blanks. The purchase of new equipment or modification of old equipment must be carried out according to the process.
Stainless steel material used for machining precision mechanical parts
1. The first is the requirements for the hardness of materials. For some occasions, the higher the hardness of materials, the better. It is only limited to the hardness requirements of machining parts. The processed materials cannot be too hard. If they are harder than parts, they cannot be machined.
2. Secondly, the material is moderately soft and hard, at least one grade lower than the hardness of the parts. At the same time, it also depends on the function of the processed devices and the reasonable material selection of the parts.
In short, precision machining still has some requirements for materials. Not all materials are suitable for processing, such as too soft or too hard materials. The former is not necessary for processing, while the latter cannot be processed.
The standard of precision parts processing industry is very strict, and there are different processes such as cutting in and cutting out in the processing process. The size will also have different specific requirements according to the product, and the machining accuracy requirements will also be different. Generally speaking, the precision of precision machining is very high, and sometimes it can even be accurate to the micron difference below 1mm. If the size difference is large, the product will become waste and need to be reprocessed to meet the requirements, which is very time-consuming and laborious. Sometimes all raw materials will be scrapped, resulting in an increase in cost. At the same time, parts must be unusable. Therefore, there are many requirements for precision parts processing.
So what are the requirements for precision parts processing?
(1) Generally, because the cutting amount, heating and cutting force of parts are different for the roughness and accuracy of parts, in order to ensure the machining accuracy of parts, rough parts and precision mechanical parts must be machined respectively. If rough machining and precision machining are carried out continuously, the precision of precision machined parts will be lost due to different stresses.
(2) Rationality of equipment selection. The machining of rough parts does not require high machining accuracy, but it is mainly to reduce machining allowance, so precision machining requires very high-precision machine tools. Heat treatment process is often arranged in the processing route of precision parts. The position arrangement of heat treatment process is as follows: in order to improve the cutting performance of metal, such as annealing, normalizing, quenching and tempering, it is generally arranged before machining of mechanical parts.
(3) Generally speaking, almost all precision parts have heat treatment process, which can improve the cutting performance of metal. The machining and manufacturing of precision parts not only need the accuracy and stability of machine tools and the accuracy of tools and fixtures, but also need precision measuring instruments for calibration and measurement. Some are in the processing process, some are post detection.
① Reduce processing time and improve processing accuracy.
The biggest feature of the five axis machining center is that it can process all five surfaces at one time. That is, the so-called processing angle avoidance. If it is a linkage machine tool, the c-axis can rotate unrestricted, and the a-axis can rotate about 130 degrees. These equipment features make it possible to process without interference. The advantage of this is that one-time clamping can not only complete the processing, but also avoid the repeated positioning error caused by multiple clamping. At the same time, one-time clamping also saves a lot of time and improves work efficiency. It can reduce the time from product to delivery and reduce the inventory.
② Reduce equipment investment cost, workshop land occupation and workshop quantity.
The left and right compound machining machines of the five axis machining center usually have t (car) function, which can be included from lathe to milling machine to vertical mill. We all know that the price of vertical mill equipment is very expensive at present. It can be found that the price of five axis is relatively high through cost, processing beat and other accounting. Previously, the production and processing may be based on project segmentation. The problem with this production mode is that there is a lot of waiting time that can not be eliminated. However, the engineering intensive production represented by the five axis composite processing equipment only needs the preliminary waiting time for debugging, and with the popularity of various complete machine simulation software in China, even the programming can be completed only by importing blank data, which can greatly shorten the preliminary preparation. Therefore, at present, foreign auto parts and high-end manufacturing are basically based on five shafts.
③ No special fixture is required and automation can be realized.
Another notable feature of the five axis is that the dependence on the fixture will be reduced. Regular workpieces can be clamped directly with three jaw and four jaw chuck, and irregular workpieces can be clamped with one side and two pins. At the same time, the five axis machining center can realize factory automation and fewer people. For example, the joints and bases of processing robots. In the past, horizontal machining and vertical machining were used. Now, only zero point tray and five axis machining center can be used to realize 24-hour operation.
Machined parts are mechanical parts processed and formed with various machining equipment, which mainly refers to the processing method without chemical reaction (or very small reaction). Machining mainly includes manual machining and NC machining.
Manual processing refers to the method of processing various materials by mechanical workers manually operating mechanical equipment such as milling machine, lathe, drilling machine and sawing machine. Manual processing is suitable for small batch and simple parts production.
Numerical control machining (CNC) means that mechanical workers use numerical control equipment to process. These numerical control equipment include machining center, turning and milling center, WEDM equipment, thread cutting machine, etc. NC machining processes workpieces in a continuous way, which is suitable for large quantities of parts with complex shapes.
Technical requirements for machining
1. Tolerance requirements
(1) The unmarked shape tolerance shall meet the requirements of gb1184-80.
(2) The allowable deviation of unmarked length dimension is ± 0.5mm.
(3) The casting tolerance zone is symmetrical to the basic dimensional configuration of the blank casting.
2. Requirements for machined parts
(1) The parts shall be inspected and accepted according to the process, and can be transferred to the next process only after the previous process is qualified.
(2) The machined parts shall not have burrs.
(3) The finished parts shall not be placed directly on the ground, and necessary support and protection measures shall be taken. The machined surface shall be free of rust, corrosion, bumps, scratches and other defects affecting performance, service life or appearance.
(4) There shall be no peeling on the surface finished by rolling.
(5) There shall be no oxide scale on the surface of the parts after heat treatment in the final process. The finished mating surface and tooth surface shall not be annealed
(6) The machined thread surface shall be free of defects such as black skin, bump, random buckle and burr.
Ultra precision machining refers to the machining technology that realizes the machining dimension error and shape error below 0.01 mm according to the principles of ultra stability and ultra micro cutting.
1. Processed materials: ultra precision machined parts have strict requirements on the chemical composition, physical and mechanical properties and processing properties of the materials. For example, the processed material shall have uniform texture, stable performance, no external and internal micro defects and no impurities; Its physical and mechanical properties, such as tensile strength, hardness, elongation, elastic modulus, thermal conductivity and expansion coefficient, shall reach a certain order of magnitude; In the process of smelting, casting, rolling and heat treatment, the slag filtration, rolling direction and temperature shall be strictly controlled to make the material pure, uniform grain size and non directionality, and meet the physical, chemical, mechanical and other performance requirements.
2. Processing equipment and its basic components: the processing equipment used for ultra precision processing has the following requirements: (1) high precision. It includes high static precision and high dynamic precision. The main performance indexes include geometric precision, positioning precision, repeated positioning precision, resolution, etc., such as spindle rotation precision, guide rail motion precision, indexing precision, etc; (2) High stiffness. It includes high static stiffness and high dynamic stiffness. In addition to its own stiffness, attention should also be paid to the contact stiffness and the stiffness of the process system composed of workpiece, machine tool, cutter and fixture; (3) High stability. After transportation and storage, the equipment shall be able to maintain high precision, anti-interference and stability for a long time under the specified working environment. The equipment shall have good wear resistance, earthquake resistance, etc; (4) High automation. In order to ensure the machining quality and reduce the influence of human factors, the machining equipment mostly adopts NC system to realize automation.
3. Processing tools: processing tools mainly refer to cutting tools and molds. For ultra precision cutting with diamond tools, the problems worth studying are: for ultra precision grinding of diamond tools, the notch blunt circle radius should reach 2 ~ 4nm, and the detection method should be solved. The blunt circle radius of the edge is closely related to the cutting thickness. If the cutting thickness is to reach 10nm, the blunt circle radius of the edge should be 2nmo. At present, ultra precision grinding with diamond micro powder grinding wheel is mainly used, This kind of grinding wheel has the problems of abrasive particle size, adhesive, dressing, etc. generally, the micro powder diamond with particle size of W20 ~ w0.5 is used, and the adhesive is resin, copper, fiber cast iron, etc.
4. Detection and error compensation: ultra precision machining must have corresponding detection methods, not only to inspect the surface quality of the workpiece, but also to inspect the accuracy of the processing equipment and basic components. Its size, shape and position accuracy can be measured by electronic micrometer, inductance micrometer, capacitance micrometer, autocollimator, etc; The surface roughness can be measured by inductive and piezoelectric crystal surface topography instruments, or non-contact measurement by optical fiber method, capacitance method, ultrasonic microwave method and tunnel microscope method; Surface stress, depth of surface metamorphic layer, surface microcrack and other defects can be measured by X-ray diffraction and laser interferometry. The detection can be carried out offline, on-site and online. Error prevention is to reduce the influence of error sources by improving the manufacturing accuracy of machine tools and ensuring the machining environment; On the basis of error separation, error compensation uses error compensation device to compensate the error value statically and dynamically, so as to eliminate the influence of error itself.