2016年8月31日星期三

Electric spark forming processing technology present situation and trend of development

Electric spark forming processing technology present situation and trend of  development
 IIntroduction
Precision metal parts As an advanced technique of manufacture important branch, the special processing technology, the electric spark machining technology, since the 20th century 40's foundations, has had been through repeatedly in particular for more than half centuries the development, has become the advanced technique of manufacture domain indispensable important constituent. Enters after in particular the human for 1990s, along with high technology and new technology and so on information technology, networking, aviation and astronautics technology, materials science technology development, the electric spark forming processing technology also faces a deeper level, the high level direction is developing. Although some traditional processing technology through own unceasing renewal development as well as with other correlation technology fusion, difficult to process the material processing domain in some (especially in mold processing domain) to display the processing efficiency higher superiority, but these technical application has been impossible to substitute for the electric spark forming processing technology difficultly to process processing domain completely and so on in the material, complex profile, mold statuses. On the contrary, the electric spark forming processing technology through profits from other processing technology the development experience, to the micro refinement, highly effective directions and so on, precision, automation, intellectualization is developing unceasingly. 
IIElectric spark forming processing technology development present situation
 Precision metal parts At present, in electric spark machining basic theory research area, because the electric discharge process itself complexity, randomness as well as the research method lack the innovation, until now not yet made the unprecedented progress. But in processing craft and control fundamental research domain, because the research results may apply directly in the production practice, therefore has become in the present electric spark forming processing engineering research a more active domain, its research hot spot mainly concentrates in the highly effective processing technology, the high precise processing technology (glassy surface processing technology), the low loss processing technology, the tiny processing technology, the non-conducting material processing technology, the electric spark surface treatment technology, the intelligent control technology (for example artificial neural networks technology, fuzzy control technology, expert system and so on) as well as aspects and so on operational safety, environmental protection. In the process unit development aspect, the present new electric spark forming processing engine bed in aspects and so on processing function, processing precision, automaticity, reliability improved comprehensively, many engine beds have had online functions and so on examination, intelligent control, modulation, no longer is in the traditional significance special processing engine bed, but looks like in the machining the numerical control engine bed even to process the center.
 IIIElectric spark forming processing technology trend of development

Precision metal parts The advanced technique of manufacture fast development and the manufacturing industry market competition aggravating proposed to the electric spark forming processing technology a higher request, simultaneously also for the electric spark forming processing technology processing theory research and the craft development, the equipment renewed has provided the new power. The next electric spark forming processing processing object will be supposed mainly to face the tradition machining not not easily to realize difficultly to process processings and so on material, complex profile, in which fine processing, the precise processing, the narrow dadoing, the deep cavity processing and so on becomes the development priorities. At the same time, but also should pay attention with other special processing technology or the traditionElectric spark forming processing technology present situation and trend of  development
 IIntroduction
Precision metal parts As an advanced technique of manufacture important branch, the special processing technology, the electric spark machining technology, since the 20th century 40's foundations, has had been through repeatedly in particular for more than half centuries the development, has become the advanced technique of manufacture domain indispensable important constituent. Enters after in particular the human for 1990s, along with high technology and new technology and so on information technology, networking, aviation and astronautics technology, materials science technology development, the electric spark forming processing technology also faces a deeper level, the high level direction is developing. Although some traditional processing technology through own unceasing renewal development as well as with other correlation technology fusion, difficult to process the material processing domain in some (especially in mold processing domain) to display the processing efficiency higher superiority, but these technical application has been impossible to substitute for the electric spark forming processing technology difficultly to process processing domain completely and so on in the material, complex profile, mold statuses. On the contrary, the electric spark forming processing technology through profits from other processing technology the development experience, to the micro refinement, highly effective directions and so on, precision, automation, intellectualization is developing unceasingly. 
IIElectric spark forming processing technology development present situation
 Precision metal parts At present, in electric spark machining basic theory research area, because the electric discharge process itself complexity, randomness as well as the research method lack the innovation, until now not yet made the unprecedented progress. But in processing craft and control fundamental research domain, because the research results may apply directly in the production practice, therefore has become in the present electric spark forming processing engineering research a more active domain, its research hot spot mainly concentrates in the highly effective processing technology, the high precise processing technology (glassy surface processing technology), the low loss processing technology, the tiny processing technology, the non-conducting material processing technology, the electric spark surface treatment technology, the intelligent control technology (for example artificial neural networks technology, fuzzy control technology, expert system and so on) as well as aspects and so on operational safety, environmental protection. In the process unit development aspect, the present new electric spark forming processing engine bed in aspects and so on processing function, processing precision, automaticity, reliability improved comprehensively, many engine beds have had online functions and so on examination, intelligent control, modulation, no longer is in the traditional significance special processing engine bed, but looks like in the machining the numerical control engine bed even to process the center.
 IIIElectric spark forming processing technology trend of development
Precision metal parts The advanced technique of manufacture fast development and the manufacturing industry market competition aggravating proposed to the electric spark forming processing technology a higher request, simultaneously also for the electric spark forming processing technology processing theory research and the craft development, the equipment renewed has provided the new power. The next electric spark forming processing processing object will be supposed mainly to face the tradition machining not not easily to realize difficultly to process processings and so on material, complex profile, in which fine processing, the precise processing, the narrow dadoing, the deep cavity processing and so on becomes the development priorities. At the same time, but also should pay attention with other special processing technology or the tradition machining technology compound application, displays each processing method difficultly to process in the material processing fully the superiority, obtains the union increment effect. Is opposite says in the machining technology, the electric spark forming processing technology was still a young technology, therefore in the next development, will be supposed to profit from the experience and the achievement which in the machining technological development process will obtain, will process own technical characteristic according to the electric spark forming, will select the suitable processing theory, the control principle and the technique, and will have in the achievement foundation in oneself to consummate, the innovation unceasingly. The electric spark forming processing engine bed the tendency which develops to the numerical control direction already irreversible, but should pay attention cannot pursue blindly “large and complete”. should take the market as the guidance, the establishment has the open numerical control system. Overall, the electric spark forming processing technology next trend of development should be the high efficiency, the high accuracy, the low loss, the micro refinement, the automation, the security, the environmental protection and so on. machining technology compound application, displays each processing method difficultly to process in the material processing fully the superiority, obtains the union increment effect. Is opposite says in the machining technology, the electric spark forming processing technology was still a young technology, therefore in the next development, will be supposed to profit from the experience and the achievement which in the machining technological development process will obtain, will process own technical characteristic according to the electric spark forming, will select the suitable processing theory, the control principle and the technique, and will have in the achievement foundation in oneself to consummate, the innovation unceasingly. The electric spark forming processing engine bed the tendency which develops to the numerical control direction already irreversible, but should pay attention cannot pursue blindly “large and complete”. should take the market as the guidance, the establishment has the open numerical control system. Overall, the electric spark forming processing technology next trend of development should be the high efficiency, the high accuracy, the low loss, the micro refinement, the automation, the security, the environmental protection and so on.

 precision metal parts

2016年8月28日星期日

Grinding technology development trend

Grinding technology development trend
 Precision CNC machining parts Grinding machining is important processing technology in mechanical manufacturing. With precision mechanical products, the requirement of increasing the reliability and service life, high hardness, high strength, high wear resistance, high functional new materials application increased, for grinding processing and put forward many new problems, such as material of grinding machining and surface integrity, super precision grinding and high efficiency grinding and grinding automation, etc. Problems to be solved.At present, the grinding technology is moving toward using super hard abrasives, development of precision and ultra precision grinding, high speed, high efficiency grinding technology and the development of high precision, high stiffness of the grinding machine automation direction. 
 One.   In-depth development of grinding theory and technology research
 Precision CNC machining parts Grinding theory research is the basis for the development of grinding technology, the grinding technology and the development of practice and research provides the opportunity for grinding theory, requirement and new topic, in recent ten years, professionals engaged in the work of grinding, grinding technology and phenomenon many factors for a lot of in-depth research and achieved fruitful results.
 Two.  Unit grinding machine high speed, high precision components manufacturing technology 

 Precision CNC machining parts High precision grinding machine spindle unit, feeding unit, bearing unit and auxiliary unit is the key parts and components. Spindle unit including spindle power, shaft, bearing, and frame sections, she affects the precision of the machining system, stability and application scope, its dynamic performance and stability of high performance precision ultra-precision grinding, play a key role. Feed unit including the position detection unit, Demand of feed units, therefore, flexible operation, high resolution, high positioning accuracy, not crawl and large movement range, both to have larger acceleration, and large enough thrust, high stiffness, quick dynamic response, high positioning accuracy. Machine tools supporting technology mainly refers to the supporting member of design and manufacturing technology. Auxiliary unit technology including fast clamping workpiece, high efficiency grinding fluid filtration system, machine safety devices, chip removal and the workpiece cleaning technology, spindle and grinding wheel dynamic balance technology, etc.

  Precision CNC machining parts

2016年8月21日星期日

General transformation of multi-axis drilling machine drilling machin

General transformation of multi-axis drilling  machine drilling machin 
Cnc milling machine small and medium enterprises in product quality and  production efficiency are the need for a new increase. But the processing means is far from sufficient. Many small and medium enterprises with their actual technical state of equipment improvements, through strengthening its own. In order to self-development.Common drilling for single-axis machine tools, but the installation will become a multi-axis multi-axle box of the drill, transformation into a multi-axis drilling, we could greatly shorten the processing time, improve production efficiency.            
   Application of multi-axis machining
 Cnc milling machine According to statistics, in general machine  tools in the workshop in general, the average cutting time rarely exceeds 15% of total working hours. The remaining time is plug-in, loading and unloading the workpiece, exchange tools, operation tools, measurements, and clear the iron filings and so forth. Although the use of CNC machine tools can improve 85%, but the purchase of costly. In some cases, even if the high productivity, but the processing of the same components, the cost is not necessarily lower than the average machine. Therefore must be more to shorten the processing time. Different processing methods have different characteristics, the drilling process, the multi-axis machining is a small investment to increase productivity through effective measures. 
The advantages of multi-axis machining
Although it is not the first in automatic  multi-axis adjustable long line applications, but only limited to high-volume production. Even with the adjustable multi-axis head expanded the scope of use is still far from being able to meet the volume is small, hole complex requirements. In particular, as industrial development, large and complex multi-axis machining is even more compelling. For example, large-scale nuclear power plants in the water-wall tube plate condenser has 15000 ψ20 holes, if radial drilling machine processing, and simply drilling holes and countersink countersunk head is necessary to 842.5 hours, while also crossed hours 151.1 hours. However, if the 8-axis CNC machining floor drilling, drilling countersink holes as long as 171.6 hours, crossed is also simple, as long as 1.9 hours. Therefore, the use of numerical control of two axis, so that proper alignment tool processing location, combined with multi-axis machining can not only expand the range of processing, but also on the basis of improving the accuracy can greatly enhance the work efficiency, easy to quickly create original processing parts. Some analysis of large high-speed diesel engine with 30 kinds of box-shaped rod-shaped parts of the more than 2,000 drilling operations, 40% could be the automatic replacement of machines using two-axis spindle box, three-axis or four-axis multi-axis machining head, the average can be reduced 20% of the processing time. Machine Tool Exhibition in Paris in 1975 also reflected the multi-axis machining using more and more the trend.   
Multi-axis machining equipment
 Cnc milling machine  Multi-axis machining is the same time in a feed  processing a number of holes or simultaneously in many of the same or different processing of a workpiece on each hole. This will not only shorten the cutting time and improve accuracy, reduce fixturing or positioning time, and in the CNC machine tool is not necessary to calculate the coordinates, reducing the number of character blocks
and simplified programming. It can be processed using the following equipment: radial drillingvertical drilling, or upload multi-axis head, multi-axis drilling machine, multi-axis modular machine tool spindle box heart and automatic replacement of machines. May even be able to automatically adjust wheelbase by two or more of the spindle axle box, junction  All CNC vertical and horizontal table two directions of movement, processing a variety of round or oval-shaped hole group of one or several steps. Now the status quo in this regard to make a profile

 Cnc milling machine

2016年8月17日星期三

Hydraulic System

Hydraulic System
  CNC machining parts The history of hydraulic power is a long onedating from mans prehistoric efforts to harness the energy in the world around himThe only sources readily available were the water and the windtwo free and moving streams.
  The watermillthe first hydraulic motorwas an early invention·  One is pictured on a mosaic at the Great Palace in Byzantiumdating from the early fifth century·The mill had been built by the Romans  But the first record of a watermill goes back even further,  to around 100 BCand the origins may indeed have been much earlier·The domestication of grain began some 5000 years before and some enterprising farmer is bound to have become tired of pounding or grinding the grain by handPerhaps  in factthe inventor was some
farmers wifesince she often drew the heavy jobs·
 CNC machining parts Manv mills staved in use until the end of the 19th centurybut they had been in the  process of being replaced by the Steam engine as a source of power for the previous 150  yearsThe transmission of the power generated by the waterwheels was by shafting and  crude gears or pulleysThe steam engine for the first time employed an enclosed moving
 stream of fluid(steam) under pressure—the principle to be later employed in hydraulic  power transmission—for transmitting power continuously from the point of generation to  the place where it was used·
  The transmission of hydrostatic power to a distant point began long before that,however Hero of A1exandriain the first century ADbuilt a device in which a fire on the temple  altar expanded air in a closed containerThe air pressure forced water to travel along a tube
 to the temple doors wherespilling into a containerit provided the force through ropes and  pulleys to magically open the doors
  Hero also produced a steam engine of sorts
 Its motion depended on the reaction forces   from jets of steamas in the present steam turbinebut it was little understood and it was no   more than an interesting curiosity·
  The invention of early forms of the hydraulic pump has a similarly early origin·The first pumps were not used to develop hydraulic powerhowever' but only to transfer water for  irrigation or to remove it from mines
 Archimedes applied the principle of the screw to hydraulic machines in the third century BC 
 His screw pumps were used to raise water for irrigation or to the level of aqueducts·The piston   pumpthe first mechanical device capable of generating pressure in a column of liquidis believed to have come from Egypt at a similarly early dateLike the screw pumpit was used only as a means for moving water and not as a means for generating hydraulic power·
  In more recent years the role of leadership in hydraulic power application has been taken over largely by some of the larger earthmoving and construction equipment manufacturers the total Power involved is often greater than that required in even the largest aircraft systemsthe concentration of this power in a few very large loadsas compared to the multitude of smaller loads in an airplanehas spurred the system designer to find newcreative ways to distribute and control the powerThis he has succeeded in doing to obtain maximum precision of control and productivity while minimizing power consumption
  in modern mobile and industrial applicationsthe system designer has made full use of the wonderful flexibiIity and adaptability of hydraulics  It can readily be directed around corners and past involving joints that virtually defy mechanical power transmission  It can be divided easily to serve individual loads or recombined to power a highsingleload demand Electrical and pneumatic power distribution have similar flexibilitybut lack the compactness
 and certain of the other important characteristics of hydraulics
   CNC machining parts A very significant feature of hydraulic power is its extreme power density Fig1 01 shows a comparison of a 400 hP(1hp=0·7457kW)hydraulic pumping source with a diesel engine and an electrical motor of the same power capacityThe contrast is obvious and is one that otters both an opportunity to the user of hydraulic power and a challenge to the designer
 of hydraulic components.

  The highpower density in a hydraulic pump or motor creates design challenges beyond those found in many other products·High loads on rapidly sliding surfacesextreme fluid   velocities and rapidly recurring pressure applications on pumping elements(vanespistons   gears) demand careful design attention to assure long lifecomplete reliability and efficient operation·The user,on the other handreaps the benefit of a family of apparatus that is highly responsivefinely controllable and simple to applyWhen the designer understands the users needs and the user understands the equipments full capabilitiesthe maximum  potential of hydraulic power can be achieved

  CNC machining parts

2016年8月14日星期日

Shaper, Planer, Milling and Grinding Machines

Shaper, Planer, Milling and Grinding Machines
 Shapers 
Precision metal parts Shapers are machine tools used primarily in the production of flat and angular surfaces. In addition, the shaper is used to machine irregular shapes and contours which are difficult to produce on other machine tools. Internal as well as external surfaces and shapes can be produced on the shaper. Common shapes produced on the shaper are flat, angular, grooves, dovetails, T-slots, keyways, slots, serrations, and contours. Single-point cutting tools similar to the type used on the lathe are used in machining most surfaces on the shaper. Contour surfaces can be produced with either a single-point tool or a formed cutting tool. When using a single-point cutting tool for contour surfaces, the depth of cut must be constantly regulated by the machine operator to achieve the proper contour . Profilingattachments can be used on some shapers to regulate the feed motion and provide duplication of other parts. Numerical control units also enable the production of irregular surfaces with constant regulation of the depth of cut.
   Shapers are classified by the plane in which the cutting action occurs, either horizontal or vertical. In addition the horizontal-type shapers are further classified as push or pull cut. A push-cut shaper cuts while the ram is pushing the tool across the work, and a pull cut machine removes material while the tool is pulled toward the machine. Vertical shapers use a pushing-type cutting action and are sometimes referred to as slotters or keyseaters.
 Planers 
Precision metal parts Planers are similar to shapers because both machines are primarily used to produce flat and angular surfaces. However, planers are capable of accommodating much larger work- pieces than the shaper. In planer operations the workpiece is mounted on the table which reciprocates in a horizontal plane providing a straight-line cutting and feed action. Single-point cutting tools are mounted on an overhead cross rail and along the vertically supported columns. The cutting tools are fed into or away from the workpiece on either the horizontal or vertical plane, thus being capable of four straight-line feed motions.  Cutting speeds are slow on the planer because of the workpiece size and type of cutting tool being used. In order to increase the production of the planer, multiple tooling stations are employed. Two tooling stations are located on the overhead cross rails, with usually one tooling station on the vertical supports. Another method of increasing production on the planer is to mount a number of workpieces on the table at the same time. This method is only feasible when the workpieces require the same cut and are relatively small in size. The planer size is designated by the maximum workpiece capacity of the machine. The height, width, and length of the workpiece that can be accommodated on the planer's worktable varies with the type of planer.
 Milling Machines
  Precision metal parts Milling machines are probably the most versatile machine tools used in modern manufacturing with the exception of the lathe. Primarily designed to produce flat and angular surfaces, the milling machine is also used to machine irregular shapes, surfaces, grooves, and slots. The milling machine can also be used for drilling, boring, reaming, and gear-cutting operations.   A number of different types of milling machines are manufactured in order to serve the multitude of needs and the diverse applications. Milling machines are classified according to their structure and include column-knee, fixed bed, planer, and special machines.
 Grinding Machines
  Grinding machines utilize abrasive grains, bonded into various shapes and sizes of wheels and belts to be used as the cutting agent. Grinding operations are used to impart a high-quality surface finish on the workpiece. In addition, the dimensional accuracy of the workpiece is improved since tolerances of 0.00001 in. [0. 00025mm] are possible in grinding operations. Both internal and external surfaces can be ground by using the variety of grinding machines available. Related operations—which use abrasivesin various forms such as paste, powder, and grains—include lapping, honing, and drum finishing.   

  Grinding machines are classified according to the type of surface produced. Common surfaces and classifications of grinding machines are surface, cylindrical, and special machines.

 Precision metal parts

2016年8月10日星期三

Design of machine elements of 2

Design of machine elements of 2
 Precisionparts Machine design is a vast field of engineering technology. As such, it begins with the conception of an idea and follows through the various phases of design analysis, manufacturing, marketing and consumerism. The following is a list of the major areas of consideration in the general field of machine design:
  Initial design conception;  Strength analysis; Materials selection;   Appearance; Manufacturing;  Safety;  Environment effects;  Reliability and life;                               
   Strength is a measure of the ability to resist, without fails, forces which cause stresses and strains. The forces may be;
  Gradually applied;  Suddenly applied;  Applied under impact;   Applied with continuous direction reversals;  Applied at low or elevated temperatures.       
 Precisionparts If a critical part of a machine fails, the whole machine must be shut down until a repair is made. Thus, when designing a new machine, it is extremely important that critical parts be made strong enough to prevent failure. The designer should determine as precisely as possible the nature, magnitude, direction and point of application of all forces. Machine design is mot, however, an exact science and it is, therefore, rarely possible to determine exactly all the applied forces. In addition, different samples of a specified material will exhibit somewhat different abilities to resist loads, temperatures and other environment conditions. In spite of this, design calculations based on appropriate assumptions are invaluable in the proper design of machine.
  Precisionparts Moreover, it is absolutely essential that a design engineer knows how and why parts fail so that reliable machines which require minimum maintenance can be designed. Sometimes, a failure can be serious, such as when a tire blows out on an automobile traveling at high speeds. On the other hand, a failure may be no more than a nuisance. An example is the loosening of the radiator hose in the automobile cooling system. The consequence of this latter failure is usually the loss of some radiator coolant, a condition which is readily detected and corrected.
 The type of load a part absorbs is just as significant as the magnitude. Generally speaking, dynamic loads with direction reversals cause greater difficulties than static loads and, therefore, fatigue strength must be considered. Another concern is whether the material is ductile or brittle. For example, brittle materials are considered to be unacceptable where fatigue is involved.     
  In general, the design engineer must consider all possible modes of failure, which include the following:

Stress; Deformation;    Wear;  Corrosion;  Vibration;    Environmental damage;     Loosening of fastening devices.                           
   The part sizes and shapes selected must also take into account many dimensional factors which produce external load effects such as geometric discontinuities, residual stresses due to forming of desired contours, and the application of interference fit joints.
  
  Precision parts

2016年8月7日星期日

Design of machine elements

Design of machine elements
    Precision metal parts  The principles of design are, of course, universal. The same theory or equations may be applied to a very small part, as in an instrument, or, to a larger but similar part used in a piece of heavy equipment. In no ease, however, should mathematical calculations be looked upon as absolute and final. They are all subject to the accuracy of the various assumptions, which must necessarily be made in engineering work. Sometimes only a portion of the total number of parts in a machine are designed on the basis of analytic calculations. The form and size of the remaining parts are designed on the basis of analytic calculations. On the other hand, if the machine is very expensive, or if weight is a factor, as in airplanes, design computations may then be made for almost all the parts.
    Precision metal parts   The purpose of the design calculations is, of course, to attempt to predict the stress or deformation in the part in order that it may sagely carry the loads, which will be imposed on it, and that it may last for the expected life of the machine. All calculations are, of course, dependent on the physical properties of the construction materials as determined by laboratory tests. A rational method of design attempts to take the results of relatively simple and fundamental tests such as tension, compression, torsion, and fatigue and apply them to all the complicated and involved situations encountered in present-day machinery
   Precision metal parts  In addition, it has been amply proved that such details as surface condition, fillets, notches, manufacturing tolerances, and heat treatment have a market effect on the strength and useful life of a machine part. The design and drafting departments must specify completely all such particulars, must specify completely all such particulars, and thus exercise the necessary close control over the finished product.
  
   Precision metal parts



2016年8月3日星期三

Machine design

Machine design
 Precision CNC machining parts Machine design is the art of planning or devising new or improved machines to accomplish specific purposes. In general, a machine will consist of a combination of several different mechanical elements properly designed and arranged to work together, as a whole. During the initial planning of a machine, fundamental decisions must be made concerning loading, type of kinematic elements to be used, and correct utilization of the properties of engineering materials. Economic considerations are usually of prime importance when the design of new machinery is undertaken. In general, the lowest over-all costs are designed.
Precision CNC machining parts  Consideration should be given not only to the cost of design, manufacture the necessary safety features and be of pleasing external appearance. The objective is to produce a machine which is not only sufficiently rugged to function properly for a reasonable life, but is at the same time cheap enough to be economically feasible.

  Precision CNC machining parts The engineer in charge of the design of a machine should not only have adequate technical training, but must be a man of sound judgment and wide experience, qualities which are usually acquired only after considerable time has been spent in actual professional work.

 Precision CNC machining parts