The material's elastic limit

The material's elastic limit

Precisionmetal parts Within the elastic  range, the limiting value of the stress up to which the stress and strain are proportional, is called the limit of proportionality. In this region, the metal obeys Hooke’s law, which states

 that the stress is  proportional to strain in the elastic range of loading (the material completely regains its original dimensions after the load is removed). In the actual plotting of the curve, the proportionality limit is obtained at a slightly lower value of the load than the elastic limit. This may be attributed to the time-lag in  the regaining of the original dimensions of the material.

  Precisionmetal parts This effect is very frequently noticed in some no-ferrous metals.  While iron and  nickel exhibit clear ranges of elasticity, copper, zinc, tin, etc, are found to be imperfectly elastic even at relatively low values of stresses. Actually the elastic limit is distinguishable from the proportionality limit more clearly depending upon the sensitivity of the measuring instrument.

 When the load is increased beyond the elastic limit, plastic deformation starts.

 Simultaneously the specimen gets work-hardened. A point is reached when the deformation starts to occur more rapidly than the  increasing load. This point is called the yield point Q. the metal which was  resisting the load till then, starts to deform somewhat rapidly, i. e. , yield. The yield stress is called yield  limit.

Precisionmetal parts The elongation of the specimen continues form Q to S and then to T. the stess-strain relation in this plastic flow period is indicated by the portion QRST of the curve. At T the specimen breaks, and

 this load is called the breaking load. The value of the maximum load S divided by the original  cross-sectional area of the specimen is referred to as the ultimate tensile strength of the metal or simply the  tensile strength. Logically speaking, once the elastic limit is exceeded, the metal should starts to yield, and finally break, without any increase in the value of stress. But the curve records an increased stress even after the elastic limit is exceeded. Two reasons can be given for this behavior:

  1. the strain hardening of the material;

  2. the diminishing cross-sectional area of the  specimen, suffered on account  of  the plastic  deformation

The numerical control transformation superiorly lacks

The numerical control transformation superiorly lacks

 Reduced investment costs, the date of delivery are short 

  With purchases the new engine bed to compare, may save 60% ~ 80% expense generally, the transformation expense is low. Large-scale, the special engine bed especially is specially obvious. The common large-scale engine bed transforms, Cnc machining only spends the new engine bed purchase

 expense 1/3, the date of delivery is short. But some peculiar circumstances, like the high speed main axle, the tray automatic switching unit manufacture and the installment too requires a lot of work, costs a great deal of money, often transforms the cost to enhance 2 ~ 3 times, with purchases the new engine bed to compare, only can economical invest about 50%.

   Machine capability stable are reliable, the structure is limited

   Uses foundation and so on lathe bed, column all is heavy but the firm casting component, but is not that kind of welding component, after the transformation engine bed performance high, the quality is good, may take the new equipment continues to use many years. But receives the original mechanism the limit, not suitably makes the unprecedented transformation.

  Familiar understood the equipment, is advantageous for the operation service  

 When purchases the new equipment, did not understand whether the new equipment can satisfy its processing request. Cnc machiningThe transformation then otherwise, may precisely calculate the engine bed the processing ability; Moreover, because many years use, the operator already understood to the engine bed characteristic, uses and services the aspect to train the time in the operation short, effective is quick. The transformation engine bed as soon as installs, may realize the capacity load revolution.

 May fully use the existing condition

  May fully use the existing ground, Cnc machining does not need to like buys when the new equipment such to have reto construct the ground.

  May use the newest control technology 

 enhances the production equipment the automated level and the efficiency, improves the equipment quality and the scale, alters to the old engine bed now the horizontal engine bed.

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.

Grinding automation and intellectualization

Grinding automation and intellectualization 

 Precision’s grinding With mechanical manufacturing in FMS (flexible manufacturing system) and CIMS (computer integrated manufacturing system), IMS (intelligent manufacturing system) height automation development direction, the grinding automation requirements are put forward. The development of the CNC grinding machine with CNC lathe, milling machine and so on started late. In the 1980 s and 90 s is a CNC grinding machine for rapid development and entered the popularizing period of practical. In recent years, almost all kinds of grinder CNC products, CNC tool grinding machine from 3 to 10 shaft axis development. Which can realize online measurement, automatic switching of grinding wheel and the emergence of the automatic unloading workpieces milling machining center, mark CNC grinding reached a new level. Grinding CNC system development also have great progress, many special grinding CNC software and systems have been commercialized. In the 1990 s, Japan announced about intelligent grinding results. Use of monitoring information and database, adaptive optimization in grinding condition and the judgment condition of grinding, using computer simulation and virtual technology, establish a realistic virtual grinding environment, to implement the intelligent of the grinding. Continuous track the use of grinding technology, making the grinding technology has made great development. 

 Grinding process monitoring and detection technology   

  Precision’s grinding  Implementation of intelligent computer control of grinding, grinding process is an important problem in the control room. Solve the grinding process, such as the phenomenon of signal identification, signal sampling, signal processing, feedback and compensation, need high sensitive sensor, also need to have expert system or intelligent system and the software design and other technical support.For grinding wheel wear and tear of using acoustic emission monitoring system. Because of the complexity of the grinding process, the grinding process of the monitoring system in theory and practical aspect still has many problems unsolved. Parts after the grinding size, shape and position accuracy, surface quality of the test is divided into offline and online detection.For super precision grinding and free abrasive machining high precision and low surface roughness obtained after detection, high-precision grinding on the surface of the on-line automatic detection are much harder than cars, milling, high sensitivity is the key to development of sensor technology and signal acquisition, recognition and processing technologies.

  Software of grinding technology

  Precision’s grinding  High performance CNC grinding machine should be equipped with a complete software system. Of intelligence information processing and data input of grinding, grinding mode selection and grinding the arrangement of the order, condition of grinding, grinding wheel dressing and grinding automatically selected, the state of the grinding process simulation and virtual detection and compensation, are in software design and development of a reasonable solution.All countries in the development of expert system and intelligent system software. Expert system is a branch of artificial intelligence research, and its essence is a kind of application system. Problem solving ability with expert level in the field of grinding process system, can effectively solve complex problems in the field of grinding.

Introduction of Machining

Introduction of Machining

  Precision CNC machining parts Machining as a shape-producing method is the most universally used and the most important of all manufacturing processes. Machining is a shape-producing process in which a power-driven device causes material to be removed in chip form. Most machining is done with equipment that supports both the work piece and cutting tool although in some cases portable equipment is used with unsupported workpiece. 

 Precision CNC machining parts  Low setup cost for small quantities. Machining has tow applications in manufacturing. For casting, forging, and pressworking, each specific shape to be p5roduced, even one part, nearly always has a high tooling cost. The shapes that may be produced, even one part, nearly always has a high tooling cost. The shapes that may be produced by welding depend to a large degree on the shapes of raw material that are available. By making use of generally high cost equipment but without special tooling, it is possible, bu machining, to start with nearly any form of any material, so long as the exterior dimensions are great enough, and produce any desired shape from any material. Therefore, machining is usually the preferred method for producing one or a few parts, even when the design of the part would logically lead to casting, forging or pressworking if a high quantity were to be produced.  Close accuracies, good finishes. The second application for machining is based on the high accuracies and surface finishes possible.

 Precision CNC machining parts  Many of the parts machined in low quantities would be produced with lower but acceptable tolerances if produced in high quantities by some other process. On the other hand, many pars are given shapes by some high quantity deformation process and machined only on selected surfaces where high accuracies are needed. Internal threads, for example, are seldom produced by any means other than machining and small holes in pressworked parts may be machined following the pressworking operations.

  

Rapid economic modeling techniques

Rapid economic modeling techniques

 Shorten the product development cycle is an effective means of market competition to win one.  Compared with the traditional mold process, cnc milling machine fast economic modeling technology is a short molding cycle, the characteristics of low cost, precision, and life can meet the production needs, overall economic efficiency is more significant in the mold manufacturing technology, specifically the following main technology. 

 (1) rapid prototyping and manufacturing (RPM). cnc milling machine

 (2) the surface forming tooling.  It refers to the use of spray, chemical corrosion, electroforming and new method for the formation of the cavity surface and a fine pattern technology. 

  (3) Casting forming tooling.  There are bismuth tin alloy tooling, zinc alloy tooling, resin composite forming technology and silicon rubber mold molding technology. 

 (4) cold extrusion mold technology and ultra-molded shapes.

  (5) multi-point forming technology. 

  (6) KEVRON steel blanking blanking tooling.

   (7) mold blank rapid manufacturing technology. Mainly dry sand Mold Casting, Vacuum Mold Casting, Resin Sand Mold Casting Lost Wax Casting, and other technologies. 

  (8) Other aspects of technology. cnc milling machineSuch as the use of nitrogen gas spring pressure side, discharge, quick die technology, stamping unit technology, and cutting edge technology and solid surfacing edge inserts die casting technology.

cutting speed

cutting speed, precision metal parts feed rate is an important parameter in the CNC machine tool cutting parameters, mainly based on the machining accuracy and surface roughness and the tool, workpiece material properties, select the maximum feed rate, machine tool stiffness and feeding system performance limitations., near the corner of contouring feed rate should be appropriately reduced in order to overcome the inertia or process systems is caused by deformation in the contour around the corner "overtravel" or "under process" phenomenon. to determine the principles of the feed rate : When the workpiece quality requirements can be guaranteed, in order to improve production efficiency, can choose a higher feed rate generally selected in the range of 100 ~ 200mm/min. processing in high-speed steel cutting tools, cutting, machining deep hole or should choose a lower feed rate, generally 20 ~ 50mm/min select range of .3 when machining accuracy, surface roughness, the feed rate should be selected smaller, generally in the 20 ~ 50mm/min range within selected .4 tool air travel, especially long-distance back to zero, you can select the CNC system given the maximum feed rate.

  precision metal parts back to eat the knife amount (or side knife to eat the amount determined under the premise of ensuring the quality of the machined surface, the back of cut (ap) should be determined according to the stiffness of the machine tool, workpiece and tool under the conditions allowed by stiffness, should as much as possible so that the back of cut allowance equal to the workpiece, thus reducing the number of tool path, and increase productivity.

   precision metal partss machining centers with axial and neck power head, to achieve the linkage of the three coordinates. Polar coordinate interpolation instruction and cylindrical interpolation instruction program optimization and development, and the machining station repeated positioning error of the effective compensation, the initial fast and reliable precision milling on the side of the rotary to improve the machining accuracy and surface finish quality.