2016年6月29日星期三

Wears of Cutting Tool

Wears of Cutting Tool 
 We already have been cnc machining parts  processed and the rattle of the countless cracks edge tool, we learn that tool wear are basically three forms : flank wear, the former flank wear and V-Notch wear. Flank wear occurred in both the main blade occurred vice blade. On the main blade, shoulder removed because most metal chip mandate, which resulted in an increase cutting force and cutting temperature increase, If not allowed to check, That could lead to the work piece and the tool vibration and provide for efficient cutting conditions may no longer exist. Vice-bladed on, it is determined work piece dimensions and surface finish. Flank wear size of the possible failure of the product and surface finish are also inferior. In most actual cutting conditions, as the principal in the former first deputy flank before flank wear, wear arrival enough, Tool will be effective, the results are made unqualified parts.
  As Tool stress on the surface uneven, chip and flank before sliding contact zone between stress, in sliding contact the start of the largest, and in contact with the tail of zero, cnc machining parts so abrasive wear in the region occurred. This is because the card cutting edge than the nearby settlements near the more serious wear, and bladed chip due to the vicinity of the former flank and lost contact wear lighter. This results from a certain distance from the cutting edge of the surface formed before the knife point Ma pit, which is usually considered before wear. Under normal circumstances, this is wear cross-sectional shape of an arc. In many instances and for the actual cutting conditions, the former flank wear compared to flank wear light, Therefore flank wear more generally as a tool failure of scale signs. But because many authors have said in the cutting speed of the increase, Maeto surface temperature than the knife surface temperatures have risen faster. but because any form of wear rate is essentially temperature changes by the significant impact. Therefore, the former usually wear in high-speed cutting happen.
 The main tool flank wear the tail is not processed with the work piece surface in contact, Therefore flank wear than wear along with the ends more visible, which is the most common. This is because the local effect, which is as rough on the surface has hardened layer, This effect is by cutting in front of the hardening of the work piece. Not just cutting, and as oxidation skin, the blade local high temperature will also cause this effect. This partial wear normally referred to as pit sexual wear, but occasionally it is very serious. Despite the emergence of the pits on the Cutting Tool nature is not meaningful impact, but often pits gradually become darker If cutting continued the case, then there cutter fracture crisis. 

 Cnc machining parts If any form of sexual allowed to wear, eventually wear rate increase obviously will be a tool to destroy failure destruction, that will no longer tool for cutting, cause the work piece scrapped, it is good, can cause serious damage machine. For various carbide cutting tools and for the various types of wear, in the event of a serious lapse, on the tool that has reached the end of the life cycle. But for various high-speed steel cutting tools and wear belonging to the non-uniformity of wear, has been found : When the wear and even to allow for a serious lapse, the most meaningful is that the tool can re-mill use, of course, In practice, cutting the time to use than the short time lapse. Several phenomena are one tool serious lapse began features : the most common is the sudden increase cutting force, appeared on the work piece burning ring patterns and an increase in noise

 cnc machining parts

2016年6月26日星期日

Primary Cutting Parameters

Primary Cutting Parameters
  Cnc machining parts  Cutting the work piece and tool based on the basic relationship between the following four elements to fully describe : the tool geometry, cutting speed, feed rate, depth and penetration of a cutting tool.
  Cutting Tools must be of a suitable material to manufacture, it must be strong, tough, hard and wear-resistant. Tool geometry -- to the tip plane and cutter angle characteristics -- for each cutting process must be correct.
 Cutting speed is the cutting edge of work piece surface rate, it is inches per minute to show. In order to effectively processing, and cutting speed must adapt to the level of specific parts -- with knives. Generally, the more hard work piece material, the lower the rate.
  Progressive Tool to speed iscut into the work piece speed.  Cnc machining parts If the work piece or tool for rotating movement, feed rate per round over the number of inches to the measurement. When the work piece or tool for reciprocating movement and feed rate on each trip through the measurement of inches. Generally, in other conditions, feed rate and cutting speed is inversely proportional to

   Depth of penetration of a cutting tool -- to inches dollars -- is the tool to the work piece distance.  Cnc machining parts Rotary cutting it to the chip or equal to the width of the linear cutting chip thickness. Rough than finishing, deeper penetration of a cutting tool depth.

  Cnc machining parts

2016年6月19日星期日

Introduciton of Machining

Introduciton of Machining
  Have a shape as a processing method, all machining process for the production of the most commonly used and most important method. Cnc machining Machining process is a process generated shape, in this process, Drivers device on the workpiece material to be in the form of chip removal. Although in some occasions, the workpiece under no circumstances, the use of mobile equipment to the processing, However, the majority of the machining is not only supporting the workpiece also supporting tools and equipment to complete.
  Machining know the process has two aspects. Small group of low-cost production. For casting, forging and machining pressure, every production of a specific shape of the workpiece, even a spare parts, almost have to spend the high cost of processing. Welding to rely on the shape of the structure, to a large extent, depend on effective in the form of raw materials. Cnc machining  In general, through the use of expensive equipment and without special processing conditions, can be almost any type of raw materials, mechanical processing to convert the raw materials processed into the arbitrary shape of the structure, as long as the external dimensions large enough, it is possible. Because of a production of spare parts, even when the parts and structure of the production batch sizes are suitable for the original casting, Forging or pressure processing to produce, but usually prefer machining. 

 Strict precision and good surface finish, Machining the second purpose is the establishment of the high precision and surface finish possible on the basis of. Many parts, if any other means of production belonging to the large-scale production, Cnc machining Well Machining is a low-tolerance and can meet the requirements of small batch production. Besides, many parts on the production and processing of coarse process to improve its general shape of the surface. It is only necessary precision and choose only the surface machining. For instance, thread, in addition to mechanical processing, almost no other processing method for processing. Another example is the blacksmith pieces keyhole processing, as well as training to be conducted immediately after the mechanical completion of the processing

 Cnc machining

2016年6月13日星期一

China's mold industry

China's mold industry
  Due to historical reasons for the formation of closed, "big and complete" enterprise features, most enterprises in China are equipped with mold workshop, in factory matching status since the late 70s have a mold the concept of industrialization and specialization of production.  Production efficiency is not high, poor economic returns. 
Mold production industry is small Precision stamping parts and scattered, cross-industry, capital-intensive, professional, commercial and technical management level are relatively low
 According to incomplete statistics, there are now specialized in manufacturing mold, the product supporting mold factory workshop (factory) near 17 000, about 600 000 employees, annual output value reached 20 billion yuan mold.  However, the existing capacity of the mold and die industry can only meet the demand of 60%, still can not meet the needs of national economic development.  At present, the domestic needs of large, sophisticated, complex and long life of the mold also rely mainly on imports.  According to customs statistics, in 1997 630 million U.S. dollars worth of imports mold, not including the import of mold together with the equipment; in 1997 only 78 million U.S. dollars export mold.  At present the technological level of China Die & Mould Industry and manufacturing capacity, China's national economy in the weak links and bottlenecks constraining sustainable economic development
 Research on the Structure of industrial products mold
    In accordance with the division of China Mould Industry Association, China mold is divided into 10 basic categories, which, stamping die and plastic molding two categories accounted for the main part.  Calculated by output, present, China accounts for about 50% die stamping, plastic molding die about 20%, Wire Drawing Die (Tool) about 10% of the Precision stamping parts world's advanced industrial countries and regions, the proportion of plastic forming die die general of the total output value 40%
 Most of our stamping die mold for the simple, single-process mode and meet the molds, precision die, precision multi-position progressive die is also one of the few, die less than 100 million times the average life of the mold reached 100 million times the maximum life of more than accuracy 3 ~ 5um, more than 50 progressive station, and the international life of the die 600 million times the highest average life of the die 50 million times compared to the mid 80s at the international advanced level.
 China's plastic molding mold design, production technology started relatively late, the overall level of low.  Currently a single cavity, a simple mold cavity 70%, and still dominant. A sophisticated multi-cavity mold plastic injection mold, plastic injection mold has been able to multi-color preliminary design and manufacturing.
 Mould is about 80 million times the average life span is about, the main difference is the large deformation of mold components, excess burr side of a large, poor surface quality, erosion and corrosion serious mold cavity,Precision stamping parts the mold cavity exhaust poor and vulnerable such as, injection mold 5um accuracy has reached below the highest life expectancy has exceeded 20 million times, the number has more than 100 chamber cavity, reaching the mid 80s to early 90s the international advanced level.
 mold Present Status of Technology   
 Technical level of China's mold industry currently uneven, with wide disparities.  Generally speaking, with the developed industrial countries, Hong Kong and Taiwan advanced level, there is a large gap. 
   The use of CAD / CAM / CAE / CAPP and other technical design and manufacture molds, both wide application, or technical level, there is a big gap between both.  In the application of CAD technology design molds, only about 10% of the mold used in the design of CAD, aside from drawing board still has a long way to go; in the application of CAE design and analysis of mold calculation, it was just started, most of the game is still in trial stages and animation; in the application of CAM technology manufacturing molds, first, the lack of advanced manufacturing equipment, and second, the existing process equipment (including the last 10 years
 the introduction of advanced equipment) or computer standard (IBM PC and compatibles, HP workstations, etc.) different, or because of differences in bytes, processing speed differences, differences in resistance to electromagnetic interference, networking is low, only about 5% of the mold manufacturing equipment of recent work in this task; in the application process planning CAPP technology, basically a blank state, based on the need for a lot of standardization work; in the mold common technology, such as mold rapid prototyping technology, polishing, electroforming technologies, surface treatment technology aspects of CAD / CAM technology in China has just started.  Computer-aided technology, software development, is still at low level, the accumulation of knowledge and experience required.  
Most of our mold factory, mold processing equipment shop old, long in the length of civilian service, accuracy, low efficiency, still use the ordinary forging, turning, milling, planing, drilling, grinding and processing equipment, mold, heat treatment is still in use salt bath, box-type furnace, operating with the experience of workers, poorly equipped, high energy consumption.  Renewal of equipment is slow, technological innovation, technological progress is not much intensity.  Although in recent years introduced many advanced mold processing equipment, but are too scattered, or not complete, only about 25% utilization, equipment, some of the advanced functions are not given full play.

    Lack of technology of high-quality mold design, manufacturing technology and skilled workers, especially the lack of knowledge and breadth, knowledge structure, high levels of compound talents.  China's mold industry and technical personnel, only 8% of employees 12%, and the technical personnel and skilled workers and lower the overall skill level.  Before 1980, practitioners of technical personnel and skilled workers, the aging of knowledge, knowledge structure can not meet the current needs; and staff employed after 80 years, expertise, experience lack of hands-on ability, not ease, do not want to learn technology.  In recent years, the brain drain caused by personnel not only decrease the quantity and quality levels, and personnel structure of the emergence of new faults, lean, make mold design, manufacturing difficult to raise the technical level.

2016年6月8日星期三

Standard model method

Standard model method 
 According to the drawing wedm in advance in processing a standard model or the qualified stamping parts, to adjust the assembly put it in
between convex, concave die, upper and lower die relative motion can be reasonable degree when appropriate.
 Measurement method
  Measuring method of the measuring tool have feeler. Precision stamping parts A feeler method after the adjustment convex, concave die clearance good uniformity, it is the commonly used method. Assembly, the punch in the concave die in the hole, convex, concave die according to the size of the clearance choose different specifications of the feeler insert convex, concave die  clearance, inspection concave die around the blade gap everywhere, and according to the measured results adjustment. If the adjustment of the punch fixed board knock until adjust good so far. 
 Adjustment method of repair match means
 Die in use after period of time, because the convex, concave die normal wear and tear. To working parts inspection, if products produce burr, convex, Precision stamping parts concave die dull and collapse the blade factors, it is because of the convex, concave die clearance for wear changed, namely bigger or not even. To make the convex, concave die restored to the original gap value out of parts can use the following method to qualified for repair match means.
Convex, concave die clearance greaten repair match means method 
 General dies in use after period of time, because normal wear will make convex, concave die gap increase gradually, thus to make the work and so on a series of problems produced burr. This kind of circumstance, can use first thickness is equal to one of the KuaiGui insert gap between the convex, concave die, if convex, concave die clearance does not too big, the grinding work part of the blade continue to use, can improve the quality of stamping. When gap value too big when, the recoverable high temperature heat of local forging the modification methods female die size make it restored to the original gap value. Workpiece cooling followed by the pressure seal the law to file to trim gap value, and with the flame hardening method to improve the blade surface hardness. 
 Convex, concave die clearance does not even repair match means method 

Dies after a period of using, clearance does not even can make blunt a local produce burr or the blade was edge chewed. In normal wear punching die, because after wearing precision guide device that reduce convex, concave die happen relatively migration, respectively in the guide pin and a guide to cover on the plating chromium layer the restored to its original size, Precision stamping partsagain through the pressure seal the law will remove file high. If it is due to the pins loosening lose positioning function and cause different convex, concave die heart, and cause convex, concave die clearance does not even. Should first will convex, concave die gap adjusting well, to match for taper pin.

 Precision stamping parts

2016年6月5日星期日

Technology Repair measures

Technology Repair measures 
 The main technological measures to adjust the gap between two kinds of the mould method:
 1. Size method 
 Processing of the punch, will the punch front-end appropriate lengthen, extended period of section size and sunken model hole processing to the same size. Assembly, Precision stamping parts make the punch into female model hole, natural form the cutting clearance, and then to the punch with fixed together with the punch mould seat on board with the pin for fixed and will last longer period of the punch front can remove form even clearance. 
2. Positioning hole method
  Process positioning hole method and the inside of the progressive die principle about. Processing, the punch in fixed board and concave die on the same position processing two positioning hole, can will locate hole and the mold cavity a cut out. Assembly, in the positioning hole insert pins to ensure that gap.
Standard model method  
According to the drawing wedm in advance in processing a standard model or the qualified stamping parts, to adjust the assembly put it in between convex,Precision stamping partsconcave die, upper and lower die relative motion can be reasonable degree when appropriate.  
 Measurement method  

Measuring method of the measuring tool have feeler. A feeler method after the adjustment convex, concave die clearance good uniformity, it is the commonly used method. Assembly, the punch in the concave die in the hole, convex, concave die according to the size of the clearance choose different specifications of the feeler insert convex, concave die clearance, Precision stamping partsinspection concave die around the blade gap everywhere, and according to the measured results adjustment. If the adjustment of the punch fixed board knock until adjust good so far.

 Precision stamping parts

2016年6月1日星期三

Convex, concave die gap between the control and adjustment of the method

Convex, concave die gap between the control and adjustment of the method
  Convex, concave die clearance control, should according to die structure, Precision stamping parts clearance size, blanking pieces of quality and practical assembly condition to selected. Convex, concave die gap between the control and adjustment method have the following kinds.
  1Pervious to light method 
 Will convex, concave die after molmerged, shone a light on the underside, observe the convex, concave die around through light and distribution to judge the size of the clearance and uniformity. If not even, to adjust to evenly between fixed again, this method is suitable for small gap plate stamping die. 
2Feeler method
  Will convex, concave die after molmerged, convex, concave die into the thickness of unilateral clearance feeler convex, concave die gaps in each direction. Precisionstamping parts  Then tighten the screw on mode. Finally put paper to stamping and will last mould seat and fixed on board with drilling, reaming positioning pin hole, and at a pin location.
 3Gaskets DiaoZhengFa
  Gasket adjustment method is simple, convenient, clearance is used widely. As shown in figure 1 shows, the mat with good contour mat iron, will gaskets wrapped in the punch to the punch into the concave mould, observe the convex, concave die clearance condition. If clearance does not even, with striking the protruding models of fixed plate method clearance adjustment, then tighten the screw on mode. Finally put paper to stamping, observation on paper cutting around burr and even rate to judge whether clearance convex, concave die even, to adjust the gap until cutting burr uniform so far. Finally the mould seat and the plate with drilling, reaming positioning pin hole, and enter the pin location. This method widely used cutting materials focusing thick large clearance and bending stamping, deep drawing mould clearance control.
  (4) Chemical method

  When the convex, concave die complex shape, the use of the above several methods more difficult to adjust the gap, the chemical method can be used to control the gap, the plating method is used. Plating method is the punch in the work surface coated with copper or zinc instead of washers. The plating thickness and unilateral gap is same, Precisionstamping parts blade people concave die hole, and check the move without block phenomenon can assembly tighten. Coating in use process will die fall off naturally, need not removed. This uniform coating, can improve the uniformity of assembling clearance.

 Precisions tamping parts