机械外文翻译文献翻译数控加工工艺.doc

英文原文CNC Machining Process First, our country's history of the development of numerical control system 1. Our country since 1958, by a group of research institutes, colleges and universities and a few started to CNC Machine Tool Plant of the research and development system. At that time, due to the low level of domestic electronic components, such as the department of economic constraints, lack of a larger development. 2. In the reform and opening up, China's numerical control technology gradually achieve substantial development. After "65" (81 - 85 years) the introduction of foreign technology, "75" (86 - 90 years) of the digestion and absorption and the "Eighth Five-Year Plan" (91 1 -95 years) National Organization of scientific and technological, that makes our country's CNC technology has a qualitative leap in acceptance at that time, through research and identification of country products including Beijing Everest's Chinese I, central China's central NC I and a few high-end Shenyang National Engineering Research Center for Control of Blue-I, as well as other through the "National Quality Supervision and Test Center machine" test NC system of qualified domestic companies such as Nanjing, four products. 3. China's CNC machine tool manufacturing industry in the 80's had the stage of rapid development, many machine tool plant products from traditional products to the NC transition. But, generally speaking, the technological level is not high, the quality of the poor, so in the early 90's facing the country's economy from a planned economy to a market economy and adjust the transfer went through the most difficult years of the Depression period, the production capacity at that time down to 50 %, more than four month inventory. From 1995, "Ninth Five-Year Plan" to expand domestic demand from the country after the machine tool market to start, so as to reinforce the approval of imports of CNC equipment, investment focused on support for key numerical control system, equipment, technologies of CNC equipment has played a significant role, especially in 1999, the country's defense industry to civilian industry and the key to putting in a lot of technical department funds, to enable CNC equipment manufacturer market thriving. Three, CNC Technology and Equipment of cars cut CNC Lathe Machining Lathe technology and processing technology similar to, but because of CNC lathe is a fixture, for automatic processing of all finish turning process, which should pay attention to the following aspects.1. A reasonable selection cutting for the high-efficiency metal-cutting processing, the processed materials, cutting tools, cutting conditions is the three major elements. These determine the processing time, tool life and processing quality. Cost-effective processing methods must be a reasonable choice of the cutting conditions. Three elements of cutting conditions: cutting speed, feed rate and cutting depth of the damage directly caused by the tool. With the increase in cutting speed, tool tip temperature will rise; will have mechanical, chemical, thermal wear and tear. 20% increase in cutting speed; tool life will reduce the 1 / 2. Feed conditions and the relationship between tool wear and tear at the back of a very small area of. However, the feed rate, cutting temperature rise, wear big behind. Than the impact of cutting speed on tool small. Depth of cut on the tools did not affect the cutting speed and feed rate, but at small cutting depth of cut when cutting materials have been hardened layer, which will affect the tool life. The user is processed according to the material, hardness, cutting status, material type, feed rate, cutting depth, such as the option of using the cutting speed. The most appropriate selections of processing conditions are at the basis of these factors is selected. Have rules, stability, worn and tear is to achieve the ideal conditions for life. However, in actual operation, the selection tool life and tool wear, the size of changes in processing, surface quality, cutting noise, heat processing and so on. In determining the processing conditions required to study the actual situation. The heat-resistant alloys such as stainless steel and hard materials, the coolant can be used best to use rigid blade. 2. Reasonable selection tool 1) when rough, it is necessary to choose high strength, good durability tool, in order to meet the rough knife when eating large back volume, the feed requirements. 2) Fine car, it is necessary to choose high precision, durability good tool to ensure that the requirements of machining accuracy. 3) In order to reduce tool change time and convenience of the knife should be used machines and machine folder knife blade. 3. A reasonable selection Fixture 1) General selection try the work piece clamping fixture to avoid the use of a dedicated fixture; 2) positioning the base parts overlap so as to reduce the positioning error. 4. To determine the processing route processing route is the index-controlled machining process, tool parts relative trajectory and direction of Sports. 1) Should be able to ensure the machining accuracy and surface roughness requirements; 2) should try to shorten the processing route, reducing travel time and air knives. 5. Processing route of contact with allowance At present, CNC lathes have not yet achieved the universal access to conditions, the general should be put on too much rough margin, especially with forging, casting hard cushion cortex in general lathe processing. Must be such as CNC lathe, the need to pay attention to process flexibility. 6. Fixture to install the main points at present, the hydraulic clamping chuck and hydraulic cylinder are connected by the rod of the implementation, in Figure 1. Hydraulic clamping chuck as follows: First of all, by moving on hand to unload the nut hydraulic cylinder, the discharge of SLIDE, and back-end from the spindle out, and then move the hands to unload screw chuck can be disposed of under the chuck. Four, effectively turning a reasonable Save processing time Index Turning Center's G200 integrated processing unit with a modular, high-power two-axis linkage axis function, thus further shortening the processing time. With other means of job-axis opposite to the concept of clamping, the use of the product can be integrated intelligent processing unit in place so that the work piece clamping and automatic processing. In other words, the automatic setup will not be affected by the processing of another axis, a feature that can be shortened about 10% of the processing time. In addition, the Four processing very quickly, you can simultaneously have two processing tool. When the machine is put into use in pairs, the efficiency becomes more apparent. In other words, the conventional hard turning and setting two cars can parallel machine. Turning conventional vehicles and hardware differences between the tool and focused only in the coolant system thermostat. However, conventional processing is different: both can be used conventional processing and a tool carrier for processing Tailstock; and hardware when using a tool only. In both types of machine tools can be carried out on the hard dry processing, only the manufacturer's technology program designed to balance the need to beat time, and Index of the module structure of machine tools to provide them with greater flexibility. To improve the productivity of high-precision with the continuous improvement of production efficiency, the user also made for a very high accuracy requirements. Turning Center G200 used for processing, the cold start up to four parts processing required to achieve tolerances of ± 6mm. Processing process, the accuracy is usually maintained at 2mm. Index so made available to the company's clients are high-precision, high efficiency, the integrity of the program, and programs to provide such high precision, requiring careful choice of spindle, bearings and other features. G200 Turning Center Landshut, Germany, BMW car factory in the application of the company achieved good results. The plant is not only the production of engines, but also by the production of cast light metal parts, plastic decorative items inside the vehicle and steering axis. Consider the quality of supervisory staff, and its very precise machining accuracy: tolerance bands for ± 15mm, for bearing tolerance ± 6.5mm. In addition, the processing of the universal joints of the Index companies use automatic intelligent processing unit. The first two parts are used for turning centers before playing pre-processing, post-processing line measurement, and then sent through the conveyor belt for hobbling, cleaning and quenching treatment. The last process using the second processing system Index. G200 Turning Center by two steering knuckle on the car bearing hard. In the machine tool to complete the online survey, then to the discharge unit. Processing unit fully integrated into the layout of the workshop, and in line with ergonomic requirements, covers an area of greatly reduced, and only two staff members to the custody of manufacturing cells. Friday, CNC turning and G00 in the magical effect of the skills to ensure dimensional accuracy CNC turning processing technology has been widely used in mechanical manufacturing industry, how efficient, reasonable, and completed by the quality of the work piece by the amount of processing, each engaged in the trade of engineering and technical personnel more or less have their own experience. I engaged in CNC teaching, training and processing for many years, accumulated a certain amount of experience and skills, is to CNC Equipment Factory Guangzhou GSK980T series of machine tool production, for example, introduce a few skills in CNC turning. First, the program first sentence skills G00 We now have access to textbooks and CNC turning technical books, procedures are set up the first sentence of work piece coordinate system, that is, G50 X Z in the first sentence as a process. According to the directive, a coordinate system can be set so that the tool at a point in this coordinate system as coordinates (X Z) (In this paper, the origin of work piece coordinate system are set at the right end of the work piece surface). Programming using this method, the knife, the knife must be moved to the established position of G50 can be set for processing, identify the location of the process is as follows. 1. of a knife, the rough work piece clamping good; 2. Spindle is to hand round the base right side knife flat work piece surface A; 3. Z-axis fixed, the release of the tool along the X axis points to C, type G50 Z0, the point of computer memory; 4. Program entry mode, type G01 W-8 F50, turning out to be one step work piece; 5. X-axis fixed, the release of the tool along the Z-axis points to C, stop turning out measuring the diameter of the work piece level , the importation of G50 X, computer memory that point; 6. Program entry mode, enter the G00 X Z, programming tool runs the specified procedure to the starting point, and then enter the G50 X Z, procedures for the origin of the computer memory. The above-mentioned steps, the steps that the tool 6 at XZ Office location is essential; otherwise, the work piece coordinate system will be modified, not the normal processing of the work piece. Processing has been the experience of the people all know that the above position will be the tool to the cumbersome process of XZ Department, in the event of an accident, X or Z-axis without servo, tracking error, power outages happen, etc., the system can restart, after restart system loss of G50 work piece coordinate values set by the memory, "reset back to zero run" is no longer working, will need to re-run the tool and reset to XZ location G50. If it is production, processing, after the End of a return to the starting point for continued processing under the G50 is, in the process some errors on the work piece coordinate system may be modified. In view of the first sentence of the above procedures using G50 work piece coordinate system set up many defects, I will want to approach the work piece coordinate system fixed on the machine will process the first sentence changed to G50 XZ after G00 X Z, problem solved. The course of its operation only to find G50 using the above-mentioned five-step process before, that is, 1,2,3,4,5 steps to achieve, it will run the tool to a safe location, out of process, and can run automatically. Even if power outages and other unforeseen circumstances occur, restart the system, in the Edit mode to move the cursor without affecting the safe processing of the work piece processing process program segment, according to automate the processing can continue. First sentence of the above procedure to replace G50 with G00 is the substance of the work piece coordinate system fixed on the machine, no longer limited to the origin G50 X Z process constraints, without changing the work piece coordinate system, easy operation, reliability, and received an unexpected effect. Chinese metal processing online Second, control of dimensional accuracy skills 1. To amend the value of a knife up to ensure dimensional accuracy First on the knife because of error or other causes beyond the work piece work piece error tolerance, can not meet the processing requirements, can be added by modifying the knife so that the work piece size to meet the requirement to ensure that the radial dimensions are as follows: a. absolute coordinate input method According to the "big decrease, a small increase" principle, a knife up at 001 004 modified. Such as cut off on the 2nd slot at a big size work piece 0.1mm, and 002 showed up knives are X3.8, may enter the X3.7, to reduce the knife on the 2nd meeting. b. the relative coordinate method as in the previous case, enter 002 knife fill U-0.1, also the same result. Similarly, the axial size of the control also and so on. Such as cylindrical with a knife on the 1st axis somewhere above processing, size, long 0.1mm, can be completed at 001 knife enter W0.1. 2. Semi-finishing to ensure that the impact of the elimination of screw gap dimensional accuracy For the majority of CNC lathe using a longer time, because of the effects of screw space and processing of the work piece dimensions are often unstable situation. At this time, we can rough after finishing a half-space to eliminate the effects of screw. 1, such as a knife with G71 cylindrical rough, you can fill in the 001 knife enter U0.3, call the G70 a fine car, parking measurements, and then fill in the 001 knife enter U-0.3, once again calling a G70 Finish . Finish a half after this time, eliminating the effects of screw clearance to ensure the stability of the dimensional accuracy. 3. To ensure dimensional accuracy Programmer a. to ensure dimensional accuracy absolute programming there is an absolute a