外文翻译加工基础.docx

1、外文翻译加工基础山东轻工业学院中英文翻译院系名称 学生姓名 专业班级 机械05-3班 指导教师 二九年五月十日Introduction of MachiningHave a shape as a processing method, all machining process for the production of the most commonly used and most important method. Machining process is a process generated shape, in this process, Drivers device on the wo

2、rkpiece 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 k

3、now 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 part, almost have to spend the high cost of processing. Welding to rely on the shape of the structure, to a large exte

4、nt, depend on effective in the form of raw materials. 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

5、 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 s

6、urface 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, Well Machining is a low-tolerance and can meet the requirements of small batch pro

7、duction. 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 chooses only the surface machining. For instance, thread, in addition to mechanical processing, almost no other processing method for proces

8、sing. Another example is the blacksmith pieces keyhole processing, as well as training to be conducted immediately after the mechanical completion of the processing.Primary Cutting ParametersCutting the work piece and tool based on the basic relationship between the following four elements to fully

9、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

10、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 T

11、ool to speed is cut into the work piece speed. 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 c

12、onditions, 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. Rotary cutting it to the chip or equal to the width of the linear cutting chip thickness. Rough than finishing, deeper penetration

13、of a cutting tool depth.Wears of Cutting ToolWe already have been 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

14、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

15、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 effect

16、ive; the results are made unqualified parts.As Tool stress on the surface uneven, chip and flank before sliding contact zone between stresses, in sliding contact the start of the largest and in contact with the tail of zero, so abrasive wear in the region occurred. This is because the card cutting e

17、dge than the nearby settlements near the more serious wear and bladed chip due to the vicinity of the former flank and lost contact wears 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.

18、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 cutti

19、ng speed of the increase, Mateo 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

20、 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

21、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 oft

22、en pits gradually become darker If cutting continued the case, then there cutter fracture crisis.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 go

23、od, 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 bee

24、n 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

25、force, appeared on the work piece burning ring patterns and an increase in noise.The Effect of Changes in Cutting Parameters on Cutting TemperaturesIn metal cutting operations heat is generated in the primary and secondary deformation zones and this result in a complex temperature distribution throu

26、ghout the tool, workpiece and chip. A typical set of isotherms is shown in figure where it can be seen that, as could be expected, there is a very large temperature gradient throughout the width of the chip as the workpiece material is sheared in primary deformation and there is a further large temp

27、erature in the chip adjacent to the face as the chip is sheared in secondary deformation. This leads to a maximum cutting temperature a short distance up the face from the cutting edge and a small distance into the chip.Since virtually all the work done in metal cutting is converted into heat, it co

28、uld be expected that factors which increase the power consumed per unit volume of metal removed will increase the cutting temperature. Thus an increase in the rake angle, all other parameters remaining constant, will reduce the power per unit volume of metal removed and cutting temperatures will red

29、uce. When considering increase in unreformed chip thickness and cutting speed the situation is more complies. An increase in unreformed chip thickness and cutting speed the situation is more complex. An increase in undeformed chip thickness tends to be a scale effect where the amounts of heat which

30、pass to the workpiece, the tool and chip remain in fixed proportions and the changes in cutting temperature tend to be small. Increase in cutting speed; however, reduce the amount of heat which passes into the workpiece and this increase the temperature rise of the chip in primary deformation. Furth

31、er, the secondary deformation zone tends to be smaller and this has the effect of increasing the temperatures in this zone. Other changes in cutting parameters have virtually no effect on the power consumed per unit volume of metal removed and consequently have virtually no effect on the power consu

32、med per unit volume of metal removed and consequently have virtually no effect on the cutting temperatures. Since it has been shown that even small changes in cutting temperature have a significant effect on tool wear rate, it is appropriate to indicate how cutting temperatures can be assessed from

33、cutting data.The most direct and accurate method for measuring temperatures in high-speed-steel cutting tools is that of Wright&Trent which also yields detailed information on temperature distributions in high-speed-steel tools which relates microstructural changes to thermal history.Trent has described measurements