机械工程专业英语课件--L1.ppt

1、课件,1,English for Mechanical Engineering,机械工程专业英语,常州工学院机电工程学院 徐红丽,课件,2,机械工程专业英语,预备知识,一、预备知识,Lesson 23 Fundamentals of Machine Tools,机床的主要部件： 床身：是基础件，一般为铸件，有较高的抗压强度，吸振 导轨和溜板箱：保证机床部件的直线运动，其精度极高，一般为内凹，为了储油。 主轴和轴承：回转精度要求较高，径向跳动、轴向窜动和角度摆动 变速机构：实现刀具相对工件的正确切削用量。机械、液压、气动、电动 动力装置：电动机,课件,3,词 汇,二、词汇,机械工程专业英语,ma

2、chine tool 机床 bed 床身 slideway 导轨 spindle 主轴 tailstock 尾座 dovetail 燕尾槽 gib 镶条 guard 防罩 roughing 粗加工 finishing 精加工 surface finish 表面光洁度,Lesson 23 Fundamentals of Machine Tools,课件,4,机械工程专业英语,In many cases products from the primary forming processes must undergo further refinements in size and surface f

3、inish to meet their design specifications. To meet such precise tolerances the removal of small amounts of material is needed. Usually machine tools are used for such operation.,课文分析,Lesson 23 Fundamentals of Machine Tools,三、课文分析,课件,5,机械工程专业英语,In many cases products from the primary forming processe

4、s must undergo further refinements in size and surface finish to meet their design specifications.,课文分析,许多情况下，经初步成形加工出来的工件必须在尺寸和表面光洁度方面进一步精加工整，以满足它们的设计要求。,rifainmntn. 精提炼, 精制; 净化; 精美 清扫除, 洗 高尚, 优雅 精致,精细, 精确,Lesson 23 Fundamentals of Machine Tools,课件,6,机械工程专业英语,To meet such precise tolerances the rem

5、oval of small amounts of material is needed. Usually machine tools are used for such operation.,课文分析,为了满足精密的公差要求，需要从工件上去掉小量材料。通常机床就是用于实现这种加工的设备。,prisais adj. 精确的, 明确的; 清晰的,恰好的; 正当,严格的; 拘泥的, 陈规的,Lesson 23 Fundamentals of Machine Tools,课件,7,机械工程专业英语,In the United States material removal is a big busin

6、essin excess of $ 36109per year, including material, labor, overhead, and machine-tool shipments, is spent. Since 60 percent of the mechanical and industrial engineering and technology graduates have something connection with the machining industry either through sale, design, or operation of machin

7、e shops, or working in related industry, it is wise for an engineering student to devote some time in his curriculum to studying material removal and machine tools.,课文分析,Lesson 23 Fundamentals of Machine Tools,课件,8,机械工程专业英语,In the United States material removal is a big businessin excess of $ 36109p

8、er year, including material, labor, overhead, and machine-tool shipments, is spent.,课文分析,在美国，材料切削业是一个很大的行业-费用每年超过36109 美元，包括材料，劳动力，杂项开支，机床运输费等所花的费用。,uvhed n. 经常开支, 普通费用 天花板; 船舱的顶板,Lesson 23 Fundamentals of Machine Tools,课件,9,机械工程专业英语,Since 60 percent of the mechanical and industrial engineering and

9、technology graduates have something connection with the machining industry either through sale, design, or operation of machine shops, or working in related industry, it is wise for an engineering student to devote some time in his curriculum to studying material removal and machine tools.,课文分析,由于60

10、机械和工业技术工程专业的毕业生做销售、设计、管理机械工厂、或在相关领域工作，总要和加工工业打交道，因此，对于工程专业学生来说，在他的学习计划中安排一段时间去学习研究材料切削和机床，是非常明智的。,grdjuit n. 毕业生,得学位者,Lesson 23 Fundamentals of Machine Tools,课件,10,机械工程专业英语,A machine tool provides the means for cutting tools to shape a workpiece to required dimensions;,课文分析,Lesson 23 Fundamentals of

11、 Machine Tools,the machine supports the tool and the workpiece in a controlled relationship through the functioning of its basic members, which are as follows:,机床通过使用切削刀具使工件成形以达到所要求的尺寸。,机床通过其基础构件的作用，支承相互联系的刀具和工件，现将基本部件列举如下：,课件,11,机械工程专业英语,(a) Bed, Structure or frame. This is the main member which pr

12、ovides a basis for, and a connection between, the spindles and slides; the distortion and vibration under load must be kept to a minimum.,课文分析,Lesson 23 Fundamentals of Machine Tools,这是一个主要部件，该部件为主轴、拖板箱等提供一个基础支撑和中间连接，在负载作用下，它必须能使变形和振动保持最小。,课件,12,机械工程专业英语,Slides and Slideways. The translation of a ma

13、chine element (e.g. the slide) is normally achieved by straight-line motion under the constraint of accurate guiding surfaces (the slideway).,课文分析,Lesson 23 Fundamentals of Machine Tools,拖板箱和导轨。机床部件（如拖板箱）的移动，通常是在精密的导轨面约束下靠直线运动来实现。,课件,13,机械工程专业英语,(c) Spindles and Bearings. Angular displacements take

14、place about an axis of rotation; the position of this axis must be constant within extremely fine limits in machine tools, and is ensured by the provision of precision spindles and bearings.,课文分析,Lesson 23 Fundamentals of Machine Tools,主轴和轴承。角位移是绕一根旋转轴线产生的，在机床中该轴线的位置必须在极其精确的范围内保持不变，是靠高精度的主轴及其轴承来保证。,

15、课件,14,机械工程专业英语,(d) Power Unit. The electric motor is the universally adopted power unit for machine tools. By suitably positioning individual motors, belt and gear transmissions are reduced to a minimum.,课文分析,Lesson 23 Fundamentals of Machine Tools,动力装置。电动机是机床中普遍采用的动力装置。通过对各个电机的合适定位，使皮带和齿轮传动装置减少到最小。

16、,课件,15,机械工程专业英语,(e) Transmission Linkage. Linkage is the general term used to denote the mechanical, hydraulic, pneumatic or electric mechanisms which connect angular and linear displacements in defined relationship.,课文分析,Lesson 23 Fundamentals of Machine Tools,变速机构。变速机构是个通用术语，用来代表机械、液压、气动或电动变速机构的，变

17、速机构保证角位移和线性位移的确定传动比。,课件,16,机械工程专业英语,There are two broad divisions of machining operations:,课文分析,Lesson 23 Fundamentals of Machine Tools,机械加工有两个主要的组成部分：,(a) Roughing, for which the metal removal rate, and consequently the cutting force, is high, but the required dimensional accuracy relatively low.,粗

18、加工。在粗加工中，金属切除率高，因而往往切削力也大，但所要求的尺寸精度较低。,课件,17,机械工程专业英语,(b) Finishing, for which the metal removal rate, and consequently the cutting force, is low, but the required dimensional accuracy relatively high.,课文分析,Lesson 23 Fundamentals of Machine Tools,精加工。精加工时，金属切除率低，因而相应的切削力也小，但所要求的尺寸精度和表面光洁度较高。,课件,18,机

19、械工程专业英语,It follows that static loads and dynamic loads, such as result from an unbalanced grinding wheel, are more significant in finishing operations than in roughing operations. The degree of precision achieved in any machining process will usually be influenced by the magnitude of the deflections

20、, which occur as a result of the force acting.,课文分析,Lesson 23 Fundamentals of Machine Tools,课件,19,机械工程专业英语,It follows that static loads and dynamic loads, such as result from an unbalanced grinding wheel, are more significant in finishing operations than in roughing operations.,课文分析,Lesson 23 Fundam

21、entals of Machine Tools,由此可见，静载荷和由不平衡的砂轮引起的动载荷，在精加工中比粗加工中有着更为重要的影响。,课件,20,机械工程专业英语,The degree of precision achieved in any machining process will usually be influenced by the magnitude of the deflections, which occur as a result of the force acting.,课文分析,Lesson 23 Fundamentals of Machine Tools,任何机械加

22、工过程所获得的精度等级通常将受到由于力的作用产生的变形量的影响。,课件,21,机械工程专业英语,Machine tool frames are generally made in cast iron, although some may be steel casting or mild-steel fabrications. Cast iron is chosen because of its cheapness, rigidity, compressive strength and capacity for damping the vibrations set-up in machine o

23、perations. To avoid massive sections in castings, carefully designed systems of ribbing are used to offer the maximum resistance to bending and tensional stresses. Two basic types of ribbing are box and diagonal. The box formation is convenient to produce, apertures in walls permitting the positioni

24、ng and extraction of cores. Diagonal ribbing provides greater tensional stiffness and yet permits swarf to fall between the sections; it is frequently used for lathe beds.,课文分析,Lesson 23 Fundamentals of Machine Tools,课件,22,机械工程专业英语,Machine tool frames are generally made in cast iron, although some m

25、ay be steel casting or mild-steel fabrications.,课文分析,Lesson 23 Fundamentals of Machine Tools,Cast iron is chosen because of its cheapness, rigidity, compressive strength and capacity for damping the vibrations set-up in machine operations.,机床床身一般是用铸铁制造的，然而有些也可能是用铸钢或中碳钢制造的。,选用铸铁是因为它价格便宜，刚性好，抗压强度高，并且有

26、减弱机床运行中振动的能力。,课件,23,机械工程专业英语,To avoid massive sections in castings, carefully designed systems of ribbing are used to offer the maximum resistance to bending and tensional stresses.,课文分析,Lesson 23 Fundamentals of Machine Tools,Two basic types of ribbing are box and diagonal.,为了避免床身铸件截面过大，精心地设计加强筋以便提

27、供最大的抗弯和抗扭应力的能力。,加强筋两种基本类型是：箱型结构和片状斜支撑式。,dainl n.对角线,斜线,课件,24,机械工程专业英语,The box formation is convenient to produce, apertures in walls permitting the positioning and extraction of cores.,课文分析,Lesson 23 Fundamentals of Machine Tools,Diagonal ribbing provides greater tensional stiffness and yet permits

28、swarf to fall between the sections; it is frequently used for lathe beds.,箱型结构便于生产，箱壁上有孔口便于型芯的定位和取出。,ptjun. 孔, 隙缝; 孔径,片状斜支撑筋条有较大的抗扭刚度，亦便于排屑。它常常用于车床床身。,sw:f n. 细铁屑 切屑,课件,25,机械工程专业英语,The slides and slideways of a machine tool locate and guide members which move relative to each other, usually changing

29、 the position of the tool relative to the workpiece. The movement generally takes the form of translation in a straight line, but is sometimes angular rotation, e.g. tilting the wheel-head of a universal thread-grinding machine to an angle corresponding with the helix angle of the workpiece thread.

30、The basic geometric elements of slides are flat, vee, dovetail and cylinder. These elements may be used separately or combined in various ways according to the applications. Features of slideways are as follows:,课文分析,Lesson 23 Fundamentals of Machine Tools,课件,26,机械工程专业英语,The slides and slideways of

31、a machine tool locate and guide members which move relative to each other, usually changing the position of the tool relative to the workpiece.,课文分析,Lesson 23 Fundamentals of Machine Tools,机床的拖板箱和导轨是支撑和引导彼此相对运动的零部件，通常是改变刀具和工件的相对位置。,课件,27,机械工程专业英语,The movement generally takes the form of translation

32、in a straight line, but is sometimes angular rotation, e.g. tilting the wheel-head of a universal thread-grinding machine to an angle corresponding with the helix angle of the workpiece thread.,课文分析,Lesson 23 Fundamentals of Machine Tools,相对运动一般以直线移动的方式，但有时也有相对转动，例如对应于工件的螺纹上的螺旋角方向而使万能螺纹磨床上的砂轮头转动一个角度

33、。,课件,28,机械工程专业英语,The basic geometric elements of slides are flat, vee, dovetail and cylinder.,课文分析,Lesson 23 Fundamentals of Machine Tools,These elements may be used separately or combined in various ways according to the applications. Features of slideways are as follows:,导轨的基本的几何结构形状有平导轨、v型导轨、燕尾导轨

34、和圆柱形导轨。,这些导轨可根据应用场合，单独的或以各种方法组合使用。导轨的特性如下：,课件,29,机械工程专业英语,(a) Accuracy of Movement. Where a slide is to be displaced in a straight line, this line must lie in two mutually perpendicular planes and there must be no slide rotation.,课文分析,Lesson 23 Fundamentals of Machine Tools,运动精确。由于拖板箱是要作直线移动的，这条直线必定

35、是由两个相互垂直的平面形成而且拖板必定不存在转动。,课件,30,机械工程专业英语,The general tolerance for straightness of machine tool slideways is 00.02mm per 1000mm; on horizontal surfaces this tolerance may be disposed so that a convex surface results, thus countering the effect of “sag” of the slideways.,课文分析,Lesson 23 Fundamentals o

36、f Machine Tools,机床导轨的直线度公差一般为每米00.02毫米，在垂直方向上这个公差可以进行处理成凸形表面，这样就抵消导轨下沉的作用,课件,31,机械工程专业英语,(b) Means of Adjustment. To facilitate assembly, maintain accuracy and eliminate “play” between sliding members after wear has taken place, a strip is sometimes inserted in the slides.,课文分析,Lesson 23 Fundamental

37、s of Machine Tools,(b)调整方法。为了便于装配、保证精度和消除磨损后相对移动构件之间出现的“窜动”，有时在拖板内装入一个扁条。,课件,32,机械工程专业英语,This is called a gib-strip. Usually, the gib is retained by socked-head screws passing through elongated slots; and is adjusted by grub-screws secured by lock nuts.,课文分析,Lesson 23 Fundamentals of Machine Tools,这

38、种扁条被叫做“镶条”。通常该镶条用穿过长孔的沉头螺钉顶住，而用平头螺钉调整好后，用锁紧螺母上紧,课件,33,机械工程专业英语,(c) Lubrication. Slideways may be lubricated by either of the following systems:,课文分析,Lesson 23 Fundamentals of Machine Tools,(c)润滑导轨可用以下两种装置进行润滑：,1) Intermittently through grease or oil nipples, a method suitable where movements are inf

39、requent and speed low.,间歇润滑，通过润滑脂嘴或油嘴进行。这是一种适于运动速度低而不频繁运动场合的润滑方法,课件,34,机械工程专业英语,2) Continuously, e.g. by pumping through a metering valve and pipe-work to the point of application; the film of oil introduced between surfaces by these means must be extremely thin to avoid the slide “floating”.,课文分析,L

40、esson 23 Fundamentals of Machine Tools,连续润滑，例如通过油阀和油道将润滑油泵送到润滑点。用这种方法引入两表面间的油膜必定是很薄的，目的是避免使拖板“浮起”。,课件,35,机械工程专业英语,If sliding surfaces were optically flat oil would be squeezed out, resulting in the surfaces sticking.,课文分析,Lesson 23 Fundamentals of Machine Tools,如果相对滑移表面似镜面般平滑，油就会被挤出而导致表面粘贴。,Hence in practice slide surfaces are either ground using the edge of a cup wheel, or scraped.,因而在实践中，拖板滑移表面是用凹面砂轮的刃进行磨削或进行刮研的。,课件,36,机械工程专业英语,Both pr