单元5 - 图文

Goals of the Course

? 扩展学生在本专业方面的英语词汇量 ? 熟悉本领域的专业术语

? 了解科技英语的表达特点及掌握专业英语翻译技巧 ? 能阅读本专业的外文资料，并具备一定的写作能力 幻灯片3 ? Note:

? without any acute angle.

? Screw should be operated smoothly; ? Anneal area as showed;

? Screw and nut should be do finish in black; ? The hole and key trough should be lined on; Do not do finish on the polish surfaces.

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? 大学英语CET 4,6级过关后就具备科技英文阅读能力吗？

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? 大学英语CET 4,6级过关后就具备科技英文阅读能力吗？

make, manufacture, fabricate, build produce, create, process, engineer

制造 幻灯片7

机械工程专业英语的特点

? 专业英语词汇特点：专业术语多，合成新词多，前后缀出现频率高，缩略词经常出现，非限定动词（尤其是分词）使用频繁，词义单一。

? 专业英语语法特点：常用形式主语和形式宾语、名词结构和被动语态使用频繁，复杂长句多，复合句多，每句包含的信息量大。 ? 专业英语的修辞特点：时态运用有限，修辞手法简单，逻辑语法使用普遍。 幻灯片8

机械工程专业英语的特点 ? 单词特点

? (1) 专业性词汇较多，且词形复杂，记忆难度大。 ? chrome-moly steel — 铬钼钢 ? antifriction bearing— 滚动轴承 ? epicyclic gear— 行星齿轮

? (2)有些单词虽词形与基础英语相同，但词义相差很大 ? pig-iron — 生铁

? bearing — 轴承 （方向，生育，忍耐） ? bolt — 螺栓（闪电，闩）

? (3)专业合成词较多，且与各原单词的含义有一定的不同 ? slide-crank mechanism —曲柄滑块机构 ? detail drawing — 零件图 four-bar linkage —四连杆机构 幻灯片9

机械工程专业英语的特点 ? 2. 语法特点

? (1)由于机械电子工程英语主要论及一些客观存在的事物，很少论及人，因此被动语态用的特别多，比比皆是。例如：

? A mechanism has been defined as “a combination of rigid or resistant bodies so formed and connected that they move upon each other with definite relative motion.”

机构被定义为：“是由刚体或者有承载能力的物体联接而形成的组合体，它们在运动时彼此之间应该有确定的相对运动” 幻灯片10

机械工程专业英语的特点 2. 语法特点

(2)机电专业英语由于要表述较复杂的概念，因此句子结构具有句子长、定语从句多、名词化结构多，非限定性谓语结构、倒装、省略、分隔结构随处可见，常出现句子套句子的情况，给阅读理解上带来了极大的困难。比如：

It is much better for design engineers to do a complete job of material analysis, selection, and specification at the development stage of design rather than to leave it to the production-design stage, where changes may be made by others, possibly less knowledgeable about all of the function aspects of the product. 幻灯片11

机械工程专业英语的特点

? It is much better for design engineers to do a complete job of material analysis, selection, and specification at the development stage of design rather than to leave it to the production-design stage, where changes may be made by others, possibly less knowledgeable

about all of the function aspects of the product. 译文：设计工程师最好能在这一阶段全部完成材料的分析、选择和确定工作，而不是将其留到生产设计阶段，因为在生产设计阶段材料的更换是由其他人员进行的，这些人对产品的所有功能的了解可能不如设计工程师。 幻灯片12

Ordinary English and Scientific English

? We made a hole in a cork and pushed it into a narrow glass tube. Then we pushed this into the neck of a bottle which we had filled with colored water. When we did this, some of the colored water went up into the tube. We marked the level of the colored water in the tube. Then we put the bottle into a pan of hot water.

? After a hole was made in a cork, a narrow glass tube was inserted and the cork was inserted into the neck of a bottle filled with colored water. On doing this, some of the colored water rose the tube. The level of the colored water in the tube was marked. Then the bottle was placed into a pan of hot water.

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Ordinary English 通俗化：常用词汇用得多 Scientific English 专业化：专业术语用得多 多义性：一词多义，使用范围广 单义性：词义相对单一，因专业而不同 人称化：人称丰富，形式多样 多时性：描述生活，时态多样 主动性：句子倾向于用主动态 简单性：单句、散句用的多 物称化：多用物称，以示客观 现时性：叙述事实多用现在时 被动性：句子倾向于用被动 复杂性：复杂单句用得多，复合句用得多 口语化：口语用得多，随意灵活 书面化：长句用得多，书卷气浓

5.1 Introduction

Conventional machining is the group of machining operations that use single- or multi-point tools to remove material in the form of chips. Metal cutting involves removing metal through machining operations. Machining traditionally takes place on lathes, drill presses, and milling machines with the use of various cutting tools. Most machining has very low set-up cost compared with forming, molding,

and casting processes. However, machining is much more expensive for high volumes. Machining is necessary where tight tolerances on dimensions and finishes are required. 幻灯片5 5.1 译文

传统机械加工是一组利用单刃或者多刃刀具以切屑形式去除材料的加工方式。金属切削意味着通过机械加工去除金属。传统的机械加工都是利用不同的刀具在车床、钻床和铣床上进行的。与成型加工、锻压和铸造工艺相比，大多数机械加工的生产准备成本都较低，然而如果是大批量生产，其成本要高得多。当对零件的尺寸公差和光洁度要求较高时，机械加工是很有必要的。 幻灯片6

5.2 Turning and Lathe

Turning is one of the most common of metal cutting operations. In turning, a workpiece is rotated about its axis as single-point cutting tools are fed into it, shearing away excess material and creating the desired cylindrical surface. Turning can occur on both external and internal surfaces to produce an axially-symmetrical contoured part. Parts ranging from pocket watch components to large diameter marine propeller shafts can be turned on a lathe.

Apart from turning, several other operations can also be

performed on lathe. 幻灯片7 marine propeller 幻灯片8

Words & expressions axially ['?ksi?li] adv.轴向地 symmetrical [si'metrik?l] a. 对称的 cylindrical [si'lindrikl] a.圆柱形的

contoured ['k?ntu?d] a.显示轮廓的，与某种形体轮廓相吻合的 译文:

在金属切削加工操作中，车削是最常见的一种。在车削过程中，工件绕其轴线回转，单刃车刀沿工件进给，切除掉多余的材料，最后形成要求的圆柱形表面。车削可以加工外面和内表面以形成具有轴对称的成形工件。从怀表的零件到大直径的船用螺旋桨轴都可以在车床上加工。

除了车削，还有另外几种加工操作都可以在车床上进行。 幻灯片9

5.2 Turning and Lathe

Boring and internal turning. Boring and internal turning are performed on the internal surfaces by a boring bar or suitable internal cutting tools. If the initial workpiece is solid, a drilling operation must be performed first. The drilling tool is held in the tailstock, and the

latter is then fed against the workpiece. When boring is done in a lathe, the work usually is held in a chuck or on a face plate. Holes may be bored straight, tapered, or to irregular contours. Boring is essentially internal turning while feeding the tool parallel to the rotation axis of the workpiece. 幻灯片10

5.2 Turning and Lathe

Words & expressions

tailstock ['teilst?k] n. 尾座 chuck [t??k] n.卡盘，夹头 译文:

利用镗杆或合适的内圆车刀可以进行镗削和车内圆。如果工件毛坯是实心的，首先要钻孔。钻头安装在尾架上，后者向工件进给。如果在车床上进行镗削加工，工件通常装夹在卡盘或者花盘上。镗出的孔可以是直孔、锥孔或者不规则轮廓。当将刀具沿工件的回转轴线平行进给时，镗削实际上就是车内圆。 幻灯片11 face plate chuck 幻灯片12

5.2 Turning and Lathe

Facing. Facing is the producing of a flat surface as the result of a tool?s being fed across the end of the rotating workpiece. Unless the work is held on a mandrel, if both ends of the work are to be faced, it must be turned around after the first end is completed and then the facing operation repeated. The cutting speed should be determined from the largest diameter of the surface to be faced.

Facing may be done either from the outside inward or from the center outward. In either case, the point of the tool must be set exactly at the height of center of rotation. 幻灯片13

5.2 Turning and Lathe

Because the cutting force tends to push the tool away from the work, it is usually desirable to clamp the carriage to the lathe bed during each facing cut to prevent it from moving slightly and thus producing a surface that is not flat. In the facing of casting or other materials that have a hard surface, the depth of the first cut should be sufficient to penetrate the hard material to avoid excessive tool wear. Words & expressions

mandrel ['m?ndr?l] n.车床心轴 clamp [kl?mp] v. 夹紧，夹住 carriage [?k?rid?] n.大刀架，拖板 penetrate ['penitreit] v. 穿透，渗透

tool wear 刀具磨损 幻灯片14

5.2 Turning and Lathe

译文:

车端面可以加工出一个平面，它是当车刀沿回转工件的端面横向进给的结果。除非工件固定在心轴上，如果工件两端都要车端面，必须将一端加工完成后，将工件调头，重复进行车端面加工。车削速度必须由所加工表面的最大直径来决定。车端面可以由外向内也可以由中心向外进行。无论哪种情况，刀尖必须准确地与回转中心对正。由于切削力有将车刀推离工件的趋势，通常最可行的就是在车端面时将拖板卡紧在床身上以避免车刀轻微移动造成加工表面不平整。在对具有硬质表面的铸件或其他材料进行车端面加工时，首次切深要足以穿透硬质材料从而避免过度的刀具磨损。 幻灯片15

5.2 Turning and Lathe

Parting. Parting is the operation by which one section of a workpiece is severed from the remainder by means of cutoff tool. Because cutting tools are quite thin and must have considerable overhang, this process is less accurate and more difficult. The tool should be set exactly at the height of axis of rotation, be kept sharp, have proper clearance angles, and be fed into the workpiece at a proper and uniform feed rate. Words & expressions

remainder [ri'meind?]剩余物 ，余数

overhang ['?uv?'h??] vt.悬于...之上 n.伸出;突出 uniform ['ju:nif?:m] a.相同的,一致的 n.制服;军服 clearance angles 后角 幻灯片16

5.2 Turning and Lathe

译文:

切断是一种利用切断刀（割刀）将工件的一部分与其剩余部分脱离的加工方法。由于切断刀非常薄而且处于悬臂状态，因此这种加工方法不太精确而且加工起来常常比较困难。切断刀必须准确地对正回转轴，保持锋利，具有合适的后角，以合适、不变的进给率沿工件进给。 幻灯片17

5.2 Turning and Lathe

Threading. Threading can be considered as turning since the path to be travelled by the cutting tool is helical. However, there are some major differences between turning and threading. While in turning, the interest is in generating a smooth cylindrical surface, in threading the interest is in cutting a helical thread of a given form and depth which can be calculated from the formulae. helical [?helik?l] a.螺旋状的 译文:

车螺纹可以看作是车削，只是车刀所形成的加工轨迹是螺旋线。但二者也存在一些不同之处。车削主要考虑能否生成光滑的圆柱形表面，而车螺纹注重的是能否切出具有按公式计算出来的规定形状和深度的螺旋线。 幻灯片18

5.2 Turning and Lathe

? There are two basic requirements for thread cutting.

? An accurately shaped and properly mounted tool is needed because thread cutting is a form-cutting operation. The resulting thread profile is determined by the shape of the tool and its position relative to the workpiece.

The second by requirement is that the tool must move longitudinally in a specific relationship to the rotation of workpiece, because this determines the lead of the thread. This requirement is met through the use of the lead screw and the split unit, which provide positive motion of carriage relative to the rotation of spindle. form-cutting operation 成形加工

longitudinally [l?:?d?i'tju:din?li] adv.纵向 lead screw 丝杠 split unit 开合机构 幻灯片19

5.2 Turning and Lathe

译文:

车螺纹有两个基本要求：首先，由于车螺纹是一种成形加工，因此车刀必须具有准确的形状而且要安装合适。所切出的螺纹外形是由车刀形状和它与工件的相对位置决定的。其次，车刀的纵向进给与工件的回转运动具有特定的关系，因此这决定了螺纹的导程。这个条件可以通过采用丝杠和开合机构得到满足，它们可以实现拖板相对于主轴回转运动的精确可靠的运动。 幻灯片20

5.2 Turning and Lathe

Lathe. Many types of lathes are used for production turning. According to purposes and construction, lathe-type machine tools can be classified as follow:

1. Engine lathes 普通车床 2. Vertical lathes 立式车床 3. Turret lathes 转塔车床

4. Single-or multiple-spindle automatic or semi-automatic lathes 5. Contouring lathes 仿形车床 6. Universal lathes 万能车床

7. Special-purpose lathes such as crankshaft lathes, camshaft lathes, car wheel lathes and backing-off lathes, etc. 幻灯片21

Figure 5.1 The engine lathe

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5.2 Turning and Lathe

Lathe bed is foundation of the engine lathe, which is heavy, rugged casting made to support the working parts of the lathe. The size and mass of the bed gives the rigidity necessary for accurate engineering tolerances required in manufacturing. On top of the bed are machined slideways that guide and align the carriage and tailstock, as they are move from one end of the lathe to the other. ? rugged adj. 健壮，坚固 ? mass n. 质量 ? slideways n.导轨

床身是普通车床的基础，它是由沉重而坚固的铸件制作而成的，其目的是为了支撑车床的工作部件。床身的尺寸和质量要使车床具有足够的刚性以保证制造过程中获得所需的工程公差。床身上的导轨可以引导和对准拖板和尾座，使它们可以从车床的一端移动到另一端。 幻灯片24

5.2 Turning and Lathe

? Headstock is clamped atop the bed at left-hand end of the lathe and contains the motor that drives the spindle whose axis is parallel to the guideways through a series of gears housed within the gearbox.

The function of gearbox is to generate a number of different spindle speeds.

? atop adv. 在(…)顶上 ? gearbox 齿轮箱

床头箱（主轴箱）紧固在床身上面的左端，内装有电机，它通过变速箱内的一组齿轮来驱动主轴转动，主轴的轴线平行于导轨。变速箱的功能是可以产生不同的主轴转速。 幻灯片25

5.2 Turning and Lathe

? A spindle gear is mounted on the rear of the spindle to transmit power through the change gears to the feeding box that distributes the power to the lead screw for threading or to the feed rod for turning.

? on the rear of 在…的尾部 ? change gears 挂轮 ? lead screw 丝杠 ? feed rod 光杠

主轴齿轮安装在主轴的尾部，通过挂轮把动力传递到进给箱，如果是车螺纹，进给箱将动力分配到丝杠上；如果是车削，就将动力分配到光杠上。

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5.2 Turning and Lathe

? The spindle has a through hole extending lengthwise through which bar stocks can be fed if continuous production is used. The hole can hold a plain lathe center by its tapered inner surface and mount a chuck, a face plate or collet by its threaded outer surface. ? taper n.坡度，锥形 v.锥度加工 ? collet n.夹头

主轴有一个纵向通孔，如果连续加工棒料，通孔就用来实现棒料的送料。这个通孔具有一个内锥面，可以安装普通车床的中心顶尖。主轴的外表面车有螺纹，可以安装卡盘，花盘或夹头。 幻灯片27 幻灯片28

5.2 Turning and Lathe

Carriage assembly is actually an H-shaped block that sits across the guideways and in front of lathe bed. The function of the carriage is to carry and move the cutting tool longitudinally. It can be moved by hand or by power and can be clamped into position with a locking nut. The carriage is composed of the cross slide, compound rest, tool saddle, and apron.

拖板组件实际上是一个H形的铸件，位于床身的前端并横跨在导轨

上。拖板的功能带动刀具纵向移动，这个可以通过手动或者自动完成。利用锁紧螺母可以将其卡紧在所需位置。拖板组件由横拖板，小刀架，刀架鞍板和溜板箱组成。 幻灯片29

5.2 Turning and Lathe

Carriage assembly 拖板组件 cross slide 横拖板 compound rest 小刀架 tool saddle 刀架鞍板 apron 溜板箱

幻灯片30 小拖板 纵向移动 刀架 装夹车刀 中拖板 横向移动 床鞍 纵向移动 溜板箱

变换箱外手柄位置，在光杠或丝杠的传动下，可使车刀按要求方向作进给运动

幻灯片31 幻灯片32

5.2 Turning and Lathe

? The cross slide is mounted on the dovetail guideways on the top of the saddle and it moved back and forth at 90°to the axis of the lathe by the cross slide lead screw. The lead screw can be hand or power activated. ? dovetail 燕尾槽

横拖板安装在刀架鞍板上部的燕尾槽导轨上。它利用横拖板丝杠于车床轴线成90度夹角的方向上前后移动。丝杠可以手动或者自动驱动。 幻灯片33

5.2 Turning and Lathe

? The compound rest is mounted on the cross slide and can be swiveled and clamped at any angle in a horizontal plane. The compound is typically used for cutting chamfers or tapers, but must also be used when cutting thread. The compound rest can only be fed by hand. There is no power to compound rest. The cutting tool and tool holder are secured in the tool post which is mounted directly to the compound rest. ? swivel ['sw?v?l] v.旋转

小刀架安装在横拖板上，它可以在水平面内转动或夹紧在任意角度位置。小刀架主要用来倒角和加工锥面，在车削螺纹时也必须用到小刀架。小刀架只能手动进给，没有动力传到小刀架上。刀具和刀夹被卡紧在直接安装在小刀架上的刀座上。 幻灯片34

5.2 Turning and Lathe

The tool saddle is an H shaped casting mounted on the top of the guideways and houses the cross slide and compound rest. It makes possible longitudinal, cross and angular feeding of the tool bit. ? 刀架鞍板是一个安装在导轨上部的H形铸件，容纳有横拖板和小刀架。它可以实现刀尖的纵向、横向和斜向进给。

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5.2 Turning and Lathe

The apron is attached to the front of the carriage and contains the gears and feed clutches which transmit motion from the feed rod or lead screw to carriage and cross slide. When cutting screw threads, power is provided to the gearbox of the apron by the lead screw. In all other turning operations, it is the feed rod that drives the carriage. ? 溜板箱位于拖板的前端，里面装有齿轮和将运动从光杠或丝杠传递至拖板或横向拖板的进给离合器。当切制螺纹时，动力通过丝杠传递到溜板箱中的变速齿轮箱。在其它车削加工时，依靠光杠

来驱动拖板。

幻灯片36

5.2 Turning and Lathe

? Tailstock is composed of a low base and the movable part of the tail-stock proper, the transverse adjustments being made with a cross screw furnished with a square head. The two parts are hold together by the holding-down bolts which secure the tailstock to the bed.

? transverse adj. 横向的，横切的； n. 横轴 ? holding-down bolts 压紧螺栓

? 尾座由底座和尾座体的可移动部件组成。课移动部件的横向调整有带有四方头的横向丝杠来完成。底座和可移动部分通过压紧螺栓连接在一起并将尾座固定在床身上。

幻灯片37

5.2 Turning and Lathe

? The tailstock is located on the opposite end of the lathe from the headstock. It supports one end of the work when machining between centers, supports long pieces held in the chuck, and holds various forms of cutting tools, such as drills, reamers, and taps.

? reamer n.铰刀 ? tap n.丝锥；v.攻丝

? 尾座位于机床上和主轴箱相反的另一端。当采用两端顶尖加工时，尾座支撑工件的一端，以支撑在卡盘中的长形零件。另外尾座还可以夹持各种刀具，如钻头、铰刀和丝锥等。

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5.3 Milling and Milling Machine

幻灯片39 Definition Milling is the process of cutting away material by feeding a workpiece past a rotating multiple tooth cutter. Type of Milling Operation ? Peripheral Milling ? Face Milling ? End Milling Classification of Milling Machine ? vertical milling machine ? horizontal milling machine Function of the Basic Components ? Column ? Knee ? Saddle ? Worktable ? Head ? Overarm

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5.3 Milling and Milling Machine

铣削方式 幻灯片41

5.3 Milling and Milling Machine

? Peripheral Milling

? The milled face is generated by teeth located on periphery of the cutter body. The axis of cutter rotation is generally in a plane parallel to the workpiece surface to be machined (shown in Fig.5.2a). ? Face Milling

? The cutter is mounted on a spindle have an axis of rotation perpendicular to the workpiece surface. ? End Milling

peripheral [p??rif?r?l] a.圆周的；外面的；次要的

perpendicular [,p?:p?n'd?kj?l?] a.垂直的 n.垂直线，垂直度 幻灯片42

? THE BASIC COMPONENTS: ? 立柱 ? 升降台 ? 床鞍 ? 工作台 ? 主轴头

横梁

幻灯片43

5.3 Milling and Milling Machine

? Column

? An oil reservoir and pump in the column keep the spindle lubricated. The column rests on a base that contains a coolant reservoir and a pump that can be used when performing any machining operation that required a coolant. ? reservoir n.油箱，容器 ； ? lubricate vt. 使滑润 ? coolant n.冷却剂，冷却液 rest on 被支撑在；依赖,依据

立柱中的油箱和油泵对主轴起润滑作用。立柱安装在底座上面，底座有一个冷却油箱和油泵，当加工过程中需要用冷却液时使用。 幻灯片44

5.3 Milling and Milling Machine

? Knee

? The feed change gearing is enclosed within the knee.

? The lever can be raised or lowered either by hand or power feed. ? gearing n.传动机构 lever n.杠杆;控制杆

? 升降台里有可以改变进给量的齿轮传动机构。 ? 操作杆向上或向下以实现手动或自动进给。

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5.3 Milling and Milling Machine

? Saddle supports the table and can move transversely, which slides on a horizontal dovetail, parallel to the axis of the spindle, on the knee. The swivel table (on universal machines only) is attached to the saddle and can be swiveled approximately 45°in either direction. ? transversely 横向 ? dovetail 燕尾槽

床鞍在升降台上，支撑着工作台，可以在平行于主轴轴线的水平燕尾槽中横向滑动。回转工作台（只有在万能铣床上）安装在床鞍上，可以沿任意方向回转大约45度 幻灯片46

5.3 Milling and Milling Machine

? Power feed mechanism is contained in the knee and controls the longitudinal, transverse (in and out) and vertical feeds.

? On some universal knee and column milling machines the feed is obtained by turning the speed selection handle until the desired rate of feed is indicated on the feed dial. ? dial [?dai?l] n.刻度盘、标度盘

? 动力进给机构位于升降台内部，控制纵向、横向及垂直进给。 ? 在有些升降台立式万能铣床中，通过旋转转速选择手柄直到所需的进给速率与进给刻度盘上的标记对齐，就可以获得所需的进给量。

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5.3 Milling and Milling Machine

? The worktable can be moved longitudinally with respect to the saddle by hand or by power.

? Place the end of the directional feed control lever to the left to feed the table to the left.

? 工作台可以相对于床鞍手动或自动纵向移动。 ? 将方向进给手柄搬到左边，工作台就向左边进给。

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5.3 Milling and Milling Machine

? Head contains the spindle and cutter holder. In vertical machines the head may be fixed or vertically adjustable.

? The front of the spindle, which is near the table, has an internal taper machined on it. The internal taper (3 ? inches per foot) permits mounting tapered-shank cutter holders and cutter arbor. Two keys, located on the face of the spindle, provide a positive drive for the cutter holder, or arbor.

? 主轴头包含哟主轴和刀夹。在立式铣床中，主轴头要么是固定的要么是垂直可调的。

? 主轴接近工作台的前端加工有一个内锥孔。内锥孔可以固定锥形刀具夹头和铣刀杆。位于主轴端面上的两个键给刀夹或刀杆提供强制驱动。

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5.3 Milling and Milling Machine

? Overarm is the horizontal beam to which the arbor support is fastened. The overarm may be single casting that slides in the dovetail guideways on the top of the column. It may consist of one or two cylindrical bars that slide through the hole in the column.

? 横梁是一个水平的梁，用以固定刀杆支架。横梁有可能是一个铸件，它可以沿着立柱上部的燕尾槽导轨滑动。它可能由一根或两根圆柱构成，穿过立柱上的孔进行滑动。

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5.3 Milling and Milling Machine

? On some machines to position the overarm, first unclamp the locknuts and then extend the overarm by turning a crank. On others, the overarm is moved by merely pushing on it. The overarm should only be extended far enough to so position the arbor support as to make the setup as rigid as possible. To place the arbor supports on an overarm, extend one of the bars approximately 1-inch farther than the other bar.

? 在一些铣床上对横梁进行定位时，首先是松开自锁螺母，然后转动曲柄将横梁伸出。在另一些铣床上，只需利用推力就可以移动横梁。横梁应该尽可能伸长以使刀杆支架的安装具有足够的刚度。为了将刀杆支架固定在横梁上，需要将一个圆柱杆比另一个圆柱杆伸长约1英寸左右。

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5.4 Drilling and Drill Press

? Definition of drill ? Hole-making operations ? Drilling ? Reaming ? Tapping ? Counterboring ? Countersinking ? Spotfacing ? Boring ? Types of drill press ? Sensitive bench type ? Upright type ? Radial type ? Special purpose type

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5.4 Drilling and Drill Press

? Definition of drill

? Drill can be defined as a rotary end cutting tool having one or more cutting lips, and having one or more helical or straight flutes for passage of chips and the admission of a cutting fluid. ? Lip n. 嘴唇，边缘，凸缘

? Flute n.长笛，横笛，凹槽

? 钻头可以定义为具有一个或者多个切削刃的回转刀具，它的一个或多个螺旋排屑槽或直排屑槽起到作为切屑排除通道和容纳切削液的作用。

幻灯片53 幻灯片54

Drilling; Reaming; Tapping; Counterboring; Countersinking; Spotfacing; Boring

钻孔、铰孔、攻丝、平底锪孔、锥底锪孔、锪孔口平面、镗孔 幻灯片55

5.4 Drilling and Drill Press

? Drilling

? Drilling involves selecting the proper twist drill or cutter for the job, properly installing the drill into the machine spindle, setting the speed and feed, drilling a smaller pilot hole, and drilling the hole to specifications within the prescribed tolerance. Drilled holes are always slightly oversized, or slightly larger than the diameter of the drill?s original designation.

WHY?

? 钻削时针对不同的工件要选择合适的钻头，将钻头正确的安装在主轴上，设定好速度和进给量，先加工一个小的导向孔，然后加工出满足公差要求的孔。钻削加工出来的孔通常都略大一些，或者说是比原始指定的钻头直径稍大一些。

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5.4 Drilling and Drill Press

? Reaming

? It is difficult, if not impossible, to drill a hole to an exact standard diameter. When great accuracy is required, the holes are fist drilled slightly undersized and then reamed to size.

When you must drill and ream a hole, it is best if the setup is not changed.

? 把孔钻削到准确的标准直径，即使并非不可能，那也是非常困难的。当精度要求很高时， 可以先钻一个小孔，然后通过铰削将孔加工到规定尺寸。

? 当你必须先钻孔再铰孔时，工件最好是一次装卡。

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5.4 Drilling and Drill Press

Tapping is cutting a thread in a drilled hole. 幻灯片58

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5.4 Drilling and Drill Press

? Counterboring

? Counterboring is the process of using a counterbore to enlarge the upper of a hole to a predetermined depth. Countebored holes are primarily used to recess socket head cap screws and similar bolt heads slightly below the surface. ? socket head cap screws 内六角螺钉 bolt heads 螺栓头

? 平底锪钻就是利用平底扩孔钻将孔德上端扩至预定深度。平底锪孔主要用于安放圆柱头内六角螺钉或类似的螺栓头，使其略低于孔平面。

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5.4 Drilling and Drill Press

? Countersinking

Countersinking is an operation in which a cone-shaped enlargement is cut at the top of a hole to form a recess below the surface. A conical cutting tool is used to produce this chamfer. When countersinking, the cutter must be properly aligned with the existing hole. Countersinking is useful in removing burrs from edges of the holes, as well as

accommodating the countersunk screw head. ? cone-shaped adj.锥形的 ? conical adj.圆锥形的 ? chamfer n.斜面、倒角、凹槽 ? burr n.毛刺

? countersunk n.沉头孔、埋头孔

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5.4 Drilling and Drill Press

? Countersinking

? Countersinking is an operation in which a cone-shaped enlargement is cut at the top of a hole to form a recess below the surface. A conical cutting tool is used to produce this chamfer. When countersinking, the cutter must be properly aligned with the existing hole. Countersinking is useful in removing burrs from edges of the holes, as well as accommodating the countersunk screw head.

锥底锪孔就是在孔的顶部扩一个略低于顶面的锥形凹坑。要加工出这个沉头孔需要锥形锪钻（锥形切削刀具） 。锪孔时，锪钻必须与底孔很好的对中。锥形锪孔主要用于去除孔边的毛刺和安放沉头螺钉。

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5.4 Drilling and Drill Press

? Spotfacing

? Spotfacing is the smoothing off and squaring of a rough or curved surface around a hole to permit level seating of washers, nuts, or bolt heads.

When rough surface, castings, and curved surfaces are not at the right angles to the cutting tool, great strain may occur on the pilot hole and counterbore, which can lead to broken tools.

? 锪孔口平面主要是将孔口周围崎岖不平的粗糙表面进行平整加工，用以平整的安放垫圈、螺帽或螺栓头。

? 当加工的是粗糙表面，铸件表面或是曲面时，锪钻与这些表面不能垂直，这样会使导向孔与锪钻之间产生很大的应变，可导致刀具破损。

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5.4 Drilling and Drill Press

? Boring

? Boring is conducted when a straight and smooth hole is needed occasionally which is too large or odd sized for drills or reams. ? To bore accurately, the setup must be rigid, machine must be sturdy, and power feed must be used. ? odd sized 非标准系列尺寸的 sturdy ['st?:di] adj. 结实的，牢固的

? 有时所加工的光滑直孔的直径太大或者不是标准系列尺寸，无法匹配钻头或铰刀时，就需要进行镗孔加工。

? 为了使镗孔加工精度高，装夹必须刚性好，机床必须牢固，而且必须采用自动进给。

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5.4 Drilling and Drill Press

? Types of drill press ? Sensitive bench type ? Upright type ? Radial type ? Special purpose type

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5.4 Drilling and Drill Press

Construction Features of Sensitive Drilling Machine Base Column Chuck

Head

Quill assembly

Table Head Quill Assembly Chuck Column Table Base 幻灯片67

Construction Features of Sensitive Drilling Machine Base It is heavy gray iron or ductile iron casting with slots to support and hold work that is too large for the table. Column The outer surface is machined to function as a precision way of aligning the spindle with table. Chuck Chuck is used to clamp and fix the drill through a cone surface locking mechanism. Table Most worktables have slots and holes for mounting vises and other workholding accessories. Head Speeds on a stepped V pulley drive are changed by changing the position of the V-belt. Speeds on a variable-speed drive mechanism are changed by a hand wheel on the head. Quill Assembly The quill moves vertically by means of a rack and pinion. Located on the lower end of the spindle is either a Morse taped hole or a threaded stub where the drill chuck is mounted. 解决各种难切削材料的加工问题

工业现 代化对 机械制 造业提 出的新 要求 解决各种复杂表面的加工问题

解决各种超精、光整或具有特殊要求的零件的加工问题 解决各种特殊材料、特殊零件的加工问题

上述工艺问题依靠传统切削已无法加工，特种加工在这种环境和条件下即应运而生。 幻灯片4

Unit6 Nontraditional Machining Processes What is main difference between traditional machining and Nontraditional Machining Processes? 幻灯片5

Unit6 Nontraditional Machining Processes ? 6.1 Introduction

……Non-traditional machining processes are defined as a group of processes that remove excess material by various techniques involving mechanical,

thermal,

electrical

or

chemical

energy

or

combinations of these energies but do not a sharp cutting tool as it is used in traditional manufacturing processes. thermal ['θ?:m?l] adj. 热的、热量的

特种加工是指这样一组加工工艺，它们通过各种涉及机械能、热能、电能、化学能或者以上能量的组合形式的技术而不使用传统加工所需的锐利刀具来去除工件的多余材料。 幻灯片6

Unit6 Nontraditional Machining Processes

? 6.1 Introduction

……Traditional machining also results in tool wear and loss of quality in the product owing to induced residual stresses during machining. owing to 由于

residual stresses 残余应力

由于在加工过程中会产生残余应力，传统加工会造成刀具磨损以及损坏产品质量。 幻灯片7

Unit6 Nontraditional Machining Processes ? 6.2 Electrical Discharge Machining (EDM) ? 知识背景（ Background ）：

电火花加工是在特定介质中，通过工具电极和工件电极之间脉冲放电时的电腐蚀作用，对工件进行加工的一种方法，可以加工各种高熔点、高硬度、高强度、高纯度、高韧性材料，广泛用于模具制造中。

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Unit6 Nontraditional Machining Processes ? 6.2 Electrical Discharge Machining (EDM)

Electrical discharge machining sometimes is colloquially referred to as spark machining, spark eroding, burning, die sinking or wire erosion. colloquially [k?'l?ukwi?li] adj.口语的，会话的 幻灯片9

Unit6 Nontraditional Machining Processes ? 6.2 Electrical Discharge Machining (EDM)

? The main attraction of EDM over traditional machining processes

such as metal cutting using different tool and grinding is that this technique utilizes thermoelectric process to erode undesired materials from the workpiece by a series of rapidly recurring discrete electrical sparks between workpiece and electrode. ? thermoelectric [?θ?:m?ui?lektrik] adj. 热电的 ? recurring adj. 循环的

? discrete adj.分离的，不相关联的 ? electrode n.电极

幻灯片10

Unit6 Nontraditional Machining Processes

? The main attraction of EDM over traditional machining processes such as metal cutting using different tool and grinding is that this technique utilizes thermoelectric process to erode undesired materials from the workpiece by a series of rapidly recurring discrete electrical sparks between workpiece and electrode.

相比利用不同刀具进行金属切削和磨削的常规加工而言，电火花加工的吸引人之处在于它利用工件和电极之间一系列重复产生的（脉冲）离散电火花所产生的热电作用从工件表面通过电腐蚀去除掉多余的材料。 幻灯片11

? 拓展词汇

? Mechanical properties 机械性能 ? 弹性 elasticity [?l?st?s?ti:] ? 塑性 plasticity [pl?'st?s?t?] ? 刚度 rigidity ? 强度 strength ? 硬度 hardness

? 冲击韧性 impact toughness ? 疲劳强度 fatigue strength 断裂韧性 fracture toughness 幻灯片12

Unit6 Nontraditional Machining Processes ? 6.2 Electrical Discharge Machining (EDM)

EDM removes material by discharging an electrical current, normally stored in capacitor bank, across a small gap between the tool (cathode) and the workpiece (anode) typically in the order of 50 volts/10apms. 电火花加工是利用存储在电容器组中的电能（一般在50伏/10安量级）在工具电极（阴极）和工件电极（阳极）之间的微小间隙进行放电来去除材料的加工方法。 幻灯片13

Unit6 Nontraditional Machining Processes ? 6.2 Electrical Discharge Machining (EDM)

? This cause conducting particles suspended in dielectric to concentrate at the points of strongest electrical field.

When the potential difference between the electrode and the workpiece is sufficiently high, the dielectric breaks down and a transient spark discharges through the dielectric fluid, removing small amount of material from the workpiece surface.

? 这就会使悬浮在电介质的导电粒子聚集在电场最强处。 ? 当工具电极和工件电极之间的电势差足够高时，电介质被击穿从而在电介质流体中会产生瞬时电火花，将少量材料从工件表面蚀除掉。

幻灯片14

Unit6 Nontraditional Machining Processes ? 6.2 Electrical Discharge Machining (EDM)

? The volume of the material removed per spark discharge is typically in the range of 10-5 to 10-6 mm3. The gap is only a few thousandths of an inch, which is maintained at a constant value by the servomechanism that actuates and controls the tool feed. ? thousandth ['θauz?ntθ] n. 千分之一 actuates vt. 驱使,激励

每次电火花蚀除的材料量通常都在10-5～10-6 mm3范围内。电极之间的间隙只有千分之几英寸，通过伺服机构驱动和控制工具

电极的进给使该值保持常量。 幻灯片15 Scientific notation

? 103 :ten to the power of three.

? 7.39×106 :seven point three nine times ten to the power of six. ? 82600=8.26×10×10×10×10=8.26×104

? This is an equation, which reads eighty-two thousand, six hundred equals eight point two six times ten, times ten, times ten, times ten equals eight point two six times ten to the power of four. ? 3×10-5: three times ten to the power of minus five.

? ―+‖plus ― – ‖ minus

幻灯片16

3245671

1—工件 2—脉冲电源 3—自动进给调节系统 4—工具 5—工作液 6—过滤器7—工作液泵

电离→放电→热膨胀（爆炸）→抛处金属（形成凹坑）→消电离

幻灯片17

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（视频演示）

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高速小孔加工工艺

? 管状电极回转并沿轴向 ? 进给，1～5MPa高压工作液 ? （去离子水、乳化液等）排 ? 屑,加工速度达60mm/min左

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