lesson 6-1.ppt

1、Review Lesson 2,Translate the following phrases. 1 the purpose of heat treatment 2 the alteration of the structure of the metal or alloy 3 heating and controlled cooling 4 improve the alloy or metal 5 remove strains after cold working,6 remove internal stresses after drawing, bending, or welding 7 i

2、ncrease the hardness of the material 8 increase wear-resisting properties 9 normalizing, spheroidizing, stress relieving, annealing, hardening, tempering, and case hardening,Answer the questions 1 What is the purpose of the heat treatment? 2 How to improve the properties of materials? 3 What is the

3、major element in the steels used in tooling? What is added to tool steels in order that the tool steel may harden? 5 Which heat treatment of ferrous materials do you know?,Lesson 6 Press Types Press 压力机,Characteristic of the press working process工艺、工序 is the application of large forces by press tool

4、s冲模 for a short time interval间隔, which results in the cutting (shearing) or deformation成形 of the work material. （冲压加工的特点是在一个短暂的时间内用冲模施加一个很大的力以切断工件上的材料或使之变形。） A pressworking operation, generally completed by a single application of pressure, often results in the production of a finished part成品零件 in l

5、ess than one second. （在压力加工时通常只需要进行一次操作就可以完成，成品零件的生产过程通常不到一秒钟。） Pressworking forces are set up产生, guided导向, and controlled in a machine referred to as a press. （压力加工的工作压力是由压力机产生、导向和控制的。）,Power Presses. 公称压力Essentially, a press is comprised of a frame机架, a bed 床身or bolster plate工作台, and a reciprocati

6、ng往复运动 member called a ram滑枕 or slide滑块which exerts施加 force upon work material through special tools mounted on the ram and bed. 压力机由机架、机身、工作台和往复运动的滑块组成。实际上公称压力就是通过装在滑块和工和台上的模具使材料成形的力 Energy stored in the rotating flywheel of a mechanical press (or supplied by a hydraulic system in a hydraulic press

7、) is transferred to the ram for its linear movements. （储存于压力机飞轮（或由液压机的液压系统提供的）的能量被转化为滑块的直线运动。）,Press Types. An open-back inclinable (OBI) press (Figure 6-1) also called a gap-frame press, has a C-shaped frame which allows access to its working space (between the bed and the ram). （开式双柱可倾式压力机也称为开式压力机

8、，它有一个“C”型的框架可以使工件进入工作台和滑块之间加工区域）。 The frame can be inclined at an angle to the base, allowing for the disposal of处理 finished parts by gravity. （机架可以相对于水平面倾斜一个角度，以利用重力来处理成品零件。） The open back allows the feeding进料 and unloading of stock毛坯, workpieces工件, and finished parts through it from front to back.

9、 （通过开式后倾式压力机可以从前至后进行装夹或卸载坯料、工件和成品零件。）,Major components部件 of a press are as follows （压力机的主要部件如下）: 1. Press Bed. A rectangular part of the frame, generally open in its center, which supports a bolster plate. （它是在中心开有口的矩形框架,用来支撑工作台.) 2. Bolster Plate（工作台）. A flat steel plate, from 2 to 5“ (51 127mm) th

10、ick, upon which press tools and accessories附件 are mounted。 （工作台是一个钢制的平板，2至5英寸厚，上面装着冲模和其他附件。） Bolsters having standard dimensions and openings are available可用的from press manufacturers。 压力机的生产厂家提供标准尺寸和孔径的工作台,3. Ram or Slide. The upper press member that moves through a stroke行程 a distance depending upo

11、n the size and design of the press. （滑块是上部的压力部件，它在一个行程中移动的距离是由压力机的设计尺寸来决定。） The position of the ram, but not its stroke, can be adjusted调整. （滑块的位置可以调整，而行程无法调整。） The distance from the top of the bed(or bolster )to the bottom of the slide, with its stroke down and adjustment up, is the shut height 闭合高

12、度of a press. （从工作台的上表面到滑块的下表面之间的距离可以上下调节，称之为压力机的闭合高度。） 4. Knockout打料杆. A mechanism operating on the upstroke of a press, which ejects顶出 workpieces or blanks冲裁件 from a press tool. （它是压力机向上行程中的一个机构，可将工件或冲裁件从冲模中顶出。）,5. Cushion气垫. A press accessory附件 located beneath下面 or within a bolster for producing a

13、n upward motion and force; it is actuated驱动 by air, oil, rubber, or springs or a combination of mechanisms。 （它是一个装在工作台下或内部的压力机附件，它用以产生一个向上的运动和力；它由气体、油、橡胶、弹簧或一个合成的机构进行驱动。） A straight side press闭式压力机 of conventional传统的 design has columns 柱子(up rights ) at the ends of the bed, usually with windows (squ

14、are or rectangular openings) to allow the feeding and unloading of stock, workpieces, and finished parts. （传统设计的闭式压力机在工作台的末端有一些支柱（向上的），通常会有方形或矩形的窗口以便于原料、工件和成品零件的加载和卸载。）,With special applications, this type of press also can be used for feeding from front to back . （利用特殊的装置，这种压力机也可以从前至后的进料。） A press

15、brake压弯机 is essentially the same as a gap-frame press开式压力机 except for its long bed from 6 to 20 feet (1.86m) or more. （压弯机本质上是和开式压力机是一样的，不同的是其拥有长达6至20英尺甚至更长的工作台。） It is used basically for various bending operations on large sheet metal parts. （它通常用于大型的金属板材零件的折弯操作。）,It can also be used with a series

16、of separate 分离sets of press tools to do light piercing冲孔, notching切边, and forming成形. （通过压力模具实现一系列冲孔、切边、成形等分离操作） This allows parts of a complex design to be accurately made without a high-cost press tool by simply breaking the complex part down into several simple operations. （将复杂零件的加工分解成几种简单的操作，这使得设

17、计复杂的零件不采用高价冲模就能进行精确制造。） This type of operation is used on low-run or prototype parts.（这种生产方法常用于生产低速（短期）产品或样件。）,The tooling cost is usually very low, but the labor cost is high as the parts are manually transferred and located in each station. （在这个过程中，机械加工的费用很低，但是由于在每一个工序都需要人工搬运和定位，故人工费用很高。） The oper

18、ator must follow good safety practices at all times to avoid injury. （操作者自始至终必须遵守良好的安全规范，避免受伤。） A hydraulic press is used basically for forming operations and a slower operating cycle time than most mechanical presses. （液压机通常用来进行成型加工，它的工作周期比机械压力机长。）,The advantages of hydraulic presses are that the w

19、orking pressure, stroke, and speed of the ram are adjustable (Figure). （液压机的优点是它的工作压力、行程、冲头的速度是可调的。） A double-action press is used for large, or deep drawing operations on sheet metal parts. （双动压力机用于金属板材大型操作或拉深操作。） This type of press has an outer ram (blank holder) and a second inner ram (punch hold

20、er). （这种压力机有一个外冲头（凹模固定板）（凹模）和一个内冲头（凸模固定板）（凸模）。）,During the operating cycle, the blank holder contacts the material first and applies pressure to allow the punch holder to properly draw the part. （在加工过程中，凹模固定板（凹模）先与材料接触并且加力使凸模固定板（凸模）在这个部位进行完全拉伸。） A triple-action press has the same inner and outer ram

21、 as the double-action press, but a third ram in the press bed moves up allowing a reverse draw to be made in one press cycle. （三动压力机同双动压力机一样有外冲头和内冲头，它还有第三个冲头，它可以向上运动，并在一个冲压循环中进行一次反向拉伸。）The triple-action press is not widely used.（三动压力机的用途不是很广。） A knuckle press is used for coining operations. （肘杆式压力机用

22、于模压加工。）,The design of the drive allows for very high pressures at the bottom of the ram stroke. （其设计可以使在冲头行程的末端有很高的压力。） This type uses a crank, which moves a joint consisting of two levers that oscillate to and from dead center and results in a short, powerful movement of the slide with slow travel near the bottom of the stroke. （这种压力机利用曲柄，在其运动关节部有两个杠杆围绕死点来回振荡，这样就在行程的末端形成了短暂、有力的缓慢滑动。） These are