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1、 专 业： 机械设计制造及其自动化 外文出处：Development of a Continuous Extrusion Machinefor Sheathing Cable with Lead Alloys附件1：外文资料翻译译文连续挤压机电缆护套铅合金的发展问题：早在五年前，一个探讨改善铅护套电缆的方式的工作小组已经成立。显然，这将合金的存在提供更好的抗蠕变强度和抗拉强度高，但很明显，这些都不是完全适合的连续或间歇性挤压。因此，工作组进行了两种类型的研究类型：1.为了寻找更好的合金和铅的替代材料等用途，四个项目在这个方向仍很活跃 或已顺利完成。2.要制定一个连续挤压机现有的工作能力较高的铅

2、合金。类似这样的程序已经在考虑由约翰罗伯逊公司的布鲁克林的工作的发展所产生的影响是由此可见作为临港产业区和罗伯逊的共同努力挤出机的发展连续的两个螺杆挤出机的主要类型被方便形容为卧式和立式螺旋机。后者被选定为最适合这项研究工作。它类似于一般常规水平螺杆机械。主要改变是一种改进的螺钉,螺杆的住房,增加的功率,和测温及控制设备。铅合金熔满一水壶将得到9000磅的铅。它通过水壶里以防止两折流板连接的渣滓,通过适当的螺杆挤出机管路的饲料。铅液流经水平连接管,并输入的下端螺杆腔。上方的铅合金凝固过程的入口。垂直沟槽或螺丝的槽腔内壁旋转防止固体铅管造成的它的飞行螺杆作为螺杆旋转使其塑性流动向上移动。顶上出现

3、了螺杆腔，铅流入其中一个模头流分裂流过一个心轴重返顶部两侧，形成一个连续的管。在这一点上,模头的配置的铅合金模头做一个直角转弯,流动现在可以安装在水平位置。电缆芯包围和携带铅管。电加热器和冷却水通道保持理想的温度时,沿着路线的关键控制点的铅的流动。正如所提到的,这种类型的挤出机是能够生产一个优质的鞘从白银级别的领导和一些轴承铜轴承领先。早在1951年初，有人试图在F- 3砷合金但经过短期发生滑动，拖延，这可能是由于种族隔离制度。要做一个光滑的工作和其他非常有用的合金F-3一个完整的修订的温度控制系统。不仅是一个很大的加热和冷却能力添加到那个传统的机器,但它被安排,使每一个小面积的铅流沿着路线受

4、到更多的精确控制。挤出机的温度控制从融化的水壶里有两组电热器的总供热能力90 k w的控制下,两个热电偶,其中之一是用于控制水壶输入端热量。第二,附近有控制加热的电源插座。水壶里流出的温度通过一个温度控制仪表使其局限在一个狭小的范围内,开关从三角形的加热元件的Y连接。离开水壶、铅流经一个在2-kwbayonet加热器的控制下的一个在热电偶附近的连接口端部。这条管道通至螺杆腔的底端。这是一种固有的安全设计,自从在不可靠的事件中失效的6自动温度控制和七个手动控制冷却线圈的这个观点被认可,铅液在水壶里能上升到仅有的高度，低于螺杆腔的顶端是安全的。螺杆的空间大约3英尺长，被分为三种可控制的加热区。电热

5、器的总容量为20至27kw，加热在螺旋槽周围的空间，并受三个并排安装的八热电偶控制。此外，有五种水冷却通道被加工在外壳上。水流量由转子流量计手动控制方式，根据预设的时间表进行控制。 这样详细的规定,预示着一个艰难的控制加热温度问题,事实上，是这样。首先考虑挤出机的运作，应对不同合金的不同熔点范围的冶金性能的问题，一部分由于它们的冷却和凝固率。此外,固体合金是被迫流过螺杆和螺丝腔表面,约5平方英尺，所有的力都来自螺杆。在这种情况下，50马力中很大的一部分通过摩擦转化成热量。在螺杆腔内温度的控制，是成功运作的一个至关重要的因素。现在，铅被迫流入机头本身。这里再次有两个水冷却回路，三个电热偶其中的两

6、个控制顶部和底部装配的温度。首先，流过护套内表面结构复杂的心轴。新兴的一端,它上空核心芯棒的地方,通过管道水形成冷却从而调节厚度的护套在模具的冷却块大部分是通过在两个较低的冷却水盘管浮子流量计控制。这些消除在模具块摩擦产生的热量并保持在温度约232。如果不冷却，这个模具块的温度将达到560F。模具块和芯棒十分相似，尽管它们在颠倒的位置，因为铅是从上面喂料而不是从下面。规格压力机的研制工作是在一个50马力1750转的电机前提下进行的。虽然这是可行的，但经验表明，可以有更大的发展空间，把一个75马力的电动机安装在模型上。提出了使用100马力的电机。在运行稳定的前提下，加热对两英寸电缆护套的挤出动力

7、可以达到120KW。马达安装在螺杆垂直区域内，驱动螺杆通过一个70比1的齿轮减速器。两个齿轮和推力轴承是被强制润滑和油冷却的。伸入到原型螺杆中的销钉被钻孔到可以通过35冷却水管中.由于这一研究成果，目前，商业单位都配备了六个组合，提供所有的必要冷却的灵活性。这个空间携带一个衬套和从21至42的垂直螺丝，防止销钉旋转。在里面有八个热电偶和其中三个控制三个电热器。另外，加热元件也是被这些控制的。尽管这些精心设计的控制系统是生产设备所必要的，但已被大大简化。冷却控制螺杆区域的的校准与最大流量的0.01GPM治理通过5个冷却回路的冷却水流量到0.11GPM（每分钟加仑）五转子流量计。模头和模具冷却是实

8、现了类似的冷却水通道控制。第二组的仪器是冷却控制部分，这是由七个转子流量计组成，每一个都有0.01 0.11之间美制加仑/分钟。第三组的其它各种仪器测量操作变量1.电缆速度记录仪，每分钟0至150英尺。2.电机负载指示和记录电流表。3.电机转速，转速表指示和记录。4.运行时间记录。5.电能表。6.相关的油和水压力计。附件2：外文原文（复印件）Development of a Continuous Extrusion Machine for Sheathing Cable with Lead AlloysThe ProblemAs early as 5 years ago, a task gro

9、up was formed within the LIA to look into ways of improving lead-sheathed cable. Apparently alloys existed which would provide better creep strength and high tensile strength, but it was evident that none of these was entirely suitable for continuous or intermittent extrusion. Therefore, the task gr

10、oup undertook two types of research:1. To find better alloys and alternate lead materials for such uses. Four projects in this direction are still active or already successfully completed.2. To develop a continuous extrusion machine capable of working existing higher alloys of lead. A program simila

11、r to this had been under consideration by the John Robertson Company of Brooklyn, N. Y .Work on the development was therefore undertaken as a joint effort of LIA andRobertson.Developing the ExtruderThe two principal types of continuous screw extrusion machines are conveniently described as horizonta

12、l and vertical screw machines. The latter was selected as the most promising for this research.In general it is similar to conventional horizontal screw machines. The principal changes are a modified screw and screw housing, increased power, and the temperature-measuring and control equipment.(The d

13、ie head has been rotated through 90 degrees in the schematic of Fig. 1. Actually, the cable core is fed from behind the plane of the illustration and the sheathed cable emerges toward the reader.)Lead alloy is melted in a kettle which will hold 9,000 pounds of lead. In the kettle it passes two baffl

14、e plates which prevent dross from passing through the connection pipe which feeds the extruder proper. Molten lead flows through the horizontal connection pipe and enters the lower end of the screw chamber. Just above the entrance the lead alloy solidifies.Vertical grooves or flutes in the inner wal

15、l of the screw chamber prevent the solid lead tube from rotating while the flight of the screw causes it to move upward (in plastic flow) as the screw is rotated. Emerging from the top of the screw chamber, the lead flows into a die head where the stream is split to flow past both sides of a mandrel

16、 to rejoin at the top, forming a continuous tube.At this point the configuration of the die head forces the lead alloy to make a right-angle turn, flowing now horizontally.The cable core is surrounded by the lead tube and carried along by it. Electric heaters and cooling water passages hold the desi

17、red temperatures at critical points along the route of the lead flow.As has been mentioned, this type of extrusion machine is capable of producing a good-quality sheath from silver bearing lead and some grades of copper bearing lead. As early as 1951, it was tried on F-3 arsenical alloy but after a

18、short run slippage and stalling occurred, probably owing to segregation.To do a smooth job with F-3 and the other desirable alloys a complete revision of the temperature control system was made. Not only was a great deal of heating and cooling capacity added to that of the conventional machine, but

19、it was arranged so that each small surface area along the route of lead flow was brought under more accurate control.TEMPERATURE CONTROLS OF THE EXTRUDERStarting at the melting kettle there are two groups of electric heaters with a total heating capacity of 90 k w under the control of two thermocoup

20、les, one of which is located at, and controls heat to, the input end of the kettle. The second, located near the outlet, controls heating there. The outflow temperature at the kettle is confined to a narrow range by means of a temperature control instrument which switches the heating elements from d

21、elta to Y connections.Leaving the kettle, the lead flows through a connection pipe with a 2-kwbayonet heater under control of a thermocouple near the exit end of the pipe. This pipe delivers the lead to the lower end of the vertical screw chamber. This is an inherently safe design since, in the unli

22、kely event of failure of the six automatic temperature controls and seven manually controlled cooling coils from this point on, molten lead could rise only to its level in the kettle, which is safely below the top of the screw chamber.The screw housing, about 3 feet long, is divided into three contr

23、olled heating zones. Electric heaters with a total capacity of 20 to 27 k w are carried in machined spiral grooves surrounding the housing and are controlled by three of the eight thermocouples mounted in a vertical row. In addition, there are five water-cooling channels machined into the housing wa

24、ll. The water flow is controlled manually by means of rotameters, according to a preset schedule.Such elaborate provisions for temperature control bespeak a difficult heat problem, and indeed, this is the case. Consider first that the extrusion machine must operate with a variety of alloys of varyin

25、g melting ranges whose metallurgical properties are controlled, in part, by their cooling and solidification rates.Furthermore, the solid alloy is forced to flow past the screw and screw housing wall surfaces, approximately 5 square ft (feet) in all, solely by the force exerted by the screw. Under s

26、uch conditions a large part of the applied 50-hp (horsepower) is converted to heat by friction. Control of temperature in the screw chamber is the most critical requirement for a successful operation.Now, the lead is forced to flow into the die head itself. Here again there are two water-cooling cir

27、cuits and two of the three thermocouples in the head control heaters at the top and bottom of the assembly. First, the lead flows over a complex mandrel which forms the inner surface of the sheath. Emerging from the end of the mandrel it passes over a core where the pipe is formed and then through w

28、ater cooled dies which regulates the thickness of the sheath.Most of the cooling in the die block is accomplished by the two lower water cooling coils under rotameter control. These remove the heat generated by friction in the die block and hold the temperature to about 450 F. Without this cooling t

29、he die block temperature would rise to about 560 F. The die block and mandrel are quite similar to those used in the intermittent press, although they lie in an inverted position, since lead is fed from beneath rather than from above.SPECIFICATIONSDevelopment work on the extrusion machine was carrie

30、d on with a 50-hp 1,750-rpm motor. While this was workable,experience showed the desirability of more power, and a 75-hp motor was installed on the prototype. Proposed larger units will be powered by 100-hp motors. In steady operation, the combination of heating and driving power for extrusion of sh

31、eath on 2-inch cable will average about 120 kw.The motor is mounted vertically beside the screw housing and drives the screw through a 70-to-1 gear reduction train . Both gears and thrust bearing are force-lubricated and cooled by oil.The prototypes screw housing was drilled and piped with water-coo

32、ling circuits and flexible hose connections to permit 35 cooling combinations.As a result of this research, present commercial units are equipped with six cooling combinations which provide all of the flexibility necessary. The housing carries a liner with from 21 to 42 vertical flutes to prevent ro

33、tation of the lead by the screw. There are eight thermocouple locations in the housing and three electric heaters to be controlled from three of the thermocouples. In addition, the heating elements in the base of the housing are also to be controlled by the thrustbearing area thermnocouple. Though t

34、his elaborate control system was necessary for the research, production equipment has been considerably simplified.Cooling of the screw housing is controlled by five rotameters calibrated to the nearest 0.01I gpm (gallons per minute)with a maximum flow of 0.11 gpm to govern flow of cooling water thr

35、ough the five cooling circuits within the housing wall. Die head and die cooling are achieved by similar cooling water passages and rotamneter control.The second group of instruments is the cooling control section. This is made up of seven rotameters, each with a range of 0.01 to 0.11 gpm.The third

36、group of instruments measures a variety of other operating variables:1. Cable speed recorder-0 to 150 feet per minute.2. Motor load-indicating and recording ammeter.3. Motor speed-indicating and recording tachometer.4. Running-time recorder.5. Watt-hour meter.6. Associated oil and water pressure gages.