General transformation of multi-axis drilling
machine drilling machin
At present, China's small and medium enterprises in product quality and production efficiency are the need for a new increase. But the processing means is far from sufficient. Many small and medium enterprises with their actual technical state of equipment improvements, through strengthening its own. In order to self-development.Common drilling for single-axis machine tools, but the installation will become a multi-axis multi-axle box of the drill, transformation into a multi-axis drilling, we could greatly shorten the processing time, improve production efficiency.
Application of multi-axis machining :According to statistics, in general machine tools in the workshop in general, the average cutting time rarely exceeds 15% of total working hours. The remaining time is plug-in, loading and unloading the workpiece, exchange tools, operation tools, measurements, and clear the iron filings and so forth. Although the use of CNC machine tools can improve 85%, but the purchase of costly. In some cases, even if the high productivity, but the processing of the same components, the cost is not necessarily lower than the average machine. Therefore must be more to shorten the processing time. Different processing methods have different characteristics, the drilling process, the multi-axis machining is a small investment to increase productivity through effective measures.
The advantages of multi-axis machining :Although it is not the first in automatic multi-axis adjustable long line applications, but only limited to high-volume production. Even with the adjustable multi-axis head expanded the scope of use is still far from being able to meet the volume is small, hole complex requirements. In particular, as industrial development, large and complex multi-axis machining is even more compelling. For example, large-scale nuclear power plants in the water-wall tube plate condenser has 15000 ψ20 holes, if radial drilling machine processing, and simply drilling holes and countersink countersunk head is necessary to 842.5 hours, while also crossed hours 151.1 hours. However, if the 8-axis CNC machining floor drilling, drilling countersink holes as long as 171.6 hours, crossed is also simple, as long as 1.9 hours. Therefore, the use of numerical control of two axis, so that proper alignment tool processing location, combined with multi-axis machining can not only expand the range of processing, but also on the basis of improving the accuracy can greatly enhance the work efficiency, easy to quickly create original processing parts. Some analysis of large high-speed diesel engine with 30 kinds of box-shaped rod-shaped parts of the more than 2,000 drilling operations, 40% could be the automatic replacement of machines using two-axis spindle box, three-axis or four-axis multi-axis machining head, the average can be reduced 20% of the processing time. Machine Tool Exhibition in Paris in 1975 also reflected the multi-axis machining using more and more the trend.
Multi-axis machining equipment :Multi-axis machining is the same time in a feed processing a number of holes or simultaneously in many of the same or different processing of a workpiece on each hole. This will not only shorten the cutting time and improve accuracy, reduce fixturing or positioning time, and in the CNC machine tool is not necessary to calculate the coordinates, reducing the number of character blocks and simplified programming. It can be processed using the following equipment: radial drilling vertical drilling, or upload multi-axis head, multi-axis drilling machine, multi-axis modular machine tool spindle box heart and automatic replacement of machines. May even be able to automatically adjust wheelbase by two or more of the spindle axle box, junction
All CNC vertical and horizontal table two directions of movement, processing a variety of round or oval-shaped hole group of one or several steps. Now the status quo in this regard to make a profile.
Multi-Axis Head :Transmission is from the main drive gear drive with two kinds of universal joint couplings. This is our familiar. Former is more efficient, simple structure, which is easy to adjust wheelbase. From the structure is concerned there is not adjustable and the adjustable two kinds. The former can not change the wheelbase, multi-use gear drive, only applies to high-volume production. Adaptability in order to expand its approval to develop a multi-axis adjustable head, in a certain range adjustable wheelbase. It is mainly mounted in a universal. Two. (1) there are two kinds of universal axis: alignment device with a spindle. Spindle mounted on adjustable bracket in an adjustable bracket can be T-shaped slot in the shell move, and the position in alignment with bolted. (2) with a tolerance of cylindrical spindle units. Set of fixed spindle hole with pieces of the same type template. The former applies to small batch and the rules of distribution of pore groups are artifacts (such as the hole groups in different diameter circle). The latter applies to a larger batch-type production of small quantities of turns, rigid better pitch accuracy is also high, but a different hole requires a different template.
Multi-axis head can be mounted on vertical drilling-type radial drilling machine, press the drill itself with the various functions work. This multi-axis processing methods, due to drilling efficiency, range and accuracy of processing of the relationship between the use of limited scope.
Multi-axle box :As also the first multi-axis as the production as a standard component. U.S. Secto's standard gear boxes, multi-axle box, etc. are not designed adjustable multi-axle box. 32 kinds of specifications, process size from 300X300 mm to 600X1050 mm, the working-axis up to 60, and power up to 22.5 kilowatts. Romai factory adjustable multi-axle box easy to adjust, as long as the gear should first be adjusted to the location near the pass and then connected with its adjustable-axis move to the correct location. Therefore, this structure changes as long as the template, will be able to pass a certain extent change the content of shoes, and can reach more than ordinary axle box smaller pitch.
According to principles of the use of group processing the first multi-axle, or a combination of multi-axis machine tool is applicable to large and medium volume production. In order to process to get good results, need to consider the following points: (1) workpiece clamping simple, there is enough coolant away iron filings. (2) The fixture rigidity, processing, without deformation, dividing the right position. (3) the possibility of using the two group knives for a group to use, another set of grinding and adjustment, thereby reducing tool change downtime. (4) The use of quality tools to monitor whether the blunt tool, drill grinding to machine. (5) Dimensions can be detected immediately when the ultra-poor.
Multi-axis drilling machine :This is a multi-axis machining to meet the requirements of the drill. Such as orientation, power, feed, speed and processing range. Displayed at the Paris Exhibition of multi-axis drilling machine with hydraulic multi-feed. Throughout its work, such as fast-forward through the bad, workers enter and clear the iron filings are all automatically. It is noteworthy that the majority of agencies with separate variable speed, so that one group can adapt to the different pore size hole processing needs. 1.2.4 automatic replacement machine tool spindle box
In order to rationalize the needs of small and medium volume production in recent years the development of the automatic replacement of modular machine tool spindle box.
(1) The automatic replacement spindle machine
Automatic replacement of rotary spindle machine tool spindle box at the top is a library, there are several non-adjustable hanging spindle box. Vertical and horizontal patch panel to the first series of good working procedures, so that the corresponding spindle box into the processing station, location and with the power connection tight, and then turn to the table with the workpiece spindle box below, upward mobility for processing. When the change processing object, as long as the exchange suspension spindle box, you can pass with different processes for different needs.
(2) The multi-axis machine tool turret
Turret to install more non-adjustable or universal coupling spindle box, turret can automatically switch to digital, and clamp the workpiece in the rotary table to feed motion. Through the rotary table can be a number of workpiece surface. Because the turret not be too big, so it is generally not exceed the median of workers 4-6. And the spindle box is also not too large. When the machining process more objects, size larger, it should automatically replace the machine tool spindle box fit, but its simple structure.
(3) Automatic replacement of modular machine tool spindle box
It consists of automatic line or a combination of standard machine parts. Non-adjustable multi-axle box and power box by home base in the horizontal, the spindle rotates, the entire case library fastening device to the system in the slip into the board. Library Headstock rotation and feed movement is based on standard routines of work. Headstock time for a few seconds. Clamping the hydraulic sub-degree rotary table so that each workpiece surface. Good fruit rotary table accompanied by discharging device, we can co-flow production automation. In the variable production system using this device, accompanied by the corresponding controller can obtain a complete processing system.
(4) 8-axis CNC drill floor
Large condenser water wall tube plate holes as many as 15,000, which linked together with the support plate processing. Diameter of 20 mm, hole depth 180 mm. Used inside the cooling pipe has a twist drill ,5-7 bar pressure, coolant directly into the cutting area is conducive to chip removal. And ground into a 90 ° drill point for the self-centering. Durable than regular twist drill, and a large quantity of feed. To shorten the processing time to 8-axis CNC machining floor.
trends in multi-axis machining :Multi-axis machining high production efficiency, low investment and production preparation cycle is short, product modification, when a small loss of equipment. And as China's CNC technology, the scope of multi-axis machining will become the broad, processing efficiency will be improved.
production tasks :A group of cast-iron joints have the same surface processing with multiple holes. In the general processing of vertical holes on the drill, usually a hole a hole drilling, production efficiency is low, use non-standard equipment, that is, combination of machining, production efficiency is high, but the large investment in equipment.
However, the number of common vertical drilling machine to transform ordinary single-axis vertical multi-axis drilling machine after transformation, multi-axis drilling machine can simultaneously perform multiple hole drilling, expansion, hinges, and other processes.
普通钻床改造为多轴钻床
目前,我国中、小型企业的产品质量和生产效率都需要有一个新的提高.但是加工手段却远远不能满足需要.许多中小型企业都结合自己的实际对设备的技术状态进行改进,通过强化自身.以求自我发展.普通钻床为单轴机床,但安装上多轴箱就会成为多轴的钻床,改造成多轴钻床后,能大大地缩短加工时间,提高生产效率。
多轴加工应用:据统计,一般在车间中普通机床的平均切削时间很少超过全部工作时间的15%。其余时间是看图、装卸工件、调换刀具、操作机床、测量 以及清除铁屑等等。使用数控机床虽然能提高85%,但购置费用大。某些情况下,即使生产率高,但加工相同的零件,其成本不一定比普通机床低。故必须更多地缩短加工时间。不同的加工方法有不同的特点,就钻削加工而言,多轴加工是一种通过少量投资来提高生产率的有效措施。
多轴加工优势:虽然不可调式多轴头在自动线中早有应用,但只局限于大批量生产。即使采用可调式多轴头扩大了使用范围,仍然远不能满足批量小、孔型复杂的要求。尤其随着工业的发展,大型复杂的多轴加工更是引人注目。例如原子能发电站中大型冷凝器水冷壁管板有15000个ψ20孔,若以摇臂钻床加工,单单钻孔与锪沉头孔就要842.5小时,另外还要划线工时151.1小时。但若以数控八轴落地钻床加工,钻锪孔只要171.6小时,划线也简单,只要1.9小时。因此,利用数控控制的二个坐标轴,使刀具正确地对准加工位置,结合多轴加工不但可以扩大加工范围,而且在提高精度的基础上还能大大地提高工效,迅速地制造出原来不易加工的零件。有人分析大型高速柴油机30种箱形与杆形零件的2000多个钻孔操作中,有40%可以在自动更换主轴箱机床中用二轴、三轴或四轴多轴头加工,平均可减少20%的加工时间。1975年法国巴黎机床展览会也反映了多轴加工的使用愈来愈多这一趋势。
多轴加工的设备:多轴加工是在一次进给中同时加工许多孔或同时在许多相同或不同工件上各加工一个孔。这不仅缩短切削时间,提高精度,减少装夹或定位时间,并且在数控机床中不必计算坐标,减少字块数而简化编程。它可以采用以下一些设备进行加工:立钻或摇臂钻上装多轴头、多轴钻床、多轴组合机床心及自动更换主轴箱机床。甚至可以通过二个能自动调节轴距的主轴或多轴箱,结
合数控工作台纵横二个方向的运动,加工各种圆形或椭圆形孔组的一个或几个工序。现在就这方面的现状作一简介。
多轴头:从传动方式来说主要有齿轮传动与万向联轴节传动二种。这是大家所熟悉的。前者效率较高,结构简单,后者易于调整轴距。从结构来说有不可调式与可调式二种。前者轴距 不能改变,多采用齿轮传动,仅适用于大批量生产。为了扩大其赞许适应性,发展了可调式多轴头,在一定范围内可调整轴距。它主要装在有万向.二种。(1)万向轴式也有二种:具有对准装置的主轴。主轴装在可调支架中,而可调支架能在壳体的T形槽中移动,并能在对准的位置以螺栓固定。(2)具有公差的圆柱形主轴套。主轴套固定在与式件孔型相同的模板中。前一种适用于批量小且孔组是规则分布的工件(如孔组分布在不同直径的圆周上)。后一种适用于批量较大式中小批量的轮番生产中,刚性较好,孔距精度亦高,但不同孔型需要不同的模板。
多轴头可以装在立钻式摇臂钻床上,按钻床本身所具有的各种功能进行工作。这种多轴加工方法,由于钻孔效率、加工范围及精度的关系,使用范围有限。
多轴箱:也象多轴头那样作为标准部件生产。美国Secto公司标准齿轮箱、多轴箱等设计的不可调式多轴箱。有32种规格,加工面积从300X300毫米到600X1050毫米,工作轴达60根,动力达22.5千瓦。Romai工厂生产的可调多轴箱调整方便,只要先把齿轮调整到接近孔型的位置,然后把与它联接的可调轴移动到正确的位置。因此,这种结构只要改变模板,就能在一定范围内容易地改变孔型,并且可以达到比普通多轴箱更小的孔距。
根据成组加工原理使用多轴箱或多轴头的组合机床很适用于大中批量生产。为了在加工中获得良好的效果,必需考虑以下数点:(1)工件装夹简单,有足够的冷却液冲走铁屑。(2)夹具刚性好,加工时不形变,分度定位正确。(3)使用二组刀具的可能性,以便一组使用,另一组刃磨与调整,从而缩短换刀停机时间。(4)使用优质刀具,监视刀具是否变钝,钻头要机磨。(5)尺寸超差时能立即发现。
多轴钻床:这是一种能满足多轴加工要求的钻床。诸如导向、功率、进给、转速与加工范围等。巴黎展览会中展出的多轴钻床多具液压进给。其整个工作循坏如快进、工进与清除铁屑等都是自动进行。值得注意的是,多数具有单独的变速机构,这样可以适应某一组孔中不同孔径的加工需要。1.2.4 自动更换主轴箱机床
为了中小批量生产合理化的需要,最近几年发展了自动更换主轴箱组合机床。
(1) 自动更换主轴机床
自动更换主轴机床顶部是回转式主轴箱库,挂有多个不可调主轴箱。纵横配线盘予先编好工作程序,使相应的主轴箱进入加工工位,定位紧并与动力联接,然后装有工件的工作台转动到主轴箱下面,向上移动进行加工。当变更加工对象时,只要调换悬挂的主轴箱,就能适应不同孔型与不同工序的需要。
(2) 多轴转塔机床
转塔上装置多个不可调或万向联轴节主轴箱,转塔能自动转位,并对夹紧在回转工作台的工件作进给运动。通过工作台回转,可以加工工件的多个面。因为转塔不宜过大,故它的工位数一般不超过4—6个。且主轴箱也不宜过大。当加工对象的工序较多、尺寸较大时,就不如自动更换主轴箱机床合适,但它的结构简单。
(3) 自动更换主轴箱组合机床
它由自动线或组合机床中的标准部件组成。不可调多轴箱与动力箱按置在水平底座上,主轴箱库转动时整个装置紧固在进给系统的溜板上。主轴箱库转动与进给动作都按标准子程序工作。换主轴箱时间为几秒钟。工件夹紧于液压分度回转工作台,以便加工工件的各个面。好果回转工作台配以卸料装置,就能合流水生产自动化。在可变生产系统中采用这种装置,并配以相应的控制器可以获得完整的加工系统。
(4) 数控八轴落地钻床
大型冷凝器的水冷壁管板的孔多达15000个,它与支撑板联接在一起加工。孔径为20毫米,孔深180毫米。采用具有内冷却管道的麻花钻,5-7巴压力的冷却液可直接进入切削区,有利于排屑。钻尖磨成90°供自动 定心。它比普通麻花钻耐用,且进给量大。为了缩短加工时间,以8轴数控落地加工。
多轴加工趋势:多轴加工生产效率高,投资少,生产准备周期短,产品改型时设备损失少。而且随着我国数控技术的发展,多轴加工的范围一定会愈来愈广,加工效率也会不断提高。
生产任务:在一批铸铁连接件上有同一个面上有多个孔加工。在普通立式钻床上进行孔加工,通常是一个孔一个孔的钻削,生产效率低,用非标设备,即组合机床加工,生产效率高,但设备投资大。
但把一批普通立式普通单轴钻床改造为立式多轴钻床,改造后的多轴钻床,可以同时完成多个孔的钻、扩、铰、等工序。