英文原文
On the NC lathe and tool changing system
CNC machine tool numerical control machine tools (Computer numerical control machine tools) abbreviation, is provided with a program control system of automatic machine tools. The logic control system can deal with the control code or other symbolic instruction specified program, and decoding the digital code, said information carrier, through the numerical control device input. After processing by CNC device control signals, control the machine movements, by drawing the shape and size requirements, will be automatically processed by the parts.
Features: CNC machine tool operation and monitoring of all completed in the numerical control unit, it is the brain of CNC machine tools. Compared with the general machine tools, CNC machine tools has the following characteristics:
● the processing object adaptability, adapt to the characteristics of mold products such as a single production, provide the appropriate processing method for die and mould manufacturing;
● high machining accuracy, processing with stable quality;
● can coordinate linkage, processing complex shape parts;
● machining parts change, only need to change the program, can save the preparation time of production;
● the machine itself high precision, rigi dity, can choose the amount of processing good, high productivity (typically 3 to 5 times that of ordinary machine tool);
The machine is a high degree of automation, reducing labor intensity;
● conducive to the production management modernization. The use of CNC machine tools and the standard code of digital information processing, information transmission, the use of computer control method, has laid the foundation for the integration of computer aided design, manufacturing and management;
● on the operato rs of higher quality, higher demands for the repair of the technical staff;
● high reliability.
Composition: CNC machine tools in general by the input medium, man-machine interactive equipment, CNC equipment, feed servo drive system, spindle servo drive system, the auxiliary control device, feedback apparatus and adaptive control device etc.. [4] in NC machining, NC milling processing is the most complex, need to solve most problems. NC programming of NC line in addition to CNC milling, cutting, CNC EDM, CNC lathe, CNC grinding, each with its own characteristics, servo system is the role of the motion signal is converted into the machine moving parts from the numerical control device of pulse. Concrete has the following parts: the structure of CNC machine tools.
Driver: he is driving parts of CNC machine tools, actuator, including spindle drive unit, feeding unit, spindle motor and feed motor. He through the electric or electro-hydraulic servo system to realize the spindle and feed drive under the control of numerical control device. When several feed linkage, can complete the positioning, processing line, plane curve and space curve.
The main performance
(1) the main dimensions.
(2) the spindle system.
(3) feed system.
(4) tool system.
(5) electrical. Including the main motor, servo motor specifications and power etc..
(6) cooling system. Including the cooling capacity, cooling pump output.
(7) dimensions. Expressed as length * width * height.
Development trend of CNC lathe:
High speed, precision, complex, intelligent and green is the general trend in the development of CNC machine tool technology, in recent years, made gratifying achievements in practicality and industrialization. Mainly in the:
1 machine tool composite technology to further expand with the CNC machine tool technology, composite processing technology matures, including milling - car compound, car milling compound, car - boring - drill - gear cutting compound, composite grinding, forming, composite processing, precision and efficiency of machining is greatly improved. "One machine is a processing factory", "one card, complete processing" concept is being accepted by more people, the development of compound processing machine tool is the trend of diversified.
Intelligent technology 2 CNC machine tools have a new breakthrough, in the performance of NC system has been reflected more. Such as: automatically adjust the interference anti-collision function, after the power of workpiece automatically exit safety power-off protection function, machining parts detection and automatic compensation function of learning, high precision machining parts intelligent parameter selection function, process automatic elimination of machine vibration functions into the practical stage, intelligent upgrade the function of machine and quality.
The 3 robots enable flexible combination of flexible combination of higher efficiency of robot and the host are widely used, make flexible line more flexible, extending the function, flexible line shorten further, more efficient. Robot and machining center, milling composite machine, grinder, gear processing machine tool, tool grinding machine, electric machine, sawing machine, punching machine, laser cutting machine, water cutting machine etc. various forms of flexible unit and flexible production line has already begun the application.
4 precision machining technology has the machining precision of CNC metal cutting machine tools from the yarn in the original (0.01mm) up to micron level (0.001mm), some varieties has reached about 0.0
5 μ M. Micro cutting and grinding machining of ultra precision CNC machine tools, precision can reach about 0.05 μ m, shape precision can reach about 0.01 μ M. Special processing precision by using optical, electrical, chemical, energy can reach nanomete r level (0.001 μ m). By optimizing the design of machine tool structure, machine tool parts of ultra precision machining and precision assembly, using high precision closed loop control and temperature, vibration and other dynamic error compensation technology, improve the geometric accuracy of machine tool processing, reduce the shape of error, surface roughness, and into the submicron, nano super finishing ti
The 5 functional component to improve the performance of functional components are at a high speed,
high precision, high power and intelligent direction, and obtain the mature application. A full digital AC servo motor and drive device, high technology content of the electric spindle, linear motor, torque motor, linear motion components with high performance, application of high precision spindle unit and other function parts, greatly improving the technical level of CNC machine tools.
The feed drive system of CNC lathe:
Effect of feed drive system,
The feed drive system of CNC machine tools will be received pulse command issued by the numerical control system, and the amplification and conversion machine movements carry the expected movement.
Two, the feeding transmission system requirements
In order to guarantee the machining accuracy of NC machine tool is high, the feed drive system of transmission accuracy, sensitivity high (fast response), stable work, high stiffness and friction and inertia small, service life, and can remove the transmission gap.
Category three, feed drive system
1, stepping motor servo system
Generally used for NC machine tools.
2, DC servo motor servo system
Power is stable, but because of the brush, the wear resulting in use need to change. Generally used for middle-grade CNC machine tools.
3, AC servo motor servo system
The application is extremely widespread, mainly used in high-end CNC machine tools.
4, the linear motor servo system
No intermediate transmission chain, high precision, the feed speed, no length limit; but the poor heat dissipation, protection requirements are particularly high, mainly used for high-speed machine.
Driving component four, feed system
1, the ball screw nut pair
NC machining, the rotary motion into linear motion, so the use of screw nut transmission mechanism. NC machine tools are commonly used on the ball screw, as shown in Figure 1-25, it can be a sliding friction into rolling friction, meet the basic requirements of the feed system to reduce friction. The transmission side of high efficiency, small friction, and can eliminate the gap, no reverse air travel; but the manufacturing cost is high, can not lock, size is not too big, generally used for linear feed in small CNC machine tool.
2, rotary table
In order to expand the scope of the process of NC machine tools, CNC machine tools in addition to make linear feed along the X, Y, Z three coordinate axes, often also need a circumferential feed movement around Y or Z axis. Circular feed motion of CNC machine tools in general by the rotary table to realize, for machining center, rotary table has become an indispensable part of.
Rotary table of commonly used CNC machine tools in the indexing table and NC rotary table.
(1) indexing table
Indexing table can only finish dividing movement, not circular feed, it is in accordance with the
instructions in the NC system, when indexing will work together with the workpiece rotation angle. When indexing can also use manual indexing. Provisions of indexing table is generally only rotary angle (such as 90, 60 and 45 degree).
(2) NC rotary table
NC rotary table appearance similar to the indexing table, but the internal structure and function is not the same. The main function of the NC rotary table is based on the numerical control device sends command pulse signal, complete circumferential feed movement, various arc processing and surface processing, it can also be graduation work.
3, guide
Rail is an important part of feed drive system, is one of the basic elements of the structure of machine tool, rigidity, precision and accuracy of NC machine tool which determines to a large extent retention. At present, guide the NC machine tool are sliding rail, rolling guideway and hydrostatic guideway.
(1) sliding guide
Sliding guide rail has the advantages of simple structure, easy manufacture, good stiffness, vibration resistance and high performance, widely used in CNC machine tools, the use of most metal plastic form, known as the plastic guide rail, as shown in figure 1-26.
On characteristics of the plastic sliding guide: friction characteristic is good, good wear resistance, stable movement, good manufacturability, low speed.
(2) rolling guide
Rolling guide is placed in the rail surface between the ball, roller or needle roller, roller, the rolling friction instead of sliding surface of the guide rail between wipe.
Rolling guide rail and the sliding rail, high sensitivity, small friction coefficient, and the dynamic, static friction coefficient is very small, so the motion is uniform, especially in the low speed movement, the stick-slip phenomenon is not easy to occur; high posit ioning accuracy, repeatability positioning accuracy is up to 0.2 μ m; traction force is small, wear small, portable in movement; good precision, long service life. But the vibration of rolling guide, high requirements on protection, complicated structure, difficult manufacture, high cost Automatic tool changer:
One, the function of automatic tool changer
Automatic tool changing device can help save the auxiliary time of CNC machine tools, and meet in an installation completed procedure, step processing requirements.
Two, on the requirement of automatic tool changer
Numerical control machine tool for automatic tool changer requirement is: tool change quickly, time is short, high repetitive positioning accuracy, tool storage capacity is sufficient, small occupation space, stable and reliable work.
Three, change the knife form
1, rotary cutter replacement
Its structure is similar to the ordinary lathe turret saddle, according to the processing of different objects can be designed into square or six angle form, consists of the NC system sends out the instruction to the rotary
cutter.
2, the replacement of the spindle head tool change
The spindle head pre-loaded required tools, in order to machining position, the main motor is switched on, drives the cutter to rotate. The advantage of this method is that eliminates the need for automatic clamping, cutting tool, clamping and cutting tool moving and a series of complex operation, reduce tool change time, improve the reliability of the tool change.
3, the use of changing tool
The processing required tools are respectively arranged in the standard tool, adjust the size of the machine after certain way add to the knife, the exchange device from the knife and the spindle take knife switch.
Four, the tool switching device
Automatic tool change device, device for knife library and the main shaft transmission and handling tool for tool exchange device. Tool exchange often have two kinds: mechanical hand tool exchange and by relative motion of knife and machine tool spindle exchange tool (cutter to the spindle tool change or movement of the spindle to the knife knife tool change position), the mechanical hand tool change is most common.
Five, the knife
The knife is one of the most important parts in automatic tool changer, have great influence on the overall design of NC machine tool and its capacity, layout and structure.
1, the capacity of the tool storage
A number of knife inventory cutters, generally depending on the processing requirements. The capacity of small knife, can not meet the processing needs; capacity is too large, will make the knife database size, covers an area of large, tool selection process for a long time, and the knife library utilization rate is low, the structure is too complex, causing great waste.
2, the knife type
Generally, the chain disc and drum type knife several.
Disc cutter tool was circular arrangement, low utilization of space, size is not large but simple structure.
Chain magazine compact structure, large capacity, link shape can also be random bed made of various forms and flexible layout, but also will change the cutter location prominent for tool change, widely used.
Drum type or lattice type knife, covers an area of small, compact structure, large capacity, but cutter selection, tool movements are complicated, for centralized knife system for FMS.
3, tool selection
Often order tool selection and random selection tool two.
The order of tool selection is before processing, the processing required tools to process sequence of insert knife knife, order not wrong, processing adjust knife in order. The work piece changes, the need to reset the tool sequence, the operation is simple, and the processing tool with a workpiece can not be repeated use.
A knife is the cutting tool has its own code, optional and can be repeatedly used in processing, also do not put in the fixed knife, knife, the knife is convenient.
Technology file is the guiding file workers during processing, process scheme is reasonable, not only affect the efficiency of NC machining, and will directly affect the machining quality. Therefore, before NC
programming, NC machining process follows the process of certain principles and combined with the characteristics of CNC lathe seriously and develop in detail the good parts.
In the CNC lathe processing parts, should according to the principle of dividing process concentrated, in a fixture as far as possible to complete the most or even all of the surface processing. Part positioning, according to the structure of different shapes, usually cylindrical, face or end clamping, and strive to design basis, process reference and programming the unification datum.
The main contents are: analysis of NC machining technology of part drawings, clear processing content; determination method, workpiece on lathe the surface processing sequence and tool feed line and cutting tools, fixtures and cutting the amount of choice.
Analysis, part drawing process
In the machining process planning of parts, first of all to carry on in-depth analysis to the processing object. For NC turning process should consider the following aspects:
1 reading part drawing, analysis of geometric conditions of part contour
In turning process of manual programming, to calculate each node coordinates; in automatic programming, to define the components outline all geometric elements. Therefore, in the analysis of parts should pay attention to:
Parts of the map is missing a dimension, the geometric conditions are not sufficient to constitute the part outline, influence;
Map location map parts of the ambiguity or dimension is not clear, so that the program can't start;
The part drawing geometry given is not reasonable, resulting in mathematical difficulties.
The part drawing dimensioning methods should adapt to the characteristics of CNC lathe processing, should size or directly given coordinate dimension with the same standard.
2 dimensional accuracy requirements
Analysis of the pattern of parts size precision requirements, to determine whether achieve the turning process, and determine the process method to control the dimension precision. In the analysis process, but also can convert some dimensions such as size, incremental and absolute size and dimension chain calculation. In the use of NC lathe turning parts, average value of components often required size and maximum and minimum limit of size size as the basis of programming.
3 shape and position accuracy requirements
Pattern of parts tolerance of shape and location given is important foundation to ensure the parts precision. When machining parts, to determine the location reference and measurement reference according to the requirements, can also carry out some technical processing according to the special needs of CNC lathe parts, in order to control effectively the shape and position accuracy.
4 requirements of surface roughness
Surface roughness is an important requirement of micro precision parts of the surface, but also the reasonable selection of NC lathe, cutting tools and cutting the amount determined on the basis of.
5 material and heat treatment requirements
The part drawing on material and heat treatment given requirements, is the choice of cutter, CNC lathe,
cutting the amount determined on the basis of model.
Automatic tool changing system is mainly to process the required tools, transmitted to the spindle clamping mechanism from the knife. A TC system by knife library, manipulator, which consists of a driving system. Basic requirements: tool 1 short change time 2 tool with high repeat positioning accuracy of 3 sufficient storage capacity of 4 knife library covers an area of small (compact) 5 safe and reliable.
The knife is a knife storage device provides the required automatic machining process and tool changing needs; the automatic tool change mechanism and can put the tool storage of the knife. Controlled by the computer program, can complete a variety of machining different needs, such as milling, drilling, boring, tapping etc.. Shorten the process, reduce the production cost.
The knife is a knife storage location, and according to the control program, to determine the correct tool to position, to exchange tool; tool change mechanism is the implementation of tool exchange action. The knife must exist at the same time and tool change mechanism, if no knife library processing required tools can't reserve; without tool change mechanism, then the processing required tools not knife Kuyi order replacement, and reduce non-cutting time to lose.
Rotary motion of the knife is composed of a three-phase asynchronous motor with brake of the power source, the three-phase power supply through the AC contactor is supplied to the motor brake open, then the knife library operation, cut off the three-phase power supply brake locking, knife immediately stop running. Through the logical combination of indexing disk motion and related test element group, can make each Daotao accurate stop at the tool change position. Knife stopped at the tool change position, controlled by the cylinder sleeve in horizontal or vertical state, to facilitate mechanical hand for the knife, knife indexing table can be clockwise or counterclockwise rotation, which can search in the shortest possible time to the tool to change. The driving system of NC machine tool automatic tool changing system with hydraulic mechanism, pressure mechanism, electric cam mechanism. Nowadays the cam tool changer is used widely. Really fast, but no other consumable parts and maintenance requirements change, the failure rate at least, life of more than one million times. Speed changer system for rapid automatic tool changing technology is mainly aimed to reduce the processing time, the comprehensive consideration of various factors of machine tools, complete the technical method of tool exchange in the shortest possible time. The machine has the following features: 1 knife arm is short 2 knife arm is not necessarily linear 3 two knife may mutually perpendicular 4 cam box is small and mobile. Its main purpose is to let the knife, the movable parts of small moment of inertia, in order to achieve the purpose of quick change knife. Foundation to improve the automatic changing device in the traditional method of knife cutter changing speed of increase movement speed, or the mechanism action faster and a driving element. For example, change the knife speed mechanical cam structure is higher than that of hydraulic and pneumatic structure. According to the high speed machine tool structure design of knife and the knife changing device of form and position. For example, the knife machine tools and tool replacing device installed at the side of an upright post, in the high speed machine tool is more feeding movable column, in order to reduce the mass of the moving parts, the knife and tool replacing device should not be installed on the upright post. The formation of the optimal cutting parameters. Machining and turning centers is composed of mechanical equipment and CNC system, high efficiency, high precision of automatic machine for machining
of complex parts. This machine can be installed several knife, automatic tool change, installed in a card, to complete the milling, boring, vehicle processing, drilling, expansion joints, tapping. The reason why this kind of processing capacity, it is because it has a set of automatic tool changer. Automatically switch to the device in a variety of forms, is the main component of the knife, a manipulator and a driving device, although the tool change, tool selection, tool storage structure, mechanical hand types are different, but all is in the numerical control device and the programmable controller control, by the motor or hydraulic or pneumatic actuator driven knife base and the manipulator and the exchange tool selection. We refer to this as continuous processing to achieve a variety of process, the processing center or turning center, device selection and exchange for tool called automatic knife device (automatic tool change ATC). The main part of ATC is the knife, a manipulator and a driving device. The knife is the function of storage tool and knife next to be used accurately to the tool change position, in exchange for tool changing manipulator to complete the old and new tool. When the tool storage capacity is large, often far away from the main configuration and integral movement is not easy, it needs between the spindle and the tool library configuration tool change mechanism to perform the action of changing knife.
The manipulator assembly is the current research focus, foreign study used camera and a force sensor and a microcomputer connected together, can identify the parts of the range to reach the aim of inlaid. At present the industry manipulator is mainly used for machining, casting, heat treatment, regardless of the number, variety and performance still can not meet the needs of industrial development. The main is to gradually expand the scope of application, mechanical hand to focus on the development of casting, heat treatment, in order to reduce labor intensity, improve working conditions, the application of special mechanical hand at the same time, the development of general machinery corresponding hand, has the condition to develop teaching manipulator, computer control of manipulator and the combination of manipulator. The motion of the manipulator components, such as expansion, swing, lifting, shifting, pitch mechanism and a clamping mechanism of different types according to the design into a common mechanism, typical, so according to the different requirements of different types of clamping mechanism, can form different manipulator path. Both for the design and manufacture, is convenient for the replacement of the workpiece, expand the scope of application. At the same time to improve speed, reduce the impact, correct positioning, in order to better play the role of manipulator. In addition to research on servo type, memory reappearance type, as well as with tactile, visual properties such as mechanical hand, and consider the connected with computer, and gradually become a basic unit of the whole machinery manufacturing system. In the mechanical manufacturing industrial manipulator is used more, faster development. Now mainly used for machine, horizontal forging press feeding and discharging, and spot welding, paint spraying operations, which can be used to complete the operation in advance in accordance with the specified procedure. In addition, the development trend of foreign manipulator is developing manipulator has some kind of intelligence. It has the ability to change sensor, can feedback to external conditions, make corresponding changes. Such as the location of a deviation, which can correct and self detection, focus on visual function and tactile function research. At present, have made certain achievements. Visual function is mounted on a manipulator has a TV camera and optical rangefinder (i.e. distance sensor) and micro computer. Work is a television camera will object image into the video signal, and
then sent to the computer, in order to analyze the types of objects, size, color and location, and sends out the instruction to control the manipulator to work. Tactile function is tactile feedback control device is mounted on a manipulator. When the mechanical hand first finger to find work, produce the tactile effect through the pressure sensitive element is arranged on the finger, and then into the front, seize the workpiece. Hand grasping force control through the sensitive element is arranged on the finger, to achieve automatic adjustment grip size. In short, as the capacity of assembly work development of mechanical sensing technology will also further improve the hand. More important is the manipulator, the flexible manufacturing system and flexible manufacturing unit combination, so as to fundamentally change the current manufacturing system operation state.
中文译文
关于数控车床和换刀系统
数控机床是数字控制机床（Computer numerical control machine tools）的简称，是一种装有程序控制系统的自动化机床。该控制系统能够逻辑地处理具有控制编码或其他符号指令规定的程序，并将其译码，用代码化的数字表示，通过信息载体输入数控装置。经运算处理由数控装置发出各种控制信号，控制机床的动作，按图纸要求的形状和尺寸，自动地将零件加工出来。
特点：数控机床的操作和监控全部在这个数控单元中完成，它是数控机床的大脑。与普通机床相比，数控机床有如下特点：
●对加工对象的适应性强，适应模具等产品单件生产的特点，为模具的制造提供了合适的加工方法；
●加工精度高，具有稳定的加工质量；
●可进行多坐标的联动，能加工形状复杂的零件；
●加工零件改变时，一般只需要更改数控程序，可节省生产准备时间；
●机床本身的精度高、刚性大，可选择有利的加工用量，生产率高（一般为普通机床的3到5倍）；
●机床自动化程度高，可以减轻劳动强度；
●有利于生产管理的现代化。数控机床使用数字信息与标准代码处理、传递信息，使用了计算机控制方法，为计算机辅助设计、制造及管理一体化奠定了基础；
●对操作人员的素质要求较高，对维修人员的技术要求更高；
● 可靠性高。
组成：数控机床一般由输入介质、人机交互设备、计算机数控装置、进给伺服驱动系统、主轴伺服驱动系统、辅助控制装置、反馈装置和适应控制装置等部分组成。[4]在数控加工中，数控铣削加工最为复杂，需解决的问题也最多。除数控铣削加工之外的数控线切割、数控电火花成型、数控车削、数控磨削等的数控编程各有其特点，伺服系统的作用是把来自数控装置的脉冲信号转换成机床移动部件的运动。具体有以下部分构成：数控机床的构造。
驱动装置：他是数控机床执行机构的驱动部件，包括主轴驱动单元、进给单元、主轴电机及进给电机等。他在数控装置的控制下通过电气或电液伺服系统实现主轴和进给驱动。当几个进给联动时，可以完成定位、直线、平面曲线和空间曲线的加工。
主要性能
(1)主要规格尺寸。
(2)主轴系统。
(3)进给系统。
(4)刀具系统。
(5)电气。包括主电动机、伺服电动机的规格型号和功率等。
(6)冷却系统。包括冷却箱容量、冷却泵输出量等。
(7)外形尺寸。表示为长×宽×高。
数控车床的发展趋势：
高速、精密、复合、智能和绿色是数控机床技术发展的总趋势，近几年来，在实用化和产业化等方面取得可喜成绩。主要表现在：
毕业设计（论文）外文参考文献及译文 英文题目Component-based Safety Computer of Railway Signal Interlocking System 中文题目模块化安全铁路信号计算机联锁系统 学院自动化与电气工程学院 专业自动控制 姓名葛彦宁 学号 200808746 指导教师贺清 2012年5月30日
Component-based Safety Computer of Railway Signal Interlocking System 1 Introduction Signal Interlocking System is the critical equipment which can guarantee traffic safety and enhance operational efficiency in railway transportation. For a long time, the core control computer adopts in interlocking system is the special customized high-grade safety computer, for example, the SIMIS of Siemens, the EI32 of Nippon Signal, and so on. Along with the rapid development of electronic technology, the customized safety computer is facing severe challenges, for instance, the high development costs, poor usability, weak expansibility and slow technology update. To overcome the flaws of the high-grade special customized computer, the U.S. Department of Defense has put forward the concept：we should adopt commercial standards to replace military norms and standards for meeting consumers’demand [1]. In the meantime, there are several explorations and practices about adopting open system architecture in avionics. The United Stated and Europe have do much research about utilizing cost-effective fault-tolerant computer to replace the dedicated computer in aerospace and other safety-critical fields. In recent years, it is gradually becoming a new trend that the utilization of standardized components in aerospace, industry, transportation and other safety-critical fields. 2 Railways signal interlocking system 2.1 Functions of signal interlocking system The basic function of signal interlocking system is to protect train safety by controlling signal equipments, such as switch points, signals and track units in a station, and it handles routes via a certain interlocking regulation. Since the birth of the railway transportation, signal interlocking system has gone through manual signal, mechanical signal, relay-based interlocking, and the modern computer-based Interlocking System. 2.2 Architecture of signal interlocking system Generally, the Interlocking System has a hierarchical structure. According to the function of equipments, the system can be divided to the function of equipments; the system
电子商务 电子商务（Electronic Commerce）是在Internet开放的网络环境下，基于浏览器/服务器应用方式，实现消费者的网上购物、商户之间的网上交易和在线电子支付的一种新型的商业运营模式 Internet上的电子商务可以分为三个方面：信息服务、交易和支付。主要内容包括：电子商情广告；电子选购和交易、电子交易凭证的交换；电子支付与结算以及售后的网上服务等。主要交易类型有企业与个人的交易(BtoC方式)和企业之间的交易(BtoB方式)两种。参与电子商务的实体有四类：顾客(个人消费者或企业集团)、商户(包括销售商、制造商、储运商)、银行(包括发卡行、收单行)及认证中心。 电子商务是Internet爆炸式发展的直接产物，是网络技术应用的全新发展方向。Internet本身所具有的开放性、全球性、低成本、高效率的特点，也成为电子商务的内在特征，并使得电子商务大大超越了作为一种新的贸易形式所具有的价值，它不仅会改变企业本身的生产、经营、管理活动，而且将影响到整个社会的经济运行与结构。 1．电子商务将传统的商务流程电子化、数字化，一方面以电子流代替了实物流，可以大量减少人力、物力，降低了成本；另一方面突破了时间和空间的限制，使得交易活动可以在任何时间、任何地点进行，从而大大提高了效率。 2．电子商务所具有的开放性和全球性的特点，为企业创造了更多的贸易机会。 3．电子商务使企业可以以相近的成本进入全球电子化市场，使得中小企业有可能拥有和大企业一样的信息资源，提高了中小企业的竞争能力。 4．电子商务重新定义了传统的流通模式，减少了中间环节，使得生产者和消费者的直接交易成为可能，从而在一定程度上改变了整个社会经济运行的方式。 5．电子商务一方面破除了时空的壁垒，另一方面又提供了丰富的信息资源，
forced concrete structure reinforced with an overviewRein Since the reform and opening up, with the national economy's rapid and sustained development of a reinforced concrete structure built, reinforced with the development of technology has been great. Therefore, to promote the use of advanced technology reinforced connecting to improve project quality and speed up the pace of construction, improve labor productivity, reduce costs, and is of great significance. Reinforced steel bars connecting technologies can be divided into two broad categories linking welding machinery and steel. There are six types of welding steel welding methods, and some apply to the prefabricated plant, and some apply to the construction site, some of both apply. There are three types of machinery commonly used reinforcement linking method primarily applicable to the construction site. Ways has its own characteristics and different application, and in the continuous development and improvement. In actual production, should be based on specific conditions of work, working environment and technical requirements, the choice of suitable methods to achieve the best overall efficiency. 1、steel mechanical link 1.1 radial squeeze link Will be a steel sleeve in two sets to the highly-reinforced Department with superhigh pressure hydraulic equipment (squeeze tongs) along steel sleeve radial squeeze steel casing, in squeezing out tongs squeeze pressure role of a steel sleeve plasticity deformation closely integrated with reinforced through reinforced steel sleeve and Wang Liang's Position will be two solid steel bars linked Characteristic: Connect intensity to be high, performance reliable, can bear high stress draw and pigeonhole the load and tired load repeatedly.
https://www.doczj.com/doc/9117230707.html,/finance/company/consumer.html Consumer finance company The consumer finance division of the SG group of France has become highly active within India. They plan to offer finance for vehicles and two-wheelers to consumers, aiming to provide close to Rs. 400 billion in India in the next few years of its operations. The SG group is also dealing in stock broking, asset management, investment banking, private banking, information technology and business processing. SG group has ventured into the rapidly growing consumer credit market in India, and have plans to construct a headquarters at Kolkata. The AIG Group has been approved by the RBI to set up a non-banking finance company (NBFC). AIG seeks to introduce its consumer finance and asset management businesses in India. AIG Capital India plans to emphasize credit cards, mortgage financing, consumer durable financing and personal loans. Leading Indian and international concerns like the HSBC, Deutsche Bank, Goldman Sachs, Barclays and HDFC Bank are also waiting to be approved by the Reserve Bank of India to initiate similar operations. AIG is presently involved in insurance and financial services in more than one hundred countries. The affiliates of the AIG Group also provide retirement and asset management services all over the world. Many international companies have been looking at NBFC business because of the growing consumer finance market. Unlike foreign banks, there are no strictures on branch openings for the NBFCs. GE Consumer Finance is a section of General Electric. It is responsible for looking after the retail finance operations. GE Consumer Finance also governs the GE Capital Asia. Outside the United States, GE Consumer Finance performs its operations under the GE Money brand. GE Consumer Finance currently offers financial services in more than fifty countries. The company deals in credit cards, personal finance, mortgages and automobile solutions. It has a client base of more than 118 million customers throughout the world
On the vehicle sideslip angle estimation through neural networks: Numerical and experimental results. S. Melzi,E. Sabbioni Mechanical Systems and Signal Processing 25 (2011)：14~28 电脑估计车辆侧滑角的数值和实验结果 S.梅尔兹,E.赛博毕宁 机械系统和信号处理2011年第25期：14~28
摘要 将稳定控制系统应用于差动制动内/外轮胎是现在对客车车辆的标准（电子稳定系统ESP、直接偏航力矩控制DYC）。这些系统假设将两个偏航率(通常是衡量板)和侧滑角作为控制变量。不幸的是后者的具体数值只有通过非常昂贵却不适合用于普通车辆的设备才可以实现直接被测量,因此只能估计其数值。几个州的观察家最终将适应参数的参考车辆模型作为开发的目的。然而侧滑角的估计还是一个悬而未决的问题。为了避免有关参考模型参数识别/适应的问题,本文提出了分层神经网络方法估算侧滑角。横向加速度、偏航角速率、速度和引导角,都可以作为普通传感器的输入值。人脑中的神经网络的设计和定义的策略构成训练集通过数值模拟与七分布式光纤传感器的车辆模型都已经获得了。在各种路面上神经网络性能和稳定已经通过处理实验数据获得和相应的车辆和提到几个处理演习(一步引导、电源、双车道变化等)得以证实。结果通常显示估计和测量的侧滑角之间有良好的一致性。 1 介绍 稳定控制系统可以防止车辆的旋转和漂移。实际上，在轮胎和道路之间的物理极限的附着力下驾驶汽车是一个极其困难的任务。通常大部分司机不能处理这种情况和失去控制的车辆。最近,为了提高车辆安全，稳定控制系统(ESP[1,2]; DYC[3,4])介绍了通过将差动制动/驱动扭矩应用到内/外轮胎来试图控制偏航力矩的方法。 横摆力矩控制系统（DYC）是基于偏航角速率反馈进行控制的。在这种情况下,控制系统使车辆处于由司机转向输入和车辆速度控制的期望的偏航率[3,4]。然而为了确保稳定，防止特别是在低摩擦路面上的车辆侧滑角变得太大是必要的[1,2]。事实上由于非线性回旋力和轮胎滑移角之间的关系，转向角的变化几乎不改变偏航力矩。因此两个偏航率和侧滑角的实现需要一个有效的稳定控制系统[1,2]。不幸的是,能直接测量的侧滑角只能用特殊设备(光学传感器或GPS惯性传感器的组合)，现在这种设备非常昂贵,不适合在普通汽车上实现。因此, 必须在实时测量的基础上进行侧滑角估计，具体是测量横向/纵向加速度、角速度、引导角度和车轮角速度来估计车辆速度。 在主要是基于状态观测器/卡尔曼滤波器(5、6)的文学资料里, 提出了几个侧滑角估计策略。因为国家观察员都基于一个参考车辆模型,他们只有准确已知模型参数的情况下，才可以提供一个令人满意的估计。根据这种观点,轮胎特性尤其关键取决于附着条件、温度、磨损等特点。 轮胎转弯刚度的提出就是为了克服这些困难,适应观察员能够提供一个同步估计的侧滑角和附着条件[7,8]。这种方法的弊端是一个更复杂的布局的估计量导致需要很高的计算工作量。 另一种方法可由代表神经网络由于其承受能力模型非线性系统，这样不需要一个参
中等分辨率制备分离的 快速色谱技术 W. Clark Still,* Michael K a h n , and Abhijit Mitra Departm(7nt o/ Chemistry, Columbia Uniuersity,1Veu York, Neu; York 10027 ReceiLied January 26, 1978 我们希望找到一种简单的吸附色谱技术用于有机化合物的常规净化。这种技术是适于传统的有机物大规模制备分离，该技术需使用长柱色谱法。尽管这种技术得到的效果非常好，但是其需要消耗大量的时间，并且由于频带拖尾经常出现低复原率。当分离的样本剂量大于1或者2g时，这些问题显得更加突出。近年来，几种制备系统已经进行了改进，能将分离时间减少到1-3h，并允许各成分的分辨率ΔR f≥（使用薄层色谱分析进行分析）。在这些方法中，在我们的实验室中，媒介压力色谱法1和短柱色谱法2是最成功的。最近，我们发现一种可以将分离速度大幅度提升的技术，可用于反应产物的常规提纯，我们将这种技术称为急骤色谱法。虽然这种技术的分辨率只是中等（ΔR f≥），而且构建这个系统花费非常低，并且能在10-15min内分离重量在的样本。4 急骤色谱法是以空气压力驱动的混合介质压力以及短柱色谱法为基础，专门针对快速分离，介质压力以及短柱色谱已经进行了优化。优化实验是在一组标准条件5下进行的，优化实验使用苯甲醇作为样本，放在一个20mm*5in.的硅胶柱60内，使用Tracor 970紫外检测器监测圆柱的输出。分辨率通过持续时间（r）和峰宽（w,w/2）的比率进行测定的（Figure 1），结果如图2-4所示，图2-4分别放映分辨率随着硅胶颗粒大小、洗脱液流速和样本大小的变化。
中英文对照外文翻译文 电子商务时代企业文化的再造 随着网络时代电子商务大规模发展，电子商务企业文化随之产生，它在一个企业在产生的一种新的价值观，使企业内部资源得到从新整合，在为企业带来降低交易成本，提高效率，缩短生产周期等诸多好处的同时，也对已有的企业文化发起了挑战。电子商务的兴起是一场由技术手段飞速发展而引发的商业运作模式的变革，传统经济活动的生存基础、运作方式和管理机制均发生了彻底改变，传统的企业文化也面临着巨大的冲击。 一、企业文化对企业价值的贡献 文化现象是一个国家和民族文明的主要见证。广义的文化，包括知识、信仰、艺术、道德、法律、习俗和任何人作为一名社会成员而获得的能力和习惯在内的复杂整体。作为“亚文化”的企业文化，对企业的生存与发展亦起着举足轻重的作用。企业文化是商品经济和市场经济的产物，符合市场经济的客观规律，体现企业的竞争实务、竞争精神和整体形象。所谓企业文化就是企业的经营管理哲学，企业面对所处的社会和商业环境，在长期的生产经营活动中，形成全体员工所接受和认同信守的、为争取事业成功的一套非正式规则。它表明企业奉行何种管理哲学，以及企业通过管理要达到一个什么样的目标。是经济管理的重要内容之一。企业文化意味着一个公司的价值观，而这些价值观成为公司员工活动和行为的规范。 企业文化的本源问题是如何增加企业利润，降低企业的成本和费用。它的要义就是怎么使企业能够有效的整合资源，以达到对外部的适应性，使公司在竞争中生存，进而实现持续发展。企业文化建设为企业开展文化管理指出一个明确的方向。企业文化建设的根本目的是建设能够对外竞争环境具有高度适应性，并能根据环境变换做出迅速反应的行为方式能力，这种能力其实就是企业所拥有的根据外部竞争的环境需要而对内部资源进行整合运用的能力。企业文化建设应促进这一能力系统的形成，并维持好这一能力系统。中国的许多企业例如海尔、联想等企业成功的秘诀之一就是发展了一整套公司理念、经营哲学，形成了自己独特的企业文化。 1、企业文化体现企业的形象和精神。树立良好的企业形象，需要企业文化的支撑。现
专业资料 学院： 专业：土木工程 姓名： 学号： 外文出处：Structural Systems to resist (用外文写) Lateral loads 附件：1.外文资料翻译译文；2.外文原文。
附件1：外文资料翻译译文 抗侧向荷载的结构体系 常用的结构体系 若已测出荷载量达数千万磅重，那么在高层建筑设计中就没有多少可以进行极其复杂的构思余地了。确实，较好的高层建筑普遍具有构思简单、表现明晰的特点。 这并不是说没有进行宏观构思的余地。实际上，正是因为有了这种宏观的构思，新奇的高层建筑体系才得以发展，可能更重要的是：几年以前才出现的一些新概念在今天的技术中已经变得平常了。 如果忽略一些与建筑材料密切相关的概念不谈，高层建筑里最为常用的结构体系便可分为如下几类： 1.抗弯矩框架。 2.支撑框架，包括偏心支撑框架。 3.剪力墙，包括钢板剪力墙。 4.筒中框架。 5.筒中筒结构。 6.核心交互结构。 7. 框格体系或束筒体系。 特别是由于最近趋向于更复杂的建筑形式，同时也需要增加刚度以抵抗几力和地震力，大多数高层建筑都具有由框架、支撑构架、剪力墙和相关体系相结合而构成的体系。而且，就较高的建筑物而言，大多数都是由交互式构件组成三维陈列。 将这些构件结合起来的方法正是高层建筑设计方法的本质。其结合方式需要在考虑环境、功能和费用后再发展，以便提供促使建筑发展达到新高度的有效结构。这并
不是说富于想象力的结构设计就能够创造出伟大建筑。正相反，有许多例优美的建筑仅得到结构工程师适当的支持就被创造出来了，然而，如果没有天赋甚厚的建筑师的创造力的指导，那么，得以发展的就只能是好的结构，并非是伟大的建筑。无论如何，要想创造出高层建筑真正非凡的设计，两者都需要最好的。 虽然在文献中通常可以见到有关这七种体系的全面性讨论，但是在这里还值得进一步讨论。设计方法的本质贯穿于整个讨论。设计方法的本质贯穿于整个讨论中。 抗弯矩框架 抗弯矩框架也许是低，中高度的建筑中常用的体系，它具有线性水平构件和垂直构件在接头处基本刚接之特点。这种框架用作独立的体系，或者和其他体系结合起来使用，以便提供所需要水平荷载抵抗力。对于较高的高层建筑，可能会发现该本系不宜作为独立体系，这是因为在侧向力的作用下难以调动足够的刚度。 我们可以利用STRESS，STRUDL 或者其他大量合适的计算机程序进行结构分析。所谓的门架法分析或悬臂法分析在当今的技术中无一席之地，由于柱梁节点固有柔性，并且由于初步设计应该力求突出体系的弱点，所以在初析中使用框架的中心距尺寸设计是司空惯的。当然，在设计的后期阶段，实际地评价结点的变形很有必要。 支撑框架 支撑框架实际上刚度比抗弯矩框架强，在高层建筑中也得到更广泛的应用。这种体系以其结点处铰接或则接的线性水平构件、垂直构件和斜撑构件而具特色，它通常与其他体系共同用于较高的建筑，并且作为一种独立的体系用在低、中高度的建筑中。
外文翻译 通常，应变计应用在两个方面：在机械和结构的实验力分析中和应用力，扭矩，压力,流量以及加速度传感器结构中。非粘贴丝式应变计通常是当作专门的转换器来使用，其结构是使用一些有预载荷的电阻丝连接成惠斯登电桥，如图4.11： 在最初的预载荷中，四根金属丝的应变和电阻在理论上是相等的，它们组成一个平衡电桥，并且e0 = 0 （参考第10章电桥电路特性）。输入端一个小的位移（满量程≈0.04 mm）将会使两根金属丝的拉力增大而使另外两根的拉力减小（假设金属丝不会变松弛），引起电阻阻值的变化，电桥失衡，输出电压与输入位移成比例。金属丝可以由砷镍、镍铬和铁镍等多种合金制造，直径约为0.03 mm，可以承受的最大应力仅为0.002 N，灵敏系数为2到4，每个桥臂的电阻为120Ω到1000Ω, 最大激励电压5到10V，满量程输出典型值为20到50mV。 粘结丝式应变计（现在主要被粘贴箔式结构的应变计取代）应用于应力分析和作为转换器。具有很细丝式敏感栅粘贴在待测试件表面，来感受应变。金属丝被埋入矩形的粘合剂中，不能弯曲从而如实地反映待测试件的压缩和拉伸应力。因为金属丝的材料和尺寸与那些非粘贴应变计相似，所以灵敏度和电阻具有了可比性。 粘贴箔式应变计采用与丝式应变计相同或类似的材料，现在主要用于多用途力分析任务及多种传感器中。 其感应元件是利用光腐蚀工艺加工成厚度小于0.0002的薄片，当其形状改变时，它具有很大的灵活性。如图4.12： 例如，这三个线形敏感栅应变计被设计成端部宽大的形状。这种局部的增大将会减小横向灵敏度，以及在测量应变沿敏感栅单元的长度方向的分量时产生的干扰输入信号。在丝式应变计中，这种端部形状也应用在纵向单元的连接处，以便增加横向抗干扰能力。并且在制造过程中也非常方便在图4.12上的全部四个应变计上焊接焊盘。
毕业设计说明书 英文文献及中文翻译 学院：专 2011年6月 电子与计算机科学技术软件工程
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英文原文： Building construction concrete crack of prevention and processing Abstract The crack problem of concrete is a widespread existence but again difficult in solve of engineering actual problem, this text carried on a study analysis to a little bit familiar crack problem in the concrete engineering, and aim at concrete the circumstance put forward some prevention, processing measure. Keyword:Concrete crack prevention processing Foreword Concrete's ising 1 kind is anticipate by the freestone bone, cement, water and other mixture but formation of the in addition material of quality brittleness not and all material.Because the concrete construction transform with oneself, control etc. a series problem, harden model of in the concrete existence numerous tiny hole, spirit cave and tiny crack, is exactly because these beginning start blemish of existence just make the concrete present one some not and all the characteristic of quality.The tiny crack is a kind of harmless crack and accept concrete heavy, defend Shen and a little bit other use function not a creation to endanger.But after the concrete be subjected to lotus carry, difference in temperature etc. function, tiny crack would continuously of expand with connect, end formation we can see without the
Dashboard From Wikipedia, the free encyclopedia This article is about a control panel placed in the front of the car. For other uses, see Dashboard (disambiguation). The dashboard of a Bentley Continental GTC car A dashboard (also called dash, instrument panel (IP), or fascia) is a control panel located directly ahead of a vehicle's driver, displaying instrumentation and controls for the vehicle's operation. Contents 1.Etymology 2.Dashboard features 3.Padding and safety 4.Fashion in instrumentation 5.See also 6.References Etymology Horse-drawn carriage dashboard Originally, the word dashboard applied to a barrier of wood or leather fixed at the front of a horse-drawn carriage or sleigh to protect the driver from mud or other debris "dashed up" (thrown up) by the horses' hooves.[1] Commonly these boards did not perform any additional function other than providing a convenient handhold for ascending into the driver's seat, or a small clip with which to secure the reins when not in use. When the first "horseless carriages" were constructed in the late 19th century, with engines mounted beneath the driver such as the Daimler Stahlradwagen, the simple dashboard was retained to protect occupants from debris thrown up by the cars' front wheels. However, as car design evolved to position the motor in front of the driver, the dashboard became a panel that protected vehicle occupants from the heat and oil of the engine. With gradually increasing mechanical complexity, this panel formed a convenient location for the placement of gauges and minor controls, and from this evolved the modern instrument panel,
高精度稳压直流电源 文摘:目前对于可调式直流电源的设计和应用现在有很多微妙的,多种多样的,有趣的问题。探讨这些问题(特别是和中发电机组有关),重点是在电路的经济适用性上,而不是要达到最好的性能。当然，对那些精密程度要求很高的除外。讨论的问题包括温度系数，短期漂移，热漂移，瞬态响应变性遥感和开关preregualtor型机组及和它的性能特点有关的的一些科目。 介绍 从商业的角度来看供电领域可以得到这样一个事实，在相对较低的成本下就可以可以获得标准类型的0.01%供电调节。大部分的供电用户并不需要这么高的规格，但是供应商不会为了减少客户这么一点的费用而把0.1%改成0.01%。并且电力供应的性能还包括其他一些因素，比如说线路和负载调解率。本文将讨论关于温度系数、短期漂移、热漂移,和瞬态的一些内容。 目前中等功率直流电源通常采用预稳压来提高功率/体积比和成本，但是只有某些电力供应采用这样的做法。这种技术的优缺点还有待观察。 温度系数 十年以前，大多数的商业电力供应为规定的0.25%到1%。这里将气体二极管的温度系数定位百分之0.01[1]。因此，人们往往会忽视TC（温度系数）是比规定的要小的。现在参考的TC往往比规定的要大的多。为了费用的减少，后者会有很大的提高，但是这并不是真正的TC。因此，如果成本要保持在一个低的水平，可以采用TC非常低的齐纳二极管，安装上差动放大电路，还要仔细的分析低TC绕线电阻器。 如图1所示，一个典型的放大器的第一阶段，其中CR1是参考齐纳二极管，R是输出电位调节器。
图1 电源输入级 图2 等效的齐纳参考电路 假设该阶段的输出是e3，提供额外的差分放大器，在稳定状态下e3为零，任何参数的变化都会引起输出的漂移；对于其他阶段来说也是一样的，其影响是减少了以前所有阶段的增益。因此，其他阶段的影响将被忽略。以下讨论的内容涵盖了对于TC整体的无论是主要的还是次要的影响。 R3的影响 CR1-R3分支的等效的电路如图2所示，将齐纳替换成了它的等效电压源E'和内部阻抗R2。对于高增益调节器，其中R3的变化对差分放大器的输入来说可以忽略不计，所以前后的变化由R3决定。 如果进一步假定IB << Iz;从（1）可以得到 同时，