机械数控专业毕业设计外文翻译

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1、Foreign Language Translation 1 At present,the main control way in automation field are rlay control,microcomputer control and PLC control. Compared with the relay control system and the microcomputer control systerm,the PLC control systerm has a series of advantages,sush as little work load of desig

2、ning,installing,wiring and debugging, short cycle of development of working environment and convenient maintenance. Meanwhile, the relay control systerm has already been few used on the machine control systerm is inferior in ability of anti-interference, high in requirement of working environment an

3、d long in desigong and developing cycle of the control systerm. So its application has being on deining trnd in the automation conrol field by year. The electrical control system of z-3040 Radial arm drill has many defects such as complex circuit, high failure rate, large maintenance workload, poor

4、reliability and flexibility. This paper introduces the z-3040 Radial arm drill relay contact analog control system reformation with PLC to guarantee the rapidity, accuracy and rationality of electric control system. It satisfied real production demand and enhance the economic benefit. The original w

5、as introduced initial controller of programmable distinguishing feature and performance. Analyses on z-3040s Radial arm drill technique property and the work cycle distance travelled by a stream of water base, expounded the initial controller of application ESs set programmable carrying on the techn

6、ological transformation system design to such, and finish come out the control procedure trapezium picture. What is a PLC control system? Since the 1960s the United States to launch programmable logic controller (Programmable Logic Controller, PLC) to replace conventional control devices since the r

7、elay, PLC has been rapid development in various parts of the world have been widely used. At the same time, PLCs function also improved. With computer technology, signal processing technology, control technology network technology development and user demand for continuous improvement, PLC in dealin

8、g with the volume switch on the basis of the increase in the amount of analog processing and motion control functions. Today, the PLC is no longer confined to the logic control, motion control, process control and other fields has also played a very important role. Discrete control of the system as

9、the preferred product, PLC in the twentieth century to the 1990s and 1980s, have achieved rapid development in the world of PLC to maintain an annual growth rate of 20% to 30%. With the factory automation and continuous improvement in the PLC and market base expansion in recent years in the PLC indu

10、stry slowdown in the growth rate of developed countries. However, China and other developing countries in the PLCs growing very rapidly. Comprehensive information, in 2004 global sales of the PLC for about 10,000,000,000 U.S. dollars, in the field of automation plays a very important position. PLC t

11、ouch by the imitation of the original relay control principle developed in the 1970s, only the PLC logic control switch, first of all applications in the automotive manufacturing industry. To the implementation of its store operations logic, the order Foreign Language Translation 2 of control, timin

12、g, counting and computing, and other operating instructions； and digital input and output operation to control all types of machinery and production process. The preparation of the user control procedures to express the production process requirements and advance into the PLC user program memory. Ru

13、n-time by storing the contents one by one the implementation of procedures to complete the process required to operate. PLCs CPU instructions with step-by-step process to store the address of the program counter, running in the process, each step in the implementation of the automatic counter plus 1

14、, step-by-step process from the start (zero-step number), followed by the final step to the implementation of the (usually END command), and then return to start step-by-step cycle of operation. Each PLC completed a cycle of the time required for the operation known as a scanning cycle. Different mo

15、dels of the PLC, scanning cycle to cycle in a microsecond between the scores of microseconds. PLC ladder program used in calculating logic, to show the advantages of quick, microsecond in the order of magnitude, calculating logic 1K procedures less than 1 ms. It all have input as a switch to handle

16、the volume, 16-bit (also 32-bit) for a simulated traffic. PLC large-scale use of a CPU to complete the simulation of the amount of computing. The results sent to the PLC controller.The same I / O points system, with PLC than DCS, the cost should be lower (about 40% of the province to around). PLC sp

17、ecial operation did not stop it with software and hardware are common, so maintenance costs much lower than the DCS. One of the PLC controller, you can receive thousands of I / O points (up to more than 8000 I / O). If the object is a chain of equipment, small loop, the PLC to adopt more appropriate

18、. As a result of General PLC control software in the design of management information systems, to be easier. Over the past 10 years, with the PLC to lower prices and growing user demand, a growing number of small and medium-sized equipment to start using PLC control, PLC in China grew rapidly. With

19、Chinas rapid economic development and the basis of the level of automation and continuous improvement in the next period of time in the PLC will continue to maintain our growth momentum. General PLC can be used in special equipment that it is an embedded controller, but in general the relative PLC a

20、nd embedded controller to have higher reliability and better stability. Practical work encountered a number of users of the original use of embedded controllers are now being used or custom-General PLC to replace the embedded controller PLC. PLC control system design main point In the modernized ind

21、ustrial production equipment, has the massive digital quantity and the simulation quantity control device, for example the electrical machinery stops, solenoid valves make and break, the product counting, the temperature, the pressure, the current capacity hypothesis and the control and so on, in th

22、e industry scenes these automatic control question, the programmable controller (PLC) has become one of solution most effective tools. When PLC control system design should pay attention to the following several spots. one, programmable controller (PLC) and programmers selecting and purchasing: in t

23、he present markets PLC product is numerous, besides Foreign Language Translation 3 the domestically produced brand, the overseas brand includes: Japanese OMRON, MITSUBISHI, FUJI, IDEC, HITACHI, do Matushita, Germanys Simens, South Koreas LG and so on, how select and purchase the PLC product? 1. The

24、system first should determine that the system uses PLC with the PLC single plane control to form the network, from this calculates the input, the output (I/O) the points, and when selects and purchases PLC must in the actual need points foundation reserve 10% remainders. 2. The definite load type ac

25、ts according to the PLC out-port to have the load is the cocurrent or the exchange, is the big electric current or the undercurrent, as well as PLC output movement frequency and so on, thus determined that the out-port uses the relay to output the transistor to output, perhaps thyristor output. The

26、different load selects the different output mode to systems steady operation is very important. 3. The storage capacity and the instruction carry out the speed are the PLC shaping important targets, generally the reserves is bigger, the speed quicker PLC price to be higher, although overseas various

27、 factories product more or less the same, but also has certain difference. 4. “COM choice, different PLC product, it COM a quantity is dissimilar, some COM belt 8 output spots, some belt 4 output spots, also has the belt 1 or 2 output spot. When the load type are many, and the electric current is bi

28、g time, uses one COM a belt 1-2 output product, when the load type minority quantity are many, uses one COM a belt 4-8 output product. 5. Because each Manufacturers development software is different, the compatibility is also systematically selects and purchases when the key point, at present had no

29、t discovered that the completely compatible product, should select the PLC product reasonably according to the system. 6. Programmers selecting and purchasing: the PLC programming may adopt three ways: First, with the general handhold programmer, it can only use in the sentence table sentence progra

30、mming which the factory stipulated. Center way easy scene debugging, and the volume small cost is low, but its efficiency low adaptation aircraft type type are few, compared with is suitable is small in the system capacity, in amount used few systems. Second, the graph programmer programming, this w

31、ay uses the graphic mode programming, facilitates intuitively, generally the electrical personnel short-term may apply freely, but the programmer price is high. Third, programs with IBM and the compatible personal computer +PLC software package, this way is the efficiency highest one way, is also th

32、e most commonly used one way, but the majority of software package price is expensive. 7. selects the big companys product as far as possible, because its product quality has the safeguard, and the technical support, the post-sale service is also generally good, will be advantageous in the later pro

33、duct expansion and the software and hardware promotion. Second, input, output circuits design 1. power source return route The PLC power supply is generally AC85-240V (also has DC24V), adapts the power source scope to be wide, but for the antijamming, should install the power source to purify the pa

34、rt (for example power source filter, 1:1 insulating transformer and so on) on 2.PLC DC24V power sources use On various companies PLC product has the DC24V power source generally, but this power source capacity is small, is several dozens milliamperes to several hundred milliamperes, with its belt load when should pay