1、On the control of plastic injection molding machine Modern plastic injection molding machine is a set of mechanical, electrical and fluid in one typical system, as this device has forming complex products, less post-processing, processing characteristics of the plastic variety, since its inception h

2、as grown rapidly, the current full Over 80% of the world's products are used plastic injection molding machine for processing.Conventional injection molding machines generally use a simple open-loop control, that is, in accordance with a pre-set value of control. In the device manufacturing proc

3、ess, pre-configured parameter values, such as the clamping force, cycle time, temperature, etc., from the machine in the production process be maintained. For example, by controlling the die temperature can be maintained the temperature of heating fluid, plastic temperature can be outside the heatin

4、g device by controlling the power to maintain. This control method of simple structure, however, poor anti-interference ability to control the temperature is relatively low.At present, more injection molding machine uses a closed-loop control, that is, according to on-line measurement value and set

5、the value of the deviation control. Closed-loop control system uses a negative feedback loop, anti-jamming ability, when the injection speed, injection pressure, mold cavity temperature, cavity pressure, melt temperature and oilpressure due to interference in the production process, deviation of the

6、 machine through the adaptive control system for automatic correction of interference. This control method of anti-interference ability, high control accuracy. More advanced control method is to apply computer controlled, that is, to build a closed-loop real-time computer control system. It includes

7、 direct digital control system (DDC, supervisory computer control system (SCC, distributed control system (DCS and multi-level control of several types.Commonly used injection molding machine control system has three kinds, namely, the traditional relay-based, programmable controllers and computer-b

8、ased control type. In recent years, programmable logic controller (referred to as PLC with its high reliability, high-performance characteristics in injection molding machine control system has been widely used. In order to improve the level of injection molding machine control system and quality, a

9、 higher level than the PLC, control system design specifically for small and medium programmable computer controller (PCC came into being. PCC integrates a standard PLC and industrial control computer features, multi-task time-sharing operating systems, data computing and processing power more power

10、ful than the PLC. PCC formed with injection molding machine control system in order to achieve, including position control, speed control, temperature control, fault control and real-time display the whole process such asinjection molding a variety of control can greatly improve the quality of plast

11、ic products will help enhance economic benefits.Control of the contents of the injection molding machineInjection molding machine process control system mainly consists of two parts: First, the temperature control system in order to right barrel, melt and mold temperature control; second motion cont

12、rol system to the process of injection pressure, velocity and displacement multiple class switching.In the temperature control, its control accuracy has reached a ± 1 . Precise temperature control in precision injection molding that help improve product quality and availability of raw materials

13、 is a very important indicator. In the plastic processing, temperature control include barrel, nozzle and mold temperature control. Barrel temperature of the barrel surface heating temperature, due to relatively thick wall barrel, so the choice of thermocouple detection point is critical, and differ

14、ent test points on the temperature curve is a large difference. Therefore, parallel detection of double-point, namely, surface and deep in the barrel at the same time set the thermocouples, will be relatively stable temperature curve is conducive to temperature control accuracy. Nozzle melt temperat

15、ure directly affects the passage of the shear flow, the quality of the products have a major impact, so the nozzle temperature control precision demanding. Mold temperature is in contact with the productmold cavity surface temperature, it will significantly affect the charge membrane, cooling and pa

16、cking process. For the mold temperature control method can be used control the heat carrier temperature method can also directly control the mold temperature. In the former approach, in order to heat the temperature for the control of the export vector objects, is relatively simple and can meet the

17、general temperature control requirements. When the temperature control precision is high generally use the second method of temperature control.Injection speed, packing pressure, back pressure is the injection of part of the sol to control the first of the three variables directly affect the accurac

18、y of its control product quality. Modern more advanced injection molding machine equipped with 5-10 multi-stage injection speed and packing, as well as melt glue back pressure control. Generally through displacement / velocity sensors, pressure sensors, closed-loop injection control, and high respon

19、se servo valves used in conjunction to achieve the process of injection molding melt glue back pressure, injection speed and packing conditions of precise control. Another relatively simple approach is to use closed-loop proportional valve, through the proportional valve spool position of their own

20、closed-loop control to improve control precision. However, spool position is an intermediate variable, so the control accuracy somewhat less.Transfer mold process control variable is the main clamping force,clamping force and time again is stable and the necessary conditions for forming the cycle. T

21、ransfer mode control of the process should be another important variable is location. On the one hand, advanced injection molding machine constant pursuit of efficiency, directly affect the speed of transfer mold molding cycle, and quickly transfer to the deceleration control mode in itself has put

22、forward higher requirements. On the other hand, due to special process of continuous development and promotion of position control precision molds have become increasingly demanding. PLC and PCCSince the late 20th century, 60 the United States the first programmable logic controller PLC inception, P

23、LC control technology has gone through a 30-year development process, especially with modern computer technology and microelectronics technology, it has been in the soft hardware technology is far out of the original "sequence control" of the prototype stage. Programmable Computer Controll

24、er (PCC is to represent the development trend of this new generation of programmable controllers.PLC compared with conventional, PCC is a for motion control, process control and network control of dedicated control system, is a standard PLC, numerical control systems and industrial performance chara

25、cteristics of the computer in one of the intelligent controller. PCC is its biggest feature is similar to a large computer time-sharingmulti-tasking operating systems and diverse software applications design. Most of the conventional single-task PLC clock scanning or monitoring procedures to deal wi

26、th the process itself of the logic operation instructions and external I / O channel status of collection and refresh. This treatment led directly to "control the speed," depends on the size of the application, this result is no doubt that I / O channels in real-time control of the high de

27、mand religions. PCC's system software the perfect solution to this problem, it uses time-sharing mechanism to build their applications multi-tasking software operating platform, so that the application program running the length of cycle and has nothing to do, but by the decision cycle of the op

28、erating system. As a result, it will scan cycle of the application with the real distinction between the external control cycle to meet the real requirements of real-time control. Of course, this control cycle in the CPU computing power to allow the premise, according to the user's actual requir

29、ements, arbitrary changes.PCC application modules from the multi-task structure, the development of application software to the project has brought great convenience. Because it can easily control the project in accordance with the various parts of the different functional requirements, such as moti

30、on control, data acquisition, alarm, PID regulator computing, communications, control, namely the preparation of a control program module (task, these modules not only operate independently, the data between one another tomaintain a certain interrelated, these modules through the step by step after

31、the independence of the development and debugging can be downloaded to the PCC along with the CPU, in the regulation and management of multi-tasking operating systems run in parallel under the joint realization of the project control requirements.PCC a single task in the preparation of the different

32、 modules with a flexible choice of the characteristics of different programming languages, which means that not only in conventional PLC has been to people familiar ladder, instruction list language can continue to be used on the PCC, but users can be used more efficient and intuitive high-level lan

33、guage (PL2000, which is a complete text for the control of language, BASIC technical personnel familiar with the syntax it will feel a kind of deja vu, which control requirements for the description of a very simple, intuitive. In addition, PCC's application software development also has an inte

34、grated "C" language program capacity, thus providing powerful data computing and processing power.On the hardware structure, PCC is characterized by very significant. In its core computing module inside, PCC for its CPU is equipped with multiple conventional PLC, mass storage unit (100K/16

35、M, this is undoubtedly a powerful system and application software provides a hardware-based monitoring. PCC on the hardware features, but also reflected in its various signals for industrial site designed many dedicatedinterface module, such as the high-frequency pulses, incremental encoder, tempera

36、ture, weighing signal and ultrasonic signal interface module. They will all forms of on-site signal is very convenient to PCC joint into the core of the digital control system, the user may need to use the system's hardware I / O channels in a single road, road, or dozens of way more than a deca

37、de as a unit module carried out dozens of point-to-hundreds of thousands of point-point expansion and networking. PCC in the industrial control powerful advantages, and demonstrate the programmable controllers and industrial control computers and DCS (Distributed Industrial Control System technology

38、, the development trend of convergence, although this is still a relatively young technology, but in its more come more and more application areas, it is increasingly demonstrating its potential for development can not be underestimated. For the injection molding machine, the current widespread appl

39、ication of the PLC control system, but as technology advances, personalized, customized products, growing demand for injection molding machine control requirements more complex, higher and higher precision, PCC as a more advanced control system, will gradually occupy a certain market share. On the o

40、ther hand, for the future network-based production requirements, obviously, PCC control system more competitive edge, so we have reason to believe, PCC control system will be in the future take place in the field of injection molding machines.This information comes from 【Wishsino Plastic Injection M

41、olding Company Website】對注塑機的控制現代塑料注塑機是一個典型的系統集機械，電氣和流體，此設備已形成了復雜的產品，少的后處理，加工各種塑料的特性，自成立以來發展迅速，目前全過世界上的產品80用于加工塑料注塑成型機。 傳統的注塑機一般采用簡單的開環控制，即按照預先設定值的控制。 在設備制造過程中，預先設定的參數值，如從機器的鎖模力，循環時間，溫度等，在生產過程中予以保留。 例如，通過控制模具溫度可以維持加熱流體的溫度，塑料溫度可控制電源，以保持外加熱裝置。 這種結構簡單的控制方法，然而，窮人的抗干擾能力，控制溫度也比較低。目前，更多的注塑機采用閉環控制，即根據上線的測量值和

42、設定值的偏差控制。 閉環控制系統采用了負反饋回路，抗干擾能力強，當注射速度，注射壓力，模腔溫度，模腔壓力，熔體溫度和壓力油，由于干擾，在生產過程中通過機器的偏差自適應控制系統的干擾進行自動修正。 這一控制方法抗干擾能力強，控制精度高。 更先進的控制方法是應用計算機控制，就是建立一個閉環實時計算機控制系統。 它包括直接數字控制系統（DDC ），監督計算機控制系統（SCC ），分布式控制系統（DCS ）和多層次的幾種類型的控制。常用的注塑機控制系統有三種，即傳統的基于繼電器，可編程控制器和基于計算機的控制類型。 近年來，可編程邏輯控制器（簡稱為PLC ）以其高可靠性，高性能的特點在注塑機控制系統已

43、被廣泛使用。 為了提高注塑機控制系統和質量水平更高的水平，比PLC 控制系統的設計專門為中小型可編程計算機控制器（PCC ）的應運而生。 政協集成了一個標準的PLC 和工業控制計算機的功能，多任務分時操作系統，數據計算和處理能力比PLC 更強大。 政協形成了注塑機控制系統，以實現包括位置控制，速度控制，溫度控制，故障控制和實時顯示整個過程中，如注塑成型的各種控制，可以大大提高塑料制品的質量有利于提高經濟效益。控制注塑機的內容注塑機過程控制系統主要由兩部分組成：一是溫度控制系統，為了權利桶，熔體和模具的溫度控制; 第二項議案注射壓力，速度和位移的多級交換過程的控制系統。在溫度控制，其控制精度達到

44、了±1。 在精密注塑精確的溫度控制，有助于提高產品質量和原料的可用性是非常重要的指標。 在塑料加工中，溫度控制主要包括料筒，噴嘴和模具的溫度控制。 料筒溫度，料筒表面加熱溫度，由于料筒的壁比較厚，因此熱電偶檢測點的選擇是至關重要的，在不同的溫度曲線測試點是一個很大的區別。 因此，雙點，即表面，在同一時間在每桶深平行檢測設置熱電偶，將是相對 穩定的溫度曲線，有利于溫度控制精度。 噴嘴熔融溫度直接影響剪 切流的推移， 產品的質量有重要影響， 因此噴嘴溫度的控制精度要求。 模具溫度是在接觸與產品模具型腔表面溫度，它會顯著影響充膜，冷 卻和包裝過程。 對于模具溫度控制方法可用于控制熱載體溫度

45、的方 法也可以直接控制模具溫度。 前一種方法中，以加熱載體的出口對 象的控制溫度，相對簡單，并能滿足一般的溫度控制要求。 當溫度 控制精度高，一般使用溫度控制的第二種方法。 注射速度，保壓壓力，背壓是注射部分溶膠控制的三個變量直接影響 其控制產品質量的準確性。 現代更先進的注塑機配備5-10多級注射 速度和包裝，以及熔膠背壓控制。 一般通過位移/速度傳感器，壓力 傳感器， 閉環注射控制， 高響應伺服閥配合使用， 實現注塑成型工藝， 熔膠背壓，注射速度和精確控制的條件下包裝。 另一種比較簡單的 方法是采用閉環比例閥，通過比例閥閥芯自己的閉環控制的位置，以 提高控制精度。 然而，閥芯位置是一個中間變量，因此控制精度稍 差。 傳輸模過程控制變量是主要的鎖模力，鎖模力和時間，又是穩定的成 型周期的必要條件。 傳輸模式控制過程應該是另一個重要的變量是 位置。 一方面，先進的注塑機不斷追求效率，直接影響轉移模具成 型周期的速度，并迅速轉移本身的減速控制模式提出了更高的要求。 另一方面， 由于特殊工藝的不斷發展和推廣的位置控制精密模具的要 求越來越高。 PLC 與 PCC 自20世紀后期以來，60，美國第一臺可編程邏輯控制器 PLC 以來， PLC