注塑机及其的控制 外文翻译

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1、 Injection molding machine and on the control of it 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 worlds 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 process,

3、 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 heating de

4、vice 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 the

5、 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 oil pressure due to interference in the production process, deviation of the m

6、achine 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 d

7、irect 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

8、-based 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

9、, a 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 p

10、owerful 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 as injection molding a variety of control can greatly improve the quality of

11、plastic products will help enhance economic benefits. Control of the contents of the injection molding machine Injection 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 moti

12、on control 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 material

13、s 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 diffe

14、rent 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 tempera

15、ture 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 product mold cavity surface temperature, it will significantly affect the charge membrane, cooling and

16、packing 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 th

17、e 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 accu

18、racy 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 res

19、ponse 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 o

20、wn 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 cyc

21、le. Transfer 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

22、 put 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 PCC Since the late 20th century, 60 the United States the first programmable logic controller PLC inception, PLC control technology has gone through a 30-year development process, especially with modern computer technology and