Control system design for inducing fully electrical vertical injection molding machine（a）

Date：2014/11/3 16:18:47

Vertical injection molding machine is a kind of special plastic molding machine, it uses thermoplastic, shear heat through the external heating andscrew rotation of the plastic raw material into the molten state, then injected into the mold cavity has been designed in advance good molten plastic,after a certain time maintaining pressure, cooling, can be obtained by theplastic products comply with all kinds of purposes.

The main drive of the traditional vertical injection molding machine arehydraulic system pressure and flow direction, produce different by pump and valve combined with different, provide the impetus and moving speed ofthe cylinder and the hydraulic motor required. The fully hydraulic vertical injection molding machine from single cylinder liquid filling type, the traditional multi cylinder liquid filling type development to two board nowdirect compression, there are certain advantages in product formingprecision, complex shape, but its control difficult technology, mechanicalmachining precision is high, the hydraulic technology is also difficult tograsp.

All electric vertical injection molding machine is the development direction ofinjection molding industry, which uses the electric motor and ball screw as a transmission mechanism to realize injection and holding pressure,plasticizing, the mold opening and push out of control, low noise, high precision, easy to keep the workplace clean and products, and can greatly reduce the cost of the cooling water, has a unique the advantages ofenvironmental protection, energy saving and performance in. Motor current use in all electric vertical injection molding machine are permanent magnet motor manufactured by Fanuc company in Japan, due to manufacturing and control technology of high power permanent magnet motor is not the hands of our country, and therefore expensive imports. The authors use the converter, motion controller in vertical injection molding machine (MC) and the programmable controller (PLC) to control the AC induction motor,successfully developed a cost-effective inducing fully electrical vertical injection molding machine.

1 vertical injection molding machine condition

The working process of vertical injection molding machine are as follows:

(1) die lock: divided into fast locking, low pressure die locking, high pressure mode locking in 3 stages.

(2) injection nozzle seat forward: close to the mould.

(3) injection: screw the material barrel front-end molten state with certain pressure and velocity of the plastic injection mold cavity.

(4) pressure: used to supplement products for cooling and contractionparts.

(5) plasticized: ready to meet certain density distribution and volume of themolten plastic.

(6) retreat: preventing plasticized melt due to expansion from the nozzlewhen overflow, appear / salivation phenomenon of 0.

(7) cooling: cooling molding plastics mold cavity.

(8) the mold: divided into slow mould, rapid tooling, mold three stagereducer.

(9) out of the top: the product from the mold ejector.

Among them, the rotating speed and plasticizing motor speed, speed of injection mold opening needs to focus on speed control; pressure and back pressure needs to emphasize the plasticization pressure control; injection,Kai Suomo, top, plasticizing need accurate position control; cooling temperature of barrel temperature, need to focus on temperature control.

2 electronic control system principle of work

By the condition of vertical injection molding machine shows that the vertical injection molding machine parts run is connected in sequence and certain time interval. In order to realize the accurate control of the order process,the system selects a PLC to coordinate between electrical motor, inverter,sensors and other various components are connected with the control.

The control system can be divided into 3 main parts: controller, MC anddriver. Among them, the control panel, PLC and programmable operation display (POD) are collectively referred to as the host controller, the main function is to set the control parameters, display control results, machine coordination in every link of the action sequence. MC in the coordination between host controller, to complete the motion control, and the controlresults and the relevant state transfer to the host controller. As the mainfunction of inverter drive is the instruction signal, receiving the MC drive motor, to complete the corresponding action.

Brief introduction of electric control system composed of 3

The 3.1 mode of operation

By inducing fully electrical injection molding machine vertical PLC there are 3 different ways of working:

(1) manually by vertical injection molding machine operation panel on the manual button, can check each program operation is normal, the runtimecan be connected on the PLC communication module and a personal computer through a RS232 line (PC), real time observation programexecution situation.

(2) semi automatic press semi automatic button, and vertical injection molding machine before and after the safety door is closed, vertical injection molding machine will complete a cycle of work after the stop waiting for the next time you start.

(3) the only difference between automatic and semi automatic working modeis that it not only completes one cycle but continuously running down. The normal work of vertical injection molding machine, the whole productionprocess is under the automatic control mode.

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