Background technology
The common all size and the injection machine of structure, hydraulic mechanism adopt quantitative oil pump and ratio flow pressure valve as the power components and parts, and injection and holding pressure control adopt common electromagnetic direction valve, and the plasticizing back pressure adopts overflow valve.The injection machine of these structures adopts open loop control mode, during device work, provides and set value the control signal of corresponding to pressure, flow by controller, and ratio flow pressure valve is by this corresponding pressure of signal controlling mechanism and flow.The control procedure of open loop can be subjected to the influence of various changing factors such as oil temperature, greasy dirt and the fluctuation of load, and its throttling and spill losses are all big, energy consumption is also higher, response speed is slow, and control accuracy is low.Its control accuracy and repeatable accuracy can only satisfy the control requirement of conventional products.
In order to improve response speed, the load-sensing formula rate variable pump machanism that has adopted high response on some injection machines is also arranged, though this kind injection machine has than much progress than traditional injection moulding machine on energy-conservation, but the response speed of mechanism is still very slow, control modes such as its flow, pressure, speed, position still are open loop control, the control accuracy of mechanism and repeatable accuracy are not high, can not be suitable for high speed, High-efficient Production or precise injection molding requirement.
External also have some injection machines to adopt all-electric servo-drive, it has adopted a plurality of AC servomotors to drive simultaneously, and has used high-precision sensor, has guaranteed the low energy consumption and the high accuracy of this device, be applicable to the manufacturing of high-accuracy property product, have excellent performance.But because cost is higher and the core technology restriction, homemade molding machine is used less.
The utility model content
The purpose of this utility model is to provide that a kind of simple and reasonable, low cost of manufacture, volume are little, compact conformation, debugging is easy, control accuracy is high, energy consumption is low, and to flow, pressure and the rotating speed plastic-injection moulding machine control device that carries out closed-loop control of device, to overcome weak point of the prior art.
The technical scheme that its technical problem that solves the utility model adopts is: a kind of control device of plastic-injection moulding machine, the hydraulic drive mechanism and the electrical control mechanism that comprise injection machine, it is characterized in that hydraulic drive mechanism is provided with the load-sensitive type proportional variable pump of high response AC servomotor and driving thereof, to realize closed-loop control.
Be provided with shaft coupling between high response AC servomotor and the proportional variable pump, shaft coupling is provided with oil pump bracket outward, in order to closed coupling and proportional variable pump.AC servomotor has been equipped with servo-driver, and when mechanism worked, power output was adjusted automatically with changes in process parameters, in order to regulate the rotating speed of AC servomotor.
Be provided with pressure sensor between proportional variable pump and the servo-driver, the pressure signal of proportional variable pump can feed back to servo-driver by pressure sensor, to realize the closed-loop control and the online detection of system pressure.
Be provided with internal encoder in the AC servomotor, internal encoder is given servo-driver with the motor speed signal feedback, to realize the closed-loop control and the online detection of motor speed.
Electrical control mechanism is provided with the PC controller, in order to send and to handle various system operational parameters.
The utility model hydraulic mechanism has adopted high response AC servomotor to drive the high-efficient energy-saving power mechanism of load-sensitive type proportional variable pump, the use of proportional variable pump, realized that hydraulic injection molding machine mechanism changed into the transformation of pump control by the valve control, make conventional throttle grverning mechanism change volumetric speed control mechanism into, the control performance index of complete machine has had new improving.In mechanism when work,, the rotating speed of the different adjustment AC servomotor by power output, thereby control and resize ratio variable pump delivery parameter (swashplate angle) come the flow output of guiding mechanism and carry out pressure and control, and can realize closed-loop control.The adjustable motor rotating speed is zero when the device cooling, proportional variable pump is output flow no longer, be in complete halted state, can not produce unloaded energy loss, consumed power of whole machine lowers greatly, compares with conventional machine, and 40%-65% can economize on electricity, energy-saving effect is obvious, than the injection machine power saving effect of present oil pressure actuated bigger improvement is arranged.
The utility model dynamic response is fast.Servomotor has high response speed, but the height of implement device response control is fit to efficient and precise injection molding.
The utility model good reproducibility.AC servomechanism cooperates various sensors, can realize the closed-loop control of machine speed and pressure.
The utility model compliance with environmental protection requirements is saved hydraulic oil and cooling water.The device heating significantly reduces, and can save hydraulic oil and cooling water more than 30%.
Electrical control mechanism output is used to control the analog control signal of different range of the load-sensing formula proportional variable pump of high response.
The utility model is simple and reasonable, low cost of manufacture, volume are little, compact conformation, but debugging is easy, control accuracy is high, the low high speed injection of energy consumption.
The specific embodiment
Referring to Fig. 1, AC servo drives variable pump mechanism and mainly comprises high response AC servomotor 1 and load-sensitive type proportional variable pump 4.AC servomotor 1 drives proportional variable pumps 4 work by shaft coupling 3, the shaft coupling 3 outer oil pump brackets 4 that are provided with, and in order to closed coupling 3 and proportional variable pump 4, when each parameter change of servomotor 1 output, mechanism pressure or flow also change thereupon.5 is servo-driver among the figure, and 6 is the PC controller.
Referring to Fig. 2, electrical control mechanism is provided with the PC controller, in order to send and to handle various default operational factors.At first, pass to proportional variable pump by the pressure and the speed of each action of technological requirement set mechanism of injection mo(u)lding, these setting values can be transformed into corresponding analog signal (current signal or voltage signal) and flow to servo-driver simultaneously.Servo-driver flows to AC servomotor with this setting signal, and this motor sets value to mechanism's outputting power by these, and realizes the work of mechanism by driving proportional variable pump.Proportional variable pump is according to receiving the dynamically working that motor is carried, and the power of received pressure signal P S and flow signal VS and motor input made comparison, the discharge capacity parameter (swashplate angle) of control and adjustment itself, provide driving needed pressure of load and flow to device, realize the online detection and the closed-loop control of pressure and flow signal.Simultaneously, the pressure signal of proportional variable pump feeds back to servo-driver by pressure sensor, has realized the closed-loop control and the online detection of device pressure.
The AC servo drive motor relies on internal encoder to give servo-driver with the motor speed signal feedback in outputting power, has realized the closed-loop control and the online detection of motor speed.