Hydraulic control of injection molding machine hydraulic system
A. The hydraulic control of the injection molding machine hydraulic system, like the hydraulic transmission, includes the power element, control element and executive element, and also transfers power through oil. The different point is the hydraulic control with feedback device, the effect of feedback device output components is the implementation of the (displacement, speed, strength and other mechanical quantity) feedback back to the input quantity (can be change, also can be a constant), comparison with the deviation of control system, the components of the output of the changes over the amount of input or constant. It is a closed loop hydraulic transmission system, also known as hydraulic servo system or hydraulic servo system.
B. The on-off or logical control elements are used in the hydraulic transmission system. For its control purposes, it is to maintain the stability of the set value or simply change the direction.
C. Servo control element is used in the hydraulic control system, which has feedback structure and is controlled by electrical device. It has high control accuracy and response speed, and the controlled pressure and flow rate are constantly changing. Output power can be amplified.
D. proportional control is a control between the above two, the proportional control valve is used in the on-off control element and servo control element on the basis of the developed a kind of electric - hydraulic control elements, some of the characteristics of both the above two kinds of components, is used to control the on-off type with the hand can't meet the requirements, but also do not need the servo valve on the hydraulic system as strict pollution control requirements of the occasion.
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