Hydraulic transmission hydraulic system of injection molding machine: hydraulic oil as the working medium, through the power components (pump) will be the prime mover of the mechanical energy into hydraulic oil pressure can be, and then through the control element, and then with the implementation of components (cylinder or motor oil) pressure can be converted to mechanical energy to drive the load to achieve a straight line or the rotary motion, and the remote control element and flow control, adjust actuator force and speed. When the external disturbance to the above system, the implementation of the output of the component in general to deviate from the original set value, resulting in a certain error.
Hydraulic control of hydraulic system of injection molding machine:
A. injection molding machine hydraulic system hydraulic control and hydraulic transmission, the system also includes the power components, control components and the implementation of components, but also through the transmission power of oil. Two different points are hydraulic control with feedback device, the feedback device is output actuator (displacement, velocity, force and other mechanical quantity) feedback back and input (can change, can also be a constant) were compared after the comparison deviation control system, make the output the actuator changes along with the input value change or remain constant. It is a kind of hydraulic drive system which forms a closed loop circuit. It is also called the hydraulic servo system or the hydraulic servo system.
B. hydraulic transmission system is used for on-off or logical control components, the purpose of its control is to maintain the stability of the fixed value or simple transformation direction, also called the set value and sequence control elements.
C. hydraulic control system is used in the servo control components, with the feedback structure, and the electrical equipment control, there is a high control precision and response speed, control of pressure and flow of the constant change. Output power can be enlarged.
D. proportional control is a control between the two parties, the proportional control valve is a hydraulic control device of electric - based on-off control element and servo control element is developed, and some characteristics of the two kinds of elements, for hand adjustable on-off control can not meet the requirements, but also does not need the servo valve on the hydraulic system that strict pollution control requirements of the occasion.
Attention should be paid to the hydraulic system of injection molding machine:
1 users should understand the working principle of hydraulic system, familiar with the operation and adjust the position of the handle and the direction of rotation, etc..
2 drive system should be checked before the adjustment handle, handwheel is not moved, electrical switch and limit switch position is normal, the host tool is installed correctly and firmly, and then exposed part of the guide rail and the piston rod to wipe, then can open the car.
3 when driving, first start the hydraulic pump control circuit, no special control of the hydraulic pump, can directly start the main hydraulic pump.
4 hydraulic oil should be regularly checked for replacement, for the new input of the use of hydraulic equipment, the use of 3 months or so should be cleaned oil tank, replace the new oil. After every six months to 1 years for cleaning and oil change time.
Should always pay attention to the oil 5 in normal work, the oil tank temperature should not exceed 60 degrees. High temperature of hydraulic oil should be cooling, and the use of high viscosity. When the temperature is too low, it should be preheated, or intermittent operation operation in advance, so the oil temperature increased gradually after re entering the formal operation state.
6 check oil level to ensure that the system has enough oil.
7 a system with an exhaust device shall be carried out, and the system of the exhaust system shall be repeated for several times, so that the natural gas can be discharged.
8 the oil tank should be sealed, and the air filter should be set up to prevent the intrusion of dirt and moisture. Oil should be filtered, so that the oil clean.
9 system should be based on the need to configure the coarse, fine filter, the filter should be regularly inspected, cleaned and replaced.
10 of the pressure control element adjustment, general first adjust the control valve pressure system, relief valve, open to zero from the pressure gradually increase the pressure, so as to achieve the required pressure value; and then adjust the loop pressure control valve. Main hydraulic pump relief valve adjustment pressure is generally greater than the implementation of the required operating pressure of the 10%--25%. Fast motion hydraulic pump pressure valve, the adjustment of the pressure is generally greater than the required pressure of 10% --20%. The pressure should be kept in the 0.3--0.6MPa range if the pressure is supplied to the control circuit and the oil circuit. Pressure relay adjustment pressure is generally lower than the supply pressure 0.5MPa 0.3--.
11 flow control valve should be transferred from small to large flow, and should be gradually adjusted. The flow control valve should be adjusted simultaneously to ensure the stability of motion.