For injection molding machine heating system master, maintenance need to pay attention to what points?

If AC contactor operates for a long time and moves too frequently, its main contact will be singed, damaged or loose. Timely maintenance is particularly important. The electromagnetic coil of its AC contactor is connected to the power supply for a long time, which will also cause heat deterioration, noise and so on, so it needs to be removed and replaced frequently.

The heater works for a long time and has a certain application period. But the common fault is the short circuit fault of power transmission line, burning the magnetic connector or heating cylinder terminal. Power short circuit faults are mostly caused by human errors, such as rubbing machine involved, plastic leakage during injection molding, loose nodes and so on. Therefore, when the heating cylinder is removed and replaced, the installation should be firm and the wiring should be reliable. The wiring of the heating cylinder terminal should be done first, and then the power plug should be connected. Generally, the heating tube works for several hours, and then carries out a moment to prevent the node from loosening due to heat expansion and cold contraction.

Temperature controller is the key of heating power circuit. Its accuracy immediately endangers the quality of injection molding products, especially in the plastic with accurate temperature regulation, otherwise the compound will burn, fade or scald. The temperature controller collects the temperature signal of the heating cylinder, compares it with the set temperature signal, and controls it according to the temperature controller whether it is heating up or heat insulation.

Thermocouple is a temperature magnetic induction component, which should be installed reliably, inserted into the temperature measuring hole properly, and the thermocouple guide wire connection should be firm and reliable. In the process of general application, the temperature control meter has a certain deviation, which can be accurately measured by the thermometer to check the temperature control accuracy. The common rubber is generally the deviation ± It can also be used at 10 ℃.

The most common fault of temperature controller is the control is not good. The key is that the contact of relay in the table is burnt and calcined to make the temperature not good and the temperature control is inaccurate. The large deviation category is caused by the fault of dial power switch or the characteristics of integrated circuit chip in temperature instrument. It can also be caused by internal power supply circuit such as voltage stabilizing diode, resistor, precision resistance and other faults. The head of the temperature gauge is broken and cannot be controlled.

The maintenance of heating power supply circuit can start from the power supply part to the heating cylinder part, accurately measure and calibrate the power supply circuit to identify the fault point and electronic devices, then remove and replace the damaged electronic devices, and finally adjust the effect. Pay attention to the model, shape, specification and main parameters when replacing electronic devices, especially the measurement range number of thermocouple, the output power of heating cylinder and its series installation. The nozzle heating cylinder should be minimized to be damaged by glue leakage.