1. Check the wire connector
Wires with loose joints will cause high temperature or sparks at the joint position and damage, and poor joints will also affect signal transmission; the joints on the contactor will be easier to loosen due to the vibration of electromagnetic action, so it is necessary to check the tightness of the wire connector regularly.
Each contact point of the injection molding machine circuit must be kept tight and must not be loose. In order to avoid affecting the heat dissipation function of the electric box, pay attention to the working performance of each exhaust fan at any time, and clean the dust on the dust screen and replace the dust screen in time. Check all wire connection points in the electric box once at the prescribed time to check whether the plastic shell of the wire is hardened to prevent leakage.
2. Check the motor
Generally, motors are air-cooled, and dust accumulation will cause heat dissipation difficulties, so regular cleaning should be done every year. Usually, a motor overload cut-off device is installed in the circuit. The limiting current of this protection device is adjustable and should be appropriately selected according to the motor power. At the same time, once the overload protector is activated, the contact should be checked to see if it is bad or the oil temperature is too high before pressing the reset switch.
3. Check the heating tube and thermocouple
The heating tube should be checked regularly to ensure effective heat transfer. In normal production, the burning of the heating tube is not easy to detect. For this reason, attention should be paid to the working conditions of the temperature control zone to judge whether the heating tube is normal. In addition, the common damage to the heating tube is the connection of the wire. Due to the poor joint, the contact resistance increases, causing the local overheating of the connection to cause the interface to oxidize and damage. The contact points of the thermocouple should be kept clean.
4. Check the AC contactor
The contactor used for the electric heating part has a relatively frequent operation frequency and its loss rate is also relatively fast. If the main contact is overheated and melted and bonded, it may cause the heating temperature to be out of control. Therefore, if the contactor is found to be overheated, makes a sound, or has a large spark when disconnected, it means that it will be damaged and should be replaced as soon as possible.
5. Check the microcomputer control part
With the application of microcomputer control technology in injection molding machines, the normal operation of the microcomputer part and its related auxiliary electronic version has put forward higher requirements for the fluctuation of power supply voltage, the temperature and humidity of the working environment, the seismic resistance of the installation, and even the interference of external high-frequency signals. Therefore, it is the basic requirements for normal operation to maintain ventilation and heat dissipation in the control box, use high-precision power supply stabilization equipment for power supply, and try to reduce the influence of external vibration on the control box. These problems should be solved and checked regularly.
6. Others
a. Check the buttons on the operation panel and whether the safety door is hit. If necessary, adjust it.
b. Check whether the travel switches and parts in the machine body are loose, whether the wires are damaged, and check each junction box.
c. Check the power distribution cabinet: clean the dust, tighten the screws of the terminals of each electrical component (contactor, terminal block, microcomputer controller), and clean up the messy wires.
d. Check the heating part: tighten the heating coil, tighten the terminal, check the heating junction box, and clean up the exposed wires.
e. Check whether the barrel temperature is normal and the thermocouple.
f. Functional inspection: pressure, flow, current inspection, input and output signal inspection, position display inspection.
g. User environment inspection: whether the voltage is normal and whether there is dust affecting the electronic control part.
And it is about the maintenance items of the electrical control system of the vertical injection molding machine. Doing a good job of the relevant maintenance of the equipment can extend the service life of the equipment, ensure the stable operation of the equipment, and save corporate costs.
