Injection molding machine ejector pin failure repair practical methods

When the ejector pin action of the hydraulic injection molding machine is abnormal, we can check and troubleshoot one by one for the following reasons: first of all, you can start the electric machine oil pump, the manual state of the injection table before and after the action or injection melt glue action, if these actions can be carried out normally, you can verify that the injection molding machine oil pump, proportional pressure valve, proportional speed valve, and related circuits are normal. Then check whether the parameters of ejector action are set correctly, such as ejector pressure, speed, position, and the number of times.

According to the ejector action, check whether there is an electrical signal to the ejector reversing valve solenoid coil, the general reversing valve solenoid coil using DC 24 volts, there are very few old machine solenoid reversing valves using AC 220 volts control. If there is no voltage signal to the two signal lines may be an off-line failure. Check the l / O electronic board output port whether there is voltage output. If not, continue down to check the output amplifier transistor or in the question whether the relay is good.

Check whether the resistance value of the solenoid coil is normal. The general coil may have an internal broken wire or burned phenomenon. Then you need to replace the solenoid coil.

The reversing valve spool has foreign matter stuck, generally foreign matter from the oil circuit to do seals or metal parts aging broken and so on into the valve, so to disassemble and clean.

Ejector cylinder seals damage caused by oil tampering or piston rod fracture can also cause the ejector action abnormal. Check whether the limit switch next to the ejector cylinder is good.

Earlier repaired an injection molding machine ejector action abnormal fault: the machine each molding can not eject the product, but it has ejector action, but can not reach the set ejector position, so the plastic parts can not be removed from the mold. It is useless to modify each parameter. The mold ejector plate is also smooth.

Normal in the computer set ejector position 40mm can be demolded, after observing the computer display, each ejector position to 17mm or so stopped, and the ejector process position value display has interval jump phenomenon.

So first check whether the electronic ruler's three signal lines are in good contact; measuring the signal voltage is also in line with the electronic ruler requirements. Electronic ruler "1" "3" feet connected to the positive and negative end of the power supply, "2" feet for the output signal, "4" feet is the ground terminal.

And then disassembled the electronic ruler, tie rod brush or good, just dirty. So the electronic special cleaning agent to clean the brush and resistance track, and then coated with Vaseline grease lubrication. Assemble and test the machine, all normal.

An injection molding machine with an electronic ruler is actually a sliding resistor. If it is dirty inside; resistance track is bad; or dynamic ruler contact shrapnel wear or deformation; electrical signal line poor contact. All may lead to abnormal action.

Do not look at the electronic ruler structure is simple, but in the assembly must be careful to pay attention to, in particular, the installation of the pull rod brush, never let the dynamic ruler shrapnel brush deformation, just let the brush and resistance track contact good