Analysis of Three Aspects of the Failure of the Injection Molding Machine to Open the Mold

In the maintenance of injection molding machine, the failure of mold opening is often encountered. Failure to open the mold is mainly divided into three fault phenomena: no action with pressure, action with pressure and no action without pressure.

1. Pressure or no action:

First, check whether the display light of the mold opening valve on the output board is on. If it is on, it indicates that the computer output is normal and there is a problem with the circuit from the computer to the mold opening valve. The simplest way is for one person to push the mold opening valve with a small electric pen and the other person to open the mold. If the mold can be opened smoothly after pushing, it is to confirm the route problem and pull a wire again to solve the (circuit problem).

2. There is pressure and mold opening action, but the mold cannot be opened:

It indicates that the output board is normal, and the circuit from the output board to the valve is also normal. There are four situations:

The first kind: the fastening screw of the piston of the mold locking oil cylinder is loose, resulting in the screw roughening in the oil cylinder, such as the piston rod is stuck.

The second kind: mechanical anti lock. The best way is to remove and unlock the die pipe and operate it with a jack, so that the machinery will not be damaged.

The third is caused by the immobility caused by the twisting machine (such as burning of the twisting edge, etc.).

Fourth: caused by interference (oil interference and circuit interference), if the valve core is clamped and the mold opening action is required at the same time, the oil supply of the oil pump cannot reach the pressure and flow required for mold opening, of course, the mold cannot be opened; Another kind of interference is the interference of the circuit. For example, the mold opening wire is connected with the mold locking wire. Because the mold opening valve and the mold locking valve work at the same time, the pressure is about 20kg, so the mold cannot be opened.

3. No pressure, no action:

However, check that the computer output board is normal, there is pressure and speed, the mold opening valve has output, and the computer home page shows it. In this case, we will check other actions, such as the shooting platform and shooting seat. It shows that this phenomenon belongs to the mold opening singleness. Generally, it is checked that one person opens the mold, and the other person uses a multimeter to measure whether the coil voltage of the mold opening valve is about 22-30v, If yes, we will temporarily pull out the plug of the mold opening valve coil and open the mold. If there is pressure but no action, we just need to disassemble the mold oil cylinder and make sure that there is a piston in it and loosen it from the piston rod.

Because the oil circuit of the injection molding machine is roughly the same, this situation exists in mold opening, and so will other actions. The maintenance focuses on induction and summary. From this fault, we find that the maintenance is simple and complex. In short, it changes in four aspects: circuit, hydraulic pressure, oil circuit and machinery.

When it comes to complexity, we generally pay attention to the troubleshooting sequence, from simple to complex, that is, circuit, hydraulic pressure, oil circuit and machinery. If the inspection sequence is inappropriate, it will be laborious and time-consuming to repair.