How many of these injection molding machines have mold opening failures?

Time：2021-03-25 15:02:49 / Popularity： / Source：

1. Injection molding machine can't open mold again. There is pressure, speed, oil to cylinder, and pressure is 120kg. Why do you often cannot open mold?

1 Is oil seal of mold opening cylinder damaged?
2 Is mechanical part of clamping mechanism stuck?
3 Check mold opening valve; see if spool is not in place?
4 Are speed, pressure, and position parameters appropriate?
5 Is mold opening position reached? Look at screen to check electronic ruler or mold opening stop travel switch.
6 If this kind of problem often occurs, first check oil circuit part, but mechanical part should pay more attention to inspection to see if there is any wear or unevenness of connecting rod.

2. It is normal when mold is opened manually. But in semi/automatic mode, when mold is opened to set position, it stops for a while without stopping, then displays P and F values set for slow and fast speed, so that mold opening overtravel cannot be produced.

Preliminary exclusion:
①P and F are set too large; there is no problem of mold opening inertia.
②Electronic ruler has been replaced.
③Program test is normal.
1 Mold opening back pressure is not set or related oil circuit is faulty.
2 Unreasonable setting of switching point of mold opening speed and slow speed position.
3 Check mold opening solenoid valve core.
4 P.Q valve check, whether spool movement is linear.
5 Is there a signal stop lag in computer output?
6 Mold opening pressure, flow setting is too large.

3. There is a Haitian 240 machine, which has been in service for less than ten years. More than a year ago, because mold was often not opened, a full set of machine hinges had been replaced. Later, machine could not be opened after mold was locked, and it needed to be knocked out manually. Then we replaced the whole set of hinged steel sleeves, but problem was not completely solved, or old problems often recurred. Specific conditions:

1. When mold is locked to low pressure protection position, two cross guide rods have signs of being lifted up, and there are signs of being pressed down when mold is opened. Reason why mold cannot be opened is that cross cannot pass ※ point, so one tap is equivalent to adding a little external force to open mold;
2. Measures that have been taken: In addition to changing hinged steel sleeve, cross copper sleeve was replaced, and balance was adjusted when suspected that Corinth column was unbalanced, but fault remained!
1 Replace 2 guide rods of crosshead! Suspected variant.
2 You can adjust foot of a moving plate, and increase moving plate a bit higher. Machine has been used for a long time, wear and other reasons lead to sinking of moving plate.
3 Confirm that failure was caused by failure of various procedures when hinge steel sleeve of machine was first dismantled and replaced, assembly errors occurred, resulting in inconsistent upper and lower crank arms. It should be listed as company's obsolete machine.
4 Never high-pressure mold clamping when shutting down.
Fourth, this situation has occurred 4 times in a plastic machine. In the past, it was used to increase system pressure and flow; use a hammer to knock arm; use a jack to open it with back of crane. This time, above methods have been used. I can't open it even after it's finished, and 4 guide pin nuts can't be loosened. Ask if there is any way to open this machine.
1 Loosen nut connecting piston rod of clamping cylinder and cross by about 1cm, then open mold, using its inertia should be 70% open.
2 Set slow mold opening position to 0, set rapid mold opening pressure and speed to maximum.
3 Check crank arm, there must be wear (replacement).
4 Guide rods on both sides of clamping cross are loosened. It can be opened at once. In addition, machine has to adjust spacing of four columns, or it won’t open.
5 First, it is necessary to distinguish whether it is a circuit problem or an oil circuit problem. When mold is not opened, check whether 24V power is on solenoid valve and whether system is under pressure.

6 There is also problem of electronic ruler. Check whether digital ruler is correct when mould is not opened.
7 Use a jack to place between crank arm cross and ejector cylinder to make it tight, then use machine tool to open mold slightly.
8 Tighten fixing screws balanced around mold (to ensure that there are more than 8 symmetrical screws). After confirming that mold is installed correctly, adjust mold opening buffer, reduce mold opening speed, then increase mold opening pressure in turn.

5. When front safety door is opened during semi-automatic operation, mold opens automatically. I don't know what went wrong?

1 Program setting stipulates that safety door (imported equipment) cannot be opened before injection action is performed during semi-automatic operation.
2 Check safety door limit switch!!
3 Check whether clamping is terminated I/O observation
4 Program error (normally made in China)

6. After mold is opened to the end, it will bounce back about 20mm. What is matter?

1.Mold opening stroke setting is unreasonable, buffer speed pressure is too large, and position is too small.
2. This phenomenon will also occur if there is air in mold opening cylinder.
3. It should be slowly crawling 20mm when ejecting. If so, check clamping valve.
4. First check position of reversing valve and cylinder seals. There is also slope of pressure.
5 Use countersunk screws to adjust opening and closing adjustment of mold opening and closing directional valve internal pilot oil small holes (X, Y) can ease.
6 It is also possible that air filter element of fuel tank is blocked and exhaust is not smooth!
7 Leakage in mold opening cylinder. Check piston seal, thread between piston and piston rod for leakage.

7. Injection molding machine was suddenly powered off just after injection. After 4 hours, machine was turned on and found that mold could not be opened. What should I do?

1 Check if there is something burnt in open circuit part (in the case of no output).
2 It is about mold, because power was cut for too long, and there were products in it, it was uplifted at once.
3 It may be that solenoid valve of switch mold is stuck. Try adding one plus pressure of mold opening.
4 Open mold after adjusting PQ. Then resume.
5 If it doesn't work, you have to use a jack to open mold plate.

8. When 150T shooting table moves or glue is shot, mold will slowly open, changeover valve for opening and closing mold can not solve problem after changing a few.

1 Have you checked hydraulic control valve under switch mold valve and whether one of springs on both sides is broken.
2 Clamping is too tight, adjust it again (semi-automatic).
3 Check internal leakage of oil seal of clamping cylinder (semi-automatic).
4 End of mold clamping stroke switch is pressed too far (semi-automatic).

9. Machine that is normally produced normally, after a restart, a strange inertia suddenly appeared. Press mold in manual mode, then release it immediately, mold will not stop moving and will move a certain distance along original route. This is phenomenon of mold-off and shooting seat. I don't know what's going on.

1 There is a problem with hydraulic oil, and there are sediments. These sediments will accumulate in oil system after machine is stopped for a period of time, which will hinder movement of spool and slow its recovery, or solenoid valve coil may generate magnetism.
2 Due to dirty hydraulic oil, spool of each action valve is returned to wrong position. Wash oil tank and replace hydraulic oil

10. There is a small injection molding machine here. Failures are as follows: Pressure gauge shows 140 when mold is locked, front and rear firing table (high pressure stick of mold is not pushed to stop switch), but there is no pressure when mold is opened, hydraulic pressure of mold is displayed when mold is opened, but mold still cannot be opened.

1 Is mold opening valve stuck?
2 See if there is no pressure relief on clamping pressure side?
3 Check opening and closing mold cylinders. You can swap two oil pipes for a try to confirm whether there is internal leakage.
4 Oil seal in mold opening and closing cylinder is broken.

11. There is a Haitian injection molding machine, and computer is from Fuji, Japan. During production process, mold opening has not been positioned, (position is set to 800, and field position is on 801.9), alarm always appears. Mold opening speed has been very slow, and it still does not work. Check that electronic ruler is not loose. May I ask what caused it.

It is judged that value of effective area of mold opening is set too small! Change allowable error of effective position to be larger. Look at parameters and set a number with more than ten digits!

12. Injection molding machine is turned off after production is completed, mold cannot be opened when production starts on second day. What is reason?

1, It must be in mold clamping and high-pressure clamping position when machine is stopped, vacuum and gravity are formed in mold.
2, Parts of opening and closing mechanism are damaged, lack of oil.
3, Due to air in opening and closing mold oil circuit.

13. After machine closes mold, mold can't be opened. In manual state, there is no response at all to open mold. Mold opening pressure also displays 0, and pressure displays 35 when mold clamping button is pressed, which is a normal value. May I ask this what is reason?

1 Increase pressure and speed to open mold!
2 Pressure pre-adjustment is to turn on after total pressure of system is increased.
3 Check piston oil seal of opening and closing mold cylinder.
4 Whether 2 proportional ammeters work, you can also turn on larger current.
5 Manual mold opening signal is not sent to computer controller. First look at pressure gauges of other action gauges, whether pressure and flow ammeter indications are normal, adjust and increase pressure to try! If machine is normal, it still can’t be turned on, check oil circuit, mold opening position, etc.!

14. After product is injection molded during production process, mold cannot be opened in a semi-automatic state.

1 First confirm whether there is a product in mold, and then treat it differently.
2 Then confirm manual and semi-automatic state control conditions respectively.
3 Mold opening signal, mold opening solenoid valve, pressure and flow conditions
4 Check whether pressure is relieved in semi-automatic state.

Gud Mould Industry Co., Ltd