Causes and solutions for 3.The angle exceeds 90° after high-pressure clamping, resulting in reverse hinge

1.The area of the mold opening hydraulic ring is too small
Mold opening force = mold opening oil pressure ring area × mold opening oil pressure
If you want to increase the mold opening force when the maximum pressure is determined, you can only increase the mold opening oil pressure ring area, and you can increase the mold opening oil pressure ring area by increasing the cylinder diameter or reducing the piston rod diameter.

2.The gap between the mold opening and the oil is too small
In the mold opening section, because the clearance between the hydraulic buffer sleeve and the inner hole of the cylinder front cover is too small, the pressure oil is slow or even difficult to enter the cylinder opening cavity, so the maximum mold opening force cannot be provided.
Increase the matching gap between the hydraulic buffer sleeve and the inner hole of the cylinder front cover, so that the pressure oil can quickly enter the cylinder opening cavity and form a mold opening force with a certain impulse, which may cause a certain impact when the mold is opened.

3.The angle exceeds 90° after high-pressure clamping, resulting in reverse hinge
The design of the hinge parameters and the stroke and installation position of the clamping cylinder determine the end position of the small hinge during the final high-pressure clamping and form a angle. The designed angle must ensure that the machine installed within the cumulative tolerance range of each part processing The angle must be absolutely less than 90°.
Once the angle exceeds 90°, the small hinge will appear reverse hinge. At the moment when the mold is opened, the hook hinge and the long hinge are leaned in a straight line to generate greater clamping force. In the end, the mold opening force is not enough to overcome the increase. Due to the deformation force generated by the large clamping force, the mold opening cannot be completed instantly.

4. The mold opening force cannot overcome the excessive deformation force
When the machine hinge of the machine reaming machine is designed, the magnification ratio of the machine hinge when it produces the predetermined clamping force to be achieved has also been determined. Based on this, the required thrust of the mold clamping cylinder can be designed to determine the diameter of the clamping cylinder. The cylinder must have sufficient mold opening force. For sufficient mold opening force, the larger the cylinder diameter, the better.
But the cylinder diameter is too large, which results in too much cylinder thrust during mold clamping, which makes the clamping force overload (when the mold adjustment is not good), the deformation force of the machine hinge is too large, and the mold opening force cannot overcome the excessive deformation force and the mold cannot be opened. .
ในกรณีนี้, it is usually possible to prevent the clamping force from overloading by limiting the high-pressure clamping pressure and flow. Be patient when adjusting the mold, and use the lower clamping pressure to adjust the clamping force as much as possible.

5. Low mold opening pressure and low flow rate, resulting in small mold opening impulse
Due to the low mold opening pressure and low flow rate, the mold opening impulse is small, which cannot overcome the deformation force of the machine hinge. การเตรียมและการอบแห้งวัตถุดิบ เนื่องจากสิ่งเจือปนในถาด IC อาจส่งผลต่อความเป็นพลาสติกของถาด IC, the first stage mold opening flow provided by the servo control system is small, and the mold opening impulse is smaller, making it more difficult to open the mold.
This problem can increase the mold opening impulse by modifying the controller’s PID and mold opening slope.

6. The temperature rise after the mold is installed and the pressure is tested, which makes it difficult to open the mold
After a period of time of pressure test, the mold heats up and expands and the clamping force increases, which makes it difficult to open the mold. Pay attention to timely adjust the modulus to make the clamping force return to the original value to avoid mold opening failure.

7. The downtime after installation and clamping is too long, resulting in failure to open the mold
After the mold is locked, the downtime is too long, which leads to the complete disappearance of the lubricating oil film of the machine hinge, and the deformation of the machine hinge further increases, which makes it impossible to open the mold.
ดังนั้น, reduce the downtime of the mold as much as possible, and remember to open the mold before shutting down, and do not shut down with the mold locked.

8. Back pressure of mold opening, resulting in insufficient mold opening impulse
Setting the mold opening back pressure in the mold opening section of the oil circuit also results in insufficient mold opening impulse. If this situation is found, the mold opening back pressure is cancelled.

9. The frictional resistance in the hinge is too large, resulting in mold opening resistance
The friction resistance between the large pin shaft and the steel sleeve in the injection molding machine hinge is too large, resulting in the need for greater mold opening force to overcome its friction resistance:
(1) The edge of the oil groove in the steel sleeve is not deburred, causing the burrs to wear into particles and enter the mating surface of the large pin shaft and the steel sleeve, and cause the mating surface to wear or burn to the mating surface.
In order to avoid this problem, it is required to trim the burrs and smooth the parts after processing these parts. Check again during installation and clean the surfaces and apply grease before installation.
(2) If there is insufficient lubrication or lubrication failure, it will also cause excessive friction resistance. ณ ขณะนี้, check whether the lubricating oil circuit is normal and whether the lubricating pump is normal.