Mold Oil Cylinder

SIDI hydraulic mold cylinders are finely crafted, exquisite in appearance, and have stable quality. Many mold manufacturers are gradually replacing imported cylinders with SIDI hydraulic mold cylinders.

Classification of mold cylinders:

1. Lightweight cylinders, front flange installation

2. Heavy-duty cylinders, front flange installation, including inductive heavy-duty cylinders, front flange installation

3. Thin cylinders, including inductive thin cylinders

4. Column cylinders

5. Thin-shaped cylinders

 1、 Die cylinder details

2、 Example Diagram of Mold Cylinder Application

3、 Use of die cylinder

Mold oil cylinders are mainly used in die-casting molds and plastic mold equipment, often using HOB heavy-duty rod type oil cylinders (convenient for disassembly and maintenance), and also using thin oil cylinders (used when installation space is limited).

1. Oil cylinder for fixed mold core pulling

The fixed mold core pulling is driven by an oil cylinder, greatly simplifying the mold structure and reducing costs; However, it is necessary to pay attention to the control of the action sequence and the locking of the slider, in order to avoid damage to the mold or insufficient locking force of the oil cylinder that prevents sealing, and insufficient core pulling force that prevents the slider from being pulled.

2. Oil cylinder is used for large stroke slider or inclined slider core pulling

When the slider stroke is large or the moving mold slider tilts towards the moving mold edge, if the inclined edge is used for core pulling, its stress is poor and it is easy to be damaged; Oil cylinders can be used to improve stress conditions.

3. Oil cylinder for product ejection

A. When the ejection stroke exceeds the ejection stroke of the injection molding machine, it can be considered to  use a hydraulic cylinder for ejection.

B. Eject from the fixed mold (commonly used structure for inverted molds).

C. Eject from the side.

In such applications, attention should be paid to the installation position of the oil cylinder, and a balance force system should be formed as much as possible between the pushing force of the oil cylinder and the force exerted by the pushing element on the ejector pin assembly plate, to reduce the overturning force of the ejector pin assembly plate moving push plate guide column and ensure smooth operation of the ejector pin assembly plate.

4、 Calculation of cylinder driving force

In general, during mold design, designers choose the oil cylinder through analogy, without calculating the driving force of the oil cylinder. But if there are no analogies or in some uncommon situations, it is necessary to calculate the driving force of the oil cylinder correctly in order to select the appropriate size of the oil cylinder. Refer to the "Pressure Cylinder Bore Stress Comparison Table".

5、 Determination of cylinder stroke

The stroke of the oil cylinder is determined based on the stroke of the moving components, and the piston end clearance of the oil cylinder must also be considered when determining the stroke of the oil cylinder. The function of the piston end gap is to provide sufficient oil pressure area for the cylinder to start smoothly, avoiding the inability to start the cylinder due to insufficient starting oil pressure area, and reducing the impact between the piston and the cylinder.

Cylinder stroke L=stroke of moving parts S+2 × Piston end play

(The end clearance of the piston is generally chosen as 5mm)

6、 Signal control of cylinder stroke

In the mold structure, the oil cylinder should have a stroke limit control switch to ensure piston end play; At the same time, it should have the necessary signal source for automatic control during mold production.

1. Signal control for cylinder ejection:

The ejector pin plate must be fully reset by the oil cylinder to avoid forced resetting during mold closing;

Therefore, it is required to have high precision of switch action and design adjustment devices.

2. Control signal of the dynamic slider oil cylinder:

Both limit positions of the slider should be designed with adjustable travel switches. When there is interference between the ejected part and the slider, the ejector pin assembly board must be reset before closing the slider, and the mold can only be closed after the slider is closed.

3. Control of the fixed mold slider oil cylinder:

When taking parts from the driven mold, the slider should be pulled out before opening the mold; Determine whether to close the slider or mold first based on the specific structure.

7、 Connection form and thread of oil cylinder

Pay attention to whether the threads connected to the oil cylinder are coarse or fine threads. It is required to indicate M outer diameter X thread pitch in the drawing, such as M18X1.5

Special emphasis:

The stroke of the oil cylinder is controlled by a stroke switch, without using time control. The opening and closing of the oil cylinder must use a travel switch.

The reset oil cylinder must be safe and reliable during ejection and reset, and the installation method can be the original body or the structure shown in the figure below. The two oil cylinder fixing plates are fixed with M16 screws, one is fixed on the movable mold fixing plate, and the other is fixed on the ejector pin plate and ejector pin base plate.

The oil pipe adopts a 3/8 quick connect plug.