You have been in the mold industry for 10 years, why no newcomer for 2 years will use oil cylinders

- Apr 06, 2020-

I remember one time I used several oil cylinders in a set of mold equipment, and suddenly one day the oil cylinders were inexplicably leaking oil, and the leaders were scolded miserably. A colleague vomited to me that the application of the cylinder in the mold is mainly to solve some large strokes and large output thrust or slippage, and some normal mold parts are difficult to achieve and require external force to push the mold output. Such as flip-mold, the operation seems to be simple, but if you do n’t pay attention to it, there may be oil leakage. The imbalance of the template will cause the phenomenon of jamming, which will cause the oil cylinder to leak and the quality of the oil cylinder is also relevant. For example, the seals used in the oil cylinder, the oil used for the first time, and whether all the assembly parts of the oil cylinder are torn, milled or die-cast, these have an impact on the life.

Next, let's take a look at some common knowledge of the use of oil cylinders to see which ones you don't know yet!

How to choose an oil cylinder? In the industry, there are thin cylinders and standard cylinders. Look at the difference between these two cylinders and how to use them.

1. The difference between standard cylinders and how to use them

Standard cylinders generally choose cylinder bore and stroke. Different installation methods can be selected according to mold structure requirements, and those with magnet induction and those without magnet induction can also be selected. (Magnet induction is transmitted to the cylinder through a certain model, so that various actions can achieve the desired effect, and some molds with specific requirements can be selected. Without magnet induction, only the push and pull in the inherent stroke of the cylinder Action) Then select the appropriate cylinder diameter and the required cylinder stroke according to the required structural force. Then select the shape of the front end of the piston rod (such as internal teeth, external teeth or T-groove, etc.), and there are high temperature resistant and non-high temperature resistant options. (Although the specifications of each cylinder manufacturing company are different, the product principle is the same)

1. Installation Example of Cylinder

2. Thin cylinder

As the name implies, the thin cylinder is thinner and smaller, and it is used on some devices with compact structure and small stroke.

According to the mold equipment, different shapes of oil cylinders and installation methods can be selected:

There are square, flat, vertical, horizontal, and oil cylinders with different oil inlet and outlet directions. You can also choose to have magnet induction or not. (With magnet induction, the stroke of the oil cylinder is fed back to the injection molding machine. Some molds with specific stroke requirements can be selected. Without the induction line, only the push and pull movements are within the inherent stroke of the oil cylinder.

According to the size of the required structural force, select the appropriate cylinder diameter and the required cylinder stroke. Then select the shape of the front end of the piston rod (such as internal teeth, external teeth or T-groove, etc.), and there are high temperature resistance and high temperature resistance options.

2. Installation Example of Cylinder

1. The position of the cylinder before pumping

The front die row is driven by an oil cylinder, which simplifies the mold structure, but it is necessary to pay attention to the control of the movement sequence and row position locking to avoid disordered movements, damage to the mold or insufficient locking force of the oil cylinder to seal the glue, and insufficient core pulling force Line position.

2 Oil cylinder pumping large stroke line position or oblique line position

When the travel of the row position is large or the row position of the moving mold is inclined to the moving mold side, if the core is pulled with the beveled edge, the force is poor and it is easy to damage. The oil cylinder can be used to improve the force.


3. The oil cylinder is used to eject the product

A. When the ejection stroke exceeds the beer machine ejection stroke, consider using a cylinder to eject

B. Ejected from the fixed mold (common structure of flip mold)

C. Eject from the side

In equipment like this, the installation position of the oil cylinder should be paid attention to, as far as possible, the ejection force of the oil cylinder and the force of the ejector element on the thimble assembly plate should be balanced to reduce the overturning force of the thimble assembly plate and the thimble assembly plate. Move smoothly.


The different methods of using different types of cylinders were introduced earlier. What should we pay attention to during the use? Let me give you the key points, you must keep in mind the five major points when using oil cylinders, reduce mistakes, and be an excellent molder.

Five-point cylinder considerations

1. The front thread of the piston rod of the oil cylinder is a small pitch, pay attention to the selection of related parts.

2. As far as possible, do not install an oil cylinder on the side of the sky to avoid oil leakage from the oil cylinder and falling on the mold and products, causing damage to the mold and defective products. The operating temperature also needs to be considered. If the temperature is higher, the seal will soften and oil leakage will occur. If necessary, heat insulation plates can be added between the mold and the oil cylinder to reduce the phenomenon of high temperature intention of the oil cylinder.

3. When there are two or more oil cylinders acting on the same plate or part at the same time, such as the two oil cylinders of the flip-chip mold, when the external oil circuit is directly connected, there may be different oil pressures at both ends, and the template is unbalanced , Leading to stuck. At this time, it is necessary to make an integrated oil circuit part, first connect the external oil to the part, and then shunt to the two oil cylinders through the part, in order to balance the pressure of the oil circuit at both ends, so that the ejection is balanced. (The integrated oil circuit parts are as follows)

4. When the mechanism of the oil cylinder needs sealing, because the injection pressure is relatively large, when the thrust of the oil cylinder is not as good as the injection pressure here, injection pressure will occur to push the mold mechanism and the oil cylinder back together, resulting in defective products or even molds. damage. Therefore, it is necessary to add a top block similar to the shovel base to prevent the parts from being pushed back during injection. As shown below.

5. When designing the oil cylinder, it is also necessary to pay attention to the space position on the mold and select a reasonable oil cylinder to reduce the size of the mold, that is, a smaller injection molding machine can be used to save equipment costs. After the cylinder is installed and the fixed stroke cannot exceed the sides of the mold thickness direction, otherwise the injection molding machine cannot be installed. When the oil cylinder is designed on the side of the mold, it is necessary to increase the foot to protect the oil cylinder mechanism.