The width of the standard mold base should be less than the distance between the two guide columns of the injection molding machine. Generally, the standard mold base should be as large as possible after the selected injection molding machine. The current application of the mold involves each product (large as automobile, aerospace, daily necessities, electrical communication, Medical products and equipment, etc.).

1. The thickness of the blank of the standard mold base H and the closing distance of the injection machine L For different types and specifications of the injection machine, different types of clamping mechanisms have different closing distances.

2. The dimensional relationship between the distance between the mold opening stroke and the fixed and movable molds and the stroke required to push the plastic parts must be calculated and determined. The opening stroke of the injection machine should be larger than the fixed and movable molds required to remove the plastic parts. The distance between the mold and the plastic part to be pushed out must be smaller than the rated ejection stroke of the hydraulic cylinder of the injection machine.

3. The standard blanks to be installed on the injection machine should be noted: the outer dimensions of the mold blank should not be affected by the spacing of the injection rods; the positioning aperture and the positioning ring should be well matched; the position of the injection rod ejection hole Whether the ejection stroke is suitable; whether the nozzle aperture and the spherical radius match the size of the gate sleeve and the concave spherical surface of the mold; the position and the aperture of the mold mounting hole match with the moving template of the injection machine and the corresponding screw hole on the fixed template.

4. The selection of standard mold base should meet the technical requirements of plastic parts and its molding process. In order to ensure the quality of plastic parts and the performance and reliability of the mold, it is necessary to accurately calculate the mechanical properties of the mold parts, especially their strength and stiffness. Check and calculate to determine the length, width and thickness of the moving and fixed stencils and support plates, so as to correctly select the specifications of the blank.

The determination of the size of the mold blank and the insert: the size of the mold mainly depends on the size and structure of the plastic part. For the mold, the more compact the structure, the better the better. According to the product's external dimensions (planar projected area and height), as well as the structure of the product itself (lateral split type slider and other structures), the outer dimensions of the insert can be determined. After determining the size of the insert, the size of the mold blank can be roughly determined. It is.

The height of the pad is determined: the height of the pad should ensure sufficient ejection stroke, and then leave a certain margin (5-10mm) to ensure that the push bar fixing plate does not hit the moving plate or move when fully ejected. Mold support plate.

Determination of the overall structure of the mould embryo: after the basic selection of the mould blank, the overall structure of the mould blank should be checked to see if the determined standard mould base is suitable for the selected injection molding machine or the size of the mould blank. , thickness, maximum mold opening stroke, ejection mode and ejection stroke.

The standard mold base is selected as an example. The existing plastic part cavity has a plane size of 200 mm × 300 mm and a height of 30 mm. It is decided to use a point gate, and the plastic part is pushed out by a push rod, and a standard mold addition is selected.

Due to the vigorous development of China's machinery, electronics, light industry, instrumentation, transportation and other industrial sectors, the standard mold base style has become more diversified, and the quality requirements are getting higher and higher, providing mold manufacturers with higher flexibility and the popularity of standard mold bases. The sex is constantly improving, pushing China's foundry mold industry into a new stage of development.