Design Of Injection Mold

To clarify the design of injection mold parts, it is required to carefully read the parts drawings of the injection mold parts, and consider the feasibility and economy of the injection molding process from the aspects of plastic variety, plastic part shape, dimensional accuracy, and surface roughness. If necessary, discuss the material type of plastic parts and the possibility of structural modification with the product designer. When clarifying the production batch of injection mold parts in small batch production, in order to reduce costs, the mold should be as simple as possible; in mass production, under the premise of ensuring the quality of plastic parts, one mold and multiple cavities or high-speed automated production should be used as much as possible , In order to shorten the production cycle and increase productivity. Therefore, strict requirements are put forward for the ejection mechanism of the mold and the automatic ejection mechanism of the plastic parts and the condensate of the runner.

Calculating the volume and quality of plastic parts The purpose of calculating the volume and quality of plastic parts is to select injection molding machines, improve equipment utilization, and determine the number of mold cavities. The structure of the injection molding machine is roughly determined according to the volume or weight of the plastic parts, and the model of the injection molding machine is initially determined. The technical parameters of the injection molding machine related to the mold design are known, such as the diameter of the positioning ring, the diameter of the nozzle front end and the spherical radius, the maximum injection volume, and the clamp Tightening force, injection pressure, area size of fixed template and movable template, installation screw hole position, tie rod spacing, closing thickness, mold opening stroke and ejection stroke. Injection mold design calculation: calculation of working size of concave and convex mold parts: calculation of plastic parts molding position and parting surface selection; determination of the number of cavities, cavity arrangement, runner layout and gate location settings; structural design of mold working parts ; Surface parting core-pulling mechanism design; ejection mechanism design; selection of tie rod form; exhaust mode design.

The overall size of the injection mold is determined, and the selection of the mold base has been gradually standardized. According to the mold base atlas provided by the manufacturer, the mold base is selected, and the complete structure diagram of the mold is initially drawn on the basis of the above-mentioned mold part design. Check the parameters of the injection molding machine, check the maximum injection volume; check the injection pressure; check the clamping force; check the relevant dimensions of the injection mold and the installation part of the injection molding machine, including the closed height, mold opening stroke, and mold seat installation dimensions. The general assembly drawing of the injection mold structure and the drawing of the part work drawing must conform to the national standard of mechanical drawing. The drawing method is in principle the same as the general mechanical drawing method, just to more clearly express the shape and gate of the molded product in the mold. Location settings. On the top view of the general drawing of the mold, the fixed mold can be removed, and only the top view of the movable mold can be drawn. The mold assembly drawing should include the necessary dimensions, such as clamping size, outline size, characteristic size (locating ring size matched with injection molding machine), assembly size, limit size (starting point and end point of moving parts) and technical conditions, and compiling parts List etc.