What are the characteristics and structure of the dynamic ejector mechanism?
(1) features of pneumatic ejector mechanism
Pneumatic ejector mechanism is to draw compressed air between the plastic parts and the mold.A device for ejecting plastic parts from moulds.This although ejection device to set up the device of compressed air, compressed air access and all kinds of pneumatic components, etc. But because it is not using some mechanical parts, such as blocks, ejector sleeve, a push rod to push the plastic parts. Dispensed with and the matching transmission mechanism, thus make the mould structure was greatly simplified, its core and concave die can use pneumatic ejection.
And at the top of the mould at any position in the process of the plastic parts.In addition, this kind of mold release due to no ejection parts of molded parts strength, so to receive strength evenly in plastic parts, no ejection trace, plastic parts ejection deformation is small, after ejection mechanism can be set in motion, on either side of the fixed mould.This ejection mechanism is especially suitable for deep cavity thin-walled vessels, especially for moulding soft plastic parts.
(2) there are many kinds of structures of pneumatic ejector mechanism. A typical structure is introduced below, as shown in FIG. 3-7.In this kind of organization. There is a valve, the work, by the spring force closure, the valve melt into the cavity, when the plastic pieces after cooling solidification, compressed air going into the 100 ~ 400 kpa, make the spring compression, open the valve, the air cavity, blowing plastic parts, plastic demoulding.
(3) matters needing attention in design
The mechanism is operated by compressed air pressure to overcome spring force and friction resistance between plastic parts and springs. For this reason, the spring force should be properly and carefully regulated.
Parliamentary air valve and mold should be carefully matched, injection molding can not leak air, therefore, high machining accuracy.
The press cannot push out the mechanism for a piece of plastic, such as one with a hole in it, that can easily run off air.
(4) the air valve generally use 90 ° ~ 90 ° cone to cooperate, and to have around 1 mm straight wall fitting surface.