Extrusion large-injection amount injection moulding device and use method thereof

Abstract

The invention discloses an extrusion large-injection amount injection moulding device and a use method of the extrusion large-injection amount injection moulding device. The extrusion large-injection amount injection moulding device comprises a pre-injection material storage mechanism, an injection mechanism, a nozzle (10) and a three-way valve (1), wherein the pre-injection material storage mechanism comprises a charging barrel (2) before preplastication, a screw (3) and a preplastication charging barrel (4); the screw (3) is arranged in the preplastication charging barrel (4); the injection mechanism comprises a pre-injection charging barrel (5), an injection charging barrel (6), a piston rod (8) sheathed with a piston (7) and an electro-hydraulic system; the piston rod (8) is arranged in the injection charging barrel (6); the electro-hydraulic system (9) is connected with the piston rod; both the pre-injection material storage mechanism and the injection mechanism are connected with the nozzle by the three-way valve; and processes, such as a preparation stage, a preplastication stage and an injection moulding stage are carried out. According to the invention, the requirement of big injection amount can be satisfied, the phenomenon that a corresponding injection machine type needs to be designed according to the injection amount can be avoided, the extrusion large-injection amount injection moulding device has the advantages of good generality, wide applicable range, energy saving and high efficiency, and the injection efficiency is improved.

Description

technical field [0001] The invention relates to the field of injection molding machines, in particular to a squeeze-type injection molding device with a large injection volume and a use method thereof. Background technique [0002] In recent years, with the expansion of market demand, especially for large plastic components, the quality requirements for large components are also getting higher and higher. However, the traditional extrusion injection machine is usually unable to meet the requirements due to the technical deficiencies in the extrusion system of the injection machine, especially when the injection volume exceeds the nominal injection volume. Because the injection volume is limited by the diameter and stroke of the piston, there is an upper limit in practical applications. Therefore, for different injection volume requirements, traditional plastic machinery generally requires different injection devices to cooperate, especially large injection volume products r...

AI Technical Summary

Problems solved by technology

In addition to the above-mentioned defects, the prior art also has the following technical problems: for example, due to the relatively long mating length of the piston and the barrel, the machining precision of the piston is required to be high and the manufacturing cost is high

At the same time, in order to ensure a small injection resistance when the piston is injected, a large gap is left between the piston and the barrel. During injection, the temperature of the molten plastic is very high, and the molten plastic is easily squeezed out from the gap between the piston and the barrel, wrapped in The surface of the piston increases the resistance of the piston movement; moreover, this part of the molten plastic is repeatedly subjected to high shear and stays for a long time, resulting in partial overburning and degradation, which affects the environment and product quality

The constant change of piston movement resistance leads to unstable operation of the piston

In addition, the plastic wrapped on the outside of the piston overflows from the rear side of the barrel with the continuous movement of the piston, which wastes materials and increases the difficulty of equipment maintenance

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