Double-layer air cylinder special for one-nozzle multi-head structure

Abstract

The invention provides a double-layer air cylinder special for a one-nozzle multi-head structure. The double-layer air cylinder special for the one-nozzle multi-head structure comprises a cylinder body. A main air cavity and a supercharging air cavity are arranged in the cavity body and are independent of each other. A main piston is arranged in the main air cavity. A supercharging piston is arranged in the supercharging air cavity. The supercharging piston and the main piston are coaxially arranged and mutually and fixedly connected. The main piston or the supercharging piston are fixedly connected with a plurality of valve needles. Each valve needle is used for being matched with a hot melt adhesive distributing nozzle. The main air cavity and the supercharging air cavity are both provided with closing air inlets. The main air cavity and the supercharging air cavity are inflated with air through the closing air inlets. The main piston can be driven to move. Under the same air pressure, due to the fact that the thrust force borne by the main piston is larger, even if the main piston or the supercharging piston is fixedly connected with the multiple valve needles, the main piston can still provide enough force to act on all the valve needles; and in this way, the hot melt adhesive distributing nozzles can be kept being effectively closed, and leakage of hot melt adhesive is avoided.

Description

technical field [0001] The invention relates to the technical field of hot runner molds, in particular to a special double-layer cylinder with one nozzle and multiple heads. Background technique [0002] Due to the large number of gates of some injection molds, the injection molds mostly adopt a hot runner structure with one nozzle and multiple heads, that is, there is a main hot melt pipeline, and the output end of the main hot melt pipeline is connected to multiple hot nozzles. Each sub-hot nozzle is pierced with a valve needle. Each valve needle is fixedly connected to the piston of the driving cylinder, and the sliding of the valve needle can control the opening and closing of the glue outlet of the sub-heat nozzle. After the driving cylinder drives the valve needle to slide to close the glue outlet of the sub-hot nozzle, the driving cylinder needs to maintain pressure to ensure that the glue outlet of each sub-hot nozzle remains closed. Due to the large number of valv...

AI Technical Summary

Problems solved by technology

The driving cylinder in the prior art is a single-piston cylinder. The driving force of the single-piston cylinder is relatively small, and it is difficult to provide the force required to keep the glue outlets of each sub-hot nozzle closed, thus resulting in failure to close the sub-hot nozzle and leakage of hot melt adhesive, etc. Phenomenon

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