Pre-plastic foaming ratio injection machine

Abstract

The invention discloses a pre-injection-molding foaming proportion injection machine. The pre-injection-molding foaming proportion injection machine is characterized in that a hydraulic loop comprises a first oil pump driven by a motor and a second oil pump driven by the motor, output oil of the first oil pump is divided into three paths through a single-proportion overflow valve or double-proportion overflow valve to be communicated with a three-position four-way valve V1, a three-position four-way valve V2 and a three-position four-way valve V3, two oil outlets of the three-position four-way valve V1 are communicated with a front oil inlet and a rear oil inlet of an injection seat oil cylinder, one oil outlet of the three-position four-way valve V2 is communicated with a front oil inlet of an injection return oil cylinder, and the other oil outlet of the three-position four-way valve V2 is communicated with a rear oil inlet of the injection return oil cylinder through a backpressure valve; two oil outlets of the three-position four-way valve V3 are communicated with an upper oil inlet and a lower oil inlet of a feeding reverse oil motor; output oil of the second oil pump passes through a one-way valve and then is communicated with the double-proportion overflow valve, and an electromagnetic overflow valve is arranged on an oil outlet pipeline, in front of the one-way valve, of the second oil pump; and pressure speed automatic control in the pre-injection-molding foaming injection process can be achieved, operation is easy and convenient, a system can stably work, accuracy and uniformity of injection density are better ensured, and the injection quality is improved.

Description

technical field [0001] The present invention relates to an improved invention of an injection machine. Background technique [0002] In the prior art injection machine (also known as injection molding machine), actions such as injection, ejection withdrawal and back pressure must be completed during the pre-plastic foaming injection process, which all need to be controlled by the hydraulic circuit of the injection machine. For example, the applicant On August 6, 2002, it applied for the invention patent of patent number 02136409.5 and the patent name "Pre-molding of injection molding machine, injection hydraulic circuit". However, the existing technology including the hydraulic circuit of the injection machine of the above-mentioned patent technology cannot realize the automatic control of the pressure and speed during the pre-plastic foaming injection process, the operation is not simple, and the system operation is also unstable, so the accurate injection density cannot be...

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Problems solved by technology

However, the prior art, including the hydraulic circuit of the injection machine of the above-mentioned patented technology, cannot realize the automatic control of the pressure and speed during the pre-plastic foaming injection process, the operation is not easy, and the system is unstable, so the accuracy of the injection density cannot be guaranteed. and homogeneous, poor injection quality

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