Pressure monitord by displacement type method for controlling fluid form machine for powder

Abstract

A pressure-type control method with shift monitor for the hydraulic forming machine using powder as raw material is disclosed. A shift sensor is used to monitor the relative shift between upper and lower moulds. The shift value is used as the feedback parameter of closed-loop hydraulic control system. When the relative shift value is correspondent with the predefined thickness variation of powder, it is determined that the powder has been pressed by a predefined pressure, so performing a closed-loop control.

Description

technical field [0001] The invention relates to a powder material hydraulic forming machine, in particular to a pressure control method of the powder material hydraulic forming machine. Background technique [0002] The main function of the powder hydroforming machine is to use a certain pressure to press the powder in the mold into a green body with a certain shape and strength. For example, the ceramic brick press used in the wall and floor tile production line uses a certain pressure to press the ceramic powder in the mold into a brick. In order to control the magnitude of the pressure, currently known powder hydraulic molding machines all use the pressure of the main cylinder monitored by the pressure sensor as the feedback parameter of the pressure closed-loop control. This pressure control mode has many disadvantages: 1. The pressure of the hydraulic oil circuit is disturbed and affected by many factors, and it is difficult to ensure the repeatability of each pressuri...

AI Technical Summary

Problems solved by technology

This pressure control mode has many disadvantages: 1. The pressure of the hydraulic oil circuit is disturbed and affected by many factors, and it is difficult to ensure the repeatability of each pressurization process. For example, the fluctuation of the output pressure of the hydraulic source will cause the pressure of the main cylinder to fluctuate. ;2. The response speed of hydraulic components will also affect the pressurized pressure; 3. Due to the limitation of the installation position of the pressure sensor, there is a certain error between the measured value of the pressure sensor and the actual pressure value of the main cylinder, and this error is random. Difficult to control; 4. The corresponding relationship between the pressure of the main cylinder and the actual pressure on the powder will be affected by the factors of mechanical resistance. Taking the moving beam ceramic tile press as an example, if the moving beam is unbalanced, it will Increase the mechanical resistance, reduce the pressure on the adobe, and affect the molding quality of the adobe

All in all, since the pressure sensor measures the dynamic pressure which is disturbed by many factors, it is difficult for the existing technology to guarantee the repeatability of each pressurization process

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