The invention discloses a
hydraulic control method for a ram
piston oil cylinder of an internal mixer. According to the method, pressurizing and floating of a pressing lead are achieved, and a
control effect of floating of the pressing lead is good. The
hydraulic control method is characterized in that the pressure and speed of a ram
piston are controlled by a main PLC of the internal mixer, and the
pressure control over the ram
piston is the
pressure control over rod end chambers of the ram piston oil cylinder; a first hydraulic oil path is connected with non-rod end chambers of the ram piston oil cylinder through oil pipes by passing an oil inlet P1, a proportional
servo valve PLV, an electromagnetic
cartridge valve YV1 and an electromagnetic
cartridge valve YV2; the other hydraulic oil path is connected with the rod end chambers of the ram piston oil cylinder through the oil pipes by passing the oil inlet P1, the proportional
servo valve PLV and an electromagnetic
cartridge valve YV4, and the rod end chambers of the ram piston oil cylinder are connected with the oil inlet P1 through a rising differential one-way valve; an electromagnetic cartridge valve YV3 connected with an oil return opening T2 is further connected between the electromagnetic cartridge valve YV1 and the electromagnetic cartridge valve YV2; an oil inlet P of the proportional
servo valve PLV is connected with the oil inlet P1, and an oil return opening T of the proportional servo valve PLV is connected with an oil return opening T1. According to the
hydraulic control method, a hydraulic control device for the ram piston oil cylinder is simplified, closed-
loop control over the pressure of the ram piston can be truly achieved, and the quality of rubber mixing is improved.