Hydraulic system of oil press and hydraulic processing method

Abstract

The invention relates to a hydraulic system of an oil press and a hydraulic processing method. A hexagon socket countersink is formed in the center of the top of a prefill valve fastening bolt. A hexagon insertion tenon is embedded in the hexagon socket countersink. An insertion tenon threaded hole is formed in the center of the hexagon insertion tenon. A cam threaded rod is rotationally connectedinto the insertion tenon threaded hole and connected to the center of the lower end face of a cam device. A cam groove extending in the axial direction is formed in the circumference of the cam device. A strong magnetic ring base is adsorbed to the outer circumference of a flange countersink of the upper end face of a refill valve flange. A switch fixing plate is adsorbed to the upper portion ofthe strong magnetic ring base. The cam device, the strong magnetic ring base and the switch fixing plate are coaxial with the prefill valve fastening bolt. A travel switch is fixed to the outer circumference of the switch fixing plate. A probe of the travel switch is embedded in the cam groove. Each operation cycle of hydraulic processing sequentially comprises the following actions of first-stagerapid descending of a sliding block, second-stage rapid descending, slow descending, working feed pressurizing, pressure maintaining and release, sliding block returning, rapid jacking of a hydraulicpad, slow jacking, retracting, stretching and forced retracting of all cylinders.

Description

technical field [0001] The invention relates to a hydraulic press, in particular to a hydraulic system of the hydraulic press. The invention also relates to a hydraulic processing method of the hydraulic press, belonging to the technical field of machine tool control systems. Background technique [0002] In order to realize the rapid downward movement of the slider and meet the requirements of the return speed, the hydraulic press usually installs a filling valve above the slider cylinder for rapid oil replenishment and oil return of the slider cylinder. The rapid downward movement of the slider of the hydraulic press is realized by the gravity of the slider and the piston rod of the oil cylinder. The fast downward speed requirement is met through the free fall. At this time, the oil volume of the oil pump is far from meeting the replenishment needs of the oil in the upper chamber of the oil cylinder. The filling valve spool is opened under the action of negative pressure g...

AI Technical Summary

Problems solved by technology

[0006] According to customer requirements, some manufacturers deliberately use two sets of pump stations to control the slider movement of the hydraulic press and the hydraulic cushion movement, that is, the operation control of the slider is controlled by the upper pump station, and the up and down control of the hydraulic cushion is controlled by the lower pump station. The group pumping station is in a completely independent state, which increases the installed power, increases the investment cost, and causes a waste of energy

In response to this situation, some manufacturers have changed the driving cylinder of the hydraulic pad to a multi-cylinder structure, usually in the form of a middle piston cylinder + plunger cylinders on both sides. The oil pump supplies oil to the middle piston cylinder and then drives the hydraulic pad to move upward. The plunger cylinder relies on the one-way valve to replenish oil to achieve rapid ejection. When the hydraulic pad moves close to the upper limit, the oil pump supplies oil to all cylinders, so as to realize full-tonnage ejection, but there will be rapid ejection and full-tonnage ejection. When the tonnage is ejected, there will be a pause, or even a small drop, and the ejection speed will not change smoothly, because the plunger cylinder only relies on negative pressure to replenish oil during the rapid ejection process.

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