A servo pump controlled hydraulic press with high precision positioning

Abstract

The invention relates to a high-precision positioning servo pump-controlled hydraulic press. The high-precision positioning servo pump-controlled hydraulic press is characterized in that the upper chamber of a main cylinder is connected with an oil tank through a prefill valve, the suction port of a servo pump is connected with the oil tank through a first one-way valve and a first oil filter, and the outlet of the servo pump is connected with the upper chamber of the main cylinder through a second electromagnetic directional valve and also connected with the oil tank through a second one-way valve and a second oil filter; the lower chamber of the main cylinder is connected with the inlet of a third one-way valve, the outlet of the third one-way valve is connected with the outlet of the first one-way valve, and a third overflow valve is connected in parallel with the two ends of the third one-way valve; the liquid control port of the prefill valve is connected with the port B of a first electromagnetic directional valve, the port P of the first electromagnetic directional valve is connected with the outlet of the third one-way valve, and the port T of the first electromagnetic directional valve is connected with the oil tank; and the lower chamber of the main cylinder is further connected with the oil tank through a quick discharge valve set. The high-precision positioning servo pump-controlled hydraulic press can realize 'give all wanted' control, reduces energy consumption, oil overflow and oil temperature rise and realizes high-precision position control of sliders.

Description

technical field [0001] The invention relates to a hydraulic machine, in particular to a high-precision positioning servo pump-controlled hydraulic machine. Background technique [0002] At present, most hydraulic machines use three-phase asynchronous motors to drive constant power variable pumps to provide energy. Although the output flow can be reduced beyond the set pressure value, the motors are always in normal operation during the entire working process. , Pressure maintaining, and loading and unloading states do not require the motor to drive the oil pump to work, so on the one hand, it will cause energy waste, and on the other hand, it will also cause the oil circulation overflow to cause the oil temperature to rise. [0003] The servo pump control hydraulic press that has been developed now only replaces the three-phase asynchronous motor-driven constant power variable pump with a servo motor-driven gear pump in the control form, so that when the flow required by the...

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Problems solved by technology

[0002] At present, most hydraulic machines use three-phase asynchronous motors to drive constant power variable pumps to provide energy. Although the output flow can be reduced beyond the set pressure value, the motors are always in normal operation during the entire working process. , pressure maintaining, up / down, and feeding / discharging state do not need the motor to drive the oil pump to work, so on the one hand, it will cause energy waste, and on the other hand, it will also cause the oil circulation overflow to cause the oil temperature to rise

[0003] The servo pump control hydraulic press that has been developed now only replaces the three-phase asynchronous motor-driven constant power variable pump with a servo motor-driven gear pump in the control form, so that when the flow required by the system changes, the motor speed follows the flow command. Change, so that the output flow of the oil pump changes, truly achieve the control of "as much as you want", and realize the energy-saving application on the hydraulic press, which is of great significance for reducing energy waste. However, this kind of servo pump control hydraulic press still uses Although the positioning accuracy of the cartridge valve hydraulic system controlled by the switch value is significantly improved compared with conventional machine tools, it still cannot meet the requirements of high-precision position control in some special industries.

[0004] In order to achieve high-precision position control, some hydraulic machines adopt the servo valve throttling control method, but this will cause a large amount of oil overflow and cause the oil temperature to rise. It is necessary to increase the cooling device to control the oil temperature.

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