Electric forklift, its hydraulic system and control method for the hydraulic system

Abstract

The invention discloses a hydraulic system of an electric forklift. The hydraulic system comprises an operating part, a motor, an oil pump, an oil tank, an oil cylinder, an electro-hydraulic proportional valve, a first acquisition circuit, a second acquisition circuit and a digital signal processor, wherein the operating part is used for being operated by a user to generate an action instruction for a mast of the electric forklift; the oil pump is driven by the motor to pump out oil in the oil tank; the electro-hydraulic proportional valve comprises an electromagnetic valve body; through the electromagnetic valve body, the oil pumped out of the oil tank flows through the electro-hydraulic proportional valve and enters the oil cylinder; the oil cylinder moves to drive the mast to act; the first acquisition circuit is used for acquiring the action instruction; the second acquisition circuit is used for acquiring the feedback current of the electromagnetic valve body; and the digital signal processor is used for controlling the motor and the electro-hydraulic proportional valve according to the action instruction for the mast and the feedback current of the electromagnetic valve body. The hydraulic system is simple in structure and high in reliability. The invention further discloses the electric forklift equipped with the hydraulic system as well as a control method of the hydraulic system.

Description

technical field [0001] The invention belongs to the technical field of vehicles, and in particular relates to a hydraulic system of an electric forklift, an electric forklift with the hydraulic system, and a control method for the hydraulic system. Background technique [0002] The electro-hydraulic proportional valve of the electric forklift is the key control device to realize the working conditions such as the rise and fall of the mast of the forklift, the forward tilt, the left shift and the right shift. With the development of electronic technology, the control accuracy and stability of the electro-hydraulic proportional valve are greatly improved. increase in magnitude. The traditional electro-hydraulic proportional valve technology is a combination of switch valve technology, proportional valve technology and servo valve technology. It is an analog control technology. Its precise control is based on closed-loop control, relying on various sensors, servo valves, and se...

AI Technical Summary

Problems solved by technology

[0004] In a nutshell, forklift electro-hydraulic proportional valve control technology is a complex system, expensive, troublesome to maintain, and high failure rate. It must be expertly designed, expertly debugged, expertly used, and expertly maintained. obstacle

The reason for the above shortcomings is that the use of analog circuits cannot use many control algorithms, the reliability is not good, the repeatability of the control system is not high, and it cannot be mass-produced and widely used.

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