Control valve, variable-amplitude oil cylinder, working method of variable-amplitude oil cylinder and aerial work platform

Abstract

The invention discloses a control valve, a variable-amplitude oil cylinder, a working method of the variable-amplitude oil cylinder and an aerial work platform, and relates to the field of aerial work. The control valve of the variable-amplitude oil cylinder comprises a first balance valve arranged on a flow path between a first oil port G and a second oil port F, and a second balance valve arranged on a flow path between a third oil port H and a fourth oil port E; and the flow path between the first oil port G and the second oil port F is also provided with a switching valve which is connected with the first balance valve in series. According to the control valve, when the first balance valve fails, oil can still be prevented from returning from the flow path between the first oil port Gand the second oil port F by shutting off the switching valve, and the working reliability of the control valve is high; and meanwhile, high-pressure oil in a rodless cavity of the variable-amplitudeoil cylinder is sealed by the control valve through the double insurance of the first balance valve and the second balance valve during the aerial operation, and a lifting arm is kept static and prevented from moving downwards to cause the inclining of a working bucket or the overall tipping of the aerial work platform, so that the safety of the high-altitude operation platform is high.

Description

technical field [0001] The invention relates to the field of aerial work, and more specifically, to a control valve, a luffing oil cylinder, a working method thereof, and an aerial work platform. Background technique [0002] Aerial work platform is an advanced aerial work machine, which can greatly improve the work efficiency, safety and comfort of aerial construction personnel, and reduce labor intensity. It has been widely used in developed countries. The use of aerial work platforms in my country is becoming more and more extensive, such as the initial general municipal street lamp maintenance, garden tree pruning, etc., and with the rapid development of my country's economy, engineering construction, industrial installation, equipment maintenance, plant maintenance, shipbuilding, Electricity, municipal administration, airports, communications, gardens, transportation, etc. have a growing demand for aerial work platforms. [0003] Chinese patent document CN201810449467.2...

AI Technical Summary

Problems solved by technology

[0008] Due to the complex structure of the balance valve, once the first balance valve connected to the rodless chamber 1 fails, as Figure 5 As shown, the oil in the rodless chamber 1 of the hydraulic cylinder enters the oil return system, the piston rod 3 of the hydraulic cylinder continues to retract, and the lifting arm descends downward. People fall, and even the center of gravity of the whole machine exceeds the tipping line, causing the aerial work platform to overturn and cause serious accidents

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