Elevated operation vehicle and platform leveling hydraulic system thereof

Abstract

The invention discloses a platform leveling hydraulic system comprising a leveling cylinder, an arm-joint amplitude cylinder, a priority valve, a first flow control valve and a second flow control valve, wherein the first flow control valve is used for controlling the liquid feeding quantity of two cavities of the leveling cylinder; the second flow control valve is used for controlling the liquidfeeding quantity of two cavities of the arm-joint amplitude cylinder; an oil inlet of the priority valve is communicated with a system pressure oil channel, a main oil port of the priority valve is communicated with an oil inlet of the first flow control valve, and a secondary oil port of the priority valve is communicated with an oil inlet of the second flow control valve; and a first control oil port for controlling the opening of the main oil port to change in an increasing trend is communicated with an oil outlet of the first flow control valve, and a second control oil port for controlling the opening of the secondary oil port to change in an increasing trend is communicated with the oil inlet of the first flow control valve. System pressure oil firstly satisfies the flow requirementof the leveling cylinder and can effectively avoid platform leveling advance or lag phenomena. On the basis, the invention also provides an elevated operation vehicle with the platform leveling hydraulic system.

Description

technical field [0001] The invention relates to the technical field of engineering machinery, in particular to an elevating work vehicle and a platform leveling hydraulic system thereof. Background technique [0002] In various high-altitude operations and fire rescue, elevating work vehicles are widely used due to their good mobility. For example, climbing platform fire trucks. [0003] Existing platform fire trucks are equipped with a lifting platform, and the control platform reaches the working position through the extension operation of the boom, so that firefighters can climb to save high-rise buildings, oil tank fires or rescue trapped people. At present, the jibs of elevating vehicles are mostly composed of two or more folding arms, and the angle changes between the platform and the jibs and the connecting hinge points of each jib are realized by the expansion and contraction of the corresponding luffing cylinders. Obviously, its boom system is one of the key compo...

AI Technical Summary

Problems solved by technology

[0008] 1. The flow rate of the leveling cylinder is not only affected by the opening size of the servo valve, but also affected by the change of load pressure, so a stable flow rate cannot be guaranteed

[0009] 2. The opening size of the leveling servo valve is limited by the speed of the crank arm. When the crank arm shakes or the speed changes greatly, the leveling will also appear shaking and leveling instability.

[0010] 3. The synchronization of leveling is completely controlled by electricity. Since it takes a response time from the sensor to obtain the signal to the controller to issue an instruction, the response time directly leads to the lag of the leveling cylinder movement.

Images