A scissor-type aerial work vehicle platform lifting and lowering hydraulic system

Abstract

The invention discloses a lifting and dropping action hydraulic system for scissor type aerial working trolley platforms. The outlet of a first one-way valve (2) is connected with the rodless cavity of a lower lifting oil cylinder (9) and a first hand-operable two-position two-way electromagnetic reversing valve (3), the first hand-operable two-position two-way electromagnetic reversing valve (3) is connected with one end of a first throttle valve (1), the rod cavity of the lower lifting oil cylinder (9) and the other end of the first throttle valve (1) are connected with an oil tank (10), the outlet of a second one-way valve (6) is connected with the rodless cavity of an upper lifting oil cylinder (8) and the inlet of a two-position two-way electromagnetic reversing valve (11), the outlet of the two-position two-way electromagnetic reversing valve (11) is connected with one end of a second throttle valve (5), the rod cavity of the upper lifting oil cylinder (8) and the other end of the second throttle valve (5) are connected with the oil tank (10), and an overflow valve (7) is connected between the rodless cavity of the upper lifting oil cylinder (8) and the oil tank (10). Hydraulic oil is always filled up in the rod cavities of the lifting oil cylinders of the lifting and dropping action hydraulic system, consequently, seals in the oil cylinders are protected, the service lives of the oil cylinders are prolonged, and emergency dropping operation is simple.

Description

technical field [0001] The invention relates to a high-altitude operation vehicle, in particular to a scissor-type high-altitude operation equipment (double-lift cylinder high-altitude operation platform) working platform ascending and descending hydraulic system. Background technique [0002] Double-lift cylinder scissor-type aerial work platform usually lifts the rodless cavity and the oil circuit of the rod cavity is separated. When the platform is lowered, the hydraulic oil in the lift cylinder rodless cavity returns to the oil tank through the oil inlet hydraulic hose, and the rod The negative pressure generated in the cavity relies on the self-priming ability to absorb oil from the hydraulic oil tank. Since the scissor-type aerial work vehicle is vertically rising and falling, the higher the lifting height, the greater the self-priming resistance, and the worse the self-priming ability, resulting in the lifting of the cylinder. The rod cavity produces air suction, whic...

AI Technical Summary

Problems solved by technology

[0002] Double-lift cylinder scissor-type aerial work platform usually lifts the rodless cavity and the oil circuit of the rod cavity is separated. When the platform is lowered, the hydraulic oil in the lift cylinder rodless cavity returns to the oil tank through the oil inlet hydraulic hose, and the rod The negative pressure generated in the cavity relies on the self-priming ability to absorb oil from the hydraulic oil tank. Since the scissor-type aerial work vehicle is vertically rising and falling, the higher the lifting height, the greater the self-priming resistance, and the worse the self-priming ability, resulting in the lifting of the cylinder. The rod cavity produces air suction, which will damage the seals. At the same time, the water in the sucked air will cause the inner wall of the rodless cavity of the cylinder and the piston rod to rust

When using emergency descent, the operation is cumbersome and needs to pull two spools at the same time

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