Hydraulic system for floating of scraper of pavement milling machine

Abstract

The invention discloses a hydraulic system for the floating of a scraper of a pavement milling machine. The hydraulic system comprises a scraper oil cylinder with a piston rod which is vertically arranged downwards, wherein the piston rod of the scraper oil cylinder is connected with the scraper which is horizontally arranged; two oil paths are led from an upper cavity of the scraper oil cylinder, one path is communicated with a first oil port (A) of a three-position four-way electromagnetic reversing valve (5), and the other path is communicated with an oil tank through a throttling valve (4); a lower cavity of the scraper oil cavity is divided into two paths after passing through a two-position two-way electromagnetic valve (6), one path is communicated with a second oil port (B) of the three-position four-way electromagnetic reversing valve (5), and the other is communicated with an oil outlet of a three-way pressure reducing valve (3); an oil inlet (P) of the three-position three-way electromagnetic reversing valve (5) is communicated with the oil tank through an auxiliary pump (1), and an oil outlet(T) of the three-position three-way electromagnetic reversing valve (5) is communicated with the oil tank; an oil inlet of the three-way pressure reducing valve (3) is communicated withthe oil tank through an oil supplementing pump (2). The hydraulic system for the floating of the scraper of the pavement milling machine is simple in structure, safe and reliable.

Description

technical field [0001] The invention relates to a hydraulic system, in particular to a hydraulic system for controlling the floating of a scraper on a road milling machine, and belongs to the technical field of milling machines. Background technique [0002] During construction work, the road milling machine uses a scraper to press the road surface to ensure that the milled materials remain in the milling bin, and then transported to the material truck through the feeding frame for transportation. When the pressing force of the scraper against the ground is too large, although the material is collected cleanly, it will bring additional resistance to the advancement of the milling machine, consume a lot of engine power, cause the wheels to slip during the forward process, and even cause the scraper to deform; If the pressing force of the scraper on the road surface is too small, although the forward resistance of the milling machine becomes smaller, the pressing force on the ...

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Problems solved by technology

[0003] For this reason, a company has developed a "road milling machine self-feedback floating scraper system" as disclosed in Chinese patent 201310114673.5, which uses CPU, pressure sensor and other electronic control methods to control the scraper, but found in actual use, Since the construction process is a dynamic forward process, the conventional pressure sensor has good pressure detection ability in the static state, but in the moving process, especially when the pressure to be measured is perpendicular to the moving direction, the measurement The error is large; and in the construction site, due to the large amount of dust and other impurities, many electronic components used in the electronic control method are easily damaged or short-circuited due to dust erosion, which makes its reliability poor

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