Method for preventing rib spalling of coal wall and roof falling in head face and hydraulic support thereof

Abstract

The invention discloses a method for preventing rib spalling of a coal wall and roof falling in a head face. The method comprises the following steps of: (1) reducing a beam-end distance of a hydraulic support to be less than 240mm, even 0mm, and reserving a top coal layer with thickness being 200-300mm when a coal mining machine mines coal; and (2) leaning a plate surface of a rib-supporting plate of the hydraulic support against the coal wall to realize surface contact between the rib-supporting plate and the coal wall. By adopting the steps, occurrences of the rib spalling and the roof falling in the head face can be avoided effectively. The invention also provides the hydraulic support for preventing rib spalling of the coal wall and the roof falling in the head face. The hydraulic support comprises a telescopic beam, wherein a gear shaper is arranged at a front end of the telescopic beam; the telescopic beam is hinged with an oscillating bar of which the other end is hinged with the primary rib-supporting plate; and a linear driving mechanism for driving the primary rib-supporting plate to lean against the coal wall is hinged with the telescopic beam. By the structure of the hydraulic support, the surface contact between the primary rib-supporting plate and the coal wall can be realized, so that the rib spalling can be prevented; and a distance between the gear shaper of the telescopic beam and the coal wall is less than 240mm, so that the roof falling in the head face can be prevented.

Description

technical field [0001] The invention relates to the technical field of coal mine mining, in particular to a method for preventing roof caving in front of a coal wall and a frame, and a hydraulic support that can adopt the method. Background technique [0002] At present, with the development of mechanized coal mining in coal mines, especially the development of fully mechanized mining, coal seams such as "three soft" coal seams, high elevation mining (some exceeding 25°) and large mining height (currently the maximum mining height support has reached 8m) are being mined. The hydraulic support is an essential equipment for supporting the roof and maintaining the coal wall. The structure of the upper part of the previous hydraulic support is usually as follows figure 1 As shown, it includes the telescopic beam 3 and the side board 4, the upper end of the side board 4 is directly hinged on the telescopic beam 3, one end of the hydraulic cylinder 5 is hinged on the telescopic be...

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Problems solved by technology

[0002] At present, with the development of mechanized coal mining in coal mines, especially the development of fully mechanized mining, coal seams such as "three soft" coal seams, high elevation mining (some exceeding 25°) and large mining height (currently the maximum mining height support has reached 8m) are being mined. The hydraulic support is an essential equipment for supporting the roof and maintaining the coal wall. The structure of the upper part of the previous hydraulic support is usually as follows figure 1 As shown, it includes the telescopic beam 3 and the side board 4, the upper end of the side board 4 is directly hinged on the telescopic beam 3, one end of the hydraulic cylinder 5 is hinged on the telescopic beam 3, and the other end is hinged on the side board 4. The oil cylinder 5 makes the bottom of the side board 4 lean against the coal wall 1, or even only makes the bottom of the side board 4 close to the coal wall 1 but does not touch it. In order to prevent the shearer drum from touching the telescopic beam 3, the telescopic beam The distance between the front end of 3 and coal wall 1 (ie figure 1 As shown in Ln, it is called beam end distance) is usually about 350mm. Due to the large beam end distance, the large-area roof 2 cannot be supported, and it is very likely that the roof will collapse in front of the frame. The support plate 4 can prevent the coal from falling The gangue falling in front of the block and the frame enters the hydraulic support and hurts people or damages the equipment, but it does not have the effect of actively preventing the coal wall and the roof from falling in front of the frame. The line contact between the support plate 4 and the coal wall 1 can even be Accelerate the gang, when a gang occurs, the behavior of the gang is as follows figure 1 As shown by the dotted line in the middle, from top to bottom and from outside to inside, there is an angle of repose of about 35°, and the roof of the roof will be exposed soon, which will easily cause the roof to fall in front of the frame

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