The working principle of the hydraulic acrow props is the same as that of the hydraulic jacks! The lever pump or hydraulic pump regulates the lifting of the main piston by hydraulic oil! How the hydraulic acrow props work is as follows:
When using, insert the liquid injection gun into the three-injection valve injection hole, hold the injection gun handle, and open the check valve steel ball with high pressure liquid . The high pressure liquid flows into the lower chamber of the acrow prop, and the column is raised;
When the metal top beam is pressed against the top surface of the working surface, the liquid injection gun handle is released. At this time, the liquid pressure in the inner cavity of the acrow prop is the pressure of the pumping station, and the initial support force of the acrow prop to the top plate is 120KN (the pumping station pressure is 15 MPa).
With the advancement of the coal mining face and the extension of the supporting time, the load acting on the acrow prop of the working face is increased. When the pressure of the roof exceeds the rated working resistance of the acrow prop, the high pressure liquid in the acrow prop opens the safety valve in the three-way valve , the liquid overflows, the acrow props are shrunk,
The pressure in the inner chamber is reduced . When the load on the column is lower than the rated working resistance, the safety valve is closed and the liquid in the cavity stops overflowing. Therefore, the working resistance of the column is always within the rated working resistance range, so it is called constant resistance type acrow prop.
When the working surface is returned to the column, the unloading handle is inserted into the three-way valve unloading hole, the unloading handle is rotated, the valve sleeve is forced to move axially to open the unloading valve in the three-way valve, and the emulsion in the column flows out through the unloading valve, the living column Retract under the action of self-weight and return spring to achieve the purpose of lowering the column .
Do you know how the hydraulic acrow props work now? For more questions, please contact China Coal Group! ! !
