Cylinder control valve for down-the-hole drill

Abstract

The invention discloses a cylinder control valve for a down-the-hole drill. A valve core (3) is at a position where a first air outlet hole (3-1) and a second air outlet hole (3-3) of the valve core (3) are sealed by a valve body (2) simultaneously; and two arc-shaped air leakage grooves on the valve core (3) are communicated with a first air hole (2-1) and a second air hole (2-3) on the valve body respectively and are communicated with an air leakage hole (2-2) through an annular air leakage groove (3-2). By the cylinder control valve, the aim that air pressure in air inlet and outlet cavities of a cylinder is balanced with outside is fulfilled, the drill can drill downwards due to dead weight, and the problem that the drill is turned over due to reacting force caused by excessive pressurization so as to cause a safety accident in the process of drilling downwards by means of aerodynamic force is solved.

Description

technical field [0001] The invention relates to a cylinder control valve, in particular to a down-the-hole drilling cylinder control valve. Background technique [0002] The existing down-the-hole drilling cylinder control valve cannot control the dual air chambers of the cylinder to release pressure at the same time, and the drill rod is always working under pressure. The operation requirements are extremely strict. Once the operation is careless, the drilling rig is easy to be overturned, resulting in production safety accidents. [0003] On the other hand, after the existing down-the-hole drilling cylinder control valve is filled with high-pressure gas, the valve core and the valve cover are too tightly matched, which affects the flexibility of the valve core rotation operation, and it is very difficult to pull the handle. [0004] Thirdly, when the spool needs to be stopped, since there is no damping mechanism, the spool tends to rotate undesirably after the handle is re...

AI Technical Summary

Problems solved by technology

[0002] The existing down-the-hole drilling cylinder control valve cannot control the dual air chambers of the cylinder to release pressure at the same time, and the drill rod is always working under pressure. The operation requirements are extremely strict. Once the operation is careless, the drilling rig is easy to be overturned, resulting in production safety accidents

[0003] On the other hand, after the existing down-the-hole drilling cylinder control valve is filled with high-pressure gas, the valve core and the valve cover are too tight, which affects the flexibility of the valve core rotation operation, and it is very difficult to pull the handle.

[0004] In the third aspect, when the spool needs to be stopped, since there is no damping mechanism, the spool is prone to undesired free rotation after the handle is released, and the positioning is inaccurate

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