AIR DRILL

摘要

The invention relates to pneumatic tools used in mining and mining-metallurgical industry, for drilling manually or from adjusting and feeding assemblies. An air drill comprises a crane grab, a cylinder with a shock inside, and a valve air-distributing assembly with a straightway end clearance, a straightway radial clearance with outlet areas for a valve and straightway channels with outlet areas. The area of the straightway section, at least one of clearances and/or one of channels is 0.03-0.06 of the cross-section of the cylinder inner cavity, and/or the area of the straight section of the outlet area of the radial clearance is 0.02-0.046 of the cross-section area of the cylinder inner cavity. The outlet areas of the straight channels are arranged at 20-70 degree to the cylinder axis. The invention provides a selection of optimum supplying the compressed air into working and idle cavities of the air drill, reducing losses of the compressed air from valve windows to the working and idle cavities of the air drill enabling to increase the efficiency of the air drill by specific consumption of the air stream.