Lower die for drilling perpendicular hole in air feeding cylinder cover

The invention discloses a lower die for drilling a perpendicular hole in an air feeding cylinder cover. The lower die comprises a base, wherein a horizontal running-through groove is formed in the base; inverted L-shaped cantilevers are oppositely arranged on two sides of the running-through groove correspondingly, so that a cross-shaped concave hole is formed between the base and the two cantilevers; perpendicular running-through holes are formed in the horizontal sections of the cantilevers; and the positions and the apertures of the running-through holes are matched with those of perpendicular mounting holes in the air feeding cylinder cover. The lower die has the advantages that by the adoption of a special perpendicular hole die, the clamping stability and the precision in an air feeding cylinder cover drilling process are effectively improved; the lower die is simple in structure, and the cylinder cover is conveniently and quickly mounted or removed; the working efficiency of drilling is greatly improve