Oil filling hydraulic system of piston type mud pulse generator

The invention relates to an oil filling hydraulic system of a piston type mud pulse generator, and belongs to the technical field of wireless measurement while drilling. The oil filling hydraulic system is characterized in that when a two-position two-way electromagnetic reversing valve I and a two-position two-way electromagnetic reversing valve III are energized, oil in an oil tank is pumped out through an unidirectional metering pump after passing through a filter and the two-position two-way electromagnetic reversing valve I; the piston type mud pulse generator is filled with a part of the oil through the two-position two-way electromagnetic reversing valve III; the other part of the oil flows back to the oil tank after passing through a pressure gauge and a pilot overflow valve; and after a two-position two-way electromagnetic reversing valve II and a two-position two-way electromagnetic reversing valve IV are energized, the oil in the piston type mud pulse generator flows back to the oil tank after sequentially passing through the two-position two-way electromagnetic reversing valve II, the unidirectional metering pump, the pressure gauge, the pilot overflow valve, the two-position two-way electromagnetic reversing valve IV and a pressure regulating valve, and oil suction action is achieved. According to the oil filling hydraulic system, reciprocating oil filling is achieved, residual air in a cavity of the piston type mud pulse generator can be exhausted, and the oil filling efficiency is high.