The invention relates to the technical field of hydraulic breaking hammers, in particular to a manufacturing method of a middle
cylinder block of a hydraulic breaking hammer. The middle
cylinder block comprises a middle
cylinder block body, wherein a
piston cavity is longitudinally formed in the middle cylinder block body; an energy accumulator cavity and a control valve
signal channel which communicate with the
piston cavity are also formed in the middle cylinder block body; a
reticulate pattern structure is uniformly distributed on the inner wall of the
piston cavity and uniformly distributed in a whole inner cavity; the outer layer of the
reticulate pattern structure is coated with a soft film; and the soft film covers the inner wall of the piston cavity. An original
signal slot is eliminated, so that the amount, demanded by the
signal slot, of hydraulic
oil can be reduced, the structural strength of the middle cylinder block body can be enhanced, and the effect of preventing internal leakage can be achieved; the soft film has certain resilience, so that hard friction strain can be prevented; through the
reticulate pattern structure, the adhesion of the soft film can be stronger; meanwhile, the soft film has the functions of adsorbing the hydraulic oil and increasing the timeliness of an
oil film staying on the inner wall of the cylinder block; and due to the fact that the
oil film is regarded as a main factor for supporting a piston in a vacuum environment of the inner cavity, the
occurrence probability of cylinder scoring can be effectively prevented.