The cover castings was left in the moving container in squeezing casting but the general hydraulic machine has no the up-pushing mechanism.The processing parameters of squeezing casting for the aluminum cover and practical die structure with up-pushing mechanism were designed
in which a small piston sub-oli-cyclinder was designed to make the connection of piston bar with up-pushing mechanism and the up-oil tube and below-oil tube can be connected with the common circuit and controlled circuit in hydraulic machine by the high-pressure soft tube
and then a up-pushing mechanism was assembled.The problems in up-pushing materials were resloved.