Abstract: A method for injecting a molten resin by an injection machine comprises the steps of opening a ring valve mounted on an injection screw by the normal revolution of a injection screw thereof; metering the molten resin; stopping the revolution of said injection screw; moving said injection screw backward, performing the reverse revolution of the injection screw at the moved-back position for the required amount to generate a differential pressure; making the ring valve come in proximity to or into contact with a valve seat at the tip of a screw body of the injection screw by said differential pressure; and injecting the metered resin by the forward movement of the injection screw so as to complete the closure of the ring valve. According to the longer stroke of the injection screw, the ring valve is certainly closed by the backward, rotative and forward movements of the injection screw and thereby an injection operation is maintained more precisely in the dispersion of the injecting quantities than before.

Abstract: A clamping apparatus of molding machine including a base; a fixed board disposed on the base; a movable board movable relative to the fixed board; a plurality of mold clamping cylinders disposed in predetermined positions of the fixed board, the mold clamping cylinders each having a mold clamping piston with a tie bar reception hole and a tie bar connection device disposed on the mold clamping piston; a plurality of tie bars with a thread at their one end, the tie bars being disposed in correspondence with the mold clamping cylinders on the movable board; a plurality of mold opening/closing cylinders for moving the movable board; and an axially movable sleeve associated with each clamping cylinder for adjusting an axial position of an associated piston to adjust an engagement position of the tie bar connection device, the sleeve being disposed in an opening in the fixed board and forming an extension of the tie bar reception hole, with one end of the sleeve abutting against a reception wall provided in each p

Abstract: A safety apparatus for a clamping device which includes a machine base, a first fixed board fixed on the base, a movable board movably disposed on the base, either a second fixed board or a bearing member fixed to the base behind the movable board, and a safety door slidably disposed on the base between an open and a closed position. The safety apparatus includes an engagement device disposed on the movable board, the engagement device having a stopper member which is vertically movable between an engaged and a disengaged position when the safety door is opened or closed, a safety rod disposed between the first fixed board and either the bearing member or the second fixed board, the safety rod having a plurality of engagement portions spaced therealong, and a drive device disposed on either the bearing member or the second fixed board for axially moving the safety rod.

Abstract: A clamping apparatus of molding machine including a base; a fixed board disposed on the base; a movable board movable relative to the fixed board; a plurality of mold clamping cylinders disposed in predetermined positions of the fixed board, the mold clamping cylinders each having a mold clamping piston with a tie bar reception hole and a tie bar connection device disposed on the mold clamping piston; a plurality of tie bars with a thread at their one end, the tie bars being disposed in correspondence with the mold clamping cylinders on the movable board; a plurality of mold opening/closing cylinders for moving the movable board; and a mold thickness adjustment device having a movable stopper for contacting an end of each tie bar to control the axial position of each of the tie bars with respect to the connection devices during clamping.

Abstract: A clamping apparatus of molding machine including a base; a fixed board disposed on the base; a movable board movable relative to the fixed board; a plurality of mold clamping cylinders disposed in predetermined positions of the fixed board, the mold clamping cylinders each having a mold clamping piston with a tie bar reception hole and a tie bar connection device disposed on the mold clamping piston; a plurality of tie bars with a thread at their one end, the tie bars being disposed in correspondence with the mold clamping cylinders on the movable board; a plurality of mold opening/closing cylinders for moving the movable board; and a differential circuit connected between a front oil chamber and a rear oil chamber of each of the plurality of mold clamping cylinder.