Patent attributes
A lubricant oil feeder 2 of a due casting machine 1 is made up of a lubricant oil feed passage 19 for feeding a lubricant oil into a clearance between the inner peripheral surface of a sleeve 7 and the outer peripheral surface of an injection piston 9, a lubricant oil feed valve 20 for opening or closing the lubricant oil feed passage, an air feed passage 16 for feeding air into a clearance between the inner peripheral surface of the sleeve and the outer peripheral surface of the injection piston, and an air feed valve 18 for opening and closing the air feed passage, and the arrangement is such that the lubricant oil feed valve is initially opened to feed the lubricant oil into the clearance between the sleeve and the injection piston and the air feed valve is then opened to pump the lubricant oil by the air.
