Abstract: A new type of plug incorporating a normally closed valve for draining oil from an oil pan of a car engine, wherein the normally closed valve is incorporated in a through hole provided as an oil draining path in a bolt type member fixed to the oil pan, an oil draining dedicated jig is assembled to the plug so as to open the normally closed valve in order to drain the oil contained in the oil pan by sucking it with a negative pressure, a movable valve disc member installed in the through hole is installed so that it is engaged with a valve seat provided near the outer end part of the through hole by a coiled spring so as to form the normally closed valve, and the tip end of the plug is made flush generally with the internal surface of the oil pan so as to prevent any structure from projecting toward the inside.

Abstract: A new type of plug incorporating a normally closed valve for draining oil from an oil pan of a car engine, wherein the normally closed valve is incorporated in a through hole provided as an oil draining path in a bolt type member fixed to the oil pan, an oil draining dedicated jig is assembled to the plug so as to open the normally closed valve in order to drain the oil contained in the oil pan by sucking it with a negative pressure, a movable valve disc member installed in the through hole is installed so that it is engaged with a valve seat provided near the outer end part of the through hole by a coiled spring so as to form the normally closed valve, and the tip end of the plug is made flush generally with the internal surface of the oil pan so as to prevent any structure from projecting toward the inside.

Abstract: A valve body member (20) is movably accommodated in an oil drain through-hole (14) of a bolt member (11) secured to an oil pan (1), with a valve body (21) of the valve body member (20) being engaged with a valve seat (12a) of the bolt member (11) by means of a spring (30) to constitute a normally-closed valve. The normally-closed valve is opened by forcing the valve body member (20) by an adapter (40) having an oil suction hose (463) connected thereto so that oil is drained off by a negative suction. At the same time, an elongated flexible tube (50) connected to the oil suction tube (463) is inserted from the adapter (40) through an opening of the valve body member (20) into the interior of the pan (1) to drain off the oil remaining on the bottom of the oil pan (1).