Patent ID: 6655498
Filing Date: 2003-12-02
Classification: F01M,F16L,Y10T

Abstract:
A drain plug for a pipe coupling designed to change oil in an engine oil pan that has a drain port, said drain plug comprising:a main body having a first end part to be attached to the drain port of the oil pan, a second end part projecting outwards from the oil pan, a recess made in an outer surface of the second end part, and an axial hole forming an oil path and capable of communicating with an interior of the oil pan, a valve holder fixed in the axial hole, positioned near the second end part and having an end face exposed to outside and an inclined surface positioned on an axially opposite side to said end face; a valve body urged against and supported by the inclined surface in the valve holder, for closing the oil path; and a seal member which is fitted to an inclined surface of the valve holder or the valve body and which seals a space between the inclined surface of the valve holder and the valve body, wherein the main body holds the valve holder at a position at which the end face does not project beyond the second end part and the valve holder holds the valve body at a position at which the valve body does not project beyond the end face, thereby preventing the valve body from being lifted easily from the inclined surface when hit by a stone or the like.