Patent ID: 7299932

Claim:
An oil filter comprising: a housing main body having an oil inlet passage and an outlet passage; a cover detachably attached to the housing main body on a vertically lower side thereof and having a recessed portion that opens toward a housing main body side; an inner tubular member comprising a partition wall, and being disposed in the recessed portion of the cover so as to be movable into and out of the recessed portion, an oil collecting space positioned between the partition wall and the cover; a seal member interposed between the inner tubular member and the cover so as to provide a seal therebetween; at least one communication hole in the inner tubular member communicatively coupled to the oil collecting space; a biasing unit for urging the inner tubular member in a direction to protrude from the recessed portion of the cover; and a filter element disposed within the housing main body and the cover; wherein when the cover is in a state of being attached to the housing main body, the inner tubular member is pushed down into the recessed portion of the cover against a bias of the biasing unit so that as the cover is being removed, the inner tubular member protrudes from the recessed portion of the cover to increase the total volume of the oil collecting space.