Various kinds of sealing devices such as a gasket and a packing have been conventionally known as devices for sealing a clearance defined between two members. They have been formed into various shapes. Moreover, there have been a variety of sealing structures in which the sealing devices are used.
Patent Document 1, for example, discloses a sealing structure, in which a bottom side of a gasket is suppressed from sliding sideways of a installation groove by curving a bottom of the installation groove, so as to prevent the gasket from falling down, and further, the gasket can be installed irrespective of the obverse and reverse thereof by forming the gasket into a symmetric shape in cross section.
Otherwise, Patent Document 2 discloses a packing for an injector, in which projections are formed on both sides in an axial direction on an inner circumferential surface and an outer peripheral surface, and further, portions with and without a squeeze margin are formed at the outer peripheral surface of the injector and the inner circumferential surface of a housing. In this manner, sealability can be exhibited irrespective of the magnitude of a pressure to be exerted on the packing, and further, an increase in filling ratio of the packing to an installation space is suppressed, so that the packing can be prevented from extending into a clearance.
Alternatively, Patent Document 3 discloses a gasket interposed between a cylinder head and a head cover in an engine, in which a clearance is formed between a bottom of a gasket containing groove and the gasket before the gasket is tightened, whereas a part of the gasket is deformed in such a manner as to fill the clearance defined between the groove bottom of the containing groove and the same during tightening, thereby suppressing an exposed portion of the gasket from extending into the clearance defined between the cylinder head and the head cover.
Patent Document 1: Japanese Patent Application Laid-Open No. 2006-200649
Patent Document 2: Japanese Patent Application Laid-Open No. 2002-340191
Patent Document 3: Japanese Utility Model Application Laid-Open No. 2-124371