Abstract: The thickness of an intermediate plate portion (31b) is smaller than the thickness of a stopper portion (31a). The thickness of a portion of a cylinder head gasket (20) having the stopper portion (31a) is set to be greater than the thickness of other portions of the cylinder head gasket (20). Before the cylinder head gasket (20) is provided between contact surfaces (12a, 13a), a space (S) is formed between the stopper portion (31a) and an adjustment stopper portion (32a), and the intermediate plate portion (31b) partially contacts the adjustment plate portion, and a bead (33a) contacts the adjustment plate portion (32b).

Abstract: The effective utilization of the elasticity of a full bead is prevented from being interfered by a thickness portion of the shim plate by providing a shim plate inside a full bead, thereby a lowering of the follow-up performance to head amplitude at the time of combustion is prevented, and the improvement of the sealability is achieved. A metal gasket 10 includes a pair of bead plates 14 and 14 having a cylinder hole 12 corresponding to a cylinder bore and a full bead 22 surrounding the cylinder hole, a first intermediate plate 18 interposed between the pair of bead plates, and a shim plate 16 interposed between the first intermediate plate and one bead plate in an area around the cylinder hole. The shim plate 16 is disposed to overlap with the full bead 22, and the thickness of a contact portion 19 to contact the shim plate 16 of the first intermediate plate changes in the peripheral direction of the cylinder hole.

Abstract: A cylinder head cover is formed by a synthetic resin outer shell, which is molded by inserting a metal valve case, which holds a oil control valve, in a mold. The valve case has a bolt fastening portion for fastening the valve case, together with the outer shell, to the cam cap. The valve fastening portion has a bolt insertion hole. The bolt fastening portion also has a flange that extends radially outward. The flange has through holes. The flange is embedded in the outer shell, and synthetic resin forming the outer shell fills the through holes.

Abstract: A valve case 12, which is a metal component, and an outer shell portion 13 of a cylinder head cover 11, which is a resin component, are joined together through a seal material 17. First, a recess 16 formed in the valve case 12 is filled with a seal material 17A in a liquid form. A skin layer 22 is then formed by curing the surface of the seal material 17A. Subsequently, the outer shell portion 13 is formed by supplying a synthetic resin material 13A onto the valve case 12 in such a manner as to cover the skin layer 22, which is provided on the surface of a non-cured portion 17a of the seal material 17. At this stage, the skin layer 22 is broken by supply pressure of the synthetic resin material 13A and thus the synthetic resin material 13A and the non-cured portion 17a of the seal material 17 are joined together as an integral body.

Abstract: A cylinder head cover covers a cylinder head of an internal combustion engine. The engine has a variable valve actuation mechanism and a control valve for controlling supply and drainage of hydraulic oil to and from the variable valve actuation mechanism. The cylinder head cover includes a cover main body fixed to the cylinder head and a valve case to which the control valve is attached. The valve case is caused to contact a side of the cover main body that corresponds to the cylinder head. Therefore, the cylinder head cover maintains a firm attachment of the valve case to the cylinder head.

Abstract: A tubular valve casing formed of metal is molded with an outer shell portion formed of synthetic resin. A valve body is inserted into the valve casing through an opening formed at an end of the valve casing and incorporated in the valve casing. An annular projection is formed in the outer shell portion and projects toward the end surface of the valve casing corresponding to the opening. A seal ring is arranged between the projection and the valve body.

Abstract: A cylinder head gasket includes a first gasket base plate at a cylinder head side, a second gasket base plate at a cylinder block side, a shim that adjusts the gasket thickness, and a pressure increasing plate that increases the surface pressure at the side of periphery portions of the cylinders. In the first and second gasket base plates full beads are swollen at the side of periphery portions of cylinders, and half beads are swollen at a site outward of the full beads. The full beads of the first and second gasket base plates are formed so that top portions of the full beads face each other at positions that are opposite to each other in the up-down direction. The shim and the pressure increasing plate are sandwiched between the top portions.

Abstract: A stay for keeping an oil control valve fastened to a sleeve extends across the outer surface of a head cover from the oil control valve and is fixed by a screw. Thus, the OCV is removable from the sleeve without dismounting the head cover from the cylinder head by loosening the screw from the outside of the head cover and detaching the stay.

Abstract: A sleeve allows insertion of an oil control valve, and is used by being inserted to an installation hole provided in a cylinder head cover. An outer surface of a sleeve main body of the sleeve is covered by a rubber-like elastic body layer. The rubber-like elastic body layer has a protrusion provided in the periphery of an oil hole provided in the sleeve main body in such a manner as to surround the oil hole. In accordance with the sleeve, it is possible to install the oil control valve to the cylinder head cover at a high oil tightness.

Abstract: A stay for keeping an oil control valve fastened to a sleeve extends across the outer surface of a head cover from the oil control valve and is fixed by a screw. Thus, the OCV is removable from the sleeve without dismounting the head cover from the cylinder head by loosening the screw from the outside of the head cover and detaching the stay.

Abstract: First and second attachment portions 6, 8 are formed integrally with a main body 4 and extend along the longitudinal direction of the main body 4. A hydraulic oil supply portion 14 is formed integrally with the main body 4 and extends along the width, or in the direction perpendicular to the axes of the attachment portions 6, 8. In this manner, providing an internal combustion engine with variable valve actuation mechanisms increases the strength of the cylinder head cover 102, while reducing the weight thereof.

Abstract: A cylinder head gasket for an internal combustion engine with a cylinder bore and a fluid hole includes a first metal plate having a curved portion around the cylinder bore and a folded portion extending from the curved portion, and a second metal plate laminated on the first metal plate and having a first full bead projecting toward the first metal plate. The first full bead is disposed on the folded portion. At least one secondary plate is inserted inside the folded portion.

Abstract: A resin cylinder head cover for an internal combustion engine includes a resin cover main body and a resin oil passage that is integrated with the cover main body. As a result, the problems of increase in the number of components and deterioration of the oil sealing performance in a resin cylinder head cover are solved.

Abstract: First and second attachment portions 6, 8 are formed integrally with a main body 4 and extend along the longitudinal direction of the main body 4. A hydraulic oil supply portion 14 is formed integrally with the main body 4 and extends along the width, or in the direction perpendicular to the axes of the attachment portions 6, 8. In this manner, providing an internal combustion engine with variable valve actuation mechanisms increases the strength of the cylinder head cover 102, while reducing the weight thereof.

Abstract: A resin cylinder head cover includes an attaching portion and a sleeve. The attaching portion is formed of resin, and is a portion of the cylinder head cover to which the oil control valve is to be attached. The sleeve is embedded in the attaching portion. The sleeve has an interior space that permits the oil control valve to be accommodated therein and oil holes. Each oil hole is selectively connected to one of ports of the oil control valve accommodated in the interior space of the sleeve. The sleeve is formed of material having higher rigidity than the resin forming the attaching portion. Therefore, the cylinder head cover maintains highly reliable attachment of an oil control valve without a large number of high precision machining steps and prevents deformation of the attaching portion.

Abstract: First and second attachment portions 6, 8 are formed integrally with a main body 4 and extend along the longitudinal direction of the main body 4. A hydraulic oil supply portion 14 is formed integrally with the main body 4 and extends along the width, or in the direction perpendicular to the axes of the attachment portions 6, 8. In this manner, providing an internal combustion engine with variable valve actuation mechanisms increases the strength of the cylinder head cover 102, while reducing the weight thereof.

Abstract: A valve case includes an attaching portion and a sleeve. The valve case is attached to a cylinder head cover main body formed of resin. The attaching portion is formed of resin and is a portion of the valve case to which an oil control valve is to be attached. The sleeve is embedded in the attaching portion, and has an interior space that permits the oil control valve to be accommodated therein and oil holes. Each oil hole is selectively connected to one of ports of the oil control valve accommodated in the interior space of the sleeve. The sleeve is formed of material having higher rigidity than the resin forming the attaching portion. Therefore, the valve case prevents deformation of the attaching portion.

Abstract: First and second attachment portions 6, 8 are formed integrally with a main body 4 and extend along the longitudinal direction of the main body 4. A hydraulic oil supply portion 14 is formed integrally with the main body 4 and extends along the width, or in the direction perpendicular to the axes of the attachment portions 6, 8. In this manner, providing an internal combustion engine with variable valve actuation mechanisms increases the strength of the cylinder head cover 102, while reducing the weight thereof.

Abstract: A cylinder head cover covers a cylinder head of an internal combustion engine. The engine has a variable valve actuation mechanism and a control valve for controlling supply and drainage of hydraulic oil to and from the variable valve actuation mechanism. The cylinder head cover includes a cover main body fixed to the cylinder head and a valve case to which the control valve is attached. The valve case is caused to contact a side of the cover main body that corresponds to the cylinder head. Therefore, the cylinder head cover maintains a firm attachment of the valve case to the cylinder head.

Abstract: A cylinder block (10) is such that a main body cylinder block (4; 404) and an outer cylinder block (6; 406) are molded separately. As a result, the portion of the die which is used to mold a water jacket (50; 450) does not need to be made thin, thereby increasing the life of the die. Further, cylinders (12; 412) are of a simple shape and the pressure in the axial direction of the cylinder (12; 412) is able to be dispersed substantially evenly between the cylinders (12; 412) and the outer cylinder block (6; 406), thus enabling the cylinders (12; 412) to be thin. Accordingly, there is an increased degree of freedom in design of the portion which forms the water jacket (50; 450). The water jacket (50; 450) and the cylinders (12; 412) can therefore both be made sufficiently thin, thereby contributing to a decrease in both the size and weight of the engine.