A cylinder head of an internal combustion engine may include an opening and a sensor sleeve. The opening may extend through the cylinder head. The sensor sleeve may be shrink fitted in the opening. The sensor sleeve may be configured to receive a sensor. The sensor may be mounted within the sensor sleeve through a mounting mechanism.

It has been difficult to manufacturing a cylinder head having an EGR gas cooling structure which has high cooling performance and can be easily configured. A cylinder head having an EGR gas cooling structure is configured in such a manner that a gas passage which guides to the air intake port side a part of the exhaust gas discharged from the exhaust port is disposed within the cylinder head water jacket to cool the exhaust gas flowing through the gas passage. The gas passage comprises a cooling section which makes contact with the coolant within the cylinder head water jacket, and also comprises a hollow pipe which has high-strength sections located at side portions of the cooling section and having higher strength than the cooling section. The high-strength sections of the gas passage are molded within and surrounded by the cylinder head.

A cylinder head for an internal combustion engine is configured to be operated with fuel, such as gaseous or liquid fuel, to provide a more complete combustion of the fuel/air mixture. The cylinder head has at least one fuel guiding section, which includes a fuel inlet valve casing for accommodating a fuel inlet valve configured to control a fuel flow rate, a fuel/air mixing chamber for mixing the fuel with air, and a fuel guiding portion connecting the fuel inlet valve casing to the fuel/air mixture chamber. The fuel guiding portion is integrally formed with the cylinder head and defines at least a first fuel feeding passage and at least a second fuel feeding passage. The first fuel feeding passage and the second fuel feeding passage extend from the fuel inlet valve casing to the fuel/air mixing chamber.

An assembly method is provided by orienting a cylinder-head at a first orientation. A first plurality of spring caps and a first plurality of retainer keys are installed into the cylinder-head in the first orientation by a first robot. A first plurality of valves is installed into the cylinder-head in the first orientation by a second robot, into engagement with the first plurality of retainer keys. An end effector is provided with an actuator supported upon an adapter plate. A shaft extends from the actuator with a mating surface to engage a spring cap. Porting is provided through the shaft to convey pressurized air upon a plurality of retainer keys within the spring cap. A plurality of gripper fingers extend from the distal end of the shaft to grip a valve spring while retaining a spring cap between the valve spring and the mating surface of the shaft.

A fluid pressure cylinder includes a cylinder tube, a piston and a solid piston rod. The piston rod includes a head-side passage defined by a head-side shaft hole extending in an axial direction, a head-side outer hole open on a part projecting from the cylinder tube and a head-side inner hole open to a head-side chamber and allowing communication between a head-side chamber and a fluid pressure source, and a bottom-side passage allowing communication between a bottom-side chamber and the fluid pressure source. The head-side shaft hole includes an opening end and a tip formed inside the piston rod. The opening end of the head-side shaft hole is sealed by a sealing member.

A cylinder of a combustion engine for a vehicle includes at least one intake duct and a spark plug which in turn includes a ground electrode. The spark plug is mounted in the cylinder such that during an operation of the combustion engine the ground electrode is cooled in as optimum a manner as possible by an airflow generated by the at least one intake duct. A spark plug and a method for manufacturing a cylinder of a combustion engine are also provided.