A method of preventing bearing seizure may include using at least one of a knock sensor, an engine oil pressure sensor, and a continuously variable valve timing (CVVT) system as a bearing seizure detection factor by a bearing controller, detecting damage of a bearing applied to an engine during operation of the engine in which a state of the bearing seizure detection factor is changed, and performing engine control using the bearing seizure detection factor when the bearing damage is detected.

A method of preventing bearing seizure may include using at least one of a knock sensor, an engine oil pressure sensor, and a continuously variable valve timing (CVVT) system as a bearing seizure detection factor by a bearing controller, detecting damage of a bearing applied to an engine during operation of the engine in which a state of the bearing seizure detection factor is changed, and performing engine control using the bearing seizure detection factor when the bearing damage is detected.

A method of preventing bearing seizure may include using each of a knock sensor, an engine oil pressure sensor, and a continuously variable valve timing (CVVT) system as a bearing seizure detection factor by a bearing controller, detecting damage of a bearing applied to an engine during operation of the engine in which a state of the bearing seizure detection factor is changed, and performing engine control using the bearing seizure detection factor when the bearing damage is detected.

A method of preventing bearing seizure may include using each of a knock sensor, an engine oil pressure sensor, and a continuously variable valve timing (CVVT) system as a bearing seizure detection factor by a bearing controller, detecting damage of a bearing applied to an engine during operation of the engine in which a state of the bearing seizure detection factor is changed, and performing engine control using the bearing seizure detection factor when the bearing damage is detected.

Each time a highly-viscous substance is extruded, a variation in weight of each cut piece of the highly-viscous substance is minimized. Metallic sodium (5) loaded in an extruder main body (3) is extruded from a nozzle (7) of the extruder main body (3) with a pressing tool (4) and, when it is detected that the metallic sodium (5) is extruded to a predetermined position, the movement of the pressing tool (4) is stopped and the extruded metallic sodium (5) is cut. In this case, an impulse (P) after stop is brought closer to a constant value until a load no longer acts on the metallic sodium (5) in the extruder main body (3) after stopping the movement of the pressing tool (4) by adjusting the movement speed of the pressing tool (4).

Each time a highly-viscous substance is extruded, a variation in weight of each cut piece of the highly-viscous substance is minimized. Metallic sodium (5) loaded in an extruder main body (3) is extruded from a nozzle (7) of the extruder main body (3) with a pressing tool (4) and, when it is detected that the metallic sodium (5) is extruded to a predetermined position, the movement of the pressing tool (4) is stopped and the extruded metallic sodium (5) is cut. In this case, an impulse (P) after stop is brought closer to a constant value until a load no longer acts on the metallic sodium (5) in the extruder main body (3) after stopping the movement of the pressing tool (4) by adjusting the movement speed of the pressing tool (4).

A cladding method for a valve seat in a cylinder head blank includes a combustion chamber, an intake port or an exhaust port communicating with the combustion chamber, and an annular countersunk groove formed in an opening end of the port on the combustion chamber side, the method being for forming a cladding layer by irradiating metal powder supplied in the countersunk groove with a laser beam. A gas flow regulating wall is provided, which projects from the countersunk groove to an inner side of the countersunk groove and to the combustion chamber side, gas is sprayed during irradiating with the laser beam, and the gas is flown by the gas flow regulating wall from the inner side to an outer side of the countersunk groove.

A cladding method for a valve seat in a cylinder head blank includes a combustion chamber, an intake port or an exhaust port communicating with the combustion chamber, and an annular countersunk groove formed in an opening end of the port on the combustion chamber side, the method being for forming a cladding layer by irradiating metal powder supplied in the countersunk groove with a laser beam. A gas flow regulating wall is provided, which projects from the countersunk groove to an inner side of the countersunk groove and to the combustion chamber side, gas is sprayed during irradiating with the laser beam, and the gas is flown by the gas flow regulating wall from the inner side to an outer side of the countersunk groove.

Provided is a method for filling a stem-side hollow area of an engine valve with metallic sodium. The method includes injecting melted metallic sodium into a cylinder having a larger diameter than an inner diameter of the hollow area of the engine valve, forming a solidified metallic sodium rod having a substantially uniform structure in the cylinder, inserting the metallic sodium into the hollow area of the engine valve through a nozzle having a small diameter, and sealing the engine valve.

Provided is a method for filling a stem-side hollow area of an engine valve with metallic sodium. The method includes injecting melted metallic sodium into a cylinder having a larger diameter than an inner diameter of the hollow area of the engine valve, forming a solidified metallic sodium rod having a substantially uniform structure in the cylinder, inserting the metallic sodium into the hollow area of the engine valve through a nozzle having a small diameter, and sealing the engine valve.