Abstract: A cylinder head gasket includes a pair of first and second gasket substrates. The gasket substrates are each formed with a first and a second projection which project in opposite directions, with a clearance therebetween. According to a first aspect of the invention, each projection undergoes a plastic deformation toward the clearance defined between them when the gasket substrates are held sandwiched between a cylinder head and a cylinder block, each projection undergoing a magnitude of plastic deformation which is greater or lesser in accordance with the magnitude of a surface pressure therebetween. According to a second aspect of the invention, each projection is formed with a radially central part which projects toward the radially central part of the other projection and which is in close contact with each other continuously in the circumferential direction.

Abstract: A cylinder head gasket includes a pair of first and second gasket substrates. The gasket substrates are each formed with a first and a second projection which project in opposite directions, with a clearance therebetween. According to a first aspect of the invention, each projection undergoes a plastic deformation toward the clearance defined between them when the gasket substrates are held sandwiched between a cylinder head and a cylinder block, each projection undergoing a magnitude of plastic deformation which is greater or lesser in accordance with the magnitude of a surface pressure therebetween. According to a second aspect of the invention, each projection is formed with a radially central part which projects toward the radially central part of the other projection and which is in close contact with each other continuously in the circumferential direction.

Abstract: A cylinder head gasket includes a pair of first and second gasket substrates. The gasket substrates are each formed with a first and a second projection which project in opposite directions, with a clearance therebetween. According to a first aspect of the invention, each projection undergoes a plastic deformation toward the clearance defined between them when the gasket substrates are held sandwiched between a cylinder head and a cylinder block, each projection undergoing a magnitude of plastic deformation which is greater or lesser in accordance with the magnitude of a surface pressure therebetween. According to a second aspect of the invention, each projection is formed with a radially central part which projects toward the radially central part of the other projection and which is in close contact with each other continuously in the circumferential direction.

Abstract: A device for controlling the rotation speed of a cooling fan of an internal combustion engine in a vehicle such as an automobile, wherein the fan is driven by a hydraulic motor powered by an operating fluid supplied by a pump directly driven by the engine, wherein the device controls partial relief of the hydraulic fluid supplied from the pump toward the motor so that, in a low engine revolution speed range, the ratio of the partial relief is decreased as the engine temperature increases, but in a high engine revolution speed range, the ratio of the partial relief is increased as the engine revolution speed increases.