In a compression-ignition engine having a two-stage cavity, the distribution ratio between fuel for an upper cavity and fuel for a lower cavity is maintained even when the operational state of the engine changes. A piston of the engine includes a lower cavity, an upper cavity, and a lip portion between the lower cavity and the upper cavity. A controller causes a main injection and at least one pilot injection to be executed when an engine operates in a first state and a second state in which the speed is higher than the speed in the first state. The fuel spray is distributed to the lower cavity and the upper cavity. The controller maintains an injection amount of the main injection and increases an injection amount of the pilot injection(s) when the engine operates in the second state as compared to when the engine operates in the first state.

In a compression-ignition engine having a two-stage cavity, the distribution ratio between fuel for an upper cavity and fuel for a lower cavity is maintained even when the operational state of the engine changes. A piston of the engine includes a lower cavity, an upper cavity, and a lip portion between the lower cavity and the upper cavity. A controller causes a main injection and at least one pilot injection to be executed when an engine operates in a first state and a second state in which the speed is higher than the speed in the first state. The fuel spray is distributed to the lower cavity and the upper cavity. The controller maintains an injection amount of the main injection and increases an injection amount of the pilot injection(s) when the engine operates in the second state as compared to when the engine operates in the first state.

The present invention provides a piston of an internal combustion engine capable of reducing a deformation amount of a piston head. A piston of an internal combustion engine includes a piston head, a pair of piston pin boss portions, a pair of skirt portions, and four apron portions connecting each of the pair of piston pin boss portions and each of the pair of skirt portions. Each of the four apron portions includes a bent portion, a boss portion-side portion positioned on one side where the pair of piston pin boss portions is located with respect to the bent portion, and a skirt portion-side portion positioned on an opposite side from the pair of piston pin boss portions with respect to the bent portion. A distance between an axis perpendicular to both an axis of a cylinder of the internal combustion engine and an axis of a piston hole and the boss portion-side portion is increasing according to an increase in a distance from the axis of the piston pin hole.

Disclosed are a piston and a method for a ring groove support structure thereof. The piston includes a piston head and a piston skirt connected with the piston head; a cooling oil cavity is arranged in the piston head; a position of the bottom of the cooling oil cavity close to the piston skirt is an open end and the open end is sealed through a supporting member; a cooling oil inlet and an oil drain port are arranged on the supporting member; the cooling oil inlet is in communication with the cooling oil cavity and an oil inlet channel of the cooling oil arranged in the piston skirt; the oil drain port is in communication with the cooling oil cavity and the oil drain channel arranged in the piston skirt; and the open end and the supporting member are welded.

A brake piston for use in a disc brake assembly having an external surface disposed along a longitudinal axis; and a non-circular end face being disposed perpendicular to the external surface and the longitudinal axis. The non-circular end-face and the external surface define a cavity and the non-circular end face is configured to engage with a brake disc when the disc brake assembly is actuated.

A brake piston for use in a disc brake assembly having an external surface disposed along a longitudinal axis; and a non-circular end face being disposed perpendicular to the external surface and the longitudinal axis. The non-circular end-face and the external surface define a cavity and the non-circular end face is configured to engage with a brake disc when the disc brake assembly is actuated.

A hydraulic device includes a cylinder, a piston that is able to move in the cylinder, and a segment which is interposed between the cylinder and the piston and which includes at least one leakage duct that is configured to generate a hydraulic film, between the segment and the piston, reducing friction and to orient a hydraulic flow leaving the leakage duct which causes the segment to rotate about the piston.

The present disclosure provides an open-faced piston with a circumferential groove into which a piston ring assembly is arranged. Openings at the bottom of the circumferential groove and between a front land of the open-faced piston and the piston face are provided. The openings are arranged to allow for a combustion reaction to propagate through the volume defined between the bottom of the piston ring assembly and the piston face such that at least a portion of an air and fuel mixture located in that volume is reacted.

A setting tool that sets a packer or bridge plug in a wellbore using an improved piston rod design.

A top surface of the piston includes a first region. A heat shielding film is formed on the first area. The top surface further includes a second region. There is no heat shielding film formed on the second region. Instead, the second area is mirror-finished. The top surface includes a central portion. A valve recess portion is formed on an intake side of the central portion. A squish portion is formed the intake side of the valve recess portion. The first area includes at least the central portion. The second area includes at least the squish portion.