A piston for an internal combustion engine including an upper part and a lower part connected by at least one threaded connection. The lower part includes a cutout positioned in the inner region of the piston above a peak of the pin bore extending toward the outer periphery of the piston. The lower part further includes at least one web positioned above the pin bore extending toward the outer periphery of the piston.

A steel piston for coupling to a connecting rod and wrist pin is provided. The piston includes a body with an upper crown presenting a combustion surface for exposure to a combustion chamber. The upper crown presents an undercrown surface which is openly exposed as viewed from an underside of the piston and not bounded by a cooling gallery. The body includes a ring belt and pin bosses depending from the ring belt and presenting a pin bore for receiving the wrist pin. The body also includes ribs disposed along the undercrown surface. The body includes a ratio of compression height to outer diameter (CH/D) ranging from 34.8% to 42.0%. The piston also includes a low heat transfer coating on the combustion surface, and the low heat transfer coating has a thermal conductivity of about 0.20 to 0.80 W/m.Math.K.

The invention relates to a piston for an internal combustion engine formed from a lower part and an upper part which are threadingly connected to one another to form a piston. In one example, an anti-rotation safeguard device is used to prevent unwanted rotation of the upper part relative to the lower part. In another example, a forged extension and a nut are used to obtain a prestress during operation of the piston. In another example, a cooling gallery including extension bores are used to increase the cooling capacity.

A piston for an opposed-piston, internal combustion engine includes a crown with an end surface having a bowl shaped to form a combustion chamber with an end surface of an opposing piston in the opposed-piston engine. A substantially circumferential top land of the crown meets the end surface at a substantially circular peripheral edge, and a skirt comprising a sidewall extends from a substantially circumferential belt region of the crown. A wristpin bore with a wristpin axis opens through the sidewall. The end surface of the piston includes a pair of injection regions across which fuel is injected into the bowl. The injection regions are disposed in substantially diametrically-opposed quadrants of the end surface which are defined by the wristpin axis and a connecting rod envelope axis substantially orthogonal to the wristpin axis. Each injection region extends along a respective arc concentric with the substantially circular peripheral edge.

A method is provided for designing and producing fiber-reinforced polymer (FRP) pistons. Pistons made with FRP have a lower mass than prior art metal pistons conferring advantageous engine efficiency and stability. FRP pistons also increase the thermal efficiency of engines by having a lower thermal conductivity, with tighter piston-to-bore clearance, and/increased air-fuel ratio than pistons of metal. The technical parameters of the piston are identified, and a piston body blank is produced. The blank is then machined, a bearing surface for the pin bore is created, the piston blank is optionally coated, is optionally subjected to Heavy Metal Ion Implantation (HMII) treatment and is subjected to sodium silicate impregnation to produce the final pistons.

Provided is a high pressure piston crown capable of withstanding a higher pressure than the existing piston crown by changing an internal structure of the piston crown reciprocating in a cylinder while being coupled with an upper portion of a piston skirt. The high pressure piston crown includes: a rib part 100 including a plurality of main ribs 110 that are radially disposed, have one side connected to a central portion C of the high pressure piston crown, and have a cross sectional area wider toward an outside of the high pressure piston crown; an oil gallery 200 formed by the rib part 100 and making cooling oil introduced from the piston skirt flow therein; and a lower plate 300 formed under the central portion C and connected to the rib part 100 to have an inside thereof connected to the oil gallery 200.

The piston and connecting rod assembly includes a connecting rod having opposed upper and lower ends, the upper end being pivotally secured to the piston by a conventional piston pin. The lower end of the connecting rod has a passage formed therein for receiving a conventional crankpin. However, an additional sleeve is provided for the piston. The sleeve has at least one sidewall, a closed upper end and an open lower end. The sleeve is releasably secured to the piston by any suitable type of releasable attachment or engagement. An upper surface of the closed upper end of the sleeve may have a plurality of apertures or recesses formed therein, allowing a tool with corresponding pins to engage the sleeve for removal thereof from the piston.

The piston and connecting rod assembly includes a connecting rod having opposed upper and lower ends, the upper end being pivotally secured to the piston by a conventional piston pin. The lower end of the connecting rod has a passage formed therein for receiving a conventional crankpin. However, an additional sleeve is provided for the piston. The sleeve has at least one sidewall, a closed upper end and an open lower end. The sleeve is releasably secured to the piston by any suitable type of releasable attachment or engagement. An upper surface of the closed upper end of the sleeve may have a plurality of apertures or recesses formed therein, allowing a tool with corresponding pins to engage the sleeve for removal thereof from the piston.

The present invention relates to a multi-piece, in particular at least two-piece, piston (1) for an internal combustion engine having a longitudinal axis (L), comprising a piston outer part (10) having a closed piston head (11), which in the fitted state defines a combustion chamber, and a piston body (13) extending axially away from the piston head (11), and a piston inner part (20), which in the fitted state is connected to a connecting rod. An outer surface (2) radially defining the piston (1) is formed exclusively by at least one portion of the piston body (13) of the piston outer part (10). The piston inner part (20), viewed in an axial direction, is arranged radially entirely inside the piston body (13) or its circumferential surface.

A method is provided of designing and producing a piston using chopped carbon ceramic pre-impregnated composite material, wherein the method allows piston designers to produce a fiber/composite preform, then machine any of several different piston designs, diameters, with different ring and chamber designs or dimensions and dimensional offsets. The piston preform is shaped in a basic form, and then machined into a piston that fits a specific engine. After the specific machining is performed, the pin bosses are bored and fitted with bronze inserts; ring lands are cut, skirts are shaped, finish machining is performed on all surfaces. Pistons are preferably then plated to seal carbon ceramic based materials, and the skirts as well as regions that engage in part-to-part moving contact, are plasma coated with anti-friction material(s). The skirts may be made as a separate skirt preform which is fitted, machined or cut to fit the specific piston. The overall process is adapted to skirt regions of differing size, length or offset that are assembled into a unitary structure of improved strength/weight characteristics. The method is useful for making high-performance engine modification parts having high strength and reduced inertial mass