A galleryless piston for an internal combustion engine and method of construction thereof are provided. The piston has a monolithic piston body extending along a central longitudinal axis. The piston body has an upper wall forming an upper combustion surface with first and second portions, with the first portion extending annularly along an outer periphery of the upper wall and the second portion forming a combustion bowl. The upper wall has an undercrown surface on an underside of the combustion bowl directly opposite the second portion of the upper combustion surface. The undercrown surface has an openly exposed surface area, as viewed looking along the central longitudinal axis, thereby providing an expansive area against which oil being splashed or sprayed can freely contact to cool the piston.

A galleryless piston for an internal combustion engine and method of construction thereof are provided. The piston has a monolithic piston body extending along a central longitudinal axis. The piston body has an upper wall forming an upper combustion surface with first and second portions, with the first portion extending annularly along an outer periphery of the upper wall and the second portion forming a combustion bowl. The upper wall has an undercrown surface on an underside of the combustion bowl directly opposite the second portion of the upper combustion surface. The undercrown surface has an openly exposed surface area, as viewed looking along the central longitudinal axis, thereby providing an expansive area against which oil being splashed or sprayed can freely contact to cool 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.

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.

Disclosed are novel bridged bi-aromatic phenol ligands and transition metal catalyst compounds derived therefrom. Also disclosed are methods of making the ligands and transition metal compounds, and polymerization processes utilizing the transition metal compounds for the production of olefin polymers.

The invention relates to a piston for an internal combustion engine having an upper part integrally joined to a lower part having a shaft and at least one pin bore. The upper part including a combustion chamber bowl recess and a piston crown with a crown edge. At least one joint is arranged in the region of a ring zone and in an outer wall of the combustion bowl recess, and the ratio of piston compression height (h.sub.1) and the diameter of the piston (d.sub.1) is less than 0.53.

This piston for internal combustion engines, which is capable of achieving high heat shielding properties and high durability, comprises: a base that is formed from aluminum or an aluminum alloy; a composite material part which is formed in a first region of the surface of the base, and which is formed from a composite material that is reinforced with inorganic fibers or whiskers; and an alumite coating film that is formed on the composite material part and a second region of the surface of the base, said second region being different from the first region.

This piston for internal combustion engines, which is capable of achieving high heat shielding properties and high durability, comprises: a base that is formed from aluminum or an aluminum alloy; a composite material part which is formed in a first region of the surface of the base, and which is formed from a composite material that is reinforced with inorganic fibers or whiskers; and an alumite coating film that is formed on the composite material part and a second region of the surface of the base, said second region being different from the first region.

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

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