Abstract: A method for producing a piston for an internal combustion engine may include arranging a piston upper part and a piston lower part in a friction welding device. The piston upper part may include a piston head with a combustion recess. The piston lower part may include two mutually opposite skirt elements connected to one another via two mutually opposite pin bosses. The method may also include arranging a deflecting device configured to deflect at least one weld bead one of on and in the friction welding device. The method may further include joining the piston upper part and the piston lower part to one another via friction welding.

Abstract: Disclosed is an engine piston structure including an outer peripheral portion (6) formed along an outer shape of a piston (1), and having a predetermined thickness, a pair of piston pin supporters (7) having peripheral walls (7b) having a predetermined thickness, and couplers (8) each coupling the pair of the piston pin supporters (7) to the outer peripheral portion (6). The outer peripheral portion (6) and the peripheral walls (7b) of the piston pin supporters (7) are solid. Each of the coupler (8) is porous. The outer peripheral portion (6), the piston pin supporters (7), and the couplers (8) are made of a metal material and are integrally formed together.

Abstract: A piston for an internal combustion engine comprises a crown, a skirt section extending from the crown, and an oil ring groove. The piston further comprises a drain hole and a cooling channel. The drain hole extends from the oil ring groove to an inside space of the piston. The cooling channel is formed in the crown at a level above the oil ring groove, and arranged to covey a cooling oil. The cooling channel includes a channel segment which is located near the drain hole and which is formed to have a sectional shape avoiding the drain hole.

Abstract: A piston for an internal combustion engine, including a crown portion that defines a combustion chamber, a ring-shaped cooling channel formed in the crown portion, through which a cooling oil flows, and a plurality of concave portions formed on at least one side of the cooling channel, in an axial direction of the piston, each of the plurality of concave portions having a curved surface.

Abstract: A piston assembly and a method of making the same. Exemplary piston assemblies may include a piston crown having a ring belt portion defining a cooling gallery, and a strut extending away from the ring belt portion to define a wrist pin bore. The piston may further include a piston skirt assembly secured to the strut. The piston skirt assembly may include two separate portions that each have a closure plate formed integrally with the portion, with the closure plate generally enclosing the cooling gallery. Exemplary methods of assembling a piston may include providing a piston crown having a ring belt portion defining a cooling gallery and a strut extending away from the ring belt portion to define a wrist pin bore. The methods may further include forming a piston skirt assembly having two portions having a closure plate integrally formed therewith, and securing the skirt to the crown.

Abstract: A piston has an upper crown portion with an upper combustion wall against which combustion forces act and a lower crown portion with a pair of pin bosses spaced for receipt of a small end of a connecting rod therebetween. The upper crown portion and the lower crown portion form an outer oil gallery and a central oil gallery in fluid communication with one another. The central oil gallery is formed in part by an annular flange extending radially inwardly from the outer oil gallery and upwardly toward the upper combustion wall to a free edge spaced from the upper combustion wall. The free edge forms an opening about a central axis of the piston and has a non-planar uppermost surface with depressions aligned diametrically opposite one another across the opening to improve the oil flow throughout the central oil gallery.

Abstract: The object is to obtain a piston apparatus having a metal cylindrical piston ring without kerf that causes substantially no gas leak.

Abstract: A one-piece piston (20) formed by an upper crown (28) and a lower crown (30) having an integral skirt (24, 26). The upper crown (28) includes an upper surface (32) and a lower surface (34, 42). The lower crown (30) includes an upper surface (50) and two pin bosses (52, 54). The upper crown (28) has a first collar (44) and the lower crown (30) has a second collar (64). In addition, skirt ribs (24, 26) connect the two pin bosses (52, 54). The first and second collars (44, 64) are secured together to form the one-piece piston (20).

Abstract: A piston of an internal combustion engine, comprises a skirt portion in sliding-contact with a cylinder wall, an inner crown-plus-boss portion having a crown portion and piston-pin boss portions, and a stay portion interconnecting the skirt portion and the inner crown-plus-boss portion at a lower portion of the piston. Also provided is an annular partition groove through which a rim of the skirt portion and the inner crown-plus-boss portion are partitioned all around the circumference of the upper portion of the piston. A thermal-expansion absorption ring is tightly fitted into the annular partition groove in a gas tight-fashion. The top face of the inner crown-plus-boss portion, the flat face of the rim of the skirt portion, and the top wall of the thermal-expansion absorption ring serve as a piston crown.

Abstract: An internal combustion engine includes a cylinder block, a piston and a piston ring. The cylinder block includes at least one cylinder bore which includes a cylinder bore surface. The piston is located within the cylinder bore of the cylinder block so as to be displaceable upwardly and downwardly in the longitudinal direction of the cylinder bore. The piston includes at least one annular groove which has at least one inclined surface such that a bottom of the annular groove is located lower than an outer edge of the annular groove. The piston ring includes an outer peripheral portion and an inner peripheral portion. The inner peripheral portion of the piston ring is located within the annular groove of the piston for sliding engagement with the inclined surface of the annular groove of the piston.

Abstract: A composite piston structure is disclosed which provides a simple and reliable means for joining a carbon-carbon or ceramic piston cap 11 with a metallic piston body 13. Attachment is achieved by means of a special geometry which compensates for differences in thermal expansion without complicated mechanical fastening devices. The shape employs a flange created by opposed frustoconical shapes 12 and 19 with coincident vertices 15 intersecting on the radial centerline of the piston in order to retain the piston cap. The use of carbon-carbon for the piston cap material allows a close fit between the piston and a cylinder wall, eliminating the need for piston rings. The elimination of extra mechanical parts of previous composite pistons provides a lightweight composite piston capable of extended high temperature operation.

Abstract: A metal and plastic two-stage composite piston including an annular metal cup, a hollow plastic annular core bonded about the periphery of the cup, a plastic high pressure piston bonded to the interior of the cup, and a plastic low pressure piston bonded about the periphery of the core at the base of the high pressure piston in a fashion such that substantially all of the pressure loads on the pistons are carried directly by the cup and the core of the composite piston.

Abstract: An exhaust gas recirculating type diesel engine wherein part of the exhaust gas is recirculated from its exhaust system to its intake system. An annular groove is formed on the circumferential surface of the piston, and a ring for preventing small particles generated within the combustion chamber from being transferred is engaged within the annular groove.

Abstract: A two-stroke cycle diesel engine having ported cylinders is provided with a piston having an accumulator volume between the two top piston rings, the volume being sized large enough in relation to the piston ring leakage area and operating conditions to limit the build-up of gas pressure between the rings to a value below that of the cylinder pressure during nearly all conditions of normal engine operation. The arrangement substantially stabilizes the position of the top piston ring against the bottom of its piston ring groove, thereby avoiding shock loading of the top ring through cyclic unseating due to differential pressure reversals.